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Articles 1321 - 1350 of 1897

Full-Text Articles in Population Biology

Morbidity And Mortality Of Captive Whooping Cranes At The International Crane Foundation 1976–2008, Barry K. Hartup, Jennifer N. Niemuth, Bridget Fitzpatrick, Maureen Fox, Cristin Kelley Jan 2010

Morbidity And Mortality Of Captive Whooping Cranes At The International Crane Foundation 1976–2008, Barry K. Hartup, Jennifer N. Niemuth, Bridget Fitzpatrick, Maureen Fox, Cristin Kelley

Proceedings of the North American Crane Workshop

Tracking the incidence of morbidity and mortality in captive animal collections helps inform husbandry and preventive medicine programs aimed at improving population health and viability. Carpenter and Derrickson (1982) and Olsen et al. (1997) published summary reports of captive whooping crane (Grus americana) mortality that served to identify key problem areas for the primary breeding flock and potential reintroduction programs involving this endangered species. We expanded on this approach and conducted an initial evaluation of morbidity and mortality factors for whooping cranes at the International Crane Foundation (ICF). The purpose of our study was to identify overrepresented factors …


Endoparasites Of Greater Sandhill Cranes In South-Central Wisconsin, Somer Hartman, Betsy Reichenberg, Jane Fanke, Anne E. Lacy, Barry K. Hartup Jan 2010

Endoparasites Of Greater Sandhill Cranes In South-Central Wisconsin, Somer Hartman, Betsy Reichenberg, Jane Fanke, Anne E. Lacy, Barry K. Hartup

Proceedings of the North American Crane Workshop

Windingstad and Trainer (1977) used both fecal sampling and postmortem examinations to document the occurrence of parasites in greater sandhill cranes (Grus canadensis tabida) from Wisconsin in the fall. We conducted repeated fecal sampling of a well-known population to expand on results of their study. Our objective was to determine whether seasonal differences exist in the prevalence of endoparasites of Wisconsin sandhill cranes. We collected 7 to 10 fecal samples approximately every other week from a consistent roost site on the Wisconsin River (43°34'52.99''N, 89°36'38.42''W) near Briggsville, Wisconsin, from 29 May through 25 September 2008. The sample size …


Impacts Of Global And Regional Climate On Whooping Crane Demography: Trends And Extreme Events, Karine Gil, William Grant, R. Douglas Slack, Enrique Weir Jan 2010

Impacts Of Global And Regional Climate On Whooping Crane Demography: Trends And Extreme Events, Karine Gil, William Grant, R. Douglas Slack, Enrique Weir

Proceedings of the North American Crane Workshop

We analyzed long-term demographic and environmental data to understand the role of large scale climatic factors (the Pacific Decadal Oscillations [PDO]) and environmental factors in 3 regions of North America on natality and mortality of the remnant migratory whooping crane (Grus americana) population. This is an endangered species that spends winters at Aransas National Wildlife Refuge (ANWR) in Texas, breeds at Wood Buffalo National Park (WBNP) in Canada and “…uses Nebraska as a primary stopover”. Long term data (27 years) of demography and environmental factors (PDO index, temperature and precipitation at WBNP, Nebraska and ANWR, pond water depth …


Longevity Records Of Rocky Mountain Greater Sandhill Cranes Banded During 1969–1987 In Idaho, Montana, Utah, And Wyoming, Roderick C. Drewien, Wendy M. Brown, Kent R. Clegg Jan 2010

Longevity Records Of Rocky Mountain Greater Sandhill Cranes Banded During 1969–1987 In Idaho, Montana, Utah, And Wyoming, Roderick C. Drewien, Wendy M. Brown, Kent R. Clegg

Proceedings of the North American Crane Workshop

Cranes species throughout the world are renowned for their longevity; however, most records are based on individuals in captivity. We compiled longevity records for wild Rocky Mountain greater sandhill cranes (Grus canadensis tabida) banded in Idaho, Montana, Utah, and Wyoming during 1969-1987. Our analysis was based on over 180 band recoveries and over 1,700 visual observations of known-age individually marked birds from 1969 to 2008. We present only those birds of age >20 years for this summary. Our results yielded 56 birds known to be >20 yrs of age when killed or last observed. Of 7 band recoveries, …


