Cooperative Wildlife Research Laboratory Research Articles

Coal Tailings Reclamation Practices: Soil Cover Variances - The Ayrshire Alternative

Reclamation of potentially acid producing coal processing waste generally requires 4 feet (1.2 m) of soil cover to comply with most state and federal requirements (Surface Mining Control and Reclamation Act of 1977 (PL 95 87)). Soil cover variances for acid coal slurry (tailings) have included alkaline amendments (agricultural limestone) and reduced soil cover depths. Direct seeding of alkaline amended coal tailings substrates has been demonstrated on more than 1,800 acres throughout the midwest since the late 1970's. Slurry reclamation practices have included upland cool season grasses and legumes, warm season native prairie grasses, and emergent and open water wetlands. Direct seeded slurry demonstrations implemented by the Cooperative Wildlife Research Laboratory SIUC during the 1980's and 1990's have received regulatory approval (bond release), as well as state and national (OSM) reclamation awards. Reclamation monitoring has documented vegetative cover, water quality, and substrate geochemistry through the period up to bond release. This annual monitoring has established a > 25-year database supporting the principles and practices of acid coal tailings reclamation. A recent soil cover variance at the Amax Ayrshire Mine (southwest Indiana) incorporated the principles of pyrite aging and weathering, and incremental limestone amendment to establish warm season grasses and shallow water wetlands on a ~170 acre (70 ha) acid producing slurry basin. Pre-treatment (1995) and posttreatment (1996 1999, 2003) substrate monitoring identified differential pyrite oxidation in unsaturated surface, and saturated subsurface profiles within the Ayrshire slurry basin. Agricultural limestone amendment (~100 150 tons/ac (225 335 Mg/ha)) has restored and maintained a favorable (alkaline) acid-base balance for seven years since the initial (1995) application. Warm season grass establishment provided > 87% aerial coverage in the direct seeded upland zones. Pretreatment acid (pH 2.6) surface water quality in the shallow wetland zone has been restored to post-treatment alkaline (pH 7.8) conditions. Additional

Reproductive Performance of Female Key Deer

The reproductive performance of the endangered Key deer (Odocoileus virginianus clavium) is a potential limiting factor in its conservation. We analyzed data collected by necropsy of 142 female Key deer from 1968 through 1989 to provide a better understanding of their reproduction. A breeding season of about 6 months was longer than for more northerly herds of white-tailed deer. Productivity of Key deer was low (0.76 fetuses/F -1 yr of age at breeding) and fetal sex ratio (74% M) was high for the species. Rates of reproductive activity (% pregnant or lactating) for females at age of breeding were 4% for fawns, 58% for yearlings, 61% for ages 2-4 years, and 90% for females -5 years of age. Eight (17%) of 48 pregnant females carried twins, and the remainder carried single fetuses. We hypothesize that poor reproductive performance of female Key deer is due to a nutrient deficiency or that it evolved as an adaptation to an insular habitat. J. WILDL. MANAGE. 55(3):386-390 The endangered Key deer of the lower Florida Keys are smallest in mass of the subspecies of North American white-tailed deer (Hardin et al. 1984) and are isolated from mainland Florida by 60 km of water. Prior to protection from hunting, the population of Key deer declined to a low of 25-80 in 1951-52 (Dickson 1955). Klimstra et al. (1978), using spotlight surveys, estimated that the population increased to 300-400 in the early 1970's. The U.S. Fish and Wildlife Service (1985) reported a decline in population to 250-300 by 1984. Low reproductive output apparently contributed to the slow recovery of the Key deer population from the low of the early 1950's (Hardin 1974). Currently, development encroaching on habitat (U.S. Fish Wildl. Serv. 1985) and mortality due to collisions with automobiles result in a precarious status for the Key deer population. Nutrition, one of the most important factors affecting productivity of white-tailed deer (Verme 1967, McCullough 1979), affects both ovulation rate and the proportion of females that become pregnant (Sadleir 1987). An imbalanced ratio of calcium (Ca) : phosphorus (P) or deficiencies of cobalt (Co), iron (Fe), or copper (Cu) probably contribute to low productivity of whitetailed deer from the southeastern United States (Smith et al. 1956, Harlow 1972, Smith and Hunter 1978). The diet of Key deer may be deficient in P (Widowski 1977) or other nutrients, forcing females <4 years old (that have not reached peak mass) to concentrate energy and nutrients on body growth rather than reproduction. We analyzed long-term data collected from mortalities of female Key deer to indirectly test this hypothesis. Numerous individuals of the National Key Deer Refuge and the Cooperative Wildlife Research Laboratory at Southern Illinois University, Carbondale contributed to the collection and examination of carcasses. We thank M. L. Folk, J. W. Hardin, J. L. Roseberry, T. G. Scott, T. J. Wilmers, and A. Woolf for reviewing a draft f the manuscript. The Key Deer Refuge pr vided use of computer facilities. This project was funded by a grant from the Richard King Mellon Foundation.

