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HomeMy WebLinkAboutAPA4132r ' ~~ ' ALASKA DEPARTMENT OF FISH & GAME Kodiak Research Center Game Research Box 1306 Kodiak, Alaska ATWELL Territory ~A=l=a=s~k=a~----- Project W-3-R-11 Date December 31, 1956 Volume 11 No. 2 QUARTERLY PROGRESS REPORT Surveys and Investigations · as required by Federal Aid in Wildlife Restoration Fish and Wildlife Service and Alaska Game Commission 1. Title: Wildlife Investigations of iUaska 2. Personnel: Supervisor Biologists· .Biological Aids Submitted: Robert F. Scott Supervisor, Game Restoration Robert F. Scott Sigurd T. Olson David R. IG.ein Ronald 0. Skoog t Robert A. Rausch Peter E~ K. Shepherd Dustin L. Sloan Approved: ALASKA GAME COMMISSION ~=~~----~~---------Clarence J. Rhode Executive Officer Date: December 31, 1956 Not for Publication (The results described in these reports are preliminary and often fragmentary in nature. Conclusions are subject to change with further investigation and interpretation.) WORK PLANA MOOSE MANAGEMENT STUDIES 1956 CONTENTS s·'U111ID.aries 0 0 0 " 0 0 0 0 0 0 0 0 () 0 0 0 0 0 Job No. 1--Herd Composition Surveys--Susitna and Copper River Valleys .•••••• Page i 1 Job No. 2--Tanana Valley and Fortymile Herd Composition. • o 43 Job No. 3--Stikine River Valley Aerial Surveys • • o o o • • 53 SUMMARIES Job Noo 1-~Herd Composition Surveys--Susitna & Copper River Valleys ierial surveys to determine the sex and age composition of the moose populations inhabiting the Lower Susitna and Matanuska Valleys, and the Upper Susitna and Copper River basins were conducted between October 19th and 30th? instead of during November, as in previous yearso ierial identification is limited to four categories& (1) bulls (yearlings), (2) adult bulls, (3) cows,. and (4) calves.o sex and age ratios are calculated)/ as indices of productivity 9 and effects of hunting in local moose populations. young Various survival, In general~ productivity was fairly good with overall calf&cow ratios of 40gl00 and 27glQO in the Lower Susitr~=Matanuska area and the Upper Susitna=Copper River basin area, respectivelyo Local areas, however, displayed great variations, with the Matanuska Valley having a high calfgcow ratio of 53:100 and the Watana-Coal Creek area having a low ratio of 2Jgl00o · Survival of young bulls in the Matanuska Valley area was very poor~ with a ratio of 4 young bulls per 100 total cows, Hunting is probably the principal decimating factor in this areao Elsewhere, survival varied, but 9 except for heavily hunted areas, was generaliy fair to goodo The effects of hunting are best illustrated in the Ma.tanuska. Valley and in the Willow area. These areas have bull:cow ratios of 10:100 and 28:100 respectivelyo In the Maclaren River and Lake Louise areas hunting is believed to be slightly reducing the bullgcow ratioo These ratios are 62:100 and 57:100 respectively, and are somewhat lower than the remainder ·or the Upper Susitna-Copper River basin area which has a ratio of 77gl00u The removal of a large proportion of the bull population does not appear to affect the annual calf reproduction. October composition counts seem to provide a good sample of the moose population, ~nd do not sample bulls disproportionately 9 as the November counts were believed to do. The incidence of twin calves is difficult to determine from aerial surveys in either October or November" The areas which had good calf production in 1955 generally showed lesser production in 1956, and conversely those having lesser calf production in 1955 had greater production in 1956o i The October counts provided an opportunity to observe moose distribution and behavior associated with breeding activities. The largest "harems" occur in areas having the highest density populations and lowest bull:cow ratios; also, the calf:cow ratio of the animals present in the "harems" is lower than that of the other groups. The "harem" groups disperse in early November, concurrent with a general population realignment. Sex and age characteristics indicate that the Matanuska Valley and Willow area moose respectively comprise identifiable local populations. Reproductive data collected from railroad-killed moose during the period January-April, 1956, indicate an embryo:cow ratio of 117:100 cows (age class II and'above)~ and an overall ratio, including yearlings and calves, of 87:100. This ratio, when compared to the October calf:cow ratio, indicates high calf mortality prior to the first winter. A browse reconaissance survey of the critical accidental kill areas along the ~aska Railroad indicates no definite relationship between moose fatalities and browse abundance alone. However, browse abundance, snow depth and high local moose populations together do show a high correlation with the distribution of moose fatalities. The survey indicates that aspen and willow are the preferred winter browse species. Examination of 30 sets of moose lungs revealed a 20 per cent incidence of Echinococcus granulosus, i.e., HYdatid disease. ii 'ill ·,. 7: "~- .p ~' Job No. 2--Tanana Valley and Fortymile Herd Composition Aerial surveys to determine sex and age composition of local moose populations were conducted during the period October 14- November 9 in the Tanana Valley and the Fortymile areas. In the Tanana Valley productivity continues good, with a calf:cow ratio of 47:100. Survival also appears excellent. with very little drop from 1955 bull calf proportions to 1956 yearling bull proportions in the samples. Hunting pressure is relatively light, and the bull:cow ratio in the area of heaviest hunting was 68:100. The Fortymile area was covered for the first time in 19S6. Productivity is high in the area, with a calf:cow ratio-of 53:100. Survival appears fair, with a young bull:male calf ratio of 60:100. Hunting has had relatively little effect on the adult sex ratio which was found to be 66 bulls per 100 cows. The ~.rboct River area is subject to J.ittle or no hunting. Comparison counts were made in the area in mid-October and early November to discover any differences in sex and age composition observed at these times. The most obvious dj_fference was a higher proportion of calves being recorded in November. Other differences also appearedp but the samples were small and conclusions tentativeo In general. moose populations in the areas surveyed appear to be in good condition. Limited access localizes hunting pressures, and hunting has had little effect on the moose populations studied. Job No. 3--Stikine River Valley Aerial Surveys ahd Hunter Harvest Information The Stikine River area is one of the few locations where moose occur in Southeastern Alaska. To date, projected aerial surveys of this moose population have been prevented by adverse weather. An estimated 125 hunters sought moose in the area in 1956, with 30 .animals being taken for a success ratio of 24~. Kill data for previous years are presented. Various tabulated reports indicate that there are probably at least 30 moose present in the Muddy River-Thomas Bay area, north of the Stikine. iii Job No. 1 METHODS Herd Coniposition·surveys Susitna & Matanuska Valleys B.y: R. A. Rausch Aerial surveys to determine sex and age composition of local moose populations were conducted during the month of October, 1956, instead of during November as in previous years. The Copper River area was covered between October 19 and 25 by NYstrom and Rausch, using a Super Cub; and the Susitna Valley was covered between October 21 and 31, using a combination of several pj_lots, observers and aircraft. Flying in the Copper River area totaled 30.8 hours, and in the Susitna area 19.7. The mean count of moose per flying hour was markedly different between areas and in comparison to last year's counts: 37.5 in the Copper and 64.7 in the Susitna; whereas the 1955 count was 75.3 in the Copper and 74.2 in the Susitna (Tables XV & XVI).' Sex and Age Categories Moose sex and age determination by aerial observers is limited to the following four categories: 1. Young Bulls--bulls with s~iked or forked antlers, usually with little or no palm development. These animals are considered "yearlings," approximately eighteen months old, though it is realized there is some overlap in ages. 2. Adult Bulls--all bulls having greater antler development than the preceding age category. 3. Cows--all cows, including yearlings. 4. Calves--calves of the year, generally five to six months old when the counts are made. AREAS COVERED The coverage of the Susitna Valley and the Copper River Basin was largely the same as in 1~55, with the following exceptions: 1. The Fort Richardson Reserve was not counted due to the lack of snow cover when aircraft~ personnel and time were available for counting. 2. The Mt. Drum portion of the Wrangell area was not adequately covered due to inclement weather. 3. Clear Creek counts of the Upper Susitna Valley were not completed because of inclement weather -1- 4. The Peters Creek-Eagle River area was covered; however, poor snow·conditions hampered the counts. 5. The Susitna Mt.-Alexander Creek portion of the Susitna Valley west of the river area was covered, and counting conditions were adequate 1 but very few moose were located--reason unknown • . RESULTS OF COUNTS Summaries of moose actually tallied, by sex and age, are given in Table I for the Susitna area, and in Table II for the Copper area. Each table shows the counts identified b,y their respective local area. The sampling included 1150 moose in the Copper area and 1275 in the Susitna area. COMPOSITION IN SUSITNA AND COPPER RIVER POPULATIONS The data from the 1956 counts were analyzed for the indicators of productivity, survival and effects of hunting as described in the March 31, 1956, P-R Report. 