Demography Of Whooping Cranes In The Eastern Migratory Population, Sarah J. Converse, Richard P. Urbanek Jan 2010

Demography Of Whooping Cranes In The Eastern Migratory Population, Sarah J. Converse, Richard P. Urbanek

Proceedings of the North American Crane Workshop

The ultimate success of the whooping crane (Grus americana) reintroduction to eastern North America rests on adequate demographic performance of the population. We are undertaking a population viability analysis (PVA) of the eastern migratory population in order to evaluate progress toward the fundamental population objective, to better understand the critical demographic thresholds that must be met to fulfill this objective, and, most importantly, to support management decision-making. The initial phase in the PVA development process involves estimation of demographic parameters to be used in later population modeling phases. Multi-state models provide an appropriate analytic framework for estimation, wherein …


Current Status Of Lesser Sandhill Cranes In Yakutia, Inga Bysykatova, Sergey Sleptsov, Nikolay Vasiliev Jan 2010

Current Status Of Lesser Sandhill Cranes In Yakutia, Inga Bysykatova, Sergey Sleptsov, Nikolay Vasiliev

Proceedings of the North American Crane Workshop

In Yakutia, the sandhill crane (Grus canadensis canadensis) was considered a common bird in 1957 on the Primorie tundra from the Kolyma River to the Alazeya River. In 1980 the area of the species’ supposed breeding grounds within the Kolyma- Indigirka interfluve comprised 34,600 km2. In 1984-85, the breeding grounds extended west to the Sundrun River, with the total area reaching 49,400 km2. At present, the westernmost sandhill crane range is on the tundra along the lower reaches of the Berelekh River. This region joins the higher density Siberian crane (G. leucogeranus) range, so that the …


Summary Of Sandhill Crane Sport Harvest In Canada 1975–2006, Adrianna C. Araya, Kammie L. Kruse, Keith D. Warner Jan 2010

Summary Of Sandhill Crane Sport Harvest In Canada 1975–2006, Adrianna C. Araya, Kammie L. Kruse, Keith D. Warner

Proceedings of the North American Crane Workshop

Knowledge of harvest in all areas where the mid-continent population (MCP) of sandhill cranes (Grus canadensis) occurs is critical to managing the population in a sustainable manner. The harvest of MCP in the U.S. has been well documented; however, the harvest in Canada has received less attention. The Canadian Wildlife Service initiated a National Harvest Survey program in 1967, but all sampling variables were not directly comparable until 1975. In this paper, we summarize crane harvest in Canada during the 1975-2006 hunting seasons for Saskatchewan and Manitoba, the 2 provinces with significant sport hunting harvest of sandhill cranes. …


Demoiselle Cranes On Agricultural Lands In The Ukraine, Yuriy Andryushchenko Jan 2010

Demoiselle Cranes On Agricultural Lands In The Ukraine, Yuriy Andryushchenko

Proceedings of the North American Crane Workshop

In Eurasia, the western range of the demoiselle crane (Anthropoides virgo) includes the southeast of Ukraine. Here the species nests, forms flying and pre-migrating concentrations, and participates in migration. The number of demoiselle cranes in April-June is about 600-700 individuals (200-250 nesting pairs), and toward the end of the year the population can reach 900-1000 individuals. Of cranes observed during 2000-2008 in the Crimea, 42.3% of pairs (n = 151) nested on agricultural fields: 21.5% on virgin land, 16.1% on cropland, and 3.4% on fallow lands. Principal characteristics of the demoiselle crane nesting locations were wavy relief, scarce herbage, …


Possible Competition Between Waterfowl And Sandhill Cranes At Hiwassee Wildlife Refuge, Tennessee, David A. Aborn Jan 2010

Possible Competition Between Waterfowl And Sandhill Cranes At Hiwassee Wildlife Refuge, Tennessee, David A. Aborn

