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Articles 721 - 750 of 903

Full-Text Articles in Terrestrial and Aquatic Ecology

Salinity And Shade Preferences Result In Ovipositional Differences Between Sympatric Tiger Beetle Species, W. Wyatt Hoback, Douglas A. Golick, Tina Marie Svatos, Stephen M. Spomer, Leon G. Higley Jan 2000

Salinity And Shade Preferences Result In Ovipositional Differences Between Sympatric Tiger Beetle Species, W. Wyatt Hoback, Douglas A. Golick, Tina Marie Svatos, Stephen M. Spomer, Leon G. Higley

Department of Entomology: Faculty Publications

1. Adult tiger beetles of the genus Cicindela often co-occur within a habitat but larvae do not. Larvae are sedentary and form usually permanent burrows at the site of oviposition where they require 1-3 years for development.

2. To test niche partitioning based on ovipositional preference, the behavior of two sympatric salt marsh tiger beetles, Cicindela circumpicta and C. togata (Coleoptera: Cicindelidae), were examined.

3. In laboratory studies, female C. circumpicta and C. togata distinguished between experimental salinities, with the former preferring 4 parts per thousand (ppt) and the latter preferring 12 ppt. In the field, C. circumpicta larvae were …


A Record Large Wolf, Canis Lupus, Pack In Minnesota, L. David Mech Jan 2000

A Record Large Wolf, Canis Lupus, Pack In Minnesota, L. David Mech

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

This report documents a pack of 22-23 Wolves (Canis lupus) in central Minnesota. This is larger than the largest pack previously observed on the mainland in the midwestern U.s. during 650 wolf pack-years. Because this record-large pack preyed on White-tailed Deer (Odocoileus virginianus), one of the Wolfs smaller prey, it is evidence that pack size and prey size are not tightly related. It also indicates the size that Wolf packs can attain in the area if fully protected from human persecution.


Lack Of Reproduction In Muskoxen And Arctic Hares Caused By Early Winter?, L. David Mech Jan 2000

Lack Of Reproduction In Muskoxen And Arctic Hares Caused By Early Winter?, L. David Mech

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

A lack of young muskoxen (Ovibos moschatus) and arctic hares (Lepus arcticus) in the Eureka area of Ellesmere Island, Northwest Territories (now Nunavut), Canada, was observed during summer 1998, in contrast to most other years since 1986. Evidence of malnourished muskoxen was also found. Early winter weather and a consequent 50% reduction of the 1997 summer replenishment period appeared to be the most likely cause, giving rise to a new hypothesis about conditions that might cause adverse demographic effects in arctic herbivores.

Durant l’été 1998, et ce, à la différence de la plupart des années depuis …


Accuracy And Precision Of Estimating Age Of Gray Wolves By Tooth Wear, Philip S. Gipson, Warren B. Ballard, Ronald M. Nowak, L. David Mech Jan 2000

Accuracy And Precision Of Estimating Age Of Gray Wolves By Tooth Wear, Philip S. Gipson, Warren B. Ballard, Ronald M. Nowak, L. David Mech

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

We evaluated the accuracy and precision of tooth wear for aging gray wolves (Canis lupus) from Alaska, Minnesota, and Ontario based on 47 known-age or known-minimum-age skuIIs. Estimates of age using tooth wear and a commercial cementum annuli-aging service were useful for wolves up to 14 years old. The precision of estimates from cementum annuli was greater than estimates from tooth wear, but tooth wear estimates are more applicable in the field. We tended to overestimate age by 1-2 years and occasionaIIy by 3 or 4 years. The commercial service aged young wolves with cementum annuli to within …


Prolonged Winter Undernutrition And The Interpretation Of Urinary Allantoin:Creatinine Ratios In White-Tailed Deer, Glenn D. Delgiudice, Ken D. Kerr, L. David Mech, Ulysses S. Seal Jan 2000

Prolonged Winter Undernutrition And The Interpretation Of Urinary Allantoin:Creatinine Ratios In White-Tailed Deer, Glenn D. Delgiudice, Ken D. Kerr, L. David Mech, Ulysses S. Seal

