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Articles 871 - 900 of 1077

Full-Text Articles in Ornithology

Patterns Of Movement And Orientation During Caching And Recovery By Clark’S Nutcrackers, Nucifraga Columbiana, Alan Kamil, Russell P. Balda, Sally Good Jan 1999

Patterns Of Movement And Orientation During Caching And Recovery By Clark’S Nutcrackers, Nucifraga Columbiana, Alan Kamil, Russell P. Balda, Sally Good

Avian Cognition Papers

Clark’s nutcrackers regularly store large numbers of pine seeds and remember the locations of the cached seeds. Although they are very accurate, they do make some errors during recovery. In an attempt to determine whether any behaviours during caching predicted the occurrence of errors during recovery, we videotaped Clark’s nutcrackers while they cached and recovered seeds under laboratory conditions. We used the videotapes to develop complete, quantitative descriptions of caching and recovery behaviour, with an emphasis on body orientation and directions of movement. During caching, the birds showed the greatest change in their orientation and direction following cache creation. During …

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How Do They, Indeed? A Reply To Biegler Et Al., Alan Kamil, Juli E. Jones Jan 1999

How Do They, Indeed? A Reply To Biegler Et Al., Alan Kamil, Juli E. Jones

Avian Cognition Papers

We trained Clark’s nutcrackers, Nucifraga columbiana, to search halfway between two landmarks while varying the distance between the landmarks (Kamil & Jones 1997). We found that the birds learned the problem readily and generalized to novel interlandmark distances within the range of distances used during training. Unlike some other studies in which responses to proportional distance were obtained (e.g. O’Keefe & Burgess 1996; Tommasi et al. 1997), the nutcrackers showed very precise search and maintained this precision during the transfer test. The distributions of digging locations around the central position were concentrated within ±1–2 cm of the central location …

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Grassland Birds And Habitat Structure In Sandhills Prairie Managed Using Cattle Or Bison Plus Fire, Randall Griebel, Stephen L. Winter, Allen Steuter Oct 1998

Grassland Birds And Habitat Structure In Sandhills Prairie Managed Using Cattle Or Bison Plus Fire, Randall Griebel, Stephen L. Winter, Allen Steuter

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

Grassland birds are known to respond to specific changes in habitat structure, such as plant height and density. However, the response of grassland bird communities to management induced changes in the regional habitat mosaic are less well understood. Grazing by ungulates and fire regimes play an important role in defining the habitat mosaic in the Great Plains. We provide information on bird abundance, distribution, and habitat structure from similar sandhill prairie landscapes managed traditionally with grazing by cattle (Bos taurus) and by a dynamic bison (Bos bison)-plus-fire regime. Although the two management regimes are dissimilar, only …

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Locational Factors Determining The Distribution Of Nesting Sites For A Colony Of Wedge-Tailed Shearwaters, Puffinus Pacificus, On West Wallabi Island, Houtman Abrolhos, Western Australia, Julie Davis Jan 1998

Locational Factors Determining The Distribution Of Nesting Sites For A Colony Of Wedge-Tailed Shearwaters, Puffinus Pacificus, On West Wallabi Island, Houtman Abrolhos, Western Australia, Julie Davis

Theses : Honours

West Wallabi Island in the Houtman Abrolhos, Western Australia, provides significant breeding habitat for the largest colony of Wedge-tailed Shearwaters, Puffinus pacificus, in the Eastern Indian Ocean. The Department of Conservation and Land Management (CALM) surveyed the Island in 1992 and estimated the population to be in excess of 1,117,000 pairs of breeding birds. Recent proposals to open the Abrolhos area to a larger number of visitors has identified the need for more detailed investigations into the relationship of birds and habitat. An understanding of this relationship provides a means of determining the ways in which populations will respond to …

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Habitat Selection, Reproductive Success, And Impaling Patterns Of A Migratory Population Of Loggerhead Shrikes, Jeffrey D. Esely Jr. Jan 1998

Habitat Selection, Reproductive Success, And Impaling Patterns Of A Migratory Population Of Loggerhead Shrikes, Jeffrey D. Esely Jr.

