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Articles 901 - 930 of 1075

Full-Text Articles in Ornithology

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 …


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 …


Faunal Diversity Among Avian Parasite Assemblages: The Interaction Of History, Ecology, And Biogeography In Marine Systems, Eric P. Hoberg Jan 1996

Faunal Diversity Among Avian Parasite Assemblages: The Interaction Of History, Ecology, And Biogeography In Marine Systems, Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Systematics and parasite biodiversity provide power and predictability in broad studies of history, ecology and biogeography in marine systems. Parasitic helminths are elegant markers of contemporary and historical ecological relationships, geographic distribution and host-phylogeny. Complex life cycles of helminths are strongly correlated with intricate food-webs. Dependence on a series of intermediate, paratenic, and definitive hosts indicates that each parasite species represents an array of organisms within a community and tracks broadly and predictably across many trophic levels. Host and geographic ranges of parasites are historically constrained by genealogical and ecological associations, and these determinents interact resulting in characteristic parasite community …


Phylogenetic Reanalysis Of Strauch's Osteological Data Set For The Charadriiformes, Philip C. Chu Feb 1995

Phylogenetic Reanalysis Of Strauch's Osteological Data Set For The Charadriiformes, Philip C. Chu

Biology Faculty Publications

Strauch's (1978) compatibility analysis of relationships among the shorebirds (Charadriiformes) was the first study to examine the full range of charadriiform taxa in a reproducible way. Subsequently Mickevich and Parenti (1980) leveled serious charges against Strauch's characters, method of phylogenetic inference, and results. To account for these charges, Strauch's characters were re-examined and recoded, and parsimony analyses were performed on the revised matrix. A parsimony analysis on 74 taxa from the revised matrix yielded 855 shortest trees, each length = 286 and consistency index = 0.385. In each shortest tree there were two major lineages, a lineage of sandpiper-like birds …


Egg Removal By Brown-Headed Cowbirds: A Field Test Of The Host Incubation Efficiency Hypothesis, Douglas R. Wood Jan 1995

Egg Removal By Brown-Headed Cowbirds: A Field Test Of The Host Incubation Efficiency Hypothesis, Douglas R. Wood

Masters Theses

Obligate brood parasites, like the Brown-headed Cowbird (Molothrus ater), lay their eggs in the nests of host species, usually to the detriment of the host's reproductive effort. In addition, Brown-headed Cowbirds often remove one or more host eggs near the time of parasitism. Although several hypotheses exist, the adaptive significance of egg removal has not been clearly established. Peer and Bollinger (in press) proposed the host incubation efficiency hypothesis which states that the number and size of host eggs influences the incubation efficiency of a parasitic egg. Thus, host egg removal by cowbirds should increase the parasitic egg's …


Reproductive Success Of Grassland Birds At East-Central Illinois Airports, Eric L. Kershner Jan 1995

Reproductive Success Of Grassland Birds At East-Central Illinois Airports, Eric L. Kershner

Masters Theses

We determined the densities and reproductive success of birds on airport grasslands in east-central Illinois. Seven airports were sampled between 10 April and 15 August 1994 in Clark, Coles, Crawford, Douglas, Edgar, Macon and Richland counties. Nineteen species were detected on the airport grasslands and 147 nests were found representing six different species. Eastern meadowlarks (Sturnella magna) were the most abundant nesting species found; 105 out of the 147 nests (71%). Other nesting species included: grasshopper sparrow (Ammodramus savannarum), savannah sparrow (Passerculus sandwichensis), red-winged blackbird (Agelaius phoeniceus), song sparrow (Melospiza melodia) and horned lark (Eremophilia alpestris). Overall nest success was …


Summer Activity Cost Of Eared Grebes At Mono Lake, Hugh I. Ellis May 1994

Summer Activity Cost Of Eared Grebes At Mono Lake, Hugh I. Ellis

Biology: Faculty Scholarship

No abstract provided.


Artificial Cavity Box Use By Eastern Screech Owl, Otus Asio, Lori A. Davis Jan 1994

Artificial Cavity Box Use By Eastern Screech Owl, Otus Asio, Lori A. Davis

Masters Theses

Screech owl use of 29 artificial cavity boxes placed in wooded habitat on a 14.6 hectare study area in east central Illinois was monitored from 1975 through 1993. A total of 28 screech owls were captured a total of 155 times. Two to 4 adults were usually present and 3 broods were reared in the boxes. The time between first and last capture of birds taken 4 or more times ranged from 270 to 2589 days (average 1740 days). Home range of 5 owls captured 8 to 17 times ranged from 0.45 to 6.0 ha. Cavity boxes were used more …


An Investigation Of The Host Specificity Of The Brown-Headed Cowbird, Brian D. Peer Jan 1993

An Investigation Of The Host Specificity Of The Brown-Headed Cowbird, Brian D. Peer

Masters Theses

We attempted to determine the factors associated with the lack of parasitism of the Common Grackle (Quiscalus quiscula) by the Brown-headed Cowbird (Molothrus ater). We investigated the breeding phenology of the two species, the responses of colonial- and noncolonial-nesting grackles to female cowbird models, the frequency of artificial egg rejection by grackles, incubation success of cowbird eggs transferred into grackle nests, and the survival rates of cowbirds cross-fostered into grackle nests.