Sandhill Crane Roost Site Characteristics in the North Platte River Valley

We documented sandhill crane (Grus canadensis) roost site characteristics in the North Platte River Valley (NPRV) of Nebraska in riverine and semipermanent palustrine wetlands from late February through mid-April in 1988 and 1989. Crane roost sites in the river were located closer to visual obstructions, in narrower channels, and in a wider range of water depths than determined previously in the Platte River. Cranes roosted in semipermanent wetlands where widths were _12 m, water depths were 5.0-24.4 cm, and distance to shore was _1 m. Based on the estimated peak number of sandhill cranes and roosting capacity estimates, availability of roosting habitat was not limiting use of the NPRV by cranes. North Platte river flows should be maintained to provide channel widths _48 m and water depths 521 cm for roosting cranes. Temporary (wet meadow) and semipermanent palustrine wetlands adjacent to the river should be preserved to provide important diurnal and nocturnal crane habitat. J. WILDL. MANAGE. 54(3):480-486 The North Platte and Platte River valleys of Nebraska are the primary spring staging areas for the midcontinental population of sandhill cranes (Benning and Johnson 1987). Cranes are dependent upon these valleys to provide high energy foods (especially corn) necessary to accumulate lipid reserves for use in nesting areas (Krapu et al. 1985, Tacha et al. 1987). Loss of grasslands and wetlands to agricultural and commercial development has altered staging habitat of sandhill cranes (Lewis et al. 1977, Currier and Ziewitz 1987). Flow reductions in the rivers allowed encroachment of woody vegetation on sandbars used by cranes for roosting. Current management of crane roosting habitat includes maintenance of water flows and costly mechanical removal of woody vegetation (Lingle 1982). Iverson et al. (1987) found up to 67,500 (45% of total) cranes using off-river temporary and semipermanent wetland roost sites in the North Platte River Valley (NPRV) and recommended the preservation of existing sites and development of additional off-river roost sites. However, no studies of roost site selection have been conducted in the NPRV. Our objectives were to determine factors associated with crane use and selection of river and adjacent wetland roosts and to estimate the roosting capacity of the NPRV. We thank G. A. Wingfield of the Nebraska Game and Parks Commission and P. McDonald of the U.S. Fish and Wildlife Service (USFWS) for providing valuable assistance in Nebraska. Landowners in the NPRV granted access to their property. P. A. Vohs and A. Woolf reviewed the manuscript. This study was funded by USFWS Purchase Orders 64412-00302-88 and 64412-8900026 and the Cooperative Wildlife Research Laboratory, Southern Illinois University at Carbondale (SIUC). Additional support was obtained from the Department of Zoology and the Graduate School at SIUC.