Masters Theses

I studied habitat selection and reproductive success of a migratory population of Loggerhead Shrikes (Lanius ludovicianus migrans) as well as the temporal and spatial patterns of impaling exhibited by this population during the nesting season. The selection of breeding habitat was investigated at different spatial scales. Thirty-eight (67%) of 57 nests were located in osage orange (Maclura pomifera) trees. Shrike territories (area ≤ 200 m from nest site) contained significantly more pasture, fenceline, and perch sites, but less com, alfalfa, and forest than random sites. At larger spatial scales, more grassland was detected within 300 m …

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A Comparison Of Predation Rates On Real And Artificial Nests Of Grassland Birds, William B. Davison Jan 1998

A Comparison Of Predation Rates On Real And Artificial Nests Of Grassland Birds, William B. Davison

Masters Theses

I compared rates of predation between real and artificial nests of grassland birds in order to test the impact of nest type, nest position, and egg size on predation rates. I distributed wicker avicultural baskets and realistic grass nests baited with a clay egg and either northern bobwhite (Colinus virginianus) or house sparrow (Passer domesticus) eggs in four Conservation Reserve Program (CRP) grasslands in east-central Illinois. Nest success averaged 86.5% for 12 days of exposure for artificial nests. For real nests, nest success was markedly lower; averaging 39% over the entire nesting cycle and 59% during approximately 12 days of …

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Breeding Densities And Habitat Of Riparian Birds Along The Lower Rio Grande, Texas, Corinna Elizabeth Rupert Dec 1997

Breeding Densities And Habitat Of Riparian Birds Along The Lower Rio Grande, Texas, Corinna Elizabeth Rupert

Theses and Dissertations - UTB/UTPA

The breeding biology of Snowy Plovers (Charadrius alexanderinus) was studied at Laguna Atascosa National Wildlife Refuge in coastal southern Texas. During 1995 and 1996 nests were found most often in high sand flat habitat and less frequently in low sand flat. Nest sites were dominated by open flat but had more rocks, pebbles and debris than control sites. Only 24% of the clutches hatched, while 67% were eaten by predators and 9% were flooded. Forty-three percent of Snowy Plover nests were within Least Tern (Sterna antillarum) colonies and these nests had a significantly greater chance of hatching than nests placed …

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Crows Do Not Use Automobiles As Nutcrackers: Putting An Oft-Repeated Anecdote To The Test, Daniel A. Cristol, Paul V. Switzer, K L. Johnson, L S. Walke Jan 1997

Crows Do Not Use Automobiles As Nutcrackers: Putting An Oft-Repeated Anecdote To The Test, Daniel A. Cristol, Paul V. Switzer, K L. Johnson, L S. Walke

Faculty Research & Creative Activity

No abstract provided.

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Crows Do Not Use Automobiles As Nutcrackers: Putting An Oft-Repeated Anecdote To The Test, Daniel Cristol, Paul Switzer, K Johnson, L Walke Jan 1997

Crows Do Not Use Automobiles As Nutcrackers: Putting An Oft-Repeated Anecdote To The Test, Daniel Cristol, Paul Switzer, K Johnson, L Walke

Faculty Research & Creative Activity

No abstract provided.

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Habitat Use By Migrant Whooping Cranes In Saskatchewan, Brian W. Johns, Eric J. Woodsworth, Ed A. Driver Jan 1997

Habitat Use By Migrant Whooping Cranes In Saskatchewan, Brian W. Johns, Eric J. Woodsworth, Ed A. Driver

Proceedings of the North American Crane Workshop

We investigated habitat use by migrating whooping cranes (Grus americana) in Saskatchewan between 1986 and 1990. At foraging and roosting sites and a sample of randomly selected sites we measured various habitat parameters. Palustrine and lacustrine wetlands were the most frequently used wetlands. Temporary and seasonal wetlands were the primary roost habitat during spring migration, and semi-permanent and permanent wetlands were frequently used during the fall. Cranes were attracted to areas of higher than average wetland density. Land use within 2 km of roost sites was intensively modified by man. Cereal crops were the most used feeding areas. …

