Showing papers in "Journal of Wildlife Management in 1984"

Clarification of a technique for analysis of utilization-availability data

Abstract: En prenant pour exemple Ovis canadensis (observe dans les Monts Harquabale, Arizona) on teste la methode statistique de Neu et coll.

Cougar food habits in southern Utah

Abstract: Diets of cougars (Felis concolor) were studied from December 1978 to August 1981, on a 4,500km2 study area near Escalante, Utah. Prey eaten by cougars was estimated from analysis of 112 animals consumed as prey and from 239 cougar scats. Composition of diet was corrected based on feeding trials using captive cougars. Mule deer (Odocoileus hemionus) were found to be the major prey item, 81% of biomass consumed. Lagomorphs, large rodents, and smaller predators were also important components of the diet. Cattle comprised less than 1% of the diet, although they were abundant on the cougars' summer range. Age structure of deer killed by cougars indicated that older (>7 years) deer were killed more often than expected (P < 0.005). J. WILDL. MANAGE. 48(1):147-155 Cougar dietary habits have been studied in Utah (Connolly 1949, Robinette et al. 1959), Idaho (Hornocker 1970), Arizona (Shaw 1977, 1982), Oregon (Toweill and Meslow 1977), British Columbia (Spalding and Lesowski 1971), and the West in general (Young and Goldman 1946). Food habits were generally similar, the diet consisting predominantly of wild and domestic ruminants, with lesser amounts of rodents, rabbits, and other predators. Results of the more intensive studies in Utah, Idaho, and Arizona differed, however, in the relative proportions of mule deer, elk (Cervus elaphus), and cattle in the diet. During years of peak snowshoe hare (Lepus americanus) abundance in British Columbia, 27% of the cougars' diet was composed of hares, indicating that cougars take advantage of numerically abundant prey. Because inferences are frequently drawn from food-habits studies of predators to predict their influence on the dynamics of prey populations, it is important tha results from such studies accurately describe the diet. Floyd et al. (1978) determined that the number of "field-collectible" scats produced by gray wolves (Canis lupus) was inversely related to prey size. Selective feeding on flesh alone resulted in loose, liquid scats that would seldom be found in the field. Consumption of smaller prey, on the other hand, would generally include more indigestible material and would result in more persistent scats. In addition, Johnson and Aldred (1982) and Weaver and Hoffman (1979) have documented differential digestibility of smaller mammals and the problems of enumerating small mammals in scats. The method employed to collect foodhabits data may further reduce general applicability. Dietary samples from cougars killed by sport hunters or damagecontrol personnel may be biased toward specific groups of cougars or may be restricted to specific seasons of the year (Young and Goldman 1946, Robinette et al. 1959, Spalding and Lesowski 1971, Toweill and Meslow 1977). Only Robinette et al. (1959) and Shaw (1982) reported summer food habits. Several authors have indicated that vulnerability of mule deer to cougar predation is influSFunding was provided by Utah Div. of Wildl. Resour. (UDWR), and the study was conducted under auspices of the Utah Coop. Wildl. Res. Unit, UDWR, Utah State Univ., U.S. Fish and Wildl. Serv., and Wildl. Manage. Inst. cooperating. 2 Present address: Idaho Department of Fish and Game, P.O. Box 21, Soda Springs, ID 83276. J. Wildl. Manage. 48(1):1984 147 This content downloaded from 157.55.39.175 on Thu, 11 Aug 2016 06:18:10 UTC All use subject to http://about.jstor.org/terms 148 COUGAR FOOD HABITS * Ackerman et al. enced by sex of the deer and season of the year (Robinette et al. 1959, Hornocker 1970, Shaw 1977) and by age of the deer (Hornocker 1970, Spalding and Lesowski 1971). This paper reports on an intensive effort to determine the year-round diet of cougars and relative vulnerability of the various age-classes of mule deer to cougar predation between December 1978 and August 1981. We are grateful to A. J. Button for his indispensable help as our houndsman and chief technician. T. Rettberg, our pilot, flew many long days for us. W. Button helped in capture operations and provided a site for our winter camp. The Button and Coleman families, M. Reid, F. Van Dyke, K. A. Johnson, D. Shepardson, K. Parr, M. H. Hemker, B. A. Blakesley, R. E. Gruenig, L. Cox, and R. D. Peters assisted with the field work. F. H. Coles, J. G. Guyman, N. V. Hancock, F. C. Jensen, and T. Gardiner of the UDWR provided important support and advice. F. Coles, J. A. Gessaman, and F. F. Knowlton gave valuable criticism of the manuscript. Cooperation was provided by the U.S. For. Serv. and Bur. of Land Manage. The Ecol. Cent. at Utah State Univ. provided assistance during the analysis stage.

