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Full-Text Articles in Life Sciences
Juvenile Rank Acquisition Is Associated With Fitness Independent Of Adult Rank, Eli D. Strauss, Daizaburo Shizuka, Kay E. Holekamp
Juvenile Rank Acquisition Is Associated With Fitness Independent Of Adult Rank, Eli D. Strauss, Daizaburo Shizuka, Kay E. Holekamp
School of Biological Sciences: Faculty Publications
Social rank is a significant determinant of fitness in a variety of species. The importance of social rank suggests that the process by which juveniles come to establish their position in the social hierarchy is a critical component of development. Here, we use the highly predictable process of rank acquisition in spotted hyenas to study the consequences of variation in rank acquisition in early life. In spotted hyenas, rank is ‘inherited’ through a learning process called ‘maternal rank inheritance.’ This pattern is very consistent: approximately 80% of juveniles acquire the exact rank expected under the rules of maternal rank inheritance. …
Blood Sampling Reduces Annual Survival In Cliff Swallows (Petrochelidon Pyrrhonota) -- La Toma De Muestras De Sangre Reduce La Supervivencia Anual En Petrochelidon Pyrrhonota, Charles R. Brown, Mary Bomberger Brown
Blood Sampling Reduces Annual Survival In Cliff Swallows (Petrochelidon Pyrrhonota) -- La Toma De Muestras De Sangre Reduce La Supervivencia Anual En Petrochelidon Pyrrhonota, Charles R. Brown, Mary Bomberger Brown
School of Biological Sciences: Faculty Publications
Researchers commonly collect blood samples from wild birds, and most workers assume that blood sampling has no adverse effect on the birds’ survival. Few studies, however, have done controlled comparisons among bled and non-bled individuals and estimated survival using modern statistical methodology. We used a data set on Cliff Swallows (Petrochelidon pyrrhonota) that included 2,945 bled and 7,822 non-bled birds captured at the same times and sites in southwestern Nebraska from 1986 to 2006 to estimate annual survival and recapture probabilities of each group. Blood was collected with brachial venipuncture in amounts varying from 0.3% to 1.2% of …
Effects Of Endogenous Steroid Hormone Levels On Annual Survival In Cliff Swallows, Charles R. Brown, Mary Bomberger Brown, Samrrah A. Raouf, Linda C. Smith, John C. Wingfield
Effects Of Endogenous Steroid Hormone Levels On Annual Survival In Cliff Swallows, Charles R. Brown, Mary Bomberger Brown, Samrrah A. Raouf, Linda C. Smith, John C. Wingfield
School of Biological Sciences: Faculty Publications
The hormone corticosterone is an important part of animals’ response to environmental stress, modulating short-term adaptive changes in behavior and physiology. The hormone testosterone is also critical, especially for males, in regulating the expression of sexual behavior and parental care. These hormones can have costly consequences, however, and within populations individuals show variation in endogenous levels of both corticosterone and testosterone. We studied how annual survival varied as a function of natural levels of these hormones in colonially breeding Cliff swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, USA, in 2000–2003. We sampled hormone levels of birds caught at colonies …
Multistate Estimates Of Survival And Movement In Relation To Colony Size In The Sociable Weaver, Charles R. Brown, Rita Covas, Mark D. Anderson, Mary Bomberger Brown
Multistate Estimates Of Survival And Movement In Relation To Colony Size In The Sociable Weaver, Charles R. Brown, Rita Covas, Mark D. Anderson, Mary Bomberger Brown
School of Biological Sciences: Faculty Publications
We estimated survival and movement probabilities in relation to breeding-colony size in the sociable weaver (Philetairus socius) by using multistate statistical methods, in which survival and movement to time t + 1 is conditional on an individual’s colony size at time t. The sociable weaver is a colonial, cooperatively breeding species that builds a massive communal nest, with colony size ranging from fewer than 20 to more than 500 individuals in some areas. We conducted an 8-year capture/mark/re-capture study of sociable weavers near Kimberley, South Africa. By comparing the fit of different multistate models to our data, we found evidence …