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Full-Text Articles in Life Sciences

Drivers Of Annual Fledging In The Mississippi Sandhill Crane Population 1991-2018, Henry W. Woolley, Scott G. Hereford, Jerome J. Howard, Jan 2022

Drivers Of Annual Fledging In The Mississippi Sandhill Crane Population 1991-2018, Henry W. Woolley, Scott G. Hereford, Jerome J. Howard,

Proceedings of the North American Crane Workshop

We studied trends in nesting, number of chicks fledged annually, and their environmental and biotic drivers in the wild population of Mississippi sandhill cranes (Grus canadensis pulla) on Mississippi Sandhill Crane National Wildlife Refuge during 1991-2018. Population size, number of nests, and number of chicks fledged annually increased slowly but significantly over the course of the study. Increases in population size were related to both number of wild-reared chicks fledged annually and number of captive-reared chicks released each year, but wild-reared chicks had significantly higher survivorship than captive-reared chicks. Hurricanes transiently raised mortality rates but only Hurricane Katrina …


Mississippi Sandhill Crane Conservation Update 2017-2019, Scott G. Hereford, Angela J. Dedrickson Jan 2022

Mississippi Sandhill Crane Conservation Update 2017-2019, Scott G. Hereford, Angela J. Dedrickson

Proceedings of the North American Crane Workshop

To manage crane habitat on the Mississippi Sandhill Crane National Wildlife Refuge during 2017-2019, 5,822 ha were treated with prescribed burns, 648 ha of woody vegetation were removed, 97 ha of invasive plants were chemically treated, and 1.2 ha of crops were planted. Mississippi sandhill crane (Grus canadensis pulla) use responded to habitat treatment; 348 of 349 VHF radio locations were in treated areas. There were 316 target predators removed. Eighteen captive-reared juveniles were acclimated and released. We detected an average of 38 nests per year, including a record 40 nests in 2019. Fifteen chicks fledged in 2019, …


Global Warming And Population Responses Among Great Plains Birds, Paul A. Johnsgard Feb 2015

Global Warming And Population Responses Among Great Plains Birds, Paul A. Johnsgard

Zea E-Books Collection

Based on an analysis of 47 years (1967–2014) of Audubon Christmas Bird Counts (CBC), evidence for population changes and shifts in early winter (late December) ranges of nearly 150 species of birds in the Great Plains states is summarized, a region defined as including the Dakotas, Nebraska, Kansas, Oklahoma, and the Texas panhandle. The rationale for this study had its origins in Terry Root’s 1988 Atlas of North American Wintering Birds. Root’s landmark study provided a baseline for evaluating the nationwide winter distributions of 253 North American birds in the mid-20th century, using data from the National Audubon Society’s …


Nesting Populations Of Double-Crested Cormorants In The United States And Canada, Laura A. Tyson, Jerrold L. Belant, Francesca J. Cuthbert, D.V. (Chip) Weseloh Dec 1997

Nesting Populations Of Double-Crested Cormorants In The United States And Canada, Laura A. Tyson, Jerrold L. Belant, Francesca J. Cuthbert, D.V. (Chip) Weseloh

Symposium on Double-Crested Cormorants: Population Status and Management Issues in the Midwest

Double-crested cormorants (Phalacrocorax auritus) are receiving increasing attention in North America because of depredations at aquaculture facilities and alleged impacts on sport and commercial fisheries. We obtained recent (most since 1994) estimates for the number of nesting double-crested cormorants in the United States and Canada from published references and by conducting telephone interviews with State and Provincial biologists. Using published data, we also determined annual rates of change in the number of cormorants since about 1990. The estimated minimum number of nesting pairs (colonies) of double-crested cormorants was 372,000 (852). Most cormorants nested in the Interior region (68 …


Changes In The Status, Distribution, And Management Of Double-Crested Cormorants In Wisconsin, Summer W. Matteson, Paul W. Rasmussen, Kenneth L. Stromborg, Thomas I. Meier, Julie Van Stappen, Eric C. Nelson Dec 1997

Changes In The Status, Distribution, And Management Of Double-Crested Cormorants In Wisconsin, Summer W. Matteson, Paul W. Rasmussen, Kenneth L. Stromborg, Thomas I. Meier, Julie Van Stappen, Eric C. Nelson

Symposium on Double-Crested Cormorants: Population Status and Management Issues in the Midwest

We reviewed and summarized historical data and conducted population surveys from 1973 through 1997 to determine the breeding status and distribution of doublecrested cormorants (Phalacrocorax auritus) in Wisconsin. Breeding cormorants historically occupied large, isolated lakes and wetlands in northern Wisconsin, but there were no known nesting sites until 1919, when cormorants were reported nesting on Lake Wisconsin in south-central Wisconsin. From the 1920’s to the 1950’s, cormorants occupied 17 colony sites in 16 counties, though no more than 7 sites were occupied during any particular year. From the 1950’s to the early 1970’s, the number of cormorant nests …