Population Biology Commons^™

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

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

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

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

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

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

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

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

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

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

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

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

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 …

Leptodactylus Savagei, W. R. Heyer, Miriam M. Heyer, Rafael O. De Sá

Biology Faculty Publications

Adult Leptodactylus savagei are large, the head is as wide as long or usually wider than long, and the hind limbs are moderate in length (Table 1; Heyer and Thompson (2000) provided definitions of adult size and leg length categories for Leptodactylus). Male vocal sacs are not visible externally. Sexually active males have hypertrophied forearms, usually 1 large black spine on each thumb, rarely with 1 large spine and a prepollical bump, and a pair of black chest spines. A pair of entire dorsolateral folds extend anteriorly from at least one_half to full distance from eye to groin, the …

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

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

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 …