By the time cowbirds began egg-laying at our study sites, 88.5 % of all grackle nests were beyond the point of successful parasitism. Grackles responded …


The Effects Of Nest-Box Visibility And Proximity On The Frequency Of Brood Parasitism In Wood Ducks, Roger W. Jansen Jan 1993

The Effects Of Nest-Box Visibility And Proximity On The Frequency Of Brood Parasitism In Wood Ducks, Roger W. Jansen

Masters Theses

I studied the effects of nest box visibility and clustering on the rate of intraspecific brood parasitism (IBP) in Wood Ducks (Aix sponsa) at Lake Shelbyville Fish and Wildlife Area in Moultrie County, IL from 2 March 1992 to 22 June 1992. Sixty-eight percent of the nest boxes sampled were used and 33% of the nests were destroyed by predators. Mean clutch sizes of unparasitized (x = 9.2) and parasitized (x = 15.2) nests were significantly different. The parasitism rate in Wood Duck nests was 54%. More visible boxes had a tendency to be parasitized at a higher rate than …


Larids, Scolopacids, And Passerines Exploiting Ephemeral Prey At Talan Island, Russia, Eric P. Hoberg, Alexander I. Kondratiev, Alexander S. Kitaysky Oct 1992

Larids, Scolopacids, And Passerines Exploiting Ephemeral Prey At Talan Island, Russia, Eric P. Hoberg, Alexander I. Kondratiev, Alexander S. Kitaysky

Harold W. Manter Laboratory of Parasitology: Faculty Publications

We report an unusual multispecies foraging assemblage that included larids, shorebirds and passerines which exploited a highly concentrated and ephemeral prey source over a period of three days in July and August 1988. During studies of breeding biology, food-habits and host-parasite ecology among a diverse colonial avifauna at Talan Island in the northern Sea of Okhotsk (59°18'N; 149°02'E) we observed the formation of mixed-species flocks during extreme high tides of July 31, August 1, and August 13, 1988.


Status, Production And Migration Of Greater Sandhill Cranes On Agassiz National Wildlife Refuge, Minnesota, Jon J. Dimatteo Jan 1992

Status, Production And Migration Of Greater Sandhill Cranes On Agassiz National Wildlife Refuge, Minnesota, Jon J. Dimatteo

Proceedings of the North American Crane Workshop

Greater sandhill cranes (Grus canadensis tabida) nesting at Agassiz National Wildlife Refuge (NWR) in northwestern Minnesota were studied from 20 April 1984 to 10 December 1985. Local birds were monitored to determine population size and age structure, reproductive success, and migration routes and wintering grounds. Forty-two pairs were identified. Thirty-four were breeding pairs and 3 were subadult (nonbreeding) pairs. Twenty nests were found; pairs at 13 of these hatched at least 1 young. Forty-three pairs hatched a minimum of 62 young, and 28 pairs fledged 42 of 47 young. Fifteen birds were colormarked, 8 of which were radio-tagged …


An Evaluation Of Three Areas For Potential Populations Of Whooping Cranes, Janet L. Mcmillen, Stephen A. Nesbitt, Mary A. Bishop, Alan J. Bennett, Laurel A. Bennett Jan 1992

An Evaluation Of Three Areas For Potential Populations Of Whooping Cranes, Janet L. Mcmillen, Stephen A. Nesbitt, Mary A. Bishop, Alan J. Bennett, Laurel A. Bennett

Proceedings of the North American Crane Workshop

Sandhill crane (Grus canadensis) populations were evaluated on the Seney NWR, Michigan, the Okefenokee Swamp, Georgia, and in southcentral Florida to evaluate their suitability to support introduced whooping cranes (G. americana). This paper compares data collected at these sites and additional data collected in northcentral Florida. The length of the egg-laying period varied from 4.5 months in central Florida to 1 month at Seney, but egg-laying ceased at all sites from mid-May to early June. Mean clutch sizes were similar 0.7-1.9). Renesting ranged from 79% in northcentral Florida to <=5% at Seney. These dates and values are consistent with nesting successes that ranged from 48% in northcentral Florida to 80% at Seney. Average annual recruitment, 12.3 juveniles/lOa adults, was highest on the Kissimmee Prairie in southcentral Florida. Average annual horne range size for the non-migratory populations were 1 km2 on the Okefenokee and 6.6 km2 on the Kissimmee. Nesting season horne range sizes ranged from 0.5 km2 on the Okefenokee to 1.8 km2 at Seney. All candidate populations successfully satisfied most of the guidelines for potential whooping crane populations as established by the Whooping Crane Recovery Team. Once reintroduction techniques have been refined, any or all of the study sites have the capacity to accommodate a flock of whooping cranes commensurate with Whooping Crane Recovery Team recommendations.