Open Access. Powered by Scholars. Published by Universities.®

Terrestrial and Aquatic Ecology Commons

Open Access. Powered by Scholars. Published by Universities.®

Behavior and Ethology

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 751 - 780 of 903

Full-Text Articles in Terrestrial and Aquatic Ecology

Use Of Dredged Material To Construct Winter Whooping Crane Habitat, Darrell E. Evans, Thomas V. Stehn Jan 1997

Use Of Dredged Material To Construct Winter Whooping Crane Habitat, Darrell E. Evans, Thomas V. Stehn

Proceedings of the North American Crane Workshop

Aransas National Wildlife Refuge (ANWR) and nearby coastal marshes serve as the winter home for the only natural flock of whooping cranes (Grus americana), In recent years shoreline erosion and the subsequent loss of wintering habitat have been observed on the refuge adjacent to the GulfIntracoastal Waterway (GIWW). In 1988 the U.S. Army Corps of Engineers (USACE) District, Galveston, Texas, and U.S. Fish and Wildlife Service (USFWS) entered into an informal agreement to attempt to slow shoreline/habitat loss on the refuge. Efforts to curtail habitat loss have included armoring the most erosive reaches with temporary concrete erosion control …


The Effect Of Disturbance On The Reproduction And Management Of Captive Cranes, Claire M. Mirande, James W. Carpenter, Ann M. Burke Jan 1997

The Effect Of Disturbance On The Reproduction And Management Of Captive Cranes, Claire M. Mirande, James W. Carpenter, Ann M. Burke

Proceedings of the North American Crane Workshop

A retrospective analysis of egg laying histories and observations of crane pairs at the International Crane Foundation and the Patuxent Wildlife Research Center indicates that disturbance associated with captivity has adverse impacts on captive breeding. Females on public display laid significantly fewer eggs than those off display (P < 0.05). Crane pairs moved to other pens (other than adjacent pens) or hetween facilities laid slightly fewer eggs than those birds which were not moved. although the results were not statistically significant (P = 0.188). Pen design and construction also appeared to have adverse impacts on breeding. In addition, human activities, intraspecific interactions, and rearing methods influence a bird's response to disturbance, and, therefore, these factors must also be considered in an effective crane management program. Modifying procedures to minimize disturbance, timing necessary disturbances after the breeding and molt seasons, and carefully monitoring birds for signs of stress can result in increased reproductive potential for captive, endangered cranes.


Use Of Cross-Fostered Whooping Cranes As Guide Birds, Roderick C. Drewien, Wendy L. Munroe, Kent R. Clegg, Wendy M. Brown Jan 1997

Use Of Cross-Fostered Whooping Cranes As Guide Birds, Roderick C. Drewien, Wendy L. Munroe, Kent R. Clegg, Wendy M. Brown

Proceedings of the North American Crane Workshop

We tested the use of wild, cross-fostered, adult whooping cranes (Grus americana) as guide birds to adopt and lead young whooping cranes on a predetermined migration route in the Rocky Mountains. We captured 3 wild adults (1 male and 1 female in 1993, 1 male in 1994) during winter at the Bosque del Apache National Wildlife Refuge (Bosque NWR), New Mexico, and moved them to captive facilities 80 kIn from Grays Lake National Wildlife Refuge (Grays Lake), Idaho, where they had originally been raised by sandhill crane (G. canadensis) foster parents. Adults were held for 6.75-7 …


Identification Of Potential Reintroduction Sites For Whooping Cranes In The Prairie Provinces Of Canada, Dale G. Hjertaas, Brian W. Johns, Wendy J. Lyon Jan 1997

Identification Of Potential Reintroduction Sites For Whooping Cranes In The Prairie Provinces Of Canada, Dale G. Hjertaas, Brian W. Johns, Wendy J. Lyon

Proceedings of the North American Crane Workshop

Action 2.3.3.2.2.1 of the national recovery plan for the whooping crane (Grus americana) calls for the establishment of an independent flock of whooping cranes in Canada, separate from the Wood Buffalo-Aransas flock, that attains a minimum of 25 breeding pairs by 2020 A. D. Potential reintroduction sites include the Prairie Provinces and possibly parts of western Ontario (Edwards et al. 1994). The first step in completing this action is to identify potential reintroduction sites in the 3 Prairie Provinces. We initially screened areas suggested to us by government and Ducks Unlimited biologists. The most important screening criteria were …