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Availability Of Stopover Habitat For Migrant Whooping Cranes In Nebraska, Dale W. Stahlecker Jan 1997

Availability Of Stopover Habitat For Migrant Whooping Cranes In Nebraska, Dale W. Stahlecker

Proceedings of the North American Crane Workshop

Four stratified random samples of 512 National Wetland Inventory (NWI) maps within the central Nebraska portion of the Wood Buffalo-Aransas whooping crane (Grus americana) migration corridor were used to evaluate the availability of wetland roost sites. Wetlands were eliminated as potential roosts if visibility was obscured by vegetation or slope, if certain human activities occurred within 100-800 ro, or if water < 30 em deep was not available. Seasonal emergent wetlands, available as roosts primarily in spring, dominated all samples, particularly in the nortb. Sixty-five percent of all wetlands >0.04 ha passed map review and 52 % passed when ground-truthed. NWI map review was a good predictor of both suitability (63 % correct) and unsuitability (73 % correct). More than one-half of all open and emergent …

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Woody Vegetation Expansion And Continuing Declines In Open Channel Habitat On The Platte River In Nebraska, Paul J. Currier Jan 1997

Woody Vegetation Expansion And Continuing Declines In Open Channel Habitat On The Platte River In Nebraska, Paul J. Currier

Proceedings of the North American Crane Workshop

Aerial videography in 1988 and 1994 of the same selected segments of the Big Bend reach of the Platte River in central Nebraska was compared. During this 6-year period, channel area declined 4 to 41 % (median 26%). In river segments where the channel had already narrowed significantly and at sites where channel habitat is actively managed declines were less (17-18%). These substantial changes occurred during a time that included a relatively low flow period (1990-92). Flows during the summer gertttination and establishment period (mid-May through August) for cottonwood (Populus deltoides) and willow (Salix spp.), the …

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Home Range And Habitat Use By Isolation-Reared Sandhill Cranes, Wenrui Duan, Theodore A. Bookhouts, Richard P. Urbanek Jan 1997

Home Range And Habitat Use By Isolation-Reared Sandhill Cranes, Wenrui Duan, Theodore A. Bookhouts, Richard P. Urbanek

Proceedings of the North American Crane Workshop

We isolation-reared, placed radio transmitters on, and released 38 greater sandhill cranes (Grus canadensis tabida) on Seney National Wildlife Refuge (Seney) in 1988-90 to develop procedures for initiating new populations of cranes. Here we report on habitat selection by breeding birds with functional radio transmitters. Home ranges established by 6 cranes in 1992, when they were 2 to 4 years old, averaged 199±50.8 (SE) ha (harmonic mean method, 75 % utilization) and were of 2 types: feeding grounds separated from nesting habitat and feeding grounds adjacent to nesting habitat. Home ranges consisted of 36% emergent palustrine wetlands, 28% …

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Recent Advances In Scheduling Strategies And Practical Techniques In Crane Artificial Insemination, Scott R. Swengel, Monica L. Tuite Jan 1997

Recent Advances In Scheduling Strategies And Practical Techniques In Crane Artificial Insemination, Scott R. Swengel, Monica L. Tuite

Proceedings of the North American Crane Workshop

We analyzed fertility patterns of 339 eggs laid 1985-93 at the International Crane Foundation by cranes whose sole means of fertility was artificial insemination (AI). Ten of 15 crane species were studied. Fertility rates increased significantly (P < 0.05) with (I) higher sperm density, (2) greater sperm motility, and (3) 2 vs. 1 vs. 0 inseminations 4-7 days before oviposition. Semen sample size was inversely related to sperm density and had no strong relationship with egg fertility. Inseminations less than 2.5-3.0 days before an egg is laid are probably too late to contribute to fertilizing the egg but may contribute substantially to fertilizing the next egg. We also describe practical knowledge gained during the past 10 years that apply to certain species or situations. Wattled cranes (Bugeranus carunculatus) have a long fertile period post-AI (up to 16 days), but may require more careful methods and special AI scheduling strategies. We also describe techniques for AI just after oviposition that are especially beneficial for Siberian cranes (Grus leucogeranus), and methods for maximizing sample delivery to the female.