Effects of wild pig rooting in a deciduous forest

Abstract: Action des porcs sauvages sur la faune superficielle, les elements nutritifs, la biomasse de la litiere forestiere et du sol

Food Intake and Foraging Energetics of Elk and Mule Deer

Abstract: The energetic cost of grazing was measured using indirect calorimetry with a tracheotomized elk (Cervus elaphus nelsoni). The cost of eating herbaceous forage averaged 0.32 kcal/kg body weight/ hour, an energetic increment of 26% over standing costs. Forage intake was quantified using esophageal fistulated elk and mule deer (Odocoileus hemionus hemionus). Dry matter consumption rate and mean bite size increased curvilinearly as functions of forage biomass for both species. Asymptotic grass intake rates were 2.22 and 14.04 g dry matter/minute for deer and elk, respectively. Consumption rate and bite size were greater in shrub-forb communities than on grass pastures of comparable biomass. Biting rate ranged from about 15 to 60 bites/minute and was inversely related to bite size. Rate of travel during foraging decreased exponentially with increasing forage availability. A computer model was constructed to evaluate the interaction of time and energy constraints on foraging ungulates. The effects of variation in forage quality, forage abundance, and snow cover on the ability of animals to meet daily energy requirements are discussed. J. WILDL. MANAGE. 48(4): 1285-1301 Foraging is the dominant activity of free-ranging ungulates. Wild ungulates typically devote 40-60% of each day to finding and consuming food (Craighead et al. 1973; White et al. 1975; Schwartz 1977; Belovsky and Jordan 1978; Collins et al. 1978; Owen-Smith 1979, 1982; Gates 1980; Hanley 1982). The energetic cost of these activities represents an important component of the animal's energy budget (Young 1966, Osuji 1974, Chappel and Hudson 1978). However, in spite of the significance of foraging in the life strategy of wild ungulates, relatively little is known about the energetics of this behavior. The literature is replete with food habits information, but such observations are of limited value without an understanding of the efficiency with which the animal harvests the food resource and extracts energy from its environment. This study was undertaken to quantify the cost-benefit functions of foraging by captive elk and mule deer relative to food availability. Specific objectives were to: (1) determine forage intake rate as a function of the biomass of acceptable food items; (2) determine the relationship of intake rate to mean bite size and biting rate to better understand the behavioral adjustments that regulate energy intake; (3) quantify locomotion rate during foraging relative to food availability; (4) measure the energetic cost of eating as distinct from expenditures for standing and locomotion; and (5) model the effects of variation in forage quality and abundance on the ability of free-ranging cervids to meet daily energy requirements. This project was funded by the U.S. For. Serv. and Washington State Univ. We thank K. L. Parker for support and assistance in data collection and M. A. Reisenauer for the care of experimental animals. L. D. Bryant and J. W. Thomas provided facilities at the U.S. For. Serv. Range and Wildl. Habitat Lab. in La Grande, Oregon. J. Wildl. Manage. 48(4):1984 1285 This content downloaded from 157.55.39.29 on Tue, 12 Apr 2016 10:03:48 UTC All use subject to http://about.jstor.org/terms 1286 INTAKE AND FORAGING ENERGETICS OF ELK AND DEER * Wickstrom et al. METHODS AND MATERIALS Elk calves and mule deer fawns were bottle-raised and habituated to the experimental protocol. Training included acceptance of gentle restraint with a head halter, manipulation of the esophageal and tracheal cannulae, and transport in a trail-

Effects of prescribed fire on nutrition of mountain sheep and mule deer during winter and spring

Abstract: Prescribed burning elevated the concentration of protein and in vitro digestible organic matter (IVDOM) in winter diets of mountain sheep (Ovis canadensis) and mule deer (Odocoileus hemionus) feeding in grassland and mountain shrub communities. We observed no effect of burning on ungulate nutrition during spring. In both communities, the magnitude of treatment effects tended to depend on the month we observed diets. Effects of burning on diet crude protein persisted for 2 years in both communities. Treatment effects on diet IVDOM lasted for 2 years in mountain shrub, but were absent during the 2nd year in grassland. Effects of fire on diet quality resulted from changes in ungulate diet selection rather than improvements in the quality of individual forages. Differences in the amount of green grass in ungulate diets accounted for much of the enhancement in diet quality we observed. We conclude that prescribed fire can improve winter habitats for mule deer and mountain sheep. J. WILDL. MANAGE. 48(2):551-560 Prescribed burning is frequently used to improve and enlarge habitats for wild ungulates. It is widely believed that fire benefits ungulates by enhancing their nu- trition. Although intuitively appealing, this belief has rarely been tested (Taber 1953, Springer 1977, Rowland 1981). Instead, many previous studies have focused on fire effects on the quality of forage. Inferences on the nutritional quality of animal diets drawn from observations on the quality of forages are unreliable whenever animals feed selectively. We tested the hypothesis that prescribed burning improves the nu- tritional quality of diets of mule deer and mountain sheep grazing in montane plant communities during winter and spring. This project was supported by Fed. Aid