'Fro<iuctivity,~' was defined to include both the initial incidence of live births to females in the population, and also, the subsequent survival of these young to the date of the aerial counts, "Survival" was defined as survival of the calves recorded on the annual sex and age composition counts to the same date one year later--i.e., survival to approximately 18 months. . . . The index used in the 1955 report to measure survival of .young bulls to 18 months was the young bullgbull calves of the year ratio. The accuracy of this ratio is dependent upon uniform calf production from year to year. It is recognized that calf production does vary; however, the young bull:bull calves of the year ratio was the only index to young bull survival in 1955, as no comparative data from previous years were available. The index to young bull survival uses as its base the cow population; and compares the bull calf:total cow ratio of 1955 to ·the young bull:total cow ratio of 1956. This yields an index to young bull survival to 18 months. A more complete discussion of this index is contained in another section of this report. Effects of hunting here refers to the extent to which hunting removes a portion of the bull population; cow'moose are not hunted. Table III summarizes these data for the Susitna Valley and Table IV for the Copper River basin; Tables XVII & XVIII summarize previous years results for these areas in the Kenai and Tanana Valley as well. -- The followi~ discussi:on outlines some of the more important trends of this year's survey. -2- tit . .. l ..., Ill\ ... PRODUCTIVITY The Matanuska Valley ~ea The Matanuska Valley has a very high'calf:cow ratio of 60:100 and a ratio of 53:100 if the Matanuska timberline counts are included. This indicates good calf production and survival to date. The young bull:adult bull ratio of 75:100 remains very high but is undoubtedly the result of great hunting pressures. Willow Area The Willow area counts indicate poor calf production or poor calf survival to mid-October, as the combined calf:cow ratio was 27:100. A sample of 46 railroad-killed cow moose, largely from the Willow area, examined during the winter of 1955-56, revealed that over 90 per cent of all cows over 2 years old were pregnant. If this sample is representative of the Willow area moose population, then the low calf:cow ratio probably is due to poor calf su~vival and not to low initial production. The Area West of the Susitna River (The majority of the moose in this $ample represent the Kahiltna Flats area.) The calf:cow ratio of 45:100 indicates fairly good production. The young bull:adult bull ratio of 23:100 may represent average production as hunting is not an important factor in this[area. Copper Area The overall calf:cow ratio of 27:100, although uniform, was appreciably lower than the 52:100 ra~io of last year, and considerably below the Susitna-Matanuska Valley area's calf:cow ratio of 40:100. The following are several··factors which could have caused this apparent decrease in calf production: 1. Good survival of last year's large calf crop, thus contributing a large number of non-producing yearling cows to the population. 2. An over-all expanding population with a large proportion of sub-adult cows, i.e., one, two and possibly three year olds. 3. Poor calf survival to late October. 4. Counting one month earlier in 1956 may have sampled the moose population in proportions different from 1955. The much lower bull:cow ratios suggest this. · One or several of these factors may have influenced this year's counts. -3- EFFECTS OF HUNTING The Matanuska Valley Area The bull:cow ratios of 5:100 on the valley floor; 18:100 above timberline, and an overall ratio of 10:100 further sUbstantiates last year's conclusions that hunting is greatly affecting sex ratios in accessible areas. This very ·unbalanced sex ratio has apparently not lowered calf production as the Matanuska area this year had the highest calf:cow ratio recorded in any of the study areas. The Willow Area The Willow area has avery.unequal hunting pressure, varying from intense along the railbeltll the-Willow _and Huston roads, .to moderate. above timberline. Nevertheless, the bull:cow ratio is low, 28:100, and is probably a result of. hunting. The Area West of the Susitna River Hunting in this area is limited and well dispersed. The bull;cow ratio is 66:100. The Unper Susitna-Copper River Area The most easily accessible areas--those along the Denali Highway, Lake Louise and the_Glenn Highway--have a bull:cow ratio of 57;100 as compared to 77:100 for the remainder of the Copper basin. In addition, the young bull:adult bull ratio is twice that of the other .Copper areas. This ratio could indica_te good productionll but in all probability represents an early· indicatiop of hunting pressure. SURVIVAL An index to moose calf survival to 18 months is provided by comparing_ the 1955 bull calf;total cow ratio with the 1956 young bull; total cow ratio. These comparisons are illustrated in Table NoD V. The "total cow" segment was s~lected as the base for an index to young bull survival to 18 months.. It was selected because cow moose are not subjected to hunting and therefore are the most constant group within the moose population. In computing the young bullgtotal cow ratio it is necessary to assume that the total number of cow moose in a local population is remaining relatively constant from one year to the next. All age classes .of female_moose are suoject to various mortality factors, particul~ly during severe winters such as 1955-56. However, the inclusion of yearling females (1955 calves) in the 1956 sex and age composition counts probably more than offsets adult female mortality and in many-local areas, particularly in the Copper River Basin, the total number of cow moose may have increased. In the areas where the moose population is increasing, the survival of young bulls, as measured by the bull calf:young bull_ index, represents -4- 111 ... 1r .... rW "' minimum survival. Therefore, the mortality figures cited in the following discussion represent a maximum estimate of young bull mortality in areas where the moose population is expanding, and, conversely, they represent a minimum estimate of mortalit.y in areas of decreasing populations. Survival to 18 Months The data from the comparison of the 1955 bull calf:total cow ratio with the 1956 young bull:total cow ratio provides interesting survival data and also provides a cross check on the reliability of the aerial sex and age counts. Lower Susitna and Matanuska Valleys The 1955 counts indicated a bull calfgtotal cow ratio~,;of 278100 for the Matanuska Valley area and 17:100 for the Matanuska timberline area. The corresponding young bull:total cow ratios in 1956 were 3:100 and 6:100. The combined~ valley and timberline, bull calf: total cow ratio in 1955 was 26:100, and the combined 1956 young bull:total cow ratio was 4:100. This indicates a young bull mortality of 85 per cent. In all probabilit.y hunting is a major decimating factor in this area. Willow Area The 1955 bull calf:total cow ratios in the Willow Valley and Willow timberline areas were 11:100 and 19:100 respectively. The corresponding young bull:total cow ratios in 1956 were 4:100 and 8:100. The combined Willow area 1955 bull calf:total cow and 1956 young bull:total cow ratios were 14:100 and 6:100. This indicates a young bull mortality of 57 per cent. The Susi tna=Copper River Basin Areas .. _ The 1955 bull calf:total cow ratio in the Maclaren River area was 32:18. The 1956 young bull:total cow ratio of the same area was 15:100, indicating a 53 per cen~mortality of young bulls. Hunting may have accounted for much of this mortality. In the Lake Louise areas the 1955 bull calf:total cow ratio was 27:100; the 1956 young bull:total cow ratio was 12:100 and indicates a yo~ bull mortality of 56 per cent. The overall 1955 bull calf:total cow and 1956 young bull:total cow ratios in the Susitna-Copper River Basins were 26:100 and 10:100. Several of the local areas had young bull:total cow ratios nearly as great or greater than the initial bull calf:total cow ratios. This was true in the St.-Anne-Kiana Lakes and Wrangell Mountain areas. The 1955 counts indicated a predominance of bulls in these areas. It is possible that the counts did not sample the moose population in its true proportions. The 1956 counts on the same areas were much smaller than those made in 1955 and also may not be representative. -5- TABLE I Area SUSITNA=MATANUSKA VALLEYS • Matanuska Valley Ma tanuska Valley Timber line. Willow B Sub=Tota1 "' a Peters Cro & Eagle River Willow Oro Timberline Susitna Valley, West of River Sub~Total TOTAL 1 ... Summary of Moose Population Composition Counts Susitna = Matanuska Valley, October 1956 Young Adult Total Lone Females Males Males Males Females 1 Calf 6 3 9 72 103 . 6 13 19 63 41 8 30 38 115 65 20 46 66 250 209 3 3 6 4 1 16 52 68 176 19 12 53 65 57 . 39 31 108 139 237 59 51 154 205 487 268 1-ji Females Total Total Total 2 Calves Females Calves Moose .., .J ~.) ' ..l. I~ .. _, . 2 177 107 293 1 105 43 167 7 187 79 304 10 469 229 764 0 5 1 12 3 198 2-5 291 . 3 99 45 209 6 302. 71 512 16 771 :300 1276 6 'If TABLI!t II ~ : ·. Suminary of Moose Population Composition Counts Susitna and Copper River Basins; October 1956 Young Adult Total Lone Females Females Total Total Total Area Males Males Males Females. 