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Sandhill Crane Hunts In The Rio Grande Valley And Southwest New Mexico, C. Gregory Schmitt, Barry Hale Jan 1997

Sandhill Crane Hunts In The Rio Grande Valley And Southwest New Mexico, C. Gregory Schmitt, Barry Hale

Proceedings of the North American Crane Workshop

Annual limited permit hunting seasons for sandhill cranes (Grus canadensis) were initiated in southwestern New Mexico (SWNM) in 1982 and in the middle Rio Grande Valley (MRGV) in 1986. Within the MRGV and SWNM are wintering areas for 3 migratory subspecies, including the lesser sandhill crane (G. c. canadensis) (lessers). Canadian sandhill crane (G. c. rowani) (Canadians), and greater sandhill crane (G. c. tabida) (greaters). We summarized annual season dates, bag limits, requirements for permits, procedures for examination of crane specimens at check stations, number of hunters, estimated harvest, mean harvest per …

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Results Of An Experiment To Lead Cranes On Migration Behind Motorized Ground Vehicles, David H. Ellis, Brian Clauss, Tsuyoshi Watanabe, R. Curt Mykut, Matthew Kinloch, Catherine H. Ellis Jan 1997

Results Of An Experiment To Lead Cranes On Migration Behind Motorized Ground Vehicles, David H. Ellis, Brian Clauss, Tsuyoshi Watanabe, R. Curt Mykut, Matthew Kinloch, Catherine H. Ellis

Proceedings of the North American Crane Workshop

Ten greater sandhill cranes (Grus canadensis tabida) , trained to enter and ride in a specially-equipped truck, were transported at ca 80 days of age from their rearing site at Patuxent Wildlife Research Center (patuxent), Maryland, to a reintroduction site located within the species' former breeding range in northern Arizona. After 5 additional weeks of training, these juvenile cranes were led south ca 600 km to a wintering area on the Arizona/Mexico border. Nine of the 10 survived the trek, 495 km of which were flown, although only a few cranes flew every stage of the route. Their …

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Corrigendum Crane Migration In Northern New Mexico, Dale W. Stahlecker Jan 1997

Corrigendum Crane Migration In Northern New Mexico, Dale W. Stahlecker

Proceedings of the North American Crane Workshop

These tables were not included in the above article. They are published here so that interested readers will have access to them while reading the results and discussion presented in that paper. It is now well documented that sandhill cranes (Grus canadensis) from outside the Rocky Mountain Population stage in spring and autumn in the San Luis Valley of southern Colorado (Benning et al. 1997). Therefore, the high autumn counts reported in the 1988 paper and discussed in relation to Table 3 could also have included cranes from other populations.

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Survival And Habitat Use Of Greater Sandhill Crane Colts On Modoc National Wildlife Refuge, California, Kevin J. Desroberts Jan 1997

Survival And Habitat Use Of Greater Sandhill Crane Colts On Modoc National Wildlife Refuge, California, Kevin J. Desroberts

Proceedings of the North American Crane Workshop

Radiotelemetry was used to monitor 13 (1990) and 14 (1992) greater sandhill crane (Grus canadensis tabida) colts on Modoc National Wildlife Refuge, California, to determine causes of mortality, brood habitat utilization, and effects of habitat management on colt survival. Colt survival rates were 0.36 (1990) and 0.54 (1992). Coyotes (Canis latrans) killed 3 colts and mink (Mustela vison) killed 4; I colt died because of a bacterial infection (Staphylococcus aureous). Broods used 6 different habitat types and 79% used more than I type. Irrigated meadows (74%), cultivated uplands (53 %), and marsh …

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Monogamy And Productivity In Sandhill Cranes, Stephen A. Nesbitt, Thomas C. Tacha Jan 1997

Monogamy And Productivity In Sandhill Cranes, Stephen A. Nesbitt, Thomas C. Tacha