Age-Related Recruitment of Canada Geese from the Mississippi Valley Population

We studied age-specific recruitment of 411 neck-banded interior Canada geese (Branta canadensis interior) from the Mississippi Valley Population (MVP) from October 1985 to April 1986 and October 1986 to January 1987. No geese 0.5 and 1.5 years old were parents, whereas 5.9% of 2.5-year-olds, and 33.2% of 3.5->5.5-year-olds were parents. Parents 2.5-4.5 years old averaged 1.3 young/brood, whereas those >5.5 averaged 2.2 young/brood. Older geese (>5 yr) comprised 16% of the posthunting population and produced 47% of young. J. WILDL. MANAGE. 53(1):97-98 Age structure and age-related productivity (Raveling 1981) are important variables affecting recruitment of Canada geese and contribute to understanding goose population dynamics and to formulating better harvest management strategies (Raveling and Lumsden 1977). However, studies of age-specific productivity and recruitment in Canada geese (Craighead and Stockstad 1964, Brakhage 1965, Raveling 1981) generally have involved more southern nesting subspecies (western [B. c. moffitti] and giant [B. c. maxima] Canada geese) that are not subjected to breeding conditions as harsh as subarctic nesting geese from the MVP (Bellrose 1980). Consequently, conclusions of previous studies may not be applicable to the MVP. The objective of our study was to document age-related recruitment of Canada geese from the MVP. We thank D. F. Caithamer, R. J. Gates, and R. D. Pritchert for field assistance, and W. D. Klimstra and D. D. Thornburg for manuscript review. Funding was provided by the Department of Zoology and Cooperative Wildlife Research Laboratory at Southern Illinois University at Carbondale.

Seasonal Movements of Sage Grouse in Southeastern Idaho

We studied seasonal movements of sage grouse (Centrocercus urophasianus) on, and adjacent to, the Idaho National Engineering Laboratory (INEL) in southeastern Idaho from summer 1977 through fall 1983. The study area included a mountain valley and sagebrush (Artemisia spp.) lowlands. Sage grouse used contiguous areas for wintering and breeding but moved as far as 82 km from winter and breeding areas to summer range. Juvenile sage grouse (n = 32) moved a mean distance of 14.9 km from summer to winter ranges and adult grouse (n = 33) moved a mean distance of 11.3 km. Male sage grouse from the mountainvalley population moved farther to summer range than did mountain-valley females and both sexes from lowland populations (P < 0.05). Movements by male and female sage grouse during fall were generally slow and meandering. Movements by females during spring were also slow and meandering compared to the relatively rapid and direct movements by males. Distances moved were not entirely influenced by the proximity of seasonal habitats, suggesting that seasonal movements tend to be traditional. Sage grouse populations should be defined on a temporal and geographic basis. Protection of sagebrush habitats within a 3.2 km radius of leks may not be sufficient to ensure the protection of year-long habitat requirements. J. WILDL. MANAGE. 52(1):116-122 Sage grouse occupy seasonal habitats, using mesic areas during summer (Klebenow 1969, Wallestad 1971) and sagebrush habitats during winter (Eng and Schladweiler 1972, Beck 1977, Remington and Braun 1985). Grouse occupying sagebrush habitats at relatively low elevation are sometimes nonmigratory (Wallestad 1975), and sage grouse inhabiting mountain valleys or areas with distinct elevational gradients are often migratory (Dalke et al. 1960, Connelly 1982). However, information on the timing and distance of seasonal movements and the spatial relationships of seasonal ranges to migration routes and breeding complexes is often lacking. Only Dalke et al. (1963) and Berry and Eng (1985) attempted to delineate these relationships. This information is necessary for defining sage grouse populations, identifying population habitats, and evaluating impacts of land use changes on this species; thus, allowing meaningful management practices to be implemented. The INEL and adjacent lands in southeastern Idaho contain mountain-valley and sagebrushlowland areas that differ in topography and precipitation (Connelly 1982, Gates 1983). Recognizing these differences, we hypothesized that seasonal movements of sage grouse occupying these areas might differ. Thus, we compared seasonal ranges and movement patterns of sage grouse using separate breeding ranges in mountain-valley and lowland areas. Our objectives were to (1) describe sage grouse seasonal movements; (2) define sage grouse seasonal ranges with respect to each other and to breeding complexes, and migration routes in both mountainvalley and lowland areas; and (3) suggest an approach to defining migratory sage grouse populations. This study was supported by the Office of Health and Environmental Research, U.S. Department of Energy. Technical assistance was supplied by the Idaho Department of Fish and Game, the U.S. Fish and Wildlife Service, and the Bureau of Land Management. We thank all of the individuals from the above agencies who contributed to this effort. We are especially grateful to O. D. Markham and W. J. Arthur for administrative guidance, advice, and field assistance. Field assistance was also provided by D. K. Halford and J. C. Hoag during various portions of this study. Earlier drafts of this manuscript were reviewed by R. E. Autenrieth, I. J. Ball, W. B. Sidle, L. D. Flake, and R. L. Present address: Idaho Department of Fish and Game, 5205 South 5th Avenue, Pocatello, ID 83204. 2 Present address: Cooperative Wildlife Research Laboratory, Southern Illinois University, Carbondale, IL 62901.