1 Calf 2 Calves Females Calves Moose UPPER SUSITNA~COPPER RIVER BASIN Maclaren River 27 87 114 1.3.3 52 0 185-52 351 Lakes Louise & Susitna 15 46 61 90 .31 2 12.3 35 219 Sub~Tota1 42 1.3.3 175 22.3 83 2 .308 87 570 '_. .... ,_ 0 Oshetna=Tyone Creek~ aJ Nelchina River 7 58 65 66 27 0 9.3 27 185. Wa tana Creek & Coal Creek 16 68 84 87 26 0 11.3 26 22.3 St o ./Anne ~ Kiana Lakes .3 15 18 10 5 0 15 5 .38 West Fork Gu1kana River 4 22 26 4.3 7 0 50 7 8.3 Wrangell Mountains .3 26 29 15 4 1 20 6 55 Sub=Tota1 .33 189 222 221 69 1 291 71 584 TOTAL 75 322 .397 444 152 .3 599 158 1154 TABL£ III Sex and lge Ratios in Susitna and Matanuska Valley Moose Populations, October 1956 Young Twin Young Young Total Bulls/ Calves/ Calf % Bulls% Bulls per Bulls/ 100 Adult Calves / 100 Cows in-Total in Total 100 Bull Total -Area 100 Cows Bulls 100 Cows w/Calf Herd Herd Calves Moose SUSITNAaMATANUSKA VALLEY Matanuska Valley 5 200 60 2 37 2 9 293 Matanuska Valle,y Timberline 18 46 41 2 26 4 27 167 Matanuska Valley Combined 10 75 53 2 31 3 17 460 Willow 20 27 48 10 29 3 18 304 8 Above Areas Combined 14 43 49 4 30 3 17 764 00 I Peters Creek & Eagle River 12 Timberline Areas, Susitna to Montana Creek 34 31 13 16 9 5 133 291 Susitna Valley West of River 66' 23 45 7 22 6 52 209 Above Areas Combined 46 29 24 9 14 6 s<r 512 SUSITNA-MATANUSKA VALLEYS COMBINED 2~ 33 40 6 24 4 33 1276 I' • " "!'P 8 ·'( TABLE IV Sex and .Age Ratios in Susitna and Copper River Basin Moose Populations~ October 1956 Young Twin Young Young Total Bulls/ Calves/ Calf % Bulls% Bulls per Bulls/ 100 Adult Calves/ 100 Cows in Total in Total 100 Bull Total Area 100 Cows Bulls 100 crows w/Calf Herd ·· ---Herd Calves* Moose UPFmR SUSITNA-COPPER RIVER BASIN Maclaren River 62 31 28 0 15 8 103 351 Lakes Louise and Susitna 50 33 29 6 16 7 83 219 Above Areas Combined 57 32 28 2 16 7e5 95 570 Oshetna-Tyone Creek~ ' 8 Nelchina River 70 12 29 0 15 4 50 185 "' __ .·, 8 Watana-Coal Creek 74 24 23 0 12 7 123 223 Sto Anne-Kiana Lakes 100 20 33 0 13 8 100 38 West Fork Gulkana River 52 18 14 0 8 5 114 83 Wrangell Mountains 152 12 31 5 ll 6 100 55 Above Areas Combined 77 17 24 2 12 6 91 583 COPPER BASIN -ALL AREAS 67 23 27 2 14 7 95 1154 *Assuming one-half the calves to be bulls TABLE V YOUNG BULL:BULL CALF RATIOS "" U1212er Susitna a:nd Co1212er'River•Basins • 1955 Total 1955 1956 1956' Total Bull Bull Calves: Total Total Young Bull: Area Cows Calves Total Cows Cows Youm Bulls ·. Total Cow Maclaren River 132 42 32:100 185 27 15:100 Lakes Louise & Susitna 73 19 27:100 123 15 12:100 Sub-Total 205 62 30:100 308 42 1{;,:100 Oshetna-Tyone Cr. & Nelchina River 159 59 37:100 93 7 8:100 Watana-Coal Cr. 113 27 24:100 113 16 14:100 St. Anne=Kiane L. 45 6 14:100 15 3 20:100 West Fork Gu1kana River 191 51 27:100 50 4 8:100 Wrangell Mts. 107 19 18:100 20 3 15:100' Sub-Total 791 200 25:100 302 33 11:100 TOTAL 996 261 26:100 771 75 t Lower Susitna and Matanuska Valle~ -... Matanuska Valley 905 242 27:100 177 6 3:100 Matanuska Timber- line 63 10.5 17:100 105 6 6:100 Sub-Total 968 252 .. 5 26:100 282 12 4:100 Willow Valley 265 29 11:100 187 8 4:100 Willow Timber= line 142 27 19:100 198 16 8:100 Sub-Total 407 56 14:100 385 24 6:100 Susitna Valley West of River __gzQ 32 M:llOO 99 12 12:100 TOTAL 1611 ;2!J:O.~ 21:100 766 !J:8 6:100 =10- • 'ti DISCUSSION Several problems and observatiqns of interest were revealed b,r the October countso These are discussed belowo October Sex and Age Composition Surveys The counts made in October seem to provide a good overall sampling of the various moose populations; however, this year 1 s surveys did not yield as great a count of moose per hour of flying as in 1955a This is most noticeable in the Copper Basin area and may have been caused, in part, b,r a change in pe~sonnel~ both pilot and observero The distribution of the moose populations in October is considerably different from November and may also have influenced the lower hourly countso The distribution of the moose populations in 1955 and 1956 are illustrated in Figures 6~ 7 and 8o Incidence of Twins The October counts, made during and immediately following the rut~ when the moose are generally banded into "harem-like" groups, did not provide an accurate twin calfgsingle calf ratioo These "harems" frequ~ntly were composed of 3 to.l2 cows~ their calves~ and several bullso The calves were generally scattered throughout the immediate area and identification of twins was impossible, The incidence of twins and some of' the difficulties in obtaining accurate twin counts in November were discussed in the March 31 9 1956, P=R · Reporto These problems are also present during the October countso . It is highly doubtf'ul that the present twin:single ratio is accurate enough to indicate true proportionso Calf Production In general~ areas of great calf production in 1955 were areas of' poor or moderate production in 1956, and conversely areas of' poor or moderate production in 1955 were areas of good production in 1956o This is best illustrated in the Copper Basin areaso In 1955 the Maclaren and Susitna areas had calfgcow ratios of 60:100, and the remaining areas showed a ratio of 50:100; thel956 ratios are 28:100 and 24:100 respectivelyo In the Susi tna=Matanuska Valley areas the differences ar.e not quite as great~ but statistical analysis indicated not more than lo5 chances per hundred that the diff'erences were due to chance aloneo The Matanuska Valley counts of' 1955 had a combined calf':cow ratio of' 37:100; the Valley proper had a ratio of' 42:100o The 1956 counts show a combined ratio of 53:100; the Valley proper shows a ratio of 60:l00o The Susitna area west of the river had a ratio of' 27:100 in 1955 and 45:100 in 1956o The Willow Area is the lone exception, having a constant ratio of 27:100 in 1955 and 1956o -11= GROUP COMPOSITION DAT& The October moose sex and age composition counts provided an unusual opportunity for observing moose breeding and seasonal grouping behavior. Moose groups or "harems" were frequently seen during mid- October when the earliest counts were made. Pres-bly, the peak of rut was past, although evidence of active rut was observed as· late as October 30. Most of the "harems" were composed of cows, bulls and ~ few calves. In an effort to gain further understanding of moose breeding behavior and population structure~ the data obtained from the October counts were re-examined. These data are presented in Tables VI -a;nd V;ri. __ The sex and age composition counts made during the period between :'.October 19 and October 31 do not represent a chronological sampling · of. any one local moose population. Instead, the. counts represent a number of local moose populations from several distinc~ geographic areas. jlthough the data from the various areas are not directly comparable, several general principles concerning moose population density, sex composition, age composition and seasonal behavior are revealed. In analyzing the group composition data it was necessary to select a uniform method of treatment which would allow the data from the various local moose populations to be compared. In addition, the method ha.d to allow for comparisons of the groups within the local population itself. The method selected involved dividing the local populations into two portions: (1} the largest groups--comprising the upper 50 per cent of the population, and (2} the remaining, smaller, groups which comprised the lower 50 per cent of the population. Frequently, 50 per cent of a local population occurred in a relatively Sm.all ,proportion' of the total groups. in example of this is the Willow area below timberline, Table VI. Here 50 per cent of the population occurred'in 20 per cent of the groups. The method used for dividing the local populations is arbitrary, but it does reveal important differences between the bull:cow and calf:cow ratios of the upper and lower groups. Population Density The counts in the Willow area made on October 21 have a group range of 1-34; a mean group size of 7.4, and an upper 50 per cent mean group size of 13.6. The Willow area group means are much greater than those from counts made on the same date in the Upper Susitna Valle,y. The counts made in the Black and Oshetna River drainages (a portion of the Upper Susitna} on October 21 had a group mean of 2.7, a range of 1-17, and an upper ~-·:50% ' group mean of 5.1. The Maclaren River area, counted on October 24, had a group range of 1-21, a mean group size of 3.4, and an upper 50 per cent mean group size of 6.8. The difference in mean group sizes between the Willow area and the Upper Susitna areas may represent differences in population densities, age structure and sex composition. The moose population per square mile in the Willow -12- ~ • "' ... "'! ' .. , ... · area is estimated to be greater than in the Upper Susitna Valley. This estimate is substantiated by the moose per hour of flying data for the two areas. In the Willow area 117 moose per hour were observed, whereas, in the Black and Oshetna Rivers 32 per hour, and 50 per hour in the Maclaren River area (Tables :XV,andnKV'I)'. :, . This apparent difference in population density could partially explain the group size differential. Sex Composition The Willow area above timberline has an overall bull:cow ratio of 29:100 and an upper 50 per cent ratio of 25:100. The Black and Oshetna Rivers had a bull:cow ratio of 96:100 and an upper 50 per cent ratio of 100:100. The Maclaren River area had a bull:cow ratio of 62:100 and an upper 50 per cent ratio of 68:100. If the groups represent "harems" it would be logical to expect larger harems in areas having few bulls and a great population density. The Willow area data seems to support this contention. Age Composition Differential age composition, assuming that the sub-adult or non-breeding females band together, may also account for some of the large groups of calfless female moose. These groups were p~ticularly noticeable in the Willow area. The exact status of these groups is not known, but apparently they were non-breeding females. The majority of the large groups observed did contain several bulls and a few calves. Tnis was also true in the upper Susitna counts, although the groups did not average as large and bulls occasionally outnumbered the cows. Group Composition Cha~ge As no large area was counted periodically, the changes in group composition are not directly comparable. However~ a definite change in the sex composition of the groups was noted. The sex composition and size of the groups observed in the Matanuska Valley on October 30 were quite different from those observed in the Willow area on October 21. These areas, while not directly comparable, do have two important similarities; (1) a high density moose population, and (2) a scarcity of bulls. The Willow area had a mean group size of 6.5 compared to a mean group size of 3.9 in the Matanuska area. The smaller mean group size in