Population Characteristics and Movement Patterns of Cougars in Southern Utah

Abstract: Twenty-two cougars (Felis concolor) were monitored by radiotelemetry between January 1979 and July 1981 in southern Utah. The population, comprised of resident, transient, and juvenile cougars, remained relatively constant during the study. Densities (0.3-0.5 cougars/100 km2) were considerably lower and home-area size of four resident females (685 km2, SE = 257, range = 396-1,454) and a single resident male (826 km2) were larger than reported for other areas. Home areas of resident females overlapped, but with the exception of family groups, close spatial associations were rare. Dispersal of male cubs appeared independent of resident adult density. Density of resident cougars was apparently regulated by a social pattern based on land tenure, but limited by the abundance of mule deer (Odocoileus hemionus), their principal prey. J. WILDL. MANAGE. 48(4):1275-1284 The elusive nature of the cougar, coupled with its common reputation as a destructive predator, has hampered field studies of this species. Work in Idaho by Hornocker (1969, 1970) and Seidensticker et al. (1973) indicated that an adult cougar population consisted of breeding residents and a variable number of transients that established residency and bred only when sites were provided by removal of residents. In addition, they concluded that social constraints maintained the population below a level set by prey densities. More recent information from Nevada (Ashman 1981), California (Sitton 1977; Koford 1978; Hopkins et al., in press), Arizona (Shaw 1977, 1979, 1982), Colorado (Currier et al. 1977), and British Columbia (Dewar and Dewar 1976) has demonstrated the behavioral variability of cougars. Although differences in density and home-area size might be expected under varying environmental conditions, differences in population composition and dispersion patterns are less easily explained. Although Shaw (1977), Sitton (1977), D. Ashman (pers. commun.), and Hopkins et al. (in press) found that resident males used overlapping areas, Hornocker (1969, 1970) and Seidensticker et al. (1973) did not observe adult males sharing areas. Similarly, female overlap was recorded in Idaho but not in California. In contrast to other investigators, Hopkins et al. (in press) reported more resident males than females and no transients in their study population of six adult cougars. The objective of our study was to investigate the movement patterns and population characteristics of an unhunted cougar population on a relatively isolated but heterogeneous study area in southcentral Utah. We are grateful to A. J. Button for his indispensable help as our houndsman and chief technician. W. Button helped in capture operations and provided a site for our winter camp. The Button and Coleman families, M. Reid, F. VanDyke, K. A. Johnson, D. Shepardson, K. Parr, M. H. Hemker, B. A. Blakesley, R. E. Gruenig, 'Funding was provided by Utah Div. of Wildl. Resour. and the study conducted under the auspices of the Utah Coop. Wildl. Res. Unit: Utah Div. of Wildl. Resour., Utah State Univ., U.S. Fish and Wildl. Serv., and Wildl. Manage. Inst. cooperating. 2 Present address: Idaho Department of Fish and Game, P.O. Box 4229, Pocatello, ID 83205. J. Wildl. Manage. 48(4):1984 1275 This content downloaded from 157.55.39.144 on Wed, 07 Sep 2016 05:49:04 UTC All use subject to http://about.jstor.org/terms 1276 SOUTHERN UTAH COUGAR POPULATION * Hemker et al. L. Cox, and R. D. Peters assisted with the fieldwork. F. H. Coles, J. G. Guyman, N. V. Hancock, F. C. Jensen, T. Gardiner, and T. Rettberg of the Utah Div. of Wildl. Resour. (UDWR) provided important support and advice. F. H. Coles, K. R. Dixon, and F. F. Knowlton gave valuable criticism of the manuscript. Cooperation was provided by the USDA For. Serv. and USDI Bur. of Land Manage. (BLM). The Utah State Ecol. Cent. provided support during the final stages of the study.

Home-range size of coyotes: a critical review

Abstract: Revue des methodes utilisees pour collecter et analyser les donnees sur l'aire de deplacement et presentation de criteres de controle de la validite des donnees existantes. Tentatives d'epreuve des hypotheses communement avancees concernant les dimensions de l'aire de deplacement

Comparison of the importance of different habitat attributes to avian community organization

Abstract: Etude de l'importance de diverses composantes du feuillage (densite, heterogeneite, diversite, etc.) sur le choix de l'habitat chez des oiseaux le long de la Riviere Colorado (450 km le long du cours inferieur)