Wetland development potential of coal mine tailings basins

Research at the Cooperative Wildlife Research Laboratory has identified the environmental and economic benefits of utilizingPhragmitesaustralia for stabilizing inactive slurry impoundments. Physical and chemical factors affecting successful vegetation establishment are controlled by the maintenance of a saturated substrate which prevents pyrite oxidation and acid production. The moist soil zones provided by the saturated slurry substrate represent a favorable root growth medium similar to natural wetlands. Implementation of this reclamation alternative for the State’s abandoned mined lands has necessitated the collection and propagation of other physiologically adapted native plant materials to identify species suitability and ensure availability of diverse planting stock. Acceptance of this reclamation atlernative can provide cost effective resolution of abandoned mined land problems as well as replace valuable wetlands being permanently lost through intensive agricultural/urban development.

Dynamics of an Unexploited Bobwhite Population in Deteriorating Habitat

The dynamics of an unexploited bobwhite (Colinus virginianus) population were investigated over a 9-year period in southern Illinois. Deteriorating habitat caused an 85% population decline from 136 to 21 birds per 100 hectares. Accompanying changes in demographic parameters are described. J. WILDL. MANAGE. 43(2):306-315 Since 1950, the Cooperative Wildlife Research Laboratory (CWRL) of Southern Illinois University-Carbondale has been investigating the ecology of a hunted bobwhite population near Carbondale (Roseberry and Klimstra 1972). A 2nd study was initiated in 1965 to obtain comparative data from a nearby unexploited population. Because of substantial changes in the latter area's carrying capacity for bobwhites, some planned analyses were precluded. However, the situation did provide opportunity to observe certain population phenomena under unique conditions. The purpose of this paper is to: (1) document a rapid and considerable decline in the abundance of a local unexploited bobwhite population, (2) describe the changes in various demographic parameters which accompanied this decline, and (3) attempt to identify the causes of the decline. This paper is a contribution from Project No. 1: Bobwhite Quail Life History and Population Studies, Cooperative Wildlife Research Laboratory, Southern Illinois University-Carbondale. The authors are grateful to the many graduate students and undergraduate student workers of the Laboratory who aided in censuses and nest hunting. Appreciation s ext nded to S. L. Wunderle, W. H. Nesbitt, and D. Urban for their special contributions to the project. The collaboration of personnel of the University Farms is acknowledged. STUDY AREA AND METHODS The study area was a 449-ha tract owned by Southern Illinois UniversityCarbondale in Jackson County, hereafter referred to as the SIU Farms. Farming activities were conducted by various departments within the School of Agriculture. The area was bounded on the south and west primarily by other SIU farmland and on the north and east by residential areas and the campus. Topography is gently rolling with maximum and minimum elevation 146 and 125 m, respectively. The glaciated soils are Hosmer and Stoy silt loams of moderate productivity and medium fertility. Distribution and abundance of bobwhites were determined 4 times each year (early November, late December, early February, and mid-March) by direct census. The entire area was systematically traversed by crews of 6-12 men and 1-2 trained bird dogs. Nest searching of selected areas employed methods described by Klimstra and Roseberry (1975:7). Live-trapping utilized wire traps described by Stoddard (1931:447) and baited with either grain or live decoy 1 Present address: 105-K East Ticonderoga Drive, Westerville, OH 43081. 306 J. Wildl. Manage. 43(2):1979 This content downloaded from 157.55.39.35 on Mon, 29 Aug 2016 05:16:09 UTC All use subject to http://about.jstor.org/terms BOBWHITE IN DETERIORATING HABITAT. Roseberry et al. 307 hens. Captured birds were marked with No. 1 aluminum leg bands (National Band and Tag Co., Newport, Ky.) and their sex, age, and weight were determined prior to release at the capture site. Land use and cover patterns were recorded on 1 July and 1 November of each year. Cover removal or other habitat alteration was recorded as it occurred.