Proceedings of the North American Crane Workshop

As a result of crop planting for waterfowl, numbers of eastern greater sandhill cranes (Grus canadensis tabida) staging and overwintering at the Hiwassee Wildlife Refuge in eastern Tennessee have sharply increased over the last 30-40 years. Peak numbers of wintering cranes have reached 14,000, and this large increase in crane numbers raises the possibility that they may be competing with waterfowl for food and space. I examined broad-scale changes in waterfowl numbers using Christmas Bird Count data, as well as small-scale changes using observations of waterfowl numbers and locations in relation to cranes on individual days. Preliminary results …


Behavior And Habitat Use Of Greater Sandhill Cranes Wintering In East Tennessee, David A. Aborn Jan 2010

Behavior And Habitat Use Of Greater Sandhill Cranes Wintering In East Tennessee, David A. Aborn

Proceedings of the North American Crane Workshop

An increase of eastern greater sandhill cranes (Grus canadensis tabida) stopping over and wintering at the Hiwassee Wildlife Refuge in east Tennessee has led to overcrowding at the refuge, resulting in crane use of private property. Proper management is needed to prevent the cranes from becoming a nuisance, increase the suitability of the refuge for waterfowl, and reduce the likelihood of a disease outbreak. Observations of cranes revealed that cranes spent 83% of their time foraging, alert, or preening. Sandhill cranes foraged primarily in agricultural and grassy fields, whereas mudflats and shallow water were used for preening and …


First Breeding Records And Historical Status Of Sandhill Cranes In New England, Scott M. Melvin Jan 2010

First Breeding Records And Historical Status Of Sandhill Cranes In New England, Scott M. Melvin

Proceedings of the North American Crane Workshop

Sandhill cranes (Grus canadensis) nested at 4 sites in south-central Maine between 2000 and 2008 and at single sites in western Massachusetts and west-central Vermont in 2007 and 2008, continuing their eastward range expansion. Of 13 nests observed, 5 were in a lacustrine marsh, 2 were in a riverine marsh, and 2 were in beaver-impounded palustrine marshes, all dominated by cattail (Typha spp.); 2 were in lacustrine fen habitat dominated by sedges (Carex spp.), sphagnum, and leatherleaf (Chamaedaphne calyculata); 1 was in a lacustrine fen dominated by slender sedge (Carex lasiocarpa …


Mechanisms Of Habitat Selection Of Reintroduced Whooping Cranes On Their Breeding Range, Kelly J. Maguire, Stanley A. Temple Jan 2010

Mechanisms Of Habitat Selection Of Reintroduced Whooping Cranes On Their Breeding Range, Kelly J. Maguire, Stanley A. Temple

Proceedings of the North American Crane Workshop

We examined several mechanisms that influenced the habitat selection of reintroduced whooping cranes (Grus americana) on their breeding range in the midwestern United States. Visual observations on 56 whooping cranes from 2001 to 2006 provided accurate locations, habitat descriptions, and bird associations. Location information on each bird was mapped to create home range and to describe the habitat. We found evidence that habitat selection in these cranes resulted from multiple mechanisms, including habitat imprinting, philopatry, site tenacity, intra-specific interactions, and environmental stochasticity. The initial home ranges of all cranes contained habitat similar to that in which they were …


Sandhill Crane Migration Chronology And Behavior In Northwestern Texas, Carroll D. Littlefield Jan 2010

Sandhill Crane Migration Chronology And Behavior In Northwestern Texas, Carroll D. Littlefield

Proceedings of the North American Crane Workshop

Migrant lesser sandhill cranes (Grus canadensis canadensis) were monitored during 1990-2000 in northwestern Texas as flocks were arriving in autumn and departing in spring; cranes were counted as they passed over an observation point 23 km north of Sudan, Lamb County, Texas. Mean flock size was 34.5 (SD ± 32.6) in autumn and 58.2 (SD ± 45.0) in spring. Most autumn migrants (69.6%) passed in the afternoon, whereas in spring 94% migrated in the morning (1000-1200 hr). Peak period of autumn passage was in October (65%), and in spring all observations were in February-March with the peak usually …