the Matanuska area probably indicates the breakup of the harems. Distribution of Bull Moose Previous aerial counts made in November have, in some instances, indicated disproportionate sampling of bulls. This yearYs counts, -13- made in October, revealed that a great percentage of the bulls were at or above timberline but that the bulls were generally associated with several cows. In late October the "harems11 were disbanding,~~ and several small bands of bulls were seen. On October 30 a count was made of the Kahiltna Flats moose population. The mean group size was 3.9, the range 1-9, and the upper 50 per cent mean group size was 6.1. The bull:cow ratio of the upper 50 per cdnt was 98:100; the lower 50 per cent was 28:100. This could have indicated active rut but close observation revealed that many of the upper 50 per cent groups were composed entirely of bulls. The calf:cow ratio of the upper 50 per cent was only slightly lower than the lower 50 per cent, 45:100 vs. 51:100. The unequal bull distribution plus the uniform calf distribution probably indicates the breakup of the "harems" and the initial forming of the bull groups. In early November a reconnaissance flight over the timberline area above the Willow burn revealed that between 150 and 200 bull moose were scattered over an area where many large harems had been observed in October; very few cows were seen. On December 29 on another flight over this timberline area only two moose were seen; one a bull with a medium sized rack, the other was presumed to be a very large bull which had shed his antlers. The whereabouts of the bulls previously located in this area are unknown. The Willow Burn Check Plot Periodic complete counts of the moose inhabiting a small burn located approximately 10 miles northeast of Willow 9 Alaska, have been made since October 21. Complete counts are possible because the burn is particularly well defined. The southern boundary of the burn is formed by the Willow road, and the three remaining sides are bounded by mature vegetation. Each count requires about 30 minutes flying. The transects are flown in such a manner as to allow the observer to pick guide posts from the prominent terrain features~ thus preventing duplication in counting. The data obtained from these counts is listed in TableVIII. The mean group size for this area decreased from 6.1 on October 21 to 3.1 on November 23. ~ slight increase to 4.4 was noted on December 3 when an influx of moose raised the total count by 90 per cent. The bull:cow ratio of 14:100 on October 21 had decreased to 10:100 by November 23. This may have been caused by the bulls shedding their antlers, or their shifting to a different area. -14~ • ~ ""(' ,. 'Of c TABLE \'I LOWER SUSITNA AND MATA.NUSKA VALLEY Group Composition~ S.ex> Age and Distribution Data -= Arranged by Date & Area ·-----------=·----Mean Mean Group Group BllllgCow Calf:Cow Bull gCow Calf gCow No. of Group Size of Range of No,. Groups Ratio of Ratio of Ratio of Ratio of !rea Uate__,_QrQYJl!2 Size UQper 50% Upper 2QJt __ JJppe:r 5Q1L __ l]~:r..2..0% ll"DP~ 50% Lower 29!__!:.ower 20% Tota.L 10/21/56 Willow Area Timberline ·.10/27/56 Will ow Below 53 7,4 !irnber~ine _30 6.4 ~ :I0/29/56 \)1 '.. ·0 ij Matanuska Valley Fishhook Area 33 Buffalo Mine & Other Areas in 4.7 Palmer Vicinity 65· 3.7 Was~;lla Burn 14 SUSITNA ~T OF RIVl!R 10/30/56 Kahiltna 3.2 Flats 48 3.9 13 .. 6 7-34 15 25gl00 8gl00 __ 12 ___ 8=16 ____ 6_' ___ , _ _12~100 31~10Q 15.,4 6.5 5.3 6.1 11~18 5-12 4-6 5-9 5 18 4 16 10:100 18:100 0:100 98:100 50:100 46:100 91:100 45:100 33gl00 12:100 21:100 458100 2:100 10:100 0:100 38:100 48:100 52:100 55:100 49:100 390 ,J2.1_ 157 240 45 189 ·' ;, :TABL£ VII -Area & Date "'-10/~<J/56 Oshetna, L. Oshetna·& Black River 10/21/56 UPPER SUSITNA AND COPPER RIVER BASIN AREAS Group Composition Sex, Age and Distribution Data--Arranged by Date & Area ·Mean Mean Group ·Group Bull:Cow · Calf:Cow BUll:Cow Calf:Cow No. of Group Size or Range of No. Groups J:tatio or Ratio of Ratio of Ratio or . Groups Size Utmer 50% Jl'DPer -'~---UlJPf3I' 50% tJpper 50% Upper _5~_L_QWm-__50% Lower 50% Total 43 3.2 6.7 3-12 96:·100 22:100 96:100 54:100 121 Upper Susi tna 42 2.8 4.5 3-7 13 100:100 10:100 86:100 26:100 116 10/2256 ~ Watana Creek 41 2.7 6 3-17 9 63:100 17:100 47:100 47:100 111 0' ' I Totals this Area 10/23/56 West Fork Gulkana 10/23/56 Mt. Drum 10/24/56 83~ __ 2.7 5.1 3-17 22 82:100 13:l00 66:100 n 33:100 227 42 2.8 6.6 3-12 7 91:100 23:100 13:100 1:100 83 12 __ ~5 9 6-13 3 127:100 18:100 177:100 44:100 55_ !frc1aren River 104 3.4 6.,8 5-21 26 68:100 23:100 56:100 33:100 351 ,., • "' cf t$· • The Calf:cow ratio between the upper and lower 50 per cent groups became more uniform as the "harems" disbanded. The groups form:i,ng the upper 50 per cent had a calf:cqw ratiorof 23:100 on October 21 find 46:100 on November 23. The groups forming the lower·-50 per :cent had a calf:cow ratio of 49:100 on October 21 and 44:100 on November 23. Comparisons of the bull:cow ratios and the calf:cow ratios suggest a general realignment of populations following the :r'Ut. Bulls had apparently shed their antlers or moved to other area:s by December 12 as no bulls have been identified on this area since that date; Several great fluctuations in moose numbers have occurred on this area since the counts started. On October 21, 123 moose were ·counted in the Willow burn. The total count varied but little until December 3 when 199 moose were, tallied; a 90 per cent increase. On De·cember 17 the total was 195, but on December 29 the total counted dropped to 119, a decrease of 40 per cent.~ The presence of many trails indicate that many J¥oose have left the burn area presumably for lower elevations. The reasons for tlieSe sudden population shifts. are not, completely understood. Weather, particularly deep }mow, is usually thought · to be a determining factor in causing moose to abandon the higher elevations. However, the snow depths preceding these moose move- ments were not sutficiently deep to bother moose" No more than 24=30 inches of snow covered the ground. This period was also marked by unseasonably warm weather. It is possible that.the high concentration of moose had greatly reduced the available browse and were moving in response to a food shortage. Another possible reason for th~ moose moving to lower elevations could be normal seasonal habitat preferenceso -17-.. J TABLE VIII WILLON BURN CHECK AREA 0 Upper 50% Mean Mean Group Bull:Cow Bull:Cow Calf:Cow Calf:Cow Total Flying Date Size Size UE~r 20% Lower 50% Upper 50%_ l:.c>wer 50% Moose Time 10/21/56 6~1 10.8 18:100 10:100 23:100 46:100 122 11/8/56 4.2 6.2 9:100 -.3:100 32:100 36:100 123 25 min. 11/23/56 3.1 6 6:100 4:100 44:100 46:100 103 27 min. 12/3/56 4.4 7 49:100*** 44:100*** 199* 30 min. I 12/17/56 1-' .35:100**** 195** 31 min. 00 I 12/29/56 * 12/3/56--8 bulls with antlers were counted ** Bulls not distinguishable ***Ratios represent calves:total adults 32:100**** 119** 30 min. **** 12/17 an<i 29--No bulls with antlers were seen. These counts were not kept by group, ·:(:·.but a running tally of adults: calves was recorded. ·-' • ~ "" Moose Per Hour 295 229 .398 377 238 it'{ • LOOAL AREAS The need for defining local moose populations was discus.sed in the March :31, 1956~ P~R Report. At present two areas seem to have many of the necessary qualifications described for local moose populations; the Matanuska Valley and Willow areaso The data from these areas are presented in Tables IX arid I c The Matanuska lrea The moose inhabiting the Matanuska Valley and associated timber- line areas should, in all probability, be considered one local moose population. This contention is supported by the data obtained from the annual sex and age composition counts. These data have revealed a bullgcow ratio of 10:100 in both 1955 and 1956. The bull:cow ratio in this area has reportedly decreased consistently as hunting pressure increased. The percentage of young bulls taken by hunters and in comparison to old bulls counted has also increased steadily. These trends strongly suggest that this is a resident population~ and that recruitment from adjoining populations is minimal. It is interesting to note that the Willow area has a bull:cow ratio nearly three times greater than the Matanuska Valley which it borders. Another factor favoring the consolidation of the Matanuska timberline and valley moose populations is the seasonal population movementso The fall counts show that the bull:cow ratio above timber- line is greater than the corresponding ratio below timberline) and that the calf':cow ratio is smaller above timberlineo Late winter reconnaissance flights indicate that the timberline moose population and the valley population have joined. The differential sex and age ratios revealed by the fall counts suggest seasonal sex and habitat preferences and not identifiable local populationso The Willow Area The location of a boundary between the Willow and Matanuska areas presents a difficult problemo However, at present the Little Susitna River appears to be the logical division. Observations made of moose tracks and numbers indicate that many of the moose inhabiting the northern portion of this drainage move into the Houston and Lake Nancy areas as winter progresseso Those moose inhabiting the head- waters and southern drainages move into the Fishhook, T;asilla and Big Lake areas. There must be some intermingling of moose along this drainage; however, this interchange does not materially affect the bull:cow or calf:cow ratios of the two areaso The calf:cow ratios in the two study areas are very different. The Willow area had a calf:cow ratio of 27:100 in both 1955 and 1956o The Matanuska area had corresponding ratios of 40:100 and 53:100o The sex and age composition counts in the Willow area support the combining of the timberline and valley moose countso Here, as in the Matanuska area, the bull:cow ratios above timberline are =19= greia.ter than the corresponding valley counts and the timberline calf:cow counts are smaller than the same ratio in the valley. The late November and December counts made of the moose inhabiting the Willow burn area (TableVIII)indicate a complete realignment of the timberline and valley populations. B,y mid-December the bulls had returned to the lower elevations and the calf:cow ratio was uniform throughout the area, although very few animals remained above timberline. The Willow area is, for pUrposes of counting, that area bounded by the Little Susitna River on the south, Montana Creek on the north, the Talkeetna Mountains on the east and the Susitna River on the west. -20- ,, .. "' """' • ... TABLE IX.