Proceedings of the North American Crane Workshop

Marked pairs of Florida (Grus canadensis pratensis) and greater sandhill cranes (G. c. tabida) were monitored for 426 pair-years. Among pair members, females averaged 3.7 ± 3.6 (SD) years older than males. Pair longevity was not correlated with pair productivity (P ~ 0.279) for pairs that were together >3 years. Forty-four percent of 72 Florida sandhill crane pair bonds were broken during the study, 67.7% due to death and 32.3 % to divorce. Among both Florida and greater sandhill cranes, the incidence of divorce was related to a failure to reproduce; 52.6% of pairs that failed to produce …

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History Of Breeding Pairs And Nesting Sites Of The Mississippi Sandhill Crane, Jacob M. Valentine Jr., Scott G. Hereford Jan 1997

History Of Breeding Pairs And Nesting Sites Of The Mississippi Sandhill Crane, Jacob M. Valentine Jr., Scott G. Hereford

Proceedings of the North American Crane Workshop

Thirty-four Composite Nesting Areas (CNA's) of endangered Mississippi sandhill cranes (Grus canadensis pulla) within the current breeding range in Jackson County, Mississippi, were located from 1965 to 1996, primarily by ground searching. Of those 34 CNA's located, 28 were on I of the 3 refuge units and 6 were off but adjacent to the refuge's Ocean Springs Unit. Five of the CNA's had 2-3 distinct smaller core nesting areas within. Two CNA's had active nests in more than 20 years, and those nests accounted for 11 % of the total. Nine CNA's accounted for 130 (63%) of the …

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Proceedings Of The Seventh North American Crane Workshop Jan 1997

Proceedings Of The Seventh North American Crane Workshop

Proceedings of the North American Crane Workshop

In 1975 a group of North American crane researchers and managers convened a workshop at the fledgling International Crane Foundation in Baraboo, Wisconsin. At the end they agreed to publish the proceedings of the workshop and to reconvene in 3 years to continue to share information, ideas, and support. This 1975 international crane workshop served as the first North American cranc workshop and was followed by workshops in 1978 (Rockport, Texas), 1981 (Grand Teton National Park, Wyoming), 1985 (Grand Island, Nebraska), and 1988 (Kissimmee Prairie, Florida). In these first 5 North American workshops, proceedings were published by the sponsoring agencies …

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A Reintroduction Technique For Migratory Birds: Leading Canada Geese And Isolation-Reared Sandhill Cranes With Ultralight Aircraft, William A. Lishman, Tighe L. Teets, Joseph W. Duff, William J. L. Sladen, Galvin G. Shire, Kirk M. Goolsby, Wayne A. Bezner Kerr, Richard Urbanek Jan 1997

A Reintroduction Technique For Migratory Birds: Leading Canada Geese And Isolation-Reared Sandhill Cranes With Ultralight Aircraft, William A. Lishman, Tighe L. Teets, Joseph W. Duff, William J. L. Sladen, Galvin G. Shire, Kirk M. Goolsby, Wayne A. Bezner Kerr, Richard Urbanek

Proceedings of the North American Crane Workshop

No successful method for establishing self-sustaining populations of whooping cranes (Grus americana), particularly in a migration situation, has been proven. This research initiated development of a reintroduction technique using ultralight aircraft to lead cranes from a natal area along a desired route to a predetermined wintering site. Canada geese (Branta canadensis) were used in initial migration efforts. Ultralight aircraft and pilots successfully led 86 juvenile geese on 3 southbound migrations from Ontario to winter sites 640-1,312 kIn from the natal area. Of 16 1993-hatched geese that survived their first winter in Virginia and 35 1994- hatched …

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Harts Basin, Colorado: A Spring Migration Stopover Area For Rocky Mountain Sandhill Cranes And Whooping Cranes, Melvin K. Peterson, Roderick C. Drewien Jan 1997

Harts Basin, Colorado: A Spring Migration Stopover Area For Rocky Mountain Sandhill Cranes And Whooping Cranes, Melvin K. Peterson, Roderick C. Drewien