Spring Population Estimates Of Rocky Mountain Greater Sandhill Cranes In Colorado, Douglas S. Benning, Roderick C. Drewien, Douglas H. Johnson, Wendy M. Brown, Erwin L. Boeker Jan 1997

Spring Population Estimates Of Rocky Mountain Greater Sandhill Cranes In Colorado, Douglas S. Benning, Roderick C. Drewien, Douglas H. Johnson, Wendy M. Brown, Erwin L. Boeker

Proceedings of the North American Crane Workshop

We developed an aerial survey to estimate the Rocky Mountain Population (RMP) of greater sandhill cranes (Grus canadensis tabidn) (greaters) annually during March 1984-95 in the San Luis Valley, Colorado (SLV). We flew aerial transects covering a 21,220-ha contiguous area. Aerial photographs of crane flocks were taken to correct for estimation errors. We employed ground surveys to correct for presence of lesser sandhill cranes (G. c. canadensis) (lessers), which mixed with RMP cranes. To adjust for RMP cranes not in the survey area, we made ground counts in traditional use areas outside the SLY. During 1984-95, 5 …


Use Of Ultralight Aircraft For Introducing Migratory Crane Populations, Kent R. Clegg, James C. Lewis, David H. Ellis Jan 1997

Use Of Ultralight Aircraft For Introducing Migratory Crane Populations, Kent R. Clegg, James C. Lewis, David H. Ellis

Proceedings of the North American Crane Workshop

Greater sandhill cranes (Grus canadensis tabida) were used as the research surrogate for whooping cranes (Grus americana) to determine if captive-reared cranes could be led by an ultralight aircraft (UL) along a migration route and if, after release on a wintering area, they would integrate with wild cranes and migrate north in spring to their natal area without assistance. In 1995, KRC raised 15 cranes to fledging and trained them to respond to his vocal imitation of a sandhill crane brood call. Chicks learned to follow him as he walked, drove an all-terrain vehicle (ATV) , …


Microsatellite Dna Loci For Genetic Studies Of Cranes, Travis C. Glenn, Ryan S. Ojerio, Wolfgang Stephan, Michael J. Braun Jan 1997

Microsatellite Dna Loci For Genetic Studies Of Cranes, Travis C. Glenn, Ryan S. Ojerio, Wolfgang Stephan, Michael J. Braun

Proceedings of the North American Crane Workshop

MicrosateIIites are short tandem arrays of simple DNA sequences (e.g., [AC]n, where n ~ 10), which are often highly polymorphic among individuals. These repetitive elements are rapidly becoming the molecular genetic marker of choice for genetic mapping, parentage analyses, and fundamental popUlation genetics. We have isolated more than 50 microsatellite loci from the whooping crane (Grus americana). The microsatellites cloned from whooping cranes are unusually short and infrequent in comparison to other birds and especially so in comparison to mammals or reptiles. However, at least 13 of the 20 primer pairs developed amplify polymorphic loci. Paternity for …


Mortality Of Radio-Equipped Sandhill Crane Colts At Malheur National Wildlife Refuge, Oregon, Gary L. Ivey, Eric J. Scheuering Jan 1997

Mortality Of Radio-Equipped Sandhill Crane Colts At Malheur National Wildlife Refuge, Oregon, Gary L. Ivey, Eric J. Scheuering

Proceedings of the North American Crane Workshop

We radio-equipped 142 greater sandhill crane (Grus canadensis tabida) colts at Malheur National Wildlife Refuge, Oregon, during 1991-95 to document prefledging mortality factors. Fates of 19 colts were undetermined. A total of 23 colts survived to fledge (19% of known fates). Evidence collected from the carcasses and death sites indicated that predators were responsible for the largest number of colt deaths (64), followed by unknown causes (13), parasitic gapeworms (Cyastoma spp.) (8), drowning (7), intraspecific aggression (5), study-related mortality (I), roadkill (I), and hay swather (1). Of 64 colts killed by predators, 26 were lost to mink …