Population Status And Geographic Distribution Of Greater Sandhill Cranes In The Mid-Continent Population, Gary L. Krapu, David A. Brandt Jan 2010

Population Status And Geographic Distribution Of Greater Sandhill Cranes In The Mid-Continent Population, Gary L. Krapu, David A. Brandt

Proceedings of the North American Crane Workshop

Number and geographic distribution of greater sandhill cranes (Grus canadensis tabida) in the mid-continent population (MCP) of sandhill cranes were evaluated. G. c. tabida comprised 7 of 133 (5.3%) individuals of 3 subspecies which projects to 31,579 ± 11,661 (SE) individuals in an estimated spring MCP of 600,000 cranes. From a platform transmitting terminal (PTT)-marked sample representative of the geographic distribution of G. c. tabida, 10 of 13 (77%) settled during the breeding season in east-central Canada/Minnesota, including 4 in northwestern Minnesota, 4 in Manitoba (2 at sites near the Minnesota border), and 2 in Ontario. Three …


Migration Patterns And Movements Of Sandhill Cranes Wintering In Central And Southwestern Louisiana, Sammy L. King, Aaron R. Pierce, Kent R. Hersey, Nicholas Winstead Jan 2010

Migration Patterns And Movements Of Sandhill Cranes Wintering In Central And Southwestern Louisiana, Sammy L. King, Aaron R. Pierce, Kent R. Hersey, Nicholas Winstead

Proceedings of the North American Crane Workshop

In this study we trapped wintering sandhill cranes (Grus canadensis) in Louisiana and fitted them with satellite transmitters to determine their migration routes. Four of the 6 sandhill cranes with validated locations and a terminus point used the Central Flyway for spring migration; 2 of these 4 (the only 2 for which we have data) also used the Central Flyway for fall migration. Two of the 6 birds used the Mississippi Flyway for spring migration. The results of this study suggest that reintroduced whooping cranes (G. americana) that intermix and migrate with sandhill cranes that winter …


Countability Of Sandhill Cranes In Aerial Surveys, Douglas H. Johnson, John W. Solberg, Courtney L. Amundson Jan 2010

Countability Of Sandhill Cranes In Aerial Surveys, Douglas H. Johnson, John W. Solberg, Courtney L. Amundson

Proceedings of the North American Crane Workshop

Aerial surveys are used to monitor populations of many wildlife species, including sandhill cranes (Grus canadensis). In addition to the usual problems of detectability (involving both availability and perceptibility), aerial surveys of concentrated animals are subject to countability issues; from a rapidly moving aircraft, observers cannot count or accurately estimate the number of animals in a large group. Calibration is sometimes performed in an effort to adjust aerial counts for incomplete detectability and countability by calculating the ratio of animals actually in a group to the number in the group estimated from the aircraft. Here we explore alternative, …


Aerial Survey Techniques For Breeding Whooping Cranes, Brian W. Johns Jan 2010

Aerial Survey Techniques For Breeding Whooping Cranes, Brian W. Johns

Proceedings of the North American Crane Workshop

Since the discovery of nesting whooping cranes in Wood Buffalo National Park, the Canadian Wildlife Service has conducted aerial surveys to monitor the population. Aerial survey techniques have varied over the years; however, they have generally followed the techniques used by the author since 1991. The technique involves flying a combination of circular flights and transects over known nesting territories and similar looking marshes likely to contain breeding whooping cranes. These aerial surveys account for nearly 100% of the breeding whooping cranes each year.