Current impact of DDE on black-crowned night-herons in the intermountain west

Abstract: Organochlorine contamination was studied in eight black-crowned night-heron (Nycticorax nycticorax) populations nesting in Washington, Oregon, and Nevada in 1978-80. DDE was detected in 220 eggs sampled; eggshell thickness was negatively correlated with residues of DDE and polychlorinated biphenyls (PCB's). Other contaminants were detected in 35% or fewer of the eggs. Except for the two Columbia River colonies in which local DDE contamination was a probable compounding factor, a strong north-south clinal pattern of DDE residues among colonies existed. Southern colonies were most contaminated, and observed productivity was below population maintenance in one colony (Ruby Lake). At DDE levels in eggs above 8 ppm, clutch size and productivity decreased, and the incidence of cracked eggs increased. No evidence of breeding-ground DDE-DDT contamination was found except along the Columbia River. J. WILDL. MANAGE. 48(1):1-13 DDT and its metabolites may have played a role in the decline of blackcrowned night-herons in the northeastern United States (Ohlendorf et al. 1978). For example, Anderson and Hickey (1972) reported 18% shell thinning by 1952 in New Jersey. The use of DDT in the United States was banned in 1972, and by the midto late 1970's, production rates at several locations in eastern North America (Wisconsin, Qu6bec, Rhode Island, and Massachusetts) appeared normal, eggshell thickness was normal or near-normal, and/ or residues of organochlorine pesticides were lower (Hoefler 1980, Tremblay and Ellison 1980, Custer et al. 1983), with the possible exception being Lake Ontario (Price 1977). Similar improvements have been reported for other species, including the osprey (Pandion haliaetus) (Henny 1977, Spitzer et al. 1978). An adult black-crowned night-heron died at Ruby Lake National Wildlife Refuge near Elko, Nev., in 1975-3 years after the DDT ban. Its brain contained 230 ppm DDE and 1.1 ppm DDT (wet weight) (Ohlendorf et al. 1979). Although DDE concentrations in eggs from the northeast were diminishing in the late 1970's, the mortality at Ruby Lake in 1975 led us to suspect that DDE was still a problem for bird populations in the Intermountain West. Most birds nesting in the region are migratory, and many winter in Latin America. We studied two colonies in 1978 and extended our efforts to eight colonies by 1980. This study was designated to (1) determine levels of DDE and other organochlorine residues in black-crowned nightheron eggs; (2) evaluate the most common contaminants in relation to shell thickness and egg breakage; (3) evaluate regional patterns and trends of DDE residues; (4) evaluate DDE in eggs in relation to productivity; (5) evaluate the source of the contaminants; and (6) evaluate residues in herons found dead to determine if pesticides were implicated. National Wildlife Refuge personnel who provided field assistance included S. H. Bouffard, J. E. Cornely, and S. P. ThompJ. Wildl. Manage. 48(1):1984 1 This content downloaded from 40.77.167.80 on Mon, 13 Jun 2016 06:09:49 UTC All use subject to http://about.jstor.org/terms 2 DDE IN BLACK-CROWNED NIGHT-HERONS * Henny et al.

Bird populations and vegetation characteristics in managed and old-growth forests, northeastern Oregon.

Abstract: Etude de la densite de population de divers oiseaux reproducteurs en fonction du couvert vegetal de forets exploitees ou non du nord-est de l'Oregon. Les especes sont plus nombreuses dans les forets entretenues que dans les vieilles forets. Conseils pour le maintien de l'habitat des oiseaux