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

The urinary allantoin:creatinine (A:C) ratio (expressed in micromoles of allantoin to micromoles of creatinine) has shown potential as an index of recent winter energy intake in preliminary controlled studies of elk (Cervus elaphus) involving mild condition deterioration (up to 11% loss of body mass). To ensure reliable nutritional assessments of free-ranging cervids by measuring A:C ratios of urine in snow, it is essential to extend this work. We assessed the effect of moderate and severe winter nutritional restriction on urinary A:C ratios of captive white-tailed deer (Odocoileus virginianus) that lost up to 32% body mass and …


The Impact Of Resident And Transient Predators On The Popultation Dynamics Of Juvenile Caribbean Spiny Lobster (Panulirus Argus) In Florida Bay, Florida, Jason Edward Schratwieser Oct 1999

The Impact Of Resident And Transient Predators On The Popultation Dynamics Of Juvenile Caribbean Spiny Lobster (Panulirus Argus) In Florida Bay, Florida, Jason Edward Schratwieser

Biological Sciences Theses & Dissertations

There has been a considerable amount of research devoted to exploring the relationship between predators and prey, but many of these studies fail to address how predation can vary over spatial and temporal scales. The tendency of ecologists to model predation as a static entity often masks its capacity for creating distinctive effects in prey populations and communities. Most predation studies also focus on the effect of a single species of predator on a prey population, an unrealistic situation in nature. In the Florida Keys, juvenile spiny lobsters are subjected to two general classes of predators: i) "resident" predators such …


Osteological Analysis Of The Killifish Genus Cynolebias (Cyprinodontiformes: Rivulidae), Marcelo Loureiro, Rafael O. De Sá Jan 1999

Osteological Analysis Of The Killifish Genus Cynolebias (Cyprinodontiformes: Rivulidae), Marcelo Loureiro, Rafael O. De Sá

Biology Faculty Publications

Relationships among the species of the annual fish Cynolebias are unclear. An analysis of the variation and utility of osteological characters for phylogenetic analysis was done using cleared and double-stained specimens representing 21 species of Cynolebias. This analysis showed that some of the characters previously used to diagnose this genus and some of the species are polymorphic. Osteologically, Cynolebias can be diagnosed by the following synapomorphies: (1) triangular-shaped parietal, (2) vomer positioned ventral to the parasphenoid, (3) long ventral process of the dentary, (4) teeth on fourth ceratobranchial, and (5) teeth on first epibranchial. In addition, characters that help …


Alpha Status, Dominance, And Division Of Labor In Wolf Packs, L. David Mech Jan 1999

Alpha Status, Dominance, And Division Of Labor In Wolf Packs, L. David Mech

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

The prevailing view of a wolf (Canis lupus) pack is that of a group of individuals ever vying for dominance but held in check by the “alpha” pair, the alpha male and alpha female. Most research on the social dynamics of wolf packs, however, has been conducted on non-natural assortments of captive wolves. Here I describe the wolf-pack social order as it occurs in nature, discuss the alpha concept and social dominance and submission, and present data on the precise relationships among members in free-living packs, based on a literature review and 13 summers of observations of wolves …


Regurgitative Food Transfer Among Wild Wolves, L. David Mech, Paul C. Wolf, Jane M. Packard Jan 1999

Regurgitative Food Transfer Among Wild Wolves, L. David Mech, Paul C. Wolf, Jane M. Packard

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

Few studies of monogamous canids have addressed regurgitation in the context of extended parental care and alloparental care within family groups. We studied food transfer by regurgitation in a pack of wolves on Ellesmere Island, North West Territories, Canada, during 6 summers from 1988 through 1996. All adult wolves, including yearlings and a post-reproductive female, regurgitated food. Although individuals regurgitated up to five times per bout, the overall ratio of regurgitations per bout was 1.5. Pups were more likely to receive regurgitations (81%) than the breeding female (14%) or auxiliaries (6%). The breeding male regurgitated mostly to the breeding female …


Alpha Status, Dominance, And Division Of Labor In Wolf Packs, L. David Mech Jan 1999

Alpha Status, Dominance, And Division Of Labor In Wolf Packs, L. David Mech

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

The prevailing view of a wolf (Canis lupus) pack is that of a group of individuals ever vying for dominance but held in check by the “alpha” pair, the alpha male and alpha female. Most research on the social dynamics of wolf packs, however, has been conducted on non-natural assortments of captive wolves. Here I describe the wolf-pack social order as it occurs in nature, discuss the alpha concept and social dominance and submission, and present data on the precise relationships among members in free-living packs, based on a literature review and 13 summers of observations of wolves …