Modeling The Population Dynamics Of Gulf Coast Sandhill Cranes, Douglas H. Johnson, William L. Kendall Jan 1997

Modeling The Population Dynamics Of Gulf Coast Sandhill Cranes, Douglas H. Johnson, William L. Kendall

Proceedings of the North American Crane Workshop

The Mid-continent Population of sandhill cranes (Grus canadensis) has a large geographic range. contains nearly 500,000 birds, and is hunted in much of its range. The population includes 3 subspecies; the numbers of 2 of these are uncertain, and they should be afforded protection from hunting that would be detrimental to their population. The 2 subspecies of concern tend to concentrate in the eastern part of the Great Plains during fall and spring and to winter along the Gulf Coast in Texas. This paper uses the limited information availahle ahout the Gulf Coast subpopulation in a model. We …


Subspecies Composition Of Sandhill Crane Harvest In North Dakota, 1968–94, William L. Kendall, Douglas H. Johnson, Stanley C. Kohn Jan 1997

Subspecies Composition Of Sandhill Crane Harvest In North Dakota, 1968–94, William L. Kendall, Douglas H. Johnson, Stanley C. Kohn

Proceedings of the North American Crane Workshop

North Dakota is a major fall staging area for the Mid-continent Population (MCP) of sandhill cranes (Grus canadensis), which is composed of 3 subspecies: the greater (G. c. tabida), Canadian (G. c. rawani), and lesser (G. c. canadensis). The number of cranes killed by hunters in North Dakota averaged 6,793 during the 1990-94 seasons, ranking second highest among crane-hunting states. The distribution of harvest among subspecies is important, due to concerns about the poorly known status of these subspecies, especially the greater. We estimated subspecies composition of the harvest in North Dakota by …


Nesting Success And Production Of Greater Sandhill Cranes During Experimental Predator Control At Malheur National Wildlife Refuge, Oregon,1982–83, Carroll D. Littlefield, John E. Cornely Jan 1997

Nesting Success And Production Of Greater Sandhill Cranes During Experimental Predator Control At Malheur National Wildlife Refuge, Oregon,1982–83, Carroll D. Littlefield, John E. Cornely

Proceedings of the North American Crane Workshop

Greater sancfrtill cranes (Grus canadensis tabida) nest commonly on Malheur National Wildlife Refuge, Oregon, but depredations by common ravens (Corvus corax) and coyotes (Canis latrans) contributed substantially to low recruitment during the 1970's. An experimental predator removal study was initiated in 1982 to determine if nesting success and recruitment would increase if predator populations were reduced. We monitored 120 crane nests located in 2 treatment areas (ravens and coyotes removed, and only ravens removed) and 1 control area (40 nests per area). Nesting success between the 2 predator control areas differed significantly during the …


Sandhill Crane Use Of The Mid-Pecos Valley Of Eastern New Mexico, James B. Montgomery Jr. Jan 1997

Sandhill Crane Use Of The Mid-Pecos Valley Of Eastern New Mexico, James B. Montgomery Jr.

Proceedings of the North American Crane Workshop

Sandhill cranes (Grus canadensis) were monitored during winters 1989-94 in the mid-Pecos River Valley of eastern New Mexico to detennine how many used this region following a population decline in the 1980's. Numbers annually increased to a late October/early November peak (X = 7,017), fluctuated around 6,000 through December, declined in January (X = 3,531), and again peaked in February/early March (X = 5,737). Annual crane use-days (weekly counts X 7) varied from 500,545 to 1,007,673 (X = 760,606). Cranes foraged mainly in corn and sorghum stubble and alfalfa fields. Crop averages (ha) during 1990-92 were alfalfa 21,449, …


An Experimental Release Of Whooping Cranes In Florida: The First Three Years, Stephen A. Nesbitt, Martin J. Folk, Marilyn G. Spalding, James A. Schmidt, Stephen T. Schwikert, Jane M. Nicolich, Marianne Wellington, James C. Lewis, Tom H. Logan Jan 1997