Autumn Movements and Habitat Use by Wood Ducks in Southern Illinois

Movements of 961 banded wood ducks (Aix sponsa), including 10 radio-instrumented birds, were observed during the autumn of 1973 in southern Illinois. Some birds moved up to 10 km each day, but most stayed within 2.2 km of the roost. Movements usually occurred during morning and evening hours. Autumn areas of activity for wood ducks ranged from 23.9 to 186.2 ha (i = 90.6 ha). Wood ducks had a significant day and nighttime preference for buttonbush (Cephalanthus occidentalis) swamp over flooded timber and open water. In managing wood ducks, habitat types which are available should be emphasized more than area size and, when possible, management areas should be located to include traditional roosting sites. J. WILDL. MANAGE. 43(1):102-108 Band-recoveries have delineated migratory movements of wood ducks (Beshears 1967, Brown 1972) and work has been done on home range and habitat use during the breeding season (Gilmer 1971). Summer movements and habitat use by females with broods also have been investigated (Hardister et al. 1963, Webster and McGilvrey 1966, McGilvrey 1969, Ball 1971). However, much is not known about activity and habitat utilized by this species. The objective of this study was to identify the habitat requirements and movements of wood ducks during autumn so that managers might have a basis for more intensive yearround management. We thank Karen Crites, R. Hileman, F. Roetker, and V. Hammer for their assistance in the field. We thank M. Sweet for supplying information on band recoveries from Oakwood Bottoms Greentree Reservoir. W. D. Klimstra, Cooperative Wildlife Research Laboratory, Southern Illinois University, provided radiotelemetry receiving equipment. We thank J. Newcomb, District Ranger, U.S. Forest Service, for allowing access to U.S. Forest Service lands. The Max McGraw Wildlife Foundation and the Illinois Department of Conservation financed part of this study. MATERIALS AND METHODS

Group Size and Composition of the Florida Key Deer

Group Size and Composition of the Florida Key Deer

The Age of Laysan Albatrosses, Diomedea immutabilis, at First Breeding

The Age of Laysan Albatrosses, Diomedea Immutabilis, at First Breeding Get access Margaret T. Van Ryzin, Margaret T. Van Ryzin Cooperative Wildlife Research Laboratory, Southern Illinois University, Carbondale, Illinois 62901 Search for other works by this author on: Oxford Academic Google Scholar Harvey I. Fisher Harvey I. Fisher Cooperative Wildlife Research Laboratory, Southern Illinois University, Carbondale, Illinois 62901 Search for other works by this author on: Oxford Academic Google Scholar The Condor, Volume 78, Issue 1, 1 January 1976, Pages 1–9, https://doi.org/10.2307/1366911 Published: 01 January 1976 Article history Accepted: 16 December 1974 Published: 01 January 1976