·· Area MATANUSKA~WILLCW Matanuska Valley Matanuska Timberline Matanuska Combined 8 l\) Willow· Railbelt 1--' I Willow Timberline Willow Combined . ··· MATANUSY.A~WILLOW COMBINED Summary of Moose Population Composition :counts Matanuska and Willow Areas, Oc1;;ober 1956 Young Adult Total Lone Females Males Males Males Females 1 Calf 6 3 9 72 103 6 13 19 63 41 12 16 28 135 144 8 30 38 115 65 16 52 68 176 19 --- 24 82 106 291 84 36.', 98 134 426 228 Females Total Total Total .2 Calves Females Calves Moose 2 177 107 293 1 105 43 167 3 282 150 460 7 187 79 304 3 198 25 291 10 385 104 595 13 667 254 1055 TABIK X ,_ Se-x and Age Ratios in Matanuska and Willow Moose Populations, October 1956 Young Twin-Young Young Total Bulls/ Calves/ Calf % _ Bulls % Bulls per Bulls/ 100 Adult Calves/ 100 Cows in Total in Total 100 Bull Total Area 100 Cows Bulls 100 Cows w/Calf · Herd Herd Calves Moose MATANOSU....WILUJI lfa taiDlska Valley 5 200 62 2 37 2 9 293 llatimuska Timberline 18 46 41 r,:_2 26 4 27 167 I MataiDlska Combined 10 75 53 1\) 2 33 3 17 460 l\) I . ·!......_ ·"-""'"·--· Will011. Railbel.t 20 27 ~-48 10 29 3 18 304 Wil1011 Timber line 34· 31-":-13 16 . 9 5 1)3 291 Wi11CJIIIJ Com.bined 28 29 27 11 17 4 46 595 IU.TABmKA..lJliii..I.DI COIIBINED 20 37 38 5 24 3 28 1055 ,. c • ~ • .. REPRODUCTIVE DATA Between January and April of 1956 the reproductive tracts of 47 railroad:...killed female moose were examined.· The data obtained from these examinations is slimmarized in Tables XI and XII. Some oftherailroad-killed moose were badly crushed,-·making examination for pregnancy data difficult; however~ 41 {89 per cent) of the 46 moose above age Class I were defi-nitely pregnant. Of the. 5 remaining,· 2 were definitelynbtpregriant, 3 were badly.crushed, and although accura:Pe pregnancy determination was difficult~ were believed barren. This pregnancy data represents very successful potential reproduction. The· lone Class I (yearling)·femaleis not considered in the computations because it is generally believed that yearling females are sexually immature. In additionj there is some doubt that many of the Class II (two year old) females breed; only i of the 3,· supposed Class II individuals, examined was pregnant. Unfortunately, the Classes· II: and III are ithe' most difficult to age, and at present no satisfactory criteria forseparating the two exist. Because of the limited data and th~ confusion surrounding the Class II individuals they are included in the pregnancy data cbmputations~' Embryos Sex determination of 32 embryos revealed 18 males and 14 f·einales. The:remaining embryos were either not.available·for examiria.tion·or were partially destroyed and sex determination impos~ible. The measurements and weights 6f 16 embryos are summarized tn Table X:t. It is hoped that a sufficieritnmnber of enibryos'can-be collected in 1957 to establish the growth curve for moose embryos. A tentative curve constructed 'from the measuremen,ts' in Table XIwas most promising. Reproductive Potential by ,Age Class An accurate knowledge of the moose population sex and age structure, and of the contribution of each age group to the annual calf crop would be a valuable management tool. The age classes and their relative calf contributions, of the railroad-killed moose, are shown in Table XII. As indicated in another portion of ·this report, the age classes are tentative, but combining the 8 breeding age classes into 4 age groups, for purposes of interpreting the pregnancy data, largely compensate for the uncertainties of aging -9riteria. The railbelt moose population has a predominance of aged female moose-; 55 per cent of all breeding age females fall in or above age Class VI. Despite their age, the Group VIII and IX cows produced the highest embryo:cow ratio--144:100 (Table XII). Age group VI and VII had an embryo:cow ratio of 100:100, and is confusing;· normally they would be expected to have an embryo~cow ratio similar to or slightly higher than age group IV and V. Possibly the sample is not adequate for this ~ge·group. The oldest group also had the highest incidence of twins; 62 sets per 100 pregnancies. -23~ Relationship of Pregnancy Data to Aerial Counts If the fertility rate (the ratio of pregnant cows to total cows) is known, .then the annual aerial sex and age composition counts should provide a measure of calf mortality to the date of the count. Aerial observers cannot distinguish yearling. females from female, moose of other age categories. Therefore, in computing a theoretical fertility rate from the data collected in early 1959, female moose of all ages, including female calves, must be combined with the adults. The inclusion of female calves is necessary because they are counted as "adultsft in the fall. In computing the fertilit,y rate only those cows of known age which were examined.for pregnancy data were included. ·Then by including the proportions of yearlings and calves found in the .sample of 146 railroad-killed female moose a weighted average of fertility was computed. This average was 87 embryos per 100 total females (Table XIII). (. . .... The inclusion of·all female calves undoubtedly causes the calculated fertilit,y rate to be minimal. This occurs because the calves were collected from January to March,r'and undoub1;ed:cy cons~derable spring calf mortality occurred in 1956~ Thus, since the female calves are not contributors to the reproducing portion of the female population their over-representation in computing the w~ighted average of fertility acts as a depressant on the fertility rate.· · The Willow area calfacow ratio computed from the October counts was 27:100. When this ratio is compared with the fertility rate of 87:100, a calf mortality of 69 per cent to October is indicated. The calf mortality in the Matanuska area was )9 per cent, and the combined Willow-Matanuska calf mortalit,y was 56 per cent. The factors causing this seemingly great mortality are unknown, but probabiy represent both pre and poet natal mortalit.Yo -24- • ,. ~ • lit .. TABLE XI MOOSE EMBRYO lVJEASUREMENTS* Hind Front Zyg()I.Jllitic C.R. or Date Area Sex H.F. Leg Leg Arch F.R. Weight 11/1/56 Houston Rd. 8-10 11/20/56 Local 35 11/2~56 182e2 37 1/18 56 . :' 187.3 F 75 112 95 ~~ 35 220 11 oz. 2/14/56 199.3 F 155 230 200 64 310 4 lb. 3 oz. 2/24/56 194 M :}.55 240 210 58 340 4 lb. 11 Ol Feb. 56 209 M 165 250 215 65 350 3/2/56 202.3 F 185 280 240 65 360 5 lb. 15 Ol March 56 208.7 M 195 290 255 67 400 3/3/56 212 F 195 315 260 69 410 7 lb. 2 oz. 3/4/56 208e4 M 195 310 260 69 400 6 lb. 11 Ol March 56 Unk. R.R. F 215 320 280 71 430 7 lb. 12 Ol 3/9/56 211.4 M 205 330 285 72 420 7 lb. 14 Ol 4/1%56 190.4 F 320 480 415 82 540 14 lb. 0 Ol 5/2 56 Susitna Lodge F 335 500 435 81 580 14 lb. 0 m 5/2/56 Susitna ,Lodge M 310 455 395 81 520 14 lb. 0 m *All measurements in MM. -25- .. TABLE XII 1=1 0 •rl +:> ro C) •rl fH •rl (I) (I) Q) ttl bOrl ~t.:l II~III rv~v 11 ~ .nm § ~ 12<0 6 11 ~;; Q) 0 c.>O J..IO' Q)ri f.l.trl 10 .. • Comparative R(;)productive D~_~a~ Wint,~r: of 1955~56. ~~ p.. +:> s 1=1 ttl Q) (I) C) (I) J..t•rl Q)..c:l 1'-1+:> 13.0 30.0 . ' . . -' ~ (I) (I) 1=1 .Pori Q) ,j!: CI)E-! 1 3 00 . .p Q) rl ~ •rl (lj .·-- 3 11 fll . . . £!;. ' •... o· ·o ·s·xo ·=· o rl 12< 1=1 .n 1=1 00 ri Q) Q) ro Q) J..t .n J..t F-1 0 J..t &lct.&l 2** 0 .$,!:i 0 ttl E-!0 :------ 5 17 4-4 00 0 •rl .p:S 1=1 .. Q) (I) Q)' C)Q)ri I> p.. J..t .-; __ s_ Q) Cl:l Q:l 'p;j-Q. fil 10.7 ~ P..oo 00 ~ Q)C) ,!:io CI:IO Ori 100 121 00 15 0 +:> 1=1 ~~ .bD ·• Q) ~tt +:> § C) H ro Q) Q) fH p.. ·rl 0 C) Q) 0 ~...; Q)Q)CI:IP.. C) 0 1=1 s ~ •rl bD ttl Q) Q) 00 'OOO.H •r! ~ Pol 00 C) •rl •rl l=lii:4-i..c:l HE-!0+:> 25 21 ~ VI~VII 0' 14 9 9 8 27 32 23 19.5 19.5 1 7 1 9 13 28.5 16.0 . 100 4 14 8 8 12 . ) I • VIII-IX Unknown Totals 46 5 3 l_7 .. o 1 '---~~-k_ 92* 100.0 .; J3':r.. 28 1 1 5 10 21.4 17.8 54 100.0 144 62 125 -__ ']__ 43 117*** 41 32 *8 per cent of the 119 females were ~e Class I and were not included· in this tabulation. **Both were considered Class II J.nd.ividuals==Only 1 .of. 3 Class Ir:'individuals was pregnant. ***The weighted average embryo: cow r.atio of this sample==ll8:100 " '* : .. 1 TABLE XIII THE WEIGHTED AVERAGE ».mRYO:C<lV RATIO (. Theoretical embryo:cow ~~Uiil ber in Per Cent· of · Embroys/100 ratio by Number in Percent· Sample of Posted Female Cows in increments of Age Classes Sample 146 Females Posted Females Sample Posted Sample each age group Calf 27 18 0 0 0. 0 I 10 6 0 .o 0 'o -- II & III 12 s 6 16 100 8 . I rv &v 32 2.2 14 37 121 '27 1\.) ....J I VI & VII 38 26 9 . 23.5 100 ~.26 VIII & IX 27 1,8 9 23.5 U4 26 Totals 146 100 ···38 100 87 *Using only the data from .38 animals-=:~8 animals.of unknown age were not includedo MOOSE BROWSE SURVEY A reconaissance survey of moose browse was made during late February, March and April, 1956, The survey was made· along that portion of the railroad between Mile Post 172 and 2.3L The Houston station at Mile Post 175 and the Talkeetna station at Mile Post 227 are the two inhabited stations most nearly defining the extremities of the study area. The section stations of Nancy, Willow, Kashwitna, Caswell and Sunshine are within the boundaries of the survey area. The segment of the Alaska Railroad traversing the survey area sustained the most critical railroad moose kill during 1956; accounting for 65 per cent of the total kill. Objectives. 