An Experimental Release Of Whooping Cranes In Florida: The First Three Years, Stephen A. Nesbitt, Martin J. Folk, Marilyn G. Spalding, James A. Schmidt, Stephen T. Schwikert, Jane M. Nicolich, Marianne Wellington, James C. Lewis, Tom H. Logan

Proceedings of the North American Crane Workshop

Fifty-two juvenile whooping cranes (Grus americana) were soft-released in Florida from February 1993 to April 1995. The birds were released in groups ranging in size from 5 to 14 individuals. The first-year survival rate was 0.42 for all years combined. First-year rates for each year were 0.36 for 1993, 0.32 for 1994, and 0.47 for 1995. Most mortality (62%) occurred during the first 3 months following release. The survival rate of 0.81 the second year after release was similar to that of Florida sandhill cranes (G. canadensis pratensis) (0.87). Predation by bobcats (Lynx rufus) …


Causes Of Mississippi Sandhill Crane Mortality In Captivity, 1984–95, Glenn H. Olsen, George F. Gee Jan 1997

Causes Of Mississippi Sandhill Crane Mortality In Captivity, 1984–95, Glenn H. Olsen, George F. Gee

Proceedings of the North American Crane Workshop

During 1984-95, 111 deaths were documented in the captive flock of Mississippi sandhill cranes (Grus canadensis pulla) housed at the Patuxent Wildlife Research Center. Trauma was the leading cause of death (37%), followed by infectious/parasitic diseases (25%), anatomic abnormalities (15%), and miscellaneous (8%). No positive diagnosis of cause of death was found in 19% of the necropsies. Chicks < 2 months old suffered 76 % of captive deaths. Trauma, the greatest cause of deaths of captive juveniles and adults, is likely limited to collisions in the wild. Infectious/parasitic diseases and anatomic abnormalities could affect wild chick survival at similar rates to those of captive chicks.


Whooping Crane Mortality At Patuxent Wildlife Research Center, 1982–95, Glenn H. Olsen, Joanna A. Taylor, George F. Gee Jan 1997

Whooping Crane Mortality At Patuxent Wildlife Research Center, 1982–95, Glenn H. Olsen, Joanna A. Taylor, George F. Gee

Proceedings of the North American Crane Workshop

Whooping cranes (Grus americana) have been reared at Patuxent Wildlife Research Center since 1966. During 1982-95 there were 103 mortalities caused by infectious and parasitic diseases (46%), trauma (21 %), anatomic abnormalities (17%), miscellaneous conditions (12 %) I and open or no diagnoses (5 %). The implications that disease may have on new whooping crane flocks in Florida and Canada are discussed, based on these mortality factors in captivity.


Summary Of Sandhill Crane Hunting Seasons In North Dakota, 1968–94, David E. Sharp, John E. Cornely Jan 1997

Summary Of Sandhill Crane Hunting Seasons In North Dakota, 1968–94, David E. Sharp, John E. Cornely

Proceedings of the North American Crane Workshop

The migratory Mid-continent Population (MCP), containing 3 subspecies, is the most numerous of all sandhill crane (Grus canadensis) populations. During fall the MCP uses major staging areas in the Canadian prairie provinces and northcentral United States. In North Dakota, sport hunting of the MCP resumed in 1968, after being closed during 1916-67. The resumption and expansion of crane hunting in North Dakota during 1968-94 followed a gradual panern of implementation. Subspecies considerations, the presence of whooping cranes (G. americana), crop depredation complaints. and public reaction influenced the geographic and temporal expansion of seasons. Harvests gradually increased …


Avian Tuberculosis In A Whooping Crane: Treatment And Outcome, S. Bret Snyder, Michael J. Richard, Carol U. Meteyer Jan 1997

Avian Tuberculosis In A Whooping Crane: Treatment And Outcome, S. Bret Snyder, Michael J. Richard, Carol U. Meteyer