Activity budgets of nonbreeding gadwalls in Louisiana

Abstract: Activity budgets of nonbreeding gadwalls (Anas strepera) in coastal southwestern Louisiana were studied from October 1977 through April 1978 and related to sex, pair status, and environmental factors. Gadwalls spent 64% of their time feeding, 11% locomoting, 11% resting, 9% alert, 5% preening, and less than 1% each in agonistic and courtship activities, respectively. Gadwalls spent significantly more time feeding during night than day (P 0.05). Time spent feeding increased from 44% in October to 77% in April. Feeding activity decreased as air temperature increased (r = -0.163, P < 0.001) and varied depending upon habitats and foods used. All gadwalls spent similar amounts of time alert, but unpaired males spent more time locomoting than those paired (P < 0.01). Gadwalls spent more time resting during night than day (P < 0.01), and birds spent more time resting and preening when using shallow-water areas on refuges than other habitats. Although males only spent 1.5% of their time courting in fall, by late November 86% of females were paired. Since gadwalls spend most of their time feeding, the primary goal of management should be to ensure that preferred feeding habitats are preserved. Observations also suggested that current land-use modifications along coastal Louisiana may be especially detrimental to gadwalls. J. WILDL. MANAGE. 48(2):371-380 Numerous studies have examined the ecology, taxonomy, and distribution of North American waterfowl, yet of 1,748 studies reviewed by Reinecke (1981), only 8% pertained to wintering waterfowl. Fretwell (1972) emphasized that factors outside the breeding season were crucial in regulating populations of migratory species. Condition of waterfowl leaving the wintering grounds is probably important to reproduction (Paulus 1980, Krapu 1981). Gadwalls have been intensively studied on the breeding grounds (Gates 1958; Oring 1968; Dwyer 1974, 1975; Serie 1974; Blohm 1979) but little is known of their wintering ecology. Over three-fourths of the North American gadwall population, numbering between 500,000 and 1 million, winter in Louisiana (Bellrose 1976). Gadwalls comprise 29% of all ducks in coastal Louisiana (H. A. Bateman, unpubl. reps., La. Wildl. and Fish. Comm., 197778) and 10% of the waterfowl harvest in Louisiana (Novara et al. 1981). Fredrickson and Drobney (1979) and Reinecke (1981) considered analysis of activity budgets a useful tool in determining he needs of wintering waterfowl. Verner (1965) suggested that each species exhibited an optimal time budget for each environmental condition and that selection favored individuals whose time budgets were most adapted. I examined activity budgets of gadwalls in winter and the influence of time of day and year, weather, and social status of individuals on activity budgets. I also examined the influence of habitat and diet on activity budgets and suitability of various management practices in providing for needs of wintering gadwalls. I thank R. D. Crawford, T. Joanen, L. L. McNease, K. Paulus, D. L. Trauger, and W. Wrenn for help during this study. A. Afton, C. D. Ankney, R. J. Blohm, R. D. Sayler, and two anonymous reviewers provided criticisms of earlier versions of the manuscript. Financial support was 'Present address: Department of Zoology-Entomology, Auburn University, Auburn, AL 36849. J. Wildl. Manage. 48(2):1984 371 This content downloaded from 157.55.39.196 on Sat, 24 Sep 2016 04:34:52 UTC All use subject to http://about.jstor.org/terms 372 ACTIVITY BUDGETS OF NONBREEDING GADWALLS * Paulus provided by U.S. Fish and Wildl. Serv., La. Dep. of Wildl. and Fish., Univ. of N.D., and Soc. of Sigma Xi. STUDY AREAS AND METHODS Gadwalls were observed in coastal southwestern Louisiana on Rockefeller and Marsh Island state wildlife refuges, both closed to hunting, and on private lands within 13 km of Rockefeller Refuge on which hunting was allowed. Brackish marsh comprised much of the study areas and several areas have been impounded to stabilize water conditions. I have described the study area in detail elsewhere (Paulus 1980, 1982). Activity budgets of gadwalls were determined by instantaneous sampling procedures (Altmann 1974, Dwyer 1975) from October 1977 through April 1978. Observations were made with a 15-40 x spotting scope and 7 x binoculars. A tape recorder, stopwatch, and super-8 movie camera were used to time and record specific events. Activity of a single individual or both members of a pair were recorded every 20 seconds at the tone of a metronome (Wiens et al. 1970). Activities were divided into seven categories: (1) feeding, (2) locomoting (walking, swimming, and flying not associated with courtship activity), (3) resting (loafing and sleeping), (4) preening (preening and bathing), (5) alert, (6) courting (displays and copulations), and (7) agonistic (bill threats, chasing, and biting). Diurnal activities were recorded during 1-hour randomly selected sampling periods. Nocturnal activities were recorded during nonrandom periods under clear to mostly cloudy skies when the moon was between the first and last quarter stages. Nocturnal observations were limited to birds within 30 m of the blind. Data collected from observation periods of <30 minutes were eliminated from analysis. During observation periods, sex and pair status of the individual observed was determined, and date, ambient temperature (C), wind velocity (using a portable anemometer), cloud cover, precipitation intensity, and water depth were recorded. For analysis, cloud cover was coded as (1) 0-25%, (2) 26-50%, (3) 51-75%, or (4) 76100%; rainfall intensity as (0) none, (1) light, (2) moderate, or (3) heavy; and water depth as (1) 0-15 cm, (2) 16-30 cm, (3) 31-45 cm, (4) 46-50 cm, and (5) 51-75 cm. Foods consumed by gadwalls were d termined from observation, aquatic vegetation analysis, or from gadwalls coll cted for food habits analysis (Paulus 1982). Habitats used were classified based upon vegetation, physiography, and water depth characteristics (Table 1). Vegetation was identified from Radford et al. (1968). Pair status was determined by observing associations of females with males. Chance or temporary associations were a potential source of error, and on many occasions even widely separated (_15 m) gadwalls later resumed close associations and were judged paired. Judgmental error was reduced by considering as paired only those birds (1) mutually avoiding or threatening other birds; (2) exhibiting consistently synchronized activities, especially locomoting; and (3) remaining within 3 m of each other during most of the observation period. The Kruskal-Wallis test and multipleconfidence-interval procedures (Marascuilo and McSweeney 1977:306-319) were used to detect differences among group means with each activity category as dependent variables and date, sex-pair status, or environmental variables as independent variables. Simple correlation (r) analysis was used to examine relationships J. Wildl. Manage. 48(2):1984 This content downloaded from 157.55.39.196 on Sat, 24 Sep 2016 04:34:52 UTC All use subject to http://about.jstor.org/terms ACTIVITY BUDGETS OF NONBREEDING GADWALLS * Paulus 373 Table 1. Characteristics of major habitats used by nonbreeding gadwalls in Louisiana during 1977-78. Water depth Major foods Habitat (cm) consumed Other characteristics Stream 30 Potamogeton pusillus Fresh to intermediate water, slow moving Shallow, natural marsh 30 Leptochloa fascicularis, Seasonally flooded in winter algae Deep, natural marsh 30 Ruppia maritima, algae Under tidal influence, intermediate to brackish Shallow impoundment 15-30 Eleocharis parvula, algae, Seasonally flooded in winter, Leptochloa fascicularis fresh Deep impoundment 30 Ruppia maritima, algae Large bodies of brackish to intermediate water not

Relationships among mule deer fawn mortality, coyotes, and alternate prey species during summer.