1. To determine the browse species composition along the right-of-way. 2. To determine if a correlation between browse abundance and moose fatalities exists • .3. To determine the approximate utilization of available browse. • • Procedure ti · The individual browse sample plots had a diameter of 2 meters; 20 such plots were taken at each mile post. The individual plots were spaced 50 feet apart along a line horizontally perpendicular to the railroad; 10 plots were taken from each side of the right-of-way. Thus the sample area was approximately 1000 feet wide and 65 miles long. The browse utilization estimates were visual, and were based on the utilization of individual plant's annual growth. The following four browse use categories were recognized: 1. 0-25 per cent (light use) 2. 25-50 per cent (moderate use) .3. 50-75 per cent (heavy use) 4. 75-100 per cent (excessive use) Browse Composition The overall composition of vegetation above the snowline, which averaged approximately 50 inches during February and '-hrch, is illustrated in Figure No. 1. · · -28- " • .. Birch and Willbw comprise over ·70 per cent o.r the total vegetation. Birch, which repre~ents over ·40 per cent of' the total vegetation· present, does not contribute in a like proportion to the available moose browse because much or the birch has grown beyond the reach of moose. The browse composition by per cent of' individuals present in each mile is represented in Figure No. 5. Browse ... Moose Fatality Relationship The possibility or the existence of' a direct correlation between moose fatalities and brow·ee abundance and distribution was studied. The 'fesults of' ·this study are shown in·Figure No. ). Browse avail- ability was.based on the number of' individual plants of' browse species present within reach of' the moose. The individual plants grown too large to contl'ibute browse were discarded. · · · There does not appear to be .a def'inii~ co~elation between avaiU.bili ty of' browse and moose fa tali ties. However, the c.ombination of' browse, deep snow and a great moose population does have a high correlation. Browse Availability and Utilization ,' .. .. .• 'Ji. ;"• . . . . ..·. . The ~vailability and utilization of' browse is illustrated in Figure 2. 'The correlation between browse availability·a;ld utili~ation is not. consistent. . . . .. . .. . · . . . ·.·· _ Browse Preference Figure No. 4 illustrates the relative availabilit,y and utilization of' the three major brows, ·species found on the study areas (l) Willow Salix sp., (2) Birch Betula tp., and (3) Aspen Polulua ap. The data · is not a quantitative representation or the relative contribution of'· each species to the moose diet, but does indicate species preference. Aspen is favored (slightlf) over willow, and birch is a poor third. PARASITES ' Observations of' moose parasites were made as opport~ty permitted. Table IIV summarizes the data obtained from examining 30 sets of' moose lungs. or the lungs examined 6, or 20 per cent, war-. i~cted with J:l1da tid cysts Eohinqggoqua qapuloaua. It is evidin.~ fr~ even this small sample that the rate or infection is greater among the older age classes; 50 per Of,nt of th.e combined VI •. ~ ancl II age classes were infected, whereas no' Of&ts were found in th•~·~oalF:.-claaa III animals • ... 29 .. Other Parasites While collecting moose stomach content samples three instances of rumen parasites were observed. The parasite, Parantbistomum sp., was identified by Dr. R. L. Rausch of the U. S. Public Health Service, Anchorage, Alaska. TABLE: XIV No. Infected Per Cent No. Clean Per Cent Total Per Cent Age· Class Lungs Infected Lungs Clean Lungs of Total Calf 0 0 2 100 2 7 I 0 0 2 100 2 7 II & III 0 0 2 100 2 7 IV & V 1 17 6 83 7 23 VI & VII 1 14 7 86 8 26 VIII & IX 3 50 3 50 6 20 Unknown Age 1 33 ~ 66 __L 10 Totals 6 20 24 80 30 100 STOMAOH · SAMPm-;~~~ During the study 81 moose stomach con~ent samples were obtained. The samples·are stored in Fairbanks and will be analyzed during the next quarter. -30- • • tl ""' • •· TABLE XV . MOOSE TAIJJF.D PER HOUR or FLnm Are& Date No. Moose n:d.~Ut 'i'ime Moose Per Hour LCMm SUSITNA AND MATANUSKA VALLEYS Willow Area (General) 10/21/56 561 4.8 ll7 Matanuska Valley (General)· 10/29/56 460 4.5 102 .. Kahiltna Flats 10/30/56 189 1.7 112 Alexander Creek 10/30/56 18 2.3 7.8 Peters Creek & Eagle River 11/29/56 12 . 1.0 12 Total* 1240 13.3 93.2 *This total includes only the time actually spent overthe area. The complete total flying time was 19.7; total moose•-1276; moose per hour--64.7. •)1- • • TABLE ..XVl MOOSE TALLIED PER HOUR OF FLYING -32- .., •• TABLI[ .XVII Comparison of Sex and Age Ratios in Moose Populations of Central Alaska Young Twin Young Young · Total Total Bulls/ Calves/ Calf% Bull%' Bulls/ Moose Bulls/ 100 Total Calves/ lQO C()WS in Total in Total 100 B~ll iri Area 100 Qow.§__ __ Bulls ___ ~ _ _lQO Q_QWf3 __ ?~lCa.l.f' ______ I!_eT<l_ _ _FI~_d ________ Calves Sample SUSITNA-MATANUSKA VALLEY 1956 27 25 40 6 24 4 33 1276 1955 28 25 35 4 21 4 39 ~850 1954** 63 --30 2 16 ----601 1953 48 14 39 8 21 3 33 '2700 1952 42 27 44 10 24 6 51 1421 1951 61 28 60 13 8 56 •'•" 1867 B 27 \.).) 1950 16 .. 1140 \.).) ------------8 Mean 48 24 41 7 21 5 42 1693 UPPER SUSITNA-COPPER R •. BASIN 1956 ·67 19 27 2 14 7 _,'.95 1154 1955 98 29 52 . 10 21 12 .. 108 .2500 1954 109 26 79 16 27 10 72 1700 1953 107 36 90 17 29 12 85 1100 1952 61 22 40 17 20 7 67/ 683 Mean 88 26 58 '12 22 10. 85 1427 **Limited sample may not be representative. TABlE XVIII Comparison of Sex and Age Ratios in Moose Populations of Central llaska Young Twiif Yourig Young· Total Total Bulls/ Calves/ Calf % Bull% Bulls/ Moose Bulls/ 100 Total ~~~v~~~s . mm~Jgar~~s in Total in Total 100 Bull iri Area 100 Cows Bulls Herd Herd Calves Sample KENAI* 1956 51 13 24 10 14 4 54 3786 1955 50 14 19 10 13 4 75 3109 ·. 1954 84 14 27 6 12 6 90 2048 1953 62 12 26 7 14 4 39 2900 I 1952 50 33 21 6 12 10 156 1136 \.>.) 1951 69 18 23 16 12 7 108 1513 ~ I 1950 ----~---7 ----1158 Mean 61 18 23 9 12 6 87 2236 TANANA VALlEY*** -- 1956 84 20 47 .. 6 20 7 71 405 1955 123 40 53 13 19 18 186 410 1954 85 35 47 5 20 13 127 :iffi09 Mean 97 32 49 8 20 16 '·'·· 128 308 *Data from Refuge Supervisor Spencero ***Young bull-adult bull identification uncertaino. • .t)) * & • " 1-3 Ill I-' @ (!) c+ ~ ,~~t;- 2\) 2\) 2\) I-' I-' 0 0 ....0 2\) .....J 1\) .....J I I I I 2\) 1\) 1\) 1\) I-' I-' 0 0 0' I-' 0' j-J 1----1---- 1---- '--- (/) 0 § Ill ~ Ol P" (!) 1-'• I-' ~ I-' s y u- '-- '- \ I-' ~· 1-' I-' ....0 00. -J 1\) -J 2\) -J I I I I I-' I-' I-' I-' ....0 ....0 00. 00. 0' I-' 0' I-' uuu I---- ~ ~ 1-'• Ol I-' ~ i 1-' ~ f-'• c+ ~ .M 0~ '- 1- 001 P~0~1BH ~s~1V a~l I-' .....:; 1\) I I-' .....J 0' 1-- ::d 8 Ol c+ 0 ::l ~ f-'• I-' f-'· 0~ h'l c+ f-'• 0 ::l 001 ~ T£G-GL... T ':1-SOd 9TWl U01'+ 1SOdlUO:J uon~'+a.l:3aA pau1qlUO:J--T a . .m.l:31.[ Figt~e 3--Comparison of Snow Depth, Browse Availability and Moose Fatalities 100 100 75 50 25 172-181 Scale on left refers to browse availability. Availabili~ is based on the average number of individual browse plants per sample plot in the respective 10 mile segments. Scale on right refers to moose fatalities~. Snow depth in inches 75 50 25 D ESJ Browse availability--relative number of plants per sample plot. § Moose fatalities -.36- • .. c 1' .. • • Figure 4--Moose Browse Availability S:nd Utilization· 10 501 100 50 w--Willow B--Birch .A--Aspen 177-181 182-186 187-191 207-211 212-216 217-221 i -f Per cent of total browse available - l\"\~1 Per cent utilization -37- 222-226' 197~201 100 50 1001 501 i \;J 100 00 I 501 ] •• Figure 5--Composition of VegetatiQn above the Snowline--Mile Post 172-231 WBAAlS 172 Q) r-i ~ 1'1) ~ WBAAl.S 180 tl.O Q) ..!>:l fll ~ WBAA1S 188 a ~ m Ql f..i P.+> 0(/) B A AI S 196 f The Alaska Railroad · W B A.AlS WBA.AlS 173 174 ~ ~ ~ s:1 ~ ~ Q) Q) ..!>:l ..!>:l .:s .:s WBAAlS. WBAAlS 181 182 ·,w B A A1S W B A & S 189 190 WBAA1S 175 ~tl Q),P &~ WBAA1S 176 W B :A .. .f\1 S W B A Al S 183. 184 ~ ~ til ~ W B AA1S WBAAlS' 177 178 ·G> r-i (l) p. +> ~ ~ •.-t ~-r-i ~ 0 :::1 ~ za;:e-t W B A .A1 S 179 1'1( a:!· Q)• ~- t;l . Q) p,· o. W B A Al S 185 W B A AlS: W B il. l1 s· 186 ;187 _· Jh~ j tl) ~ W BAAl rS· W B A.A1S w·B JA.Ill.S W B AA1S W BAAlS 191. 192 193 . 194 195 :_ ~ .p •r.i .a~ fll p. .a:l•ri ~:.:~r:x:: WBAAlS ... 199 .. • B A Al S 200 • ' I \.>.) '-.() I :! . Figure 5 (Continued) 100 I Q) ~ 71. 50 I I I p.. rll ~ ! bD til ~ =11-L,~n n r1l 0 g :i li2< WBAA.lS WBAAlS WBAAlS W B AAl S WB AA.lS W B AA.lS W B!AlS' 100 I . ·------r 205 206 207 208 209 210 211 Q) ~ Q) Q) Q) Q) G) 71. H ~ ~ H H p.. ft p.. p.. l a @ ~ ~ ~ Qj ~ til Cl] Cfl Cfl g g ~ 0 l2; ~ g ,g WBAAlS W B A A1 S W B I. Al S W'BAAlS WBAA15 WB!AlS· WBAAlS WBAAlS 212 213 214 215 216 217 218 219 100 I . . p:: Q) Q) ~ ~ ,..!:cj H 50 I ~~ rn r-ll Jl n JL p.. ..,:» ..,:» rll ~ .. Q) Q) D Q) Q) ,J:lQ) ~'B~ r1l H ..-1-f-:l g Qj Qj IO:ttn E-t (\1 E-t 100 50 W B A Al S 220 i (/) ~ WBAA.lS 228 WBA.AlS W BAAlS 221 222 W B AA.lS W BAAlS 229 230 )V B All S 223 W B AU S 231 W B AA.l S WBAAlS 224 225 WBAAlS 226 W--Willow B--Birch A--Aspen n--Alder s--S.pruce WBAAlS 227 t ..... N \ \ \ \ 152° 152° .. ~c:. ~,. "~-'~.._~ ... <i'P-~'1- ~-p.~'o~'P-'- 150° ,/· ~W.$No.,-60. z.z. IJ-H 148° // /' /' 148° s SUSITNA RIVER BASIN Figure 6--Areas Covered and Relative Distribution of Moose Tallied October 1956 Aerial Surveys -:? 25 20 15 10 5 0 25 Miles SCALE NELCHINA. CARIBOU RANGE Figure 7--Areas Covered and Relative Distribution of Moose Tallied, November 1955. 16 0 16 32 HAAAAAAAI -·-··--SCALE OF MILl:.~ Palmer ~ummit L. AMC NELCHINA CARIBOU RANGE Figure 8--Areas Covered and Relative Distribution of Moose Tallied, October 1956. 