Some Morphological Characteristics of the Crab Orchard Deer Herd

Whole and dressed body weights were obtained from 1,009 white-tailed deer (Odocoileus virginianus) from Crab Orchard National Wildlife Refuge, Williamson County, Illinois. Chest girths, hindfoot lengths, lower mandible lengths, and antler dimensions were taken from somewhat smaller samples. The data were analyzed by sex and age, and relationships with body weight were established. Males generally were larger than like-aged females with respect to all measurements. Both sexes reached near-maximum size at 4.5 years of age but females matured earlier than males, especially with regard to body weight. Indices of condition (body weight and antler size) indicated that the previously unharvested Crab Orchard herd compared favorably with nearby hunted populations with the possible exception of yearling males. J. WILDL. MANAGE. 39(1):48-58 This paper describes certain morphological features of a large sample of whitetailed deer from a previously unharvested herd. Body weights, chest girths, hindfoot lengths, lower mandible lengths, and antler measurements are analyzed by sex and age classes and growth patterns are discussed. Body weights and antler measurements are used to compare general condition of the herd with that of deer in nearby hunted range. The sample was obtained during a controlled harvest to reduce herd size on Crab Orchard National Wildlife Refuge (CONWR), Williamson County, Illinois (Roseberry et al. 1969). All deer were taken from a 7,285-ha (18,000-acre) portion of the Refuge that normally is closed to hunting. The herd was first established in 1942 and has been under intensive study since 1960 by the Cooperative Wildlife Research Laboratory (CWRL) of Southern Illinois University at Carbondale. The habitat, which is considered ideal for deer (Hawkins et al. 1971), has been described previously (Autry 1967, Hawkins and Klimstra 1970). Population density prior to the January 1966 special harvest was estimated to be 1 deer/3.2 ha (1 deer/8 acres) (Autry 1967). The authors are indebted to the many graduate and undergraduate workers of the Cooperative Wildlife Research Laboratory who aided in the collection of data. We also acknowledge officials of the Crab Orchard National Wildlife Refuge and personnel of the Illinois Department of Conservation for assistance. This paper is a contribution from Project No. 15 of the Laboratory: Big Game Investigations. METHODS AND MATERIALS All harvested deer were processed at one of two check stations operated by Laboratory personnel. The animals initially were weighed 0.45 kg (1 pound) with a Viking spring balance, eviscerated, then reweighed. The maximum chest girth of all deer with rib cage intact was measured ? 0.32 cm (1 inch) with a flexible tape measure. Length of the hindfoot from hock to the tip of the longest claw was measured by the same procedure (Brohn and Robb 1955, Park and Day 1942). Antler beam diameter was measured to the nearest 1.0 mm with a vernier caliper. The beam diameter was taken 2.54 cm (1 inch) above the burr and, when possible, did not include bony protuberances (Anderson and Medin 1969). Antler length was measured ? 0.32 cm 48 J. Wildl. Manage. 39(1):1975 This content downloaded from 40.77.167.54 on Sat, 14 May 2016 06:18:18 UTC All use subject to http://about.jstor.org/terms MORPHOLOGICAL CHARACTERISTICS OF DEER * Roseberry and Klimstra 49 ('s inch) with a flexible steel tape measure along the outside of the main beam from burr to tip. Length and diameter were recorded from the left beam, but the undamaged right beam was measured when the left was damaged. All antler protuberances over 2.54 cm long, excluding brow tines, were counted (as the number of antler points) on both beams. A lower mandible was removed from most animals for purposes of age determination. Age classes in this study were established on the basis of tooth eruption and wear (Severinghaus 1949). Total length of the mandible, from its most anterior point to the posterior rim of the angle of ramus (dentary length) was measured to the nearest 1.0 mm with a modified meter rule. The distance between the alveola of the anterior premolar and the corner incisor (diastema length) was measured to the nearest 0.1 mm with a vernier caliper (Bergerud 1964). All data were placed on 80-column IBM cards and processed with an IBM 370/155 computer at the data processing facilities of Southern Illinois University at Carbondale.

Differential Vulnerability during a Controlled Deer Harvest

Differential Vulnerability during a Controlled Deer Harvest

Weights of Branta canadensis interior during Winter

Based on weights of Branta canadensis interior obtained from three sampling periods during winter 1964-65 at Crab Orchard National Wildlife Refuge, Illinois, the following results and conclusions emerged: adults expectedly lost weight in late winter; yearlings and immatures did not lose weight through the winter; geese at Crab Orchard were usually heavier and did not show as many nor as large weight losses as reported from other southern Illinois localities, probably because of the relationships of numbers of geese and available food; Crab Orchard geese appeared to be in excellent condition throughout the winter. Concern has been expressed over food supplies and weight losses of Canada geese during winter in southern Illinois (Elder 1946). Approximately 200,000 B. c. interior concentrate largely on three refuges totaling approximately 36,000 acres (Crab Orchard National Wildlife Refuge, Union County and Horseshoe Lake state refuges). Knowledge of weights of geese from these large concentrations and the factors that influence weight fluctuations serve as indices to the birds' efficiency in obtaining food and food availability on refuges and adjacent countryside. Elder (1946) and Hanson (1962a) studied Canada goose weights in southern Illinois (Horseshoe Lake and Union County refuges). Because there are important differences in management and goose populations at Crab Orchard as compared to the other refuges, 559 Canada geese were weighed at Crab Orchard during the winter of 1964-65. Additionally, more refined methods of age identification, especially of yearlings (Hanson 1962b), and increased knowledge of the taxonomic identity of geese (Hanson, personal communication) 1 This work was carried out in conjunction with a study of Canada goose behavior supported by the National Science Foundation (GB-623); additional support was provided by the Cooperative Wildlife Research Laboratory, Southern Illinois University, Carbondale, Dr. W. D. Klimstra, Director. 2 Present address: Canadian Wildlife Service, 114-A Garry Street, Winnipeg 1, Manitoba. 412 provided the basis for better estimating weight fluctuations of B. c. interior. L. A. Mehrhoff, Jr., Project Manager, and Robert G. Personius, Refuge Manager, Crab Orchard National Wildlife Refuge, are acknowledged for their cooperation. J. Robert Rice, Crab Orchard Refuge, conducted most of the trapping and assisted in weighing geese, as did Wendell E. Crews, Cooperative Wildlife Research Laboratory, Southern Illinois University. Dr. H. C. Hanson, Illinois Natural History Survey, provided access to unpublished data which made possible the identification of Canada geese other than B. c. interior. Dr. W. D. Klimstra provided helpful criticism of the