Abstract: The extent, timing, and causes of summer mortality of mule deer (Odocoileus hemionus) fawns were studied in relation to coyote (Canis latrans) population level, alternate prey population levels, and coyote food habits. Additionally, fawn mortality rates were related to supplementary information on vegetation production and fawn hiding cover. A minimum of 90% of summer mortality of fawns was the result of predation by coyotes. Fawn mortality was lowest when microtine rodent populations were high. Mortality rate of fawns was not directly related to population levels of coyotes, deer mice (Peromyscus maniculatus), white-tailed jack rabbits (Lepus townsendii), or Nuttall's cottontails (Sylvilagus nuttallii). Vegetation production and winter snow cover may have been factors regulating microtine populations and thereby fawn mortality rates. Coyote predation can reduce fawn survival in nutritionally healthy deer populations, but alternate prey population levels and cycle phase should be determined by managers prior to decisions about predator control to increase deer populations. J. WILDL. MANAGE. 48(2):489-499 Mule deer populations associated with timbered breaks-badlands habitats in north-central Montana declined sharply during the early 1970's, apparently as a result of extensive overwinter mortality in 1971-72 followed by low fawn production or survival (R. J. Mackie, unpubl. rep., Mont. Dep. Fish and Game, Fed. Aid Proj. W-120-R-7, 1976). Recruitment remained low into the mid-1970's despite apparently favorable habitat conditions. A similar population decline associated with overwinter mortality during 1964-65 was followed by increased fawn production/survival and population recovery within 2 years (Fig. 1). Concomitant with the decline in deer populations, increases in coyote populations were reported in north-central Montana and elsewhere following the 1972 ban on the use of toxicants, especially compound 1080, in predator control. Although quantitative data on coyote population trends in north-central Montana were lacking, studies by C. J. Knowles (unpubl. rep., Mont. Dep. Fish and Game, Fed. Aid Proj. W-120-R-7, 1976) indicated that predation by coyotes on mule deer was occurring in breaks habitat along the Miss uri River and may have been a major factor affecting fawn recruitment. The fact that fawn: doe ratios were low in early winter further indicated that, if predation was the cause of low recruitment, it was especially important during the summer-fall periods. This study was established during the summer of 1976 to quantify the extent, timing, and causes of summer mortality among mule deer fawns; specifically, the role and importance of coyote predation in fawn recruitment to early winter. Intensive studies were conducted annually from early June through mid-September from 1976 through 1981 as one segment of broader studies on the population ecology and habitat relationships of mule deer I Send reprint requests to senior author at Box 5, Montana State University, Bozeman, MT 59717. J. Wildl. Manage. 48(2):1984 489 This content downloaded from 157.55.39.124 on Fri, 13 Jan 2017 18:13:03 UTC All use subject to http://about.jstor.org/terms 490 MULE DEER, COYOTES, AND ALTERNATE PREY * Hamlin et al.

Food habits of Florida black bears.

Abstract: annular cementum rings of their teeth. N.Y. Fish and Game J. 20:54-61. PETRIDES, G. A. 1950. The determination of sex and age ratios in fur animals. Am. Midl. Nat. 43:355-382. SIMON, D. E., AND M. J. FRYDENDALL. 1981. Age study of Minnesota red fox using cementum annulae counts and tooth X-rays. J. Minn. Acad. Sci. 46:2-5. SULLIVAN, E. G., AND A. O. HAUGEN. 1956. Age determination of foxes by X-ray of forefeet. J. Wildl. Manage. 20:210-212. TUMLISON, R., AND V. R. MCDANIEL. 1983. A reliable celloidin technique for dental cementum analysis. J. Wildl. Manage. 47:274-278. WOOD, J. E. 1958. Age structure and productivity of a gray fox population. J. Mammal. 39:74-86.

The need for distance data in transect counts

Abstract: This paper compares the strip and line transect sampling methods of estimating the density (number of objects per unit area) of biological populations. We assume the objects of interest (e.g., birds, mammals, nests, sign, etc.) do not move in response to the observer prior to detection. Methods dealing with ways to use incomplete counts are emphasized and several general approaches are reviewed. We conclude that for reasons of efficiency and validity, transect count studies should record perpendicular distance data.