Proceedings of the North American Crane Workshop

A whooping crane (Grus americana) confirmed as suffering from Mycobacterium avium infection was treated for 1 year with daily doses of rifampin (45 mg/kg) and ethambutol (30 mg/kg) and 2 doses of M. vaccae antigen. Remission of disease occurred during therapy; however, recrudescence to active infection was suspected by 10 months after the antitubercular drugs were discontinued when the crane exhibited weight loss and had thickening of bowel wall as seen on radiographs. A second therapeutic regimen using azithromycin was then initiated (40 mg/kg fed daily) and was accompanied by a second remission within 6 weeks. After 16 …


Metal Consumption By Whooping Cranes And Possible Zinc Toxicosis, Marilyn G. Spalding, Stephen A. Nesbitt, Martin J. Folk, Lee R. Mcdowell, Maria S. Sepulveda Jan 1997

Metal Consumption By Whooping Cranes And Possible Zinc Toxicosis, Marilyn G. Spalding, Stephen A. Nesbitt, Martin J. Folk, Lee R. Mcdowell, Maria S. Sepulveda

Proceedings of the North American Crane Workshop

Fourteen captive-reared whooping cranes (Grus americana) were transferred to a pen for soft-release in Florida. Nine were killed by predators within 6 months. We found metal objects in the stomachs of 6 of these 9 either by radiography or at necropsy. All 6 had elevated serum zinc (Zn) concentrations (x = 10.3 ± 2.7 flg/ml, range 7.2-14 .ug/ml) when compared to 3 without metal in their stomachs (X = 2.4 ± 0.92 flg/ml, range 1.6-3.4 J1.g/ml). We observed lethargy, abnormal posture, anemia, and elevated white blood cell counts in 2 cranes at or near the time of elevated …


Pair Formation By Color-Marked Whooping Cranes On The Wintering Grounds, Thomas V. Stehn Jan 1997

Pair Formation By Color-Marked Whooping Cranes On The Wintering Grounds, Thomas V. Stehn

Proceedings of the North American Crane Workshop

Observations were made of color-marked whooping cranes (Grus americana) at Aransas during the 1977-94 winters. Suhadult cranes wintered near their juvenile home ranges in flocks averaging 3.12 birds. One and 2 winters prior to nesting, subadults at Aransas tended to form duos apart from other subadults. Frequencies of association 1 year prior to nesting averaged 65.4%. However, 27.7 % of pair bonds (n = 18) formed during spring migration or on the breeding grounds without any observed prior association at Aransas. Sixty-eight banded cranes formed pairs. Pair members averaged 1.06 years difference in age. Winter territories of adults …


Food And Energy Intake Rates Of Wintering Whooping Cranes Foraging On Two Selected Food Items, Felipe Chavez-Ramirez, Jay T. Nelson, R. Douglas Slack Jan 1997

Food And Energy Intake Rates Of Wintering Whooping Cranes Foraging On Two Selected Food Items, Felipe Chavez-Ramirez, Jay T. Nelson, R. Douglas Slack

Proceedings of the North American Crane Workshop

Number, mass, and potential energy of food items consumed by wintering whooping cranes (Grus americana) foraging on blue crab (Callinectes sapidus) and woltberry (Lycium carolinianum) fruit were estimated and compared between 2 consecutive winter periods. Mass consumed was determined through field observations by quantifying the number of items taken per unit time and the average, or modal, weight of each food item determined from collections. Gross energy intake was determined by calculating the product of mass consumed times gross energy (kJ/g) of each food item. Potential energy retained was calculated by determining metabolizable energy …


Semen Collection And Fertility In Naturally Fertile Sandhill Cranes, Guojun Chen, George F. Gee, Jane M. Nicolich, Joanna A. Taylor Jan 1997

Semen Collection And Fertility In Naturally Fertile Sandhill Cranes, Guojun Chen, George F. Gee, Jane M. Nicolich, Joanna A. Taylor

Proceedings of the North American Crane Workshop

Aviculturists often ask if semen collection will interfere with fertility in naturally fertile pairs of cranes. We used 12 naturally fertile Florida sandhill crane (Grus canadensis pratensis) pairs for this study, 6 control and 6 experimental. All pairs had produced fertile eggs in previous years and were in out-of-doors pens scattered throughout different pen complexes, within auditory range but physically isolated. Semen was collected on Tuesday mornings and Friday afternoons from 26 February 1993 to 4 June 1993. We used standard artificial insemination methods to collect and to evaluate the semen and spermatozoa. Semen collection did not affect semen quality …