Whooping Crane Migrational Habitat Use Of The Platte River, Nebraska, 2001–2006, Shay Howlin, Clayton Derby, Dale Strickland Jan 2010

Whooping Crane Migrational Habitat Use Of The Platte River, Nebraska, 2001–2006, Shay Howlin, Clayton Derby, Dale Strickland

Proceedings of the North American Crane Workshop

The Platte River Endangered Species Partnership monitored whooping crane (Grus americana) habitat use along the Platte River between Chapman and Lexington, Nebraska during 11 migration seasons from 2001 to 2006. Daily aerial surveys took place in the morning from 21 March to 29 April in the spring and from 9 October to 10 November in the fall. Decoy detection trials were conducted during each of the 11 survey seasons to calculate actual sample inclusion probabilities for crane groups detected during monitoring flights. The detectability model found significant differences in detectability among strata (upland or channel), contractor, and altitude …


Mississippi Sandhill Crane Conservation Update 2006–2008, Scott G. Hereford, Lauren E. Billodeaux Jan 2010

Mississippi Sandhill Crane Conservation Update 2006–2008, Scott G. Hereford, Lauren E. Billodeaux

Proceedings of the North American Crane Workshop

The Mississippi sandhill crane (MSC, Grus canadensis pulla) is an endangered non-migratory subspecies found in the wild only on and near the Mississippi Sandhill Crane National Wildlife Refuge (MSCNWR) in Jackson County in southeastern Mississippi (Gee and Hereford 1995). The MSC is adapted to the wet pine savannas and open pinelands of the Southeastern Outer Gulf Coastal Plain. By the 1970s, their numbers had decreased to 30-40 individuals including only 5-6 nesting pairs. The firemaintained savannas, once a dominant feature of the landscape, were converted to pine plantations and human development or had degraded to overgrown pine scrub. The …


Development Of The Whooping Crane Tracking Project Geographic Information System, Martha Tacha, Andy Bishop, Justin Brei Jan 2010

Development Of The Whooping Crane Tracking Project Geographic Information System, Martha Tacha, Andy Bishop, Justin Brei

Proceedings of the North American Crane Workshop

The highest losses in the Aransas-Wood Buffalo whooping crane population occur during migration. Conservation and recovery of the endangered whooping crane requires understanding of migration patterns to identify important stopover areas and potential sources of mortality or disturbance. We converted the Cooperative Whooping Crane Tracking Project database, containing more than 3 decades of data on whooping crane sightings, to a geographic information system (GIS) to allow coarse scale spatial analyses of whooping crane migration patterns in the United States portion of the Central Flyway. At this writing, the geodatabase contains point data for 1,981 confirmed whooping crane sightings through the …


A Retrospective Serological Survey For Infectious Bursal Disease Virus In Free-Ranging Sandhill Cranes In South-Central Wisconsin, Richard R. Sim, Barry K. Hartup Jan 2010

A Retrospective Serological Survey For Infectious Bursal Disease Virus In Free-Ranging Sandhill Cranes In South-Central Wisconsin, Richard R. Sim, Barry K. Hartup

Proceedings of the North American Crane Workshop

A retrospective serosurvey of resident sandhill cranes (Grus candensis pratensis) in Florida suggested Infectious Bursal Disease Virus (IBDV, family Birnaviridae) may have been enzootic there as early as 1992, with 13-63% seroprevalence among age classes and wide geographic distribution of seropositive cranes. The purpose of our study was to describe the prevalence of antibodies to IBDV serotype 2 in a local population of greater sandhill cranes (G. c. tabida) near Briggsville, Wisconsin, that overlapped with resident Florida birds in winter during the same time period. Blood samples were collected June through October between 1996 and 1999 …


Summary Of Sandhill Crane Hunting Seasons In Kansas 1993–2007, David E. Sharp, Helen M. Hands, James A. Dubovsky, John E. Cornely Jan 2010

Summary Of Sandhill Crane Hunting Seasons In Kansas 1993–2007, David E. Sharp, Helen M. Hands, James A. Dubovsky, John E. Cornely

Proceedings of the North American Crane Workshop

The mid-continent population of sandhill cranes (Grus canadensis) is the largest population of cranes in North America. Hunting seasons for sandhill cranes were closed in 1916 and gradually resumed in Mexico (1940), the United States (1961), and Canada (1964). As knowledge of the biology of cranes and experience with hunting seasons increased, areas in which hunting was permitted expanded, and by 1992 all but 2 states (Nebraska and Kansas) in the U.S. portion of the Central Flyway conducted sport hunting seasons for this population. In 1993 Kansas resumed hunting and initial seasons were limited to specified geographic areas of …