Northern sea lion distribution and abundance: 1956-80

Abstract: The present distribution and abundance of the northern sea lion (Eumetopias jubatus) was determined from surveys made between 1975 and 1980 and compared to estimates made approximately 20 years earlier. The previous population estimate of 240,000-300,000 is similar to our estimate of 245,000290,000. Declines appear to have occurred in the eastern Aleutian Islands, Pribilof Islands, and near Kodiak Island in the Gulf of Alaska. Increases may have occurred principally in the western and central Aleutians and west of Kodiak Island. Seasonal movements and indirect and direct effects by humans are considered the likely causes for regional changes in distribution and abundance. J. WILDL. MANAGE. 48(3):729-740 The breeding range of the northern sea lion, the most abundant sea lion in the northern hemisphere, extends around the North Pacific Ocean rim from the Kuril Islands and Okhotsk Sea, through the Aleutian Islands and southern Bering Sea, along Alaska's southern coast, and south to California (Scheffer 1958, Rice 1977). Northern sea lions are gregarious, polygynous, and utilize traditional rookeries and haul-out sites, usually located on remote and exposed islands. Extensive surveys were carried out between 1956 and 1958 along the Alaskan coast in the Gulf of Alaska (Mathisen and Lopp 1963) and in the 1960's in the Bering Sea and Aleutian Islands (Kenyon 1960, 1962c, Kenyon and Rice 1961). Kenyon and Rice (1961) summarized the available data and estimated that the entire northern sea lion population numbered between 240,000 and 300,000 in the late 1950's and early 1960's. Interest in the present status of northern sea lions has been stimulated by concern over the potential interactions between marine mammals, commercial fisheries, and oil and gas exploration in the Gulf of Alaska and Bering Sea and a marked decline in sea lion numbers in the Aleutian Islands (Braham et al. 1980). A coincidence of several recent land-based, boat, and aerial surveys to determine regional distribution and abundance of sea lions resulted in an unusually thorough coverage of sea lion distribution between 1975 and 1980. The objectives of this study are to describe the present world distribution of northern sea lions, to report our estimate of the relative population size, and to compare our estimate to that reported 20 years earlier by Kenyon and Rice (1961). We wish to acknowledge the cooperation of G. A. Antonelis, B. Bartels, M. L. Bonnell, D. G. Calkins, R. L. DeLong, T. J. Early, F. H. Fay, J. M. Francis, M. D. Griswold, C. A. Hansen, M. Hunt, B. W. Johnson, P. A. Johnson, P. Kozloff, J. L. Martin, M. K. Nerini, and A. B. Taber who allowed us to use their unpublished counts of sea lions. A. M. Johnson allowed us to use field records of 1959-60 and 1962-65 Aleutian Island surveys. K. W. Kenyon assisted us in reviewing his data from previous surveys in the Aleutian Islands. Graphics were made by R. P. Radek of the Northwest and Alaska Fish. Cent. Secretarial support was supplied by L. K. Hietala, M. A. Wood, and J. L. Waychoff of the Natl. Mar. Mammal Lab. (NMML). G. A. Antonelis, H. W. Braham, R. L. DeLong, R. L. Gentry, A. M. Johnson, D. W. Rice, D. E. Withrow, J. W. Brooks, and especially D. G. Calkins J. Wildl. Manage. 48(3):1984 729 This content downloaded from 157.55.39.177 on Tue, 15 Nov 2016 04:02:17 UTC All use subject to http://about.jstor.org/terms 730 SEA LION DISTRIBUTION * Loughlin et al. reviewed the manuscript and provided many helpful comments.

Habitat use by migrant sandhill cranes in Nebraska

Abstract: The principal spring staging areas of the midcontinent population of sandhill cranes (Grus can- adensis) are along the Platte and North Platte rivers in south-central Nebraska. Most of these lands are privately owned and managed for corn and cattle production. Diurnal habitat use by radio-tagged cranes was primarily in cropland (55%), native grassland (28%), and tame hayland (15%). Ninety-nine percent of the cropland use was in cornfields; 55% as grazed stubble, 36% as disced, cultivated, and plowed stubble, 7% as ungrazed stubble, and 1% unclassified. Grazed pastures accounted for 93% of the grassland locations and mowed alfalfa fields 77% of the tame hayland locations. Other habitats were seldom used. Time budget analyses indicated that cranes, while in croplands, grasslands, and haylands, spent 35, 36, and 50% of the time foraging, respectively Cranes roosted in the shallows and on nearby sandbars of about 111 km of river channel. Cranes usuallv roosted where the channel was at least 150 m wide and avoided stretches narrower than 50 m. Height of woody vegetation along shorelines and on islands influenced where cranes roosted when unobstructed channel width was less than 150 m; bridges or roads adjacent to the channel also reduced use by about half. Management recommendations are made for maintaining suitable habitat for sandhill cranes on their staging areas in Nebraska. J. WILDL. MANAGE. 48(2):407-4 17 Approximately one-half million sand- hill cranes (four-fifths of the continental population) gather annually along the Platte and North Platte rivers in Nebraska during March and early April while en route to their breeding grounds in central and arctic Canada, Alaska, and Siberia (US. Fish and Wildl. Serv., unpubl. data). Water developments in the upper Platte River Basin during this century have dras- tically reduced flows, causing major changes in channel width in the Big Bend reach (Williams 1978) where most of the cranes gather. Extensive encroachment by woody vegetation has accompanied chan- nel shrinkage (Currier 1982), and pro- posed developments would cause addi- tional habitat degradation and loss (Krapu et al. 1982), raising concern for the well-