16 0 16 32 HAAAAQAAI SCALE OF MILE~ Palmer Summit L. ~ " ~ : /:1 .. / ... ; A/IIIC Job No. 2 METHODS Tanana Valley and Fortymile Herd Composition By: Sigurd T. Olson During the period October 14 -November 9, aerial surveys were con- ducted to determine age and sex co¢position. In addition to the usual counts made in November, a count was conducted in October during the rut to determine whether or not counts made during this period were feasible. This count was made in an area which was again surveyed in November. The Tanana Valle,y and tributary valle,ys were covered on October 14 and November 6, 7, and 9 by Olson, Jones, Shepherd and Miner using Piper Supercubs. The Forty- mile area was covered by Frost and Pinkham using a Piper Pacer on November 6th. Counting techniques used were basically similar to those used in previous years. ~adding another class of bulls (mediums), it is believed there was less tendency to include medium sized or small adults in the year- ling class of bulls. Counts were recorded by. the various geographical areas in the Tanana Valley and its tributray valleys to determine whether or not differences in herd composition exist between these areas. AREAS COVERED The Tanana Valley proper was covered between the Little Delta and the Nenana Rivers. Tributary valleys of the Chena River, Chatanika River, Salcha River and Shaw Creek were also covered as far up as their respective drain- ages were subjeQt to hunting pressure. The Wood River coverage was generally confined to the'area at its head and the foothills of the Alaska Range. The headwaters of the Tatlanika and Totalanika were also included in this area. For the first time the Fortymile region was covered by this particular type of survey. Since only that part of the area penetrated by the Taylor Highway can b.~ hunted, the country lying between Mt. Fairplay, Ketchumstuk Flats and Chicken was chosen as representative and given intensive coverage. RESULTS A summary of all moose tallied by sex and for the Tanana Valley and Fortymile are presented in Table 1. The major areas are broken down into local units and the herd composition presented for each. A total of seven hundred and forty moose were tallied during the 17.4 hours of flying time devoted to the survey. The average number of moose seen per hour was 42.5. -43- HERD COMPOSITION IN TANANA VALLEY AND FORTYMILE POPULATIONS The data in this report will be presented in essentially the same form as that presented in the report by Scott on the Susitna and Copper River moose populations in the Quarterly Progress Report' for 1955 (Vol. 10, No. 3). This has been done for the sake of uniformity and comparison be- tween various areas being studied. The sex and age composition data for the Tanana Valley and Fortymile regions are shown in Table 2 •. The interpretations of these data are presented in the following discussion. . TANANA VALLEY AREA a. Productivity -Productivity. in all areas .in the Tanana Valley appeared to be fairly consiste.nt and can be considered as good. The calf: cow ratio of' 47:100 is slightly lower than the ratio of' 53:.100 in 1955· but on a par witl,l 1954. The rate of' twinning in 1956 is le~ss than one,.half' of that in 195 5 and in part explains the difference in the. calf': cow x-a tios for the two years. The calf' percentage (20%) of' the total herd however, has not varied over one percent during the last three years and indicates therefore a fairly uniform level of' productivity. Productivity in the Tanana Valley cannot measure up to the.Copper.River Area .in 1952 (52 calves per 100 cows) but is considerably better than Kenai (19 calves per 100 cows) or the Suaitna-Matanuska area (35 calves per 100 cows). Young bull:total bull ratios are very similar throughout the Tanana Valley as a wholeo In the Chena River, Chatanika River, and Shaw Creek areas, this ratio was somewhat higher than .elsewhe~re and probably reflects the heavier hunting pressure in that ar.eao . There· is no indication however, that hunting creates any problem in these areas as yet. The similarity of these ratios is another indication of the. sameness of the productivity in the Tanana area. The slightly sreater hunting pressure mentioned·ea:t"lier in the Chena, Ohatanika and Shaw Creek accounts for the slightly higher young bull ratio as compared to the rest of the area, b. Suryival -Young bullsmale.;,calf' ratios. indicate good survival and the .overall light.hunt:tng pressure ohl.raoterist:Lo of moat of ·the area, The survival as indicated b,y the young bull•,le oalf ratios is al:Lghtly higher in the Wood River area and lowest on the anana flats, howeveZ', they are not so diverse as to suggest any a:Lgnifioanttdts•:t.milarity of aurtival rates over the area as a wholeu A further oheok of survival oan be mac!e b)' oomparinl the :ratioa ot youns bulls :reoordec! in 1956 to male calve• reoorl!a4 in 19,, 'r;)y uains-ai!.ther the number of oalvea and yearling bulla per 100 al!ulte or their peroent111e of total animala. The premise involved it that the oloaer tho ourrent yearlins bull ratio approaohee last yeo.r 1a bull oalf' ratio, the better the stu•vivalc One bas:to anumpt:Lon must be made J namely, that to oaloulate the number of adult1r, that 11!1 1 animals two years or older, it ia neoeoeary to asl!ume a w.iJ+t.J. 1> • . .. t:!' .... ~ TABLE lo Summary of Moose Population Counts Tanana Valley = 40 Mile = Oct. = Nov. 1956 Young Adult Total Lone Cows Cows Total Total Total Area Bulls Bulls Bulls Cows 1 calf 2 Calves Cows Calves Moose TANANA VALLEY Chena-River"' Shaw Creek 9 7 23 .30 28 1.3 3 44 19 93 Chatanika 9 Olnes Tanana Flats 15 65 80 55 40 0 9.5 46 221 (S. of river) Wood River 7 30 37 21 15 1 37 17 91 (Hd~ Tat1anlka & Totatlanika ) Sub=-Total 29 118 147 104 68 4 176 82 405 8 ·~ FORTY;;;MILE VI H Fairplay~ Westfork.9 It' .:> 17 . 22 14 17 0 31 17 70 Mo sqtii to Fork Ketchumstuk Flats 4 1.3 17 14 14 0 28 14 59 Sub=Total 9 30 39 28 31 0 59 31 129 ~ WOOD RIVER (Octo count in Rut) 12 75 87 65 26 0 91 28 206 GRAND TOTAL 50 22.3 273 197 125 4 326 141 740 =============================================================================== f) '!; ~' ~ # . ' .. TABLE 2Q Sex and Age Ratios in Tanana Valley = 40 Mile Moose Population = 1956 (1954=55 Sex and Age Eatios for Tanana Valley included for Comparison) Young Twin Young Young Total Bulls/ Calves/ Calf % Bulls% Bulls per Bull$/-. 100 Total Calves/ too Cows in Total in Total 100 Bull Total. 100 Cow~ Bulls 100 Cows w/Calf Herd Hero Calves Moose TANANA VALLEY Chena~ Shaw Creek~ 68 23 43 19 20 8 77 93 Chatanika- Tanana Flats 84 19 48 0 •21 1 65 221 Wood River 100. 19 46 6 19 8 87 "91 ~ ~ Above Areas Combined 83 20 47 5 20 7 71 405 ()'. u 1955 123" 40 53 13 19 18 186 uo 1954 85 35 47 5 20 13 127 109 FORTY=MIL"E Fairplay3 Westfork~ 71 23 55 0 24 7 63 70 MosqUito Fork Ketchumstuk Flats 64 23 50 0 24 7 57 59 Above Areas Combined 66 23 53 0 24 7 60 129 WOOD RIVER 105 14 31 0 14 6 86 206 (Oct. count) 50:50-calf and yearling sex ratio.. This does not take the harvest of year- ling bull moose into consideration, however it is felt that the hunting . pressure is not heavy enough to alter it significantly in view of the overall bull:cow ratio for the Tanana Valley -Wood River Area., The above compari- sons are presented in Table 3o The 1956 figures, of course, exclude the current calf crop .. On the basis of lOO:fidUits, survival appears to be good with less than a one percent drop from calf to yearlfng stage.. The same is true when com- parison is made based on percent of total animals.. Recognizing the obvious sources of error, such as disproportionate tally of bulls or a sex ratio possibly differing from the assumed one, it still seems apparent that year- . ling survival is good in the Tanana Valley o Herd composition data are not available for 1955 in the Fortymile area, thus similar comparisons are not possible .. It is believed, as pointed out earlier, that the current young bull figures are more reliable than in previous years due to improved classifi- cation techniqueso This appears evident by the drop in the ratio of young bulls to male calves from 127 and 186 per lQO in~l954 and 1955 to 7lin 1956. The excessively high ratios in 1954 and 1955 indicate a dispropor- tionate sampling of bulls in those years. c.. Effects of hunting -Hunting pressure in the Tanana Valley as a whole can be considered as light. The only areas surveyed which received -any appreciable hunting pressure are the Chena, Chatanika, Shaw Creek areas. _These areas are accessible in part by roads, trails, boat, or in case of Shaw Creek, numer9us lakes provide landing places for aircraft.. The sex ratio for this atea of 68 'bulls to 100 cows, is compared to 84 and 100 bulls per 100 cows for .the Tanana Flats and 'Wood River areas suggests a moderate removal of bulls'due to hunting. The effect however, cannot be considered significant.beyond the fact that hunting pressure bas not altered the sex ratio to a ·pOint where a shortage of bulls appears imminent .. ) FORTYMILE AREA a.. Productivity -Calf:cow ratio;-of 53:100 indicates good produc- tivity in the Fortymile.. This is about the same level of productivity as found in the Copper area in 1955 (52: 100) o Young bull proportions are a bout the same as found in the Tanana Valley o Calf percentages, calf: cow ratios and young bull ratios point to·a slightly higher rate of productivity in the Fortymile as compared to the Tanana Valley o b. Survival -Fair survival is. apparent as shown by the young bull: male calf ratio of 60:100. The proportion df young bulls to total bulls (23:100) when cross-checked with the good rate of productivity also suggests fair survival .. Co Effects of hunting -The bull:cow ratio of 66:100 is indicative o~ light overall hunting pressure, being about the same as the Chena, Chatanika, Shaw Creek areas. Hunting in the Fortymile is confined principally to the areas immediately adjacent to the Taylor High~y.. There are very few -4'7-- accessible trails or roads branching·from it and no lakes for landing back froiD. the roads by aircraft. Thus, for all practic·al purposes the major por-tion of the Fortymile is ilnhunted. There is, then, no indication that hunting is having any appreciable effect on the·moose population sampled in the Fortymile areao . Comparison of counts made in October and November--These counts were made in the Wood River area where outside factor·s, particularly