Twenty-Year Home-Range Dynamics Of A White-Tailed Deer Matriline, Michael E. Nelson, L. D. Mech Jan 1999

Twenty-Year Home-Range Dynamics Of A White-Tailed Deer Matriline, Michael E. Nelson, L. D. Mech

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

We examined the seasonal migration and home-range dynamics of a multigeneration white-tailed deer (Odocoileus virginianus) matriline comprising six females from four generations spanning a 20-year period in northeastern Minnesota. All, from the matriarch to her great-granddaughter, migrated to the same summer and winter ranges, the longest individual record being 14.5 years. Three maternal females concurrently occupied exclusive fawning sites within their ancestral matriarch’s summer range, while two nonmaternal females explored new areas and ranged near their mothers. One great-granddaughter expanded her summer range 1 km beyond the matriarch’s summer range while essentially vacating half of her ancestors’ range …


The Annual Reproductive Cycle Of Oryzomys Palustris In A Virginia Tidal Marsh, Erin A. Dreelin Jul 1997

The Annual Reproductive Cycle Of Oryzomys Palustris In A Virginia Tidal Marsh, Erin A. Dreelin

Biological Sciences Theses & Dissertations

The objectives of my study were to determine when the marsh rice rat (Oryzomys palustris) begins and ends reproduction during the year, if there are seasonal changes in litter size, and the weight at which sexual maturity is reached. Monthly samples of rice rats were trapped from May 1995 to May 1996 in Northampton County, Virginia. Rice rats were trapped with Fitch live traps, euthanized in the field, and brought to the lab for necropsy. Data from two other studies of rice rats in Northampton County were also examined. Potential breeders did not reproduce with equal intensity throughout the …


Stomach Content Analysis Of Stranded Bottlenose Dolphins, Tursiops Truncatus, In Virginia, 1987-1996, John Mcgurk Jul 1997

Stomach Content Analysis Of Stranded Bottlenose Dolphins, Tursiops Truncatus, In Virginia, 1987-1996, John Mcgurk

Biological Sciences Theses & Dissertations

I examined the stomach contents from 94 bottlenose dolphins, Tursiops truncatus, that were stranded along the Virginia coastline from 1987 through 1996. Samples from 1987 through 1991 were obtained from the National Museum of Natural History (NMNH) and samples from 1992 through 1996 were collected by the Virginia Marine Science Museum (VMSM) Stranding Team. Prey species were identified using fish otoliths and cephalopod beaks.

The dolphins examined fed on 23 species of fish and one genus of cephalopods. The primary prey species was Atlantic croaker (Micropogonias undulatus); secondary species were weakfish (Cynoscion regalia), spot (Leiostomus xanthurus), silver perch (Bairdiella chrysoura), …


Diet And Growth Of Larval And Juvenile Grass Pickerel, Esox Americanus Vermiculatus, And Central Mudminnow, Umbra Limi, In The Green Bottom Wildlife Management Area, Cabell County, West Virginia, Erica Midkiff Jan 1997

Diet And Growth Of Larval And Juvenile Grass Pickerel, Esox Americanus Vermiculatus, And Central Mudminnow, Umbra Limi, In The Green Bottom Wildlife Management Area, Cabell County, West Virginia, Erica Midkiff

Theses, Dissertations and Capstones

The grass pickerel, Esox americanus vermiculatus, is listed as Undetermined on the Vertebrate Species List of Concern in West Virginia. The central mudminnow, Umbra limi, is a disjunct population in Green Bottom Swamp. The lentic, vegetated areas that are required for spawning for the grass pickerel and the central mudminnow have been reduced by residential, agricultural, and industrial developments. Green Bottom Swamp, a naturally occurring wetland of 58 ha, and a nearby mitigated wetland of 29 ha, provides spawning habitat for the grass pickerel and the mudminnow. Fishes were collected in beds of Potamogetan crispus and Ceratophyllum demursum …


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. …


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 …


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 …


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% …


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.


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 …


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 …


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.


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 …


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 …


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 …


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 …


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 …


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 …


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 …


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 …