Proceedings Of The Eleventh North American Crane Workshop: Preface And Contents Jan 2010

Proceedings Of The Eleventh North American Crane Workshop: Preface And Contents

Proceedings of the North American Crane Workshop

The North American Crane Working Group (NACWG) is an organization of professional biologists, aviculturists, land managers, and other interested individuals dedicated to the conservation of cranes and their habitats in North America. Our group meets approximately every 3 years to exchange new information on research and conservation of sandhill and whooping cranes and occasionally reports from abroad. Our meeting in Wisconsin Dells, Wisconsin, 23-27 September 2008, was no exception. The workshop was ably organized by Tom Hoffman, the scientific program was well-constructed by Jane Austin, and George Archibald and Richard Urbanek helped to bring together a memorable field day in …


Wintering Sandhill Crane Distribution And Habitat Use Patterns At Bosque Del Apache National Wildlife Refuge, New Mexico, Tandi L. Perkins, Leigh H. Fredrickson Jan 2010

Wintering Sandhill Crane Distribution And Habitat Use Patterns At Bosque Del Apache National Wildlife Refuge, New Mexico, Tandi L. Perkins, Leigh H. Fredrickson

Proceedings of the North American Crane Workshop

The single most important factor regulating sandhill crane (Grus canadensis) populations is their ability to carry out annual life cycle events while responding to changing habitat availability and distribution across local, regional, and continental landscapes. Wetland and cropland resource availability and distribution across the landscape have become increasingly unpredictable. Recent changes in farming practices, urbanization, and prevailing drought conditions in New Mexico have transformed and reduced dynamic, heterogeneous landscapes into scattered fragments of the original setting. Concerns are increasing for the cumulative influence of these often irreversible actions in providing the type of resources needed by cranes at …


Promiscuous Mating In Feral Pigs (Sus Scrofa) From Texas, Usa, Johanna Delgado-Acevedo, Angeline Zamorano, Randy W. Deyoung, Tyler A. Campbell, David G. Hewitt, David B. Long Jan 2010

Promiscuous Mating In Feral Pigs (Sus Scrofa) From Texas, Usa, Johanna Delgado-Acevedo, Angeline Zamorano, Randy W. Deyoung, Tyler A. Campbell, David G. Hewitt, David B. Long

United States Department of Agriculture Wildlife Services: Staff Publications

Context. Feral pigs represent a significant threat to agriculture and ecosystems and are disease reservoirs for pathogens affecting humans, livestock and other wildlife. Information on the behavioural ecology of feral pigs might increase the efficiency and effectiveness of management strategies.

Aims. We assessed the frequency of promiscuous mating in relation to oestrous synchrony in feral pigs from southern Texas, USA, an agroecosystem with a widespread and well established population of feral pigs. An association between multiple paternity of single litters and synchrony of oestrous may indicate alternative mating strategies, such as mateguarding.

Methods. We collected gravid sows at …


Seasonal Variability In Ichthyoplankton Abundance And Assemblage Composition In The Northern Gulf Of Mexico Off Alabama, Frank J. Hernandez, Jr, Sean P. Powers, William M. Graham Jan 2010

Seasonal Variability In Ichthyoplankton Abundance And Assemblage Composition In The Northern Gulf Of Mexico Off Alabama, Frank J. Hernandez, Jr, Sean P. Powers, William M. Graham

University Faculty and Staff Publications

Multiyear ichthyoplankton surveys used to monitor larval fish seasonality, abundance, and assemblage structure can provide early indicators of regional ecosystem changes. Numerous ichthyoplankton surveys have been conducted in the northern Gulf of Mexico, but few have had high levels of temporal resolution and sample replication. In this study, ichthyoplankton samples were collected monthly (October 2004–October 2006) at a single station off the coast of Alabama as part of a long-term biological survey. Four seasonal periods were identified from observed and historic water temperatures, including a relatively long (June–October) “summer” period (water temperature >26°C). Fish egg abundance, total larval abundance, and …