Lek attendance of male sage grouse

Abstract: Le comptage des mâles sur les sites de reproduction est utilise pour estimer les tendances de la population en vue d'une bonne gestion de ce gibier (Centrocercus urophasianus). On precise ici la presence quotidienne des mâles sur les leks

Sexual size dimorphism and age-related size variation in bald eagles

Abstract: Patterns of size variation between sex and among plumage classes of bald eagles (Haliaeetus leucocephalus) were examined by measuring 10 variables on museum study skins. Using multivariate statis- tical techniques, a field method was devised to correctly identify the sex of 98.1% of bald eagles examined. Plumage maturation in this species and the problems associated with previous descriptions of plumage succession are discussed.

Elk and deer diets in old-growth forests in western Washington

Abstract: Etude de la qualite du regime et du degre de chevauchement de la niche ecologique d'Odocoileus hemionus columbianus et de Cervus elaphus roosevelti, sympatriques dans des forets anciennes de l'Olympic National Park

Movements and management of sea otters in Alaska

Abstract: Etude menee de 1979 a 1982 sur 104 Enhydra lutris equipes d'emetteurs radio (denombrements aeriens et en surface), faisant apparaitre des sites preferentiels de repos et d'alimentation et des deplacements saisonniers lies a la reproduction, a l'elevage des jeunes, au trafic maritime, aux tempetes. La peche intensive des crabes par l'homme est une menace pour cette espece

Ecological Distribution and Crude Density of Breeding Birds on Prairie Wetlands

Abstract: Les populations reproductrices de 28 especes d'oiseaux de zones humides (autres que les anatides) sont recensees sur 1321 de ces zones dans le Dakota du Nord. La repartition ecologique et la densite en fonction de l'habitat sont precisees pour 22 especes les plus communes

Do Field Observers Attract Nest Predators and Influence Nesting Success of Common Eiders

Abstract: Les mouettes (et non les corbeaux) sont un peu attirees par l'agitation au sein des Somateria mollissima en couvaison provoquee par des observateurs humains. La predation apres cette agitation est un peu plus elevee mais le succes reproducteur ne change pas

Breeding biology of Pacific white-fronted geese

Abstract: Nidification; caracteristiques du nid; densite des nids et leur repartition; taille de la couvee; epoque d'eclosion; succes des couvees (etude menee en 1977-79, dans le delta du Yukon-Kuskokwim, Alaska)

Relationships of Food to Spatial and Temporal Breeding Strategies of Mallards in Sweden

Abstract: The function of poor and rich breeding habitats of mallards (Anas platyrhynchos) was studied in an oligotrophic forest lake area in southwestern Sweden during 1975-79. The lakes were ranked according to an increasing degree of fish competition for food. Mallard pair density during egg-laying was highest in small lakes lacking fish. From ice breakup until June, adults and larvae of water insects formed abundant potential food for laying female ducks. However, the number of some invertebrate groups, and especially their mean individual size, was lower in lakes containing fish. Duckling hatching coincided with the peak of insect emergence. Experimentally-released young ducklings obtained significantly more food in lakes without fish. Although the size of the emerging insects increased during the duckling hatching period, flying insects were significantly smaller in lakes with fish. The size and number of food items for laying females and small ducklings were reduced because of fish competition. During other phases of reproduction when the protein demand was lower, the seed and vegetative production was adequate. As a result, there is a shift between different food resources and the breeding mallard may use two types of lakes, the hatching lake and the rearing lake. In optimal habitat, breeding mallards adapt well to temporary and fluctuating food resources in a home range composed of lakes with and without fish. These lakes must be managed in different

Birds as grazing indicator species in southeastern Arizona

Abstract: Etude conduite dans un sanctuaire de la Societe Audubon dans le comte de Santa Cruz (Arizona) et dans un ranch adjacent. Deux plateaux tabulaires sont pris en reference, on compare les densites et les habitats de 4 especes sur sites pâtures ou non

Movements of translocated wolves in Minnesota

Abstract: De fevrier 1975 a mai 1978, 104 Canis lupus, captures pres de fermes du Minnesota ou ils avaient cause des depredations sur le betail furent transportes vers le nord et l'est a 50-317 km du point de capture. Le resultat est tres decevant, nombre d'animaux retournant a leur gite primitif. Peut-etre que l'âge des animaux au moment du transport est a reconsiderer