Results Of Eight Years Of Predator Control To Enhance Sandhill Crane Production On Malheur National Wildlife Refuge, Oregon, Gary L. Ivey Jan 1997

Results Of Eight Years Of Predator Control To Enhance Sandhill Crane Production On Malheur National Wildlife Refuge, Oregon, Gary L. Ivey

Proceedings of the North American Crane Workshop

Because of a 21 % decline in breeding pairs of greater sandhill cranes (Grus canadensis tabida) on Malheur National Wildlife Refuge from 1971 to 1985, a predator control program was initiated in 1986 to enhance production. The primary cause for the decline was low recruitment of young due to high predation by ravens (Corvus corax). raccoons (Procyon lotor), and coyotes (Canis latrans), On average, predators destroyed 46% of all crane nests and 90% of the prefledged colts. Mink (Mustela vison) were added to the program in 1993 after a study …


Long Bone Fracture Management In A Sandhill Crane: A Case Report, Patrice N. Klein, Dorothy Thompson Jan 1997

Long Bone Fracture Management In A Sandhill Crane: A Case Report, Patrice N. Klein, Dorothy Thompson

Proceedings of the North American Crane Workshop

A 65-day-old, juvenile Mississippi sandhill crane (Grus canadensis pulla) sustained an oblique fracture of the right middiaphyseal femur. Internal fixation by use of an intramedullary pin and full cerclage wire was performed to stabilize the fracture site. Post-operative medical management of these fractures is often unsuccessful due to secondary complications associated with long-term restraint. This report describes the successful recovery of an endangered sandhill crane with a long bone fracture of the pelvic limb through a program of incremental physical therapy beginning 2 weeks post-femoral fracture repair. Sling support, assisted walking, and hydrotherapy were methods effective in preventing …


Resolutions Passed By The North American Crane Working Group Jan 1997

Resolutions Passed By The North American Crane Working Group

Proceedings of the North American Crane Workshop

RECOGNITION OF THE CONTRIBUTIONS OF TOM TACHA TO CRANE RESEARCH

Participants of the Seventh North American Crane Workshop wish to recognize Tom Tacha's many contributions to the understanding of Mid-continent sandhill crane behavior, ecology, and taxonomy. Tom published 30 papers on cranes between 1979 and 1995 and was chief editor of Migratory Shore and Upland Game Bird Management in North America, published shortly before his death. Tom's Ph.D. work and other morphological and behavioral studies strongly influenced our notions of the boundaries among, and validity of. the 3 migratory sandhill crane subspecies. He set new standards for quantitative analysis of …


Comparison Of Waterbird Utilization Of Two Northwest Arkansas Reservoirs, Jefferey T. Briggler, Robert C. Dobbs Jan 1997

Comparison Of Waterbird Utilization Of Two Northwest Arkansas Reservoirs, Jefferey T. Briggler, Robert C. Dobbs

Journal of the Arkansas Academy of Science

Waterbird use of two moderately-sized reservoirs in northwest Arkansas was studied in the autumns of 1993 and 1995. In addition to waterbird counts; surface area, water temperature, conductivity, pH, turbidity, dissolved oxygen, macrophyte presences, number of total macroin vertebrates and degree of human activity were evaluated. Lake Fayetteville supported a greater overall waterbird species richness and species abundance than Lake Wedington. The observed number of ducks per hectare showed a significant difference between the lakes in both 1993 and 1995. Surface feeding birds were significantly more abundant at Lake Fayetteville in both 1993 and 1995, whereas diving birds, which feed …


The Diet Of Oryzomys Palustris Based On Stomach Content Analysis, Shannon L. Wright Oct 1996

The Diet Of Oryzomys Palustris Based On Stomach Content Analysis, Shannon L. Wright