The Ratio Of Gametophytes To Tetrasporophytes Of Intertidal Chondrus Crispus (Gigartinaceae) Across A Salinity Gradient, Michele Guidone, Sean Grace Jan 2010

The Ratio Of Gametophytes To Tetrasporophytes Of Intertidal Chondrus Crispus (Gigartinaceae) Across A Salinity Gradient, Michele Guidone, Sean Grace

Biology Faculty Publications

Population studies of the Gigartinaceae (Rhodophyta) have often observed that the ratio of gametophytes to tetrasporophytes varies with the location of the population or the time of sampling. For some species, patterns have emerged that correlate this ratio to one or a few particular environmental variables, such as elevation, wave exposure, or season. Identifying these distributional patterns is an important step towards understanding what (if any) ecological differences exist between the two free-living life history stages.

The purpose of this study was to measure the ratio of gametophytes to tetrasporophytes of intertidal populations of Chondrus crispus across a decreasing salinity …


Reproductive Behavior In Horseshoe Crabs: Does Density Matter?, Jennifer Mattei, Mark Beekey, Adam Rudman, Alyssa Woronik Jan 2010

Reproductive Behavior In Horseshoe Crabs: Does Density Matter?, Jennifer Mattei, Mark Beekey, Adam Rudman, Alyssa Woronik

Biology Faculty Publications

While the four species of horseshoe crabs share many common reproductive traits with respect to their reproductive systems, they do differ with respect to their mating behavior (monogamy vs. polygynandry). Past research has attributed these differences to a number of factors including: spawning densities, operational sex ratios (OSR’s), male condition (or age), environmental and/or genetic factors, or a combination thereof. Mating behaviors in the three Asian horseshoe crab species (Tachypleus gigas , T. tridentatus, and Carcinoscorpius rotundicauda ) with low spawning densities and 1:1 operational sex ratios are typically monogamous. In Limulus polyphemus , mating behavior is more …


Movement Patterns And Population Genetics Of The American Horseshoe Crab In Relation To Long Island Sound Conservation Strategies, Jo-Marie Kasinak, Kirk A. Bartholomew, Mark Beekey, Jennifer Mattei Jan 2010

Movement Patterns And Population Genetics Of The American Horseshoe Crab In Relation To Long Island Sound Conservation Strategies, Jo-Marie Kasinak, Kirk A. Bartholomew, Mark Beekey, Jennifer Mattei

Biology Faculty Publications

The Connecticut Department of Environmental Protection (CTDEP) established three no-harvest zones for the horseshoe crab (Limulus polyphemus) population as part of a conservation plan for the species. Data from a long-term mark/recapture study of horseshoe crabs in conjunction with a microsatellite-based genetic survey of the population were analyzed to determine if this plan was appropriate to conserve genetic diversity and broaden our knowledge of movement patterns of Limulus in Long Island Sound (LIS). To date, ~53,000 crabs have been tagged over a 10 year period through the Project Limulus program with an annual average recapture rate of 12 …


Predicting Leptodactylus (Amphibia, Anura, Leptodactylidae) Distributions: Broad-Ranging Versus Patchily Distributed Species Using A Presence-Only Environmental Niche Modeling Technique, Miguel Fernández, Daniel Cole, W. R. Heyer, Stephen Reichle, Rafael O. De Sá Aug 2009

Predicting Leptodactylus (Amphibia, Anura, Leptodactylidae) Distributions: Broad-Ranging Versus Patchily Distributed Species Using A Presence-Only Environmental Niche Modeling Technique, Miguel Fernández, Daniel Cole, W. R. Heyer, Stephen Reichle, Rafael O. De Sá

Biology Faculty Publications

Locality data available for many, if not most, species of Neotropical frogs are based on written descriptions of the collecting sites, not on GPS device determined coordinate data. The pre-GPS device data are imprecise relative to GPS data. Niche modeling is a powerful technique for predicting geographic distributions that provides the best results when the locality data are precise. The purpose of this study is to determine whether imprecise historical locality data are sufficient such that niche modeling techniques can yield realistic new insights to species-level distributions. Two sets of frogs of the genus Leptodactylus that have known different kinds …