Factors Affecting Age Ratios of Samples of Canada Geese Caught with Cannon-Nets

Widely differing opinions are held concerning the reliability of age-ratio statistics derived from samples of Canada geese trapped with cannon-nets. The 95 percent confidence limits of an age-ratio estimate of 41.3 percent immature derived from 35 catches involving 2,451 geese were 35.3-50.5 percent immature. These data indicate the potential for error when such data are used to analyze population dynamics. Based on a study of behavior of marked Canada geese of all ages and sexes and family units, utilizing radio telemetry, reasons are suggested for age-ratio fluctuations of cannon-net trap samples. Important interrelated factors causing such cannon-net trap age-ratio differences are time of year, time of day, food availability, behavior changes, length of time on bait, and weather. When these factors cause Canada geese to crowd densely onto a baited-trap site, a higher percentage of adults would usually be obtained than when trap catches represent different levels of aggression, family defense, and less crowded conditions. Alternative explanations are offered of data that led Funk and Grieb (1965) to conclude that age ratios from baited-trap samples reliably indicate population structure-a conclusion different from that reached in this paper. Realistic estimation of sex and age composition of a population provides the axiomatic necessary foundation for evaluating and understanding past reproductive successes which in turn provide the basis for predicting future population fluctuations. Predicting the size of an ensuing year's population is an important aspect of the management of Canada geese (Branta canadensis interior) in the Mississippi Flyway, for the legal hunter-harvest is calculated as a percentage of geese expected to make up the coming year's population. This estimate is based upon many factors, one of the more important being the estimate of the age composition of the population that returned in the spring to the breeding grounds. Throughout the United States, cannonnet trapping (Dill and Thornsberry 1950, and many subsequent technique modifications) is one of the major methods, and often the only method, used to capture Canada geese during the migration and winter periods. Many persons who have done considerable goose trapping with cannon-nets have learned that age ratios of individual catches may fluctuate greatly and, as a result, place little confidence in the use of such age ratios in population dynamics analyses. Until recently, however (Nass 1964, Funk and Grieb 1965), little statistical or methodological examination of age-ratio data from trap samples has been reported, and only tentative explanations have been offered of possible factors influencing such age-ratio fluctuations or biases. The purpose of this paper is to present an evaluation of the variability of trap-sample age ratios obtained from 35 cannon-net c tches involving 2,451 Canada geese (nearly all B. c. interior). Based on a study of Canada goose behavior including observations of marked individuals of all ages and sexes and family groups at bait sites, explanations are offered as to why age ratios of cannon-net catches may vary rather widely. Results are part of a more comprehensive study of Canada goose behavior in winter, utilizing radio telemetry. The program was supported chiefly by the National Science Foundation (GB-623); additional support was provided by the Cooperative Wildlife Research Laboratory, Southern Illinois Univ rsity, for which I am indebted to Dr. W. D. Klimstra, Director. Findings are

Food Habits of the Green Frog, Rana clamitans, in Southern Illinois

Food Habits of the Green Frog, Rana clamitans, in Southern Illinois