hunting, would not tend to distort the pictureo The comparison is made on the basis of the data break-down in ~able 2 and for convenience is shown in Table~. Examination of the ratios shows that some disparity iri the counts exists between the two periodso The most obvious difference is the differ- ence in calves perlOO cows. The ratio rises from 31 to 46 calves in less than one montho This represents a 33 percent change in the level of produc- tivity. This same phenomena -was noted in comparative counts 11JB.de in 1955 o Counts in the Tanana Valley in September-October showed a calf:cow ratio of 42:100 and by November it had risen to 53:100. The only explanation at hand seems to be that the cows are more in evidencein October due to the rut and their increased activity. The calves would tend to be missed being more in the background at this timeo This is also borne out by the fact that the calf percent increased from 14 to 19 percent over this same period~ Increased activity of the larger bulls in October appears evident by virtue of the young bull:adult bull ratio being smaller in October than November. The difference ::\.n the nUm.ber of· bulls per 100 cows does not change enough to more than lend a little additional evidence to the foregoingo It would seem that although it is possible to obtain composition counts in the rut prior to November, such counts would tend to be biased qy the , selective rutting activity. Bulls, particularly the larger ones, are on the move and the cows are also more in evidence. Calves seem to get pushed to the sidelines. Yearling bulls do not show up as well as the a:dul t bl;llls since they do not have the antler development and are more or less found on the outskirts of any rutting activity. There is also the possibility of lack of snow in Octobero Antlers of larger moose serve to catch the observer's eye at such tiiqes and dispropor- tionate sampling of bulls can resulto B.r November a good snow cover is invariably present and moose are usually spotted by seeing a black object on the landscape in deference to catching the flash of an antler. · It is believed that November 1 -15 is the ideal period in'which to obtain moose population data. At this time there appears to be less o'ppor- tunity tor bias than at any other time. The data is admittedly sketchy, but it tends to support general observations as well as similar data ob- tained in 1955 for this area (Quarterly Progress Report, Voi. 10 -No. 2, pp 16-20). ~.~ ~ <tP • il l!i ... ~ .r,- ~· DISCUSSION It appears by examination and cro~s checking of the young bull ratios obtained in 1956 tPat the problem of disproportionate ,sampling of bulls has been overcome to a cons~deraple extento This seems particularly true when compared with the ratios obtained in 1954 and 1955o Although the "medium" class of bulls was not used in the final analysis of data it served its pur- pose by establishing more definitive limits on the "young" bull classo It was immediately evident that although it was quite easy to separate medium bulls from the young bulls, it was hard to know where to draw the line rela- tive to large bulls 9 thus the dividing line between the medium and small classes was quite positive 9 however it became rather vague between the medium and large classeso For this reason 9 the medium and large classes were lumped togethero In an attempt to obtain a further check on the ~urvival factor~ cows without calves were supposed to be tallied as "adults" or "young"o This :BJ::Q:~~d to be practically impossible to doo The principal reason was lack of a ~size or age gauge 11 o Antler size sets yearling bulls apart and relative size often helps as a check 9 however 9 in the case of cows 9 particularly when seen alone 9 there is nothing to compare size with and a fairly small cow could be easily classed as an adult if there were no other moose to compare size witho It is believed that after enough experience one observer might be able to set up an index, however 9 when several observers are involved, differences in observational abilities are apt to convey considerable bias into the resultso Although the current counts in the Tanana area did not indicate extreme differences in population characteristics 9 it is believed that future surveys should continue along the same lines to prevent overlooking important local population changes which could feasibly be masked by an overall surveyo This is particularly true of those ;Limited areas accessible to hunterso Future surveys should be aimed principally at the latter areaso Occasional checkss perhaps one every two years 9 on the more remote areas like the Tanana ~lats and the Wood River would serve to show any significant trends or changes in those areaso The Fortymile counts indicate that the area surveyed has a relatively homogeneous population structUre exhibiting the effects of light hunting pressure and a slightly higher level of productivity thari the Tanana Valleyo Present data indicate that the moose population in the Tanana Valley and adjacent areas is relatively stableo Productivity continues to remain at a satisfactory level and fair to good survival as indicated by the various young bull ratios denotes a healthy moose herdo The data from the Fortymile area, though available for the first time, seems to indicate a similarly healthy condition for the moose population in that areao Both the Tanana and Fortymile appear to continue to enjoy a higher level of productivity and survival than either the Kenai or the Susitna areas as of 1955o The Copper still seems to hold forth as the prime moose popula- tion in Alaska at present 9 howevero =49= .. One problem in particUlar ia. characteristic of both the Tanana and Fortymileo Hunting is lo~lized along certain accessible areaso · Greater disbursement of pressure i6Uld result in a larger number of moose being taken without substantially changing the population characteristics 'of the herd as a whole. Bull ratios and bull:cow ratios would likely be altered somewhat, even so~ productivity would not be affected adverselyo =50= ~ y._, • ~ .. ·f} ... .. ~ I. ~ "r.' 8 TABLE t3 Year 1955 1956 Noo Calves 79 Comparison of 1955 Male ~lf Ratios With 1956 Yearling Male Batios 1 Noo a , Noo Total · ·:, Calves Adults Moose .. ···-· ---·· ------- 39 331 410 a' Calves per 100 Adults llo7 To~l-2 Noo a' Noo Adults (less Total moose a'Yrlings I._rlii1e:s ___ ~ ... ~lmgs __ U.Q x.rlings) (less Calves) per 100 adults 5S 29 265 323 Note: 1. Assume even sex ratio (100 d\100 ~ calves) 2. ~sstime even sex ratio (29 a'_represents actual count) Therefore ar + ~ = 5S. 10o9 %a' Calves of Total 9.5 % a' Yrlings of Total S.9 TABLE jf. Total Bulls/ Period lOO·Cows .. ·.1 October 15 96 Jt, November 7 100 !\.) B ;",~ . ., Young Bulls/ Comparison of Sex and Age Ratios in October and November of the Moose Population on Wood River Twin Young Calves/ Calf % Bulls % 100 Total Calves/ 100 Cows in Total in Total Bulls 100 Cows w/Calf Herd Herd 14 31 0 14 6 19 46 6 19 8 -It '~· Young Bulls per 100 Bull Total Calves Moose 86 206 87 91 I'~ e? • Job Noo 3 AERIAL SURVEYS Stikine River Valley Aerial . Surveys and Hunter Harvest Information By: David Ro Klein Oontinuing unfavorable flight conditions have prevented the completion of aerial surveys in the Stikine Valleyo These surveys will be completed as soon as weather conditions permito EVALUATION· OF TEE 1956 H~VEST The 1956 moose harvest on the Stikine River was distinguished by a heavier than normal killo High waterlevels and favorable weather during the first week of the season partial~ contributed to the higher hunter successo However, falling waterlevels and heavy rains on the lower river discouraged many hunters during the last week of the season and accounted for fewer hunters in the areao Table 1 showsthe total kill, hunter success and number of hunters on the Stikine River for the years 1952-1956. Several parties of hunters from Wrangell met the Canadian requirements for hunting on. the Stikine River in British Columbia and hunted with the Canadian guide, Walter Simpson. Success among this group was particularly high. Eleven moose were killed in the 10 miles of river valley from the international boundary to the Iskut Rivero TABLE 1--Total Kill and Hunter Success Ratios on the Stikine River, Alaska, in Relation to Length of Season 1 1952-1956 Length of Est. Noo Noo of Moose Percent Year Season of Hunters Taken Success 1952 4 weeks 300 31 10 1953 0 2 weeks 100 12 12 1954 3 weeks 125 14 11 1955 3 weeks 150 16 11 1956 3 weeks 125 30 24 -53- '#. · MUDDY RIVER-THOMAS BAY Reports from loggers at Muddy River and Thomas Bay and moose hunters indicate that the size of the moose herd occuP,ying the Muddy River-Thomas Bay area is considerably larger than was estimated in 1955. Two bulls were killed in the Muddy River valley near the Brown Cove Lakes during this year's open season. Observations of 18 different moose were made from the ground on October 3, 4 and 5 and hunters using a plane counted nine moose in-the same general areas. A breakdown of these and other observations is shown in . Table 2. Approximately nine tenths of the area is timbered with a mature spruce-hemlock forest and the remainder is open muskeg, gravel bars and marsh areas. Due to the relatively dense cover, conditions are not favorable for the observation of moose. Consequently, from the above observations it appears that only a Slilall percentage of the total number of moose present in the area were seen. It seems quite likely that there are at least thirty moose present in this area. TABm 2--ob-servations of Moose in the Muddy River-Thomas Bay Area, 1956 Location of Moose Observed Date Observer Observation Bulls Cows Calves Uniden. Total 10/3 F. File. Brown Cove Lakes 4 4 10/3 B. File Brown Cove Lakes to Patterson Glacier 9 9 10/4 G. Reid 2 mi. up Muddy River 1 4 2 7 10/4 G. Reid Mouth Muddy River Fresh tracks near camp 10/5 Loggers Patterson River 2 5 7 10/25 Loggers Brown Cove 2 2 -54- ~, '~ It'· ""' "' r-. ~- .. • {;;.