Proceedings of the North American Crane Workshop

Greater sandhill cranes (Grus canadensis tabida) from the Rocky Mountain Population (RMP) and whooping cranes (G. americana) reared by RMP foster parents were monitored during 1980-95 at a traditional spring migration stopover at Harts Basin in western Colorado. Counts during March and April 1986-93 showed that a mean of 10,656 RMP sandhill cranes stopped annually for 1 or more nights en route from their spring staging area in the San Luis Valley, Colorado, to summer grounds. More than 96% stopped between 11 March and 10 April. Count data indicated that > 50 % of the RMP stopped …

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Vocalizations Of Sandhill Cranes, Stephen A. Nesbitt, Richard A. Bradley Jan 1997

Vocalizations Of Sandhill Cranes, Stephen A. Nesbitt, Richard A. Bradley

Proceedings of the North American Crane Workshop

The structure and context of 20 vocalizations given by adult or juvenile sandhill cranes (Grus canadensis) are described. Purr calls were given under various circumstances (e.g., pre-flight, feeding, aggression) and communicated information over a short distance. Flight calls, guard calls, and urtison calls were full-voiced calls that carried information over greater distances. Calls given in flight were distinguishable from other calls. Guard calls were given in several different circumstances and served multiple functions; other calls were given in very specific contexts. Beyond the basic communication of information to other cranes, vocalizations may function in mate selection and in …

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Computer Simulations Of Possible Futures For Two Flocks Of Whooping Cranes, Claire M. Mirande, John R. Cannon, Kimberly Agzigian, Rozanne E. Bogart, Sarah Christiansen, Jason Dubow, A. Katya Fernandez, Dustin K. Howarth, Claudia Jones, Katherine G. Munson, Sonal I. Pandya, Gina Sedaghatkish, Kevin L. Skerl, Susan A. Stenquist, Jennifer Wheeler Jan 1997

Computer Simulations Of Possible Futures For Two Flocks Of Whooping Cranes, Claire M. Mirande, John R. Cannon, Kimberly Agzigian, Rozanne E. Bogart, Sarah Christiansen, Jason Dubow, A. Katya Fernandez, Dustin K. Howarth, Claudia Jones, Katherine G. Munson, Sonal I. Pandya, Gina Sedaghatkish, Kevin L. Skerl, Susan A. Stenquist, Jennifer Wheeler

Proceedings of the North American Crane Workshop

We conducted computer simulations using the program VORTEX (version 7) to project population sizes, growth rates, genetic diversity, and probabilities of extinction over the next 100 years for 2 flocks of whooping cranes (Grus americana), the Aransas/Wood Buffalo population and the experimental Florida population. Standard runs based on best estimates of demographic. genetic, and environmental parameter values were used as a baseline to which several alternative scenarios were compared. Results generally supported the conclusion of the earlier Population Viability Assessment (Mirande et al. 1991) that the AransaslWood Buffalo population will continue to grow steadily with less than a …

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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 …

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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.

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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 …

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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 …

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Adaptive Significance Of Re-Nesting Following Nest Abandonment In The Blue-Gray Gnatcatcher (Polioptila Caerulea), Melissa Nicole Helton Jan 1997

Adaptive Significance Of Re-Nesting Following Nest Abandonment In The Blue-Gray Gnatcatcher (Polioptila Caerulea), Melissa Nicole Helton

Masters Theses

We studied the adaptive significance of nest abandonment and re-nesting in the Blue-gray Gnatcatcher (Polioptila caerulea) in east-central Illinois from 1995 through 1997. This Neotropical migrant is widely distributed and highly persistent in re-nesting following nest abandonment. Nest abandonment may be a response to brood parasitism, predation or other nest disturbances. We studied the nesting behavior of gnatcatchers and investigated the cues which may elicit nest abandonment. We monitored 57 pairs of gnatcatchers which built a total of 98 nests. Twenty pairs successfully fledged a total of 63 young and overall nest success was only 8.5%. Daily mortality rates for …

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