Biological Sciences Theses & Dissertations

Oryzomys palustris (Harlan) is unusual in that it is one of two carnivorous mammals in the Family Muridae in North America. A diet analysis of Oryzomys palustris. the marsh rice rat, was done based on stomach contents. This was accomplished by taking the animals from two study areas located on the Eastern Shore of Virginia. The animals were taken monthly for one year. Once caught, the animals were sacrificed and their stomach contents were identified to the lowest taxonomic level possible. This study showed that rice rats were omnivorous mammals, eating a variety of foods, including dicots, monocots, crabs, …


Brown-Headed Cowbird (Molothrus Ater) Range Expansion Into The Southeast: Effects On The Passerine Populations Using North American Breeding Bird Survey Data, Elizabeth Pruitt Henderson Oct 1996

Brown-Headed Cowbird (Molothrus Ater) Range Expansion Into The Southeast: Effects On The Passerine Populations Using North American Breeding Bird Survey Data, Elizabeth Pruitt Henderson

Biological Sciences Theses & Dissertations

North American Breeding Bird Survey data that were collected from 1971-1992 in Virginia, North Carolina, south Carolina, Georgia, Florida, Alabama and Tennessee were used in this analysis of the impact of Brown-headed Cowbird range expansion on four warbler and four vireo host species.

Maps of mean cowbird abundances were produced using kriging for the periods 1971-1975, 1976-1980, 1981-1985, 1986-1990 and 1991-1992. These maps illustrated a complex invasion of the southeastern United States by Brown-headed Cowbird.

Linear regression analyses of host and cowbird abundances within physiographic strata, showed no species to be in decline or increasing in abundance over the entire …


Movement Patterns And Habitat Use Of The Copperhead Snake (Agkistrodon Contortrix) In Southeastern Virginia, Christopher Edwin Petersen Oct 1995

Movement Patterns And Habitat Use Of The Copperhead Snake (Agkistrodon Contortrix) In Southeastern Virginia, Christopher Edwin Petersen

Biological Sciences Theses & Dissertations

Radiotelemetry was used to study seasonal movement patterns, habitat use, and thermal relations of nine copperhead snakes, Agkistrodon contortrix, in southeastern Virginia from May 1993 to May 1995. Daily movements ranged from 0-450 m, with 0-5 m movements accounting for 65% of the observations. The seasonal movements of males were more extensive than those of females. Differences in seasonal movements between the sexes may be due to reproductive activity of the snakes. Both males and females significantly reduced their movements prior to shedding. More time was spent using upland deciduous forests than lowland river swamps or anthropogenic habitat. Copperheads …


Behavioral Responses To Pine Needle Oil In The Northern Pocket Gopher, Gisela Epple, Dale L. Nolte, J. Russell Mason, Eugeny Aronov, Shirley Wager-Page Aug 1995

Behavioral Responses To Pine Needle Oil In The Northern Pocket Gopher, Gisela Epple, Dale L. Nolte, J. Russell Mason, Eugeny Aronov, Shirley Wager-Page

National Wildlife Research Center Repellents Conference 1995

For many herbivorous mammals, oils from conifers are feeding repellents. Our study investigated effects of pine needle oil on feeding and other behaviors of northern pocket gophers. In one-choice feeding trials pocket gophers were offered sweet potato from single feeding stations placed into each subject's home cage. Stations contained either a scent dispenser with pine needle oil or with mineral oil. Pine needle oil did not inhibit food retrieval under these conditions. Responses to pine needle oil and to a control odorant, d-pulegone, were also tested in mazes where subjects were offered choices between two goal boxes, each containing food …


The Challenge And Opportunity Of Recovering Wolf Populations, L. David Mech Apr 1995

The Challenge And Opportunity Of Recovering Wolf Populations, L. David Mech

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

The gray wolf once inhabited a wide variety of habitats throughout most of the northern hemisphere north of 20°N latitude. Because the animal preyed on livestock and competed with humans for wild prey, it was extirpated from much of its range outside of wilderness areas. Environmental awareness in the late 1960s brought for the wolf legal protection, increased research, and favorable media coverage. The species has increased in both Europe and North America, is beginning to reoccupy semiwilderness and agricultural land, and is causing increased damage to livestock. Because of the wolfs high reproductive rate and long dispersal tendencies, the …