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Wednesday, 7 May 2014

Ecology and Evolution Volume 4 Issue 9 May 2014: Bird related papers

Cover image for Vol. 4 Issue 9

Ecology and Evolution

© 2014 John Wiley & Sons Ltd

Volume 4, Issue 9 Pages i - iii, 1505 - 1727, May 2014
The latest issue of Ecology and Evolution is available on Wiley Online Library

Issue Information

Issue Information (pages i–iii)
Article first published online: 5 MAY 2014 | DOI: 10.1002/ece3.803

Original Research
On estimation and identifiability issues of sex-linked inheritance with a case study of pigmentation in Swiss barn owl (Tyto alba) (pages 1555–1566)
Camilla T. Larsen, Anna M. Holand, Henrik Jensen, Ingelin Steinsland and Alexandre Roulin
Article first published online: 29 MAR 2014 | DOI: 10.1002/ece3.1032

A nestling Swiss barn owl (Tyto alba) displaying many large black spots. Photo Alexandre Roulin.

Genetic evaluation using animal models or pedigree-based models generally assume only autosomal inheritance. Bayesian animal models provide a flexible framework for genetic evaluation, and we show how the model readily can accommodate situations where the trait of interest is influenced by both autosomal and sex-linked inheritance. This allows for simultaneous calculation of autosomal and sex-chromosomal additive genetic effects. Inferences were performed using integrated nested Laplace approximations (INLA), a nonsampling-based Bayesian inference methodology. We provide a detailed description of how to calculate the inverse of the X- or Z-chromosomal additive genetic relationship matrix, needed for inference. The case study of eumelanic spot diameter in a Swiss barn owl (Tyto alba) population shows that this trait is substantially influenced by variation in genes on the Z-chromosome (inline image and inline image). Further, a simulation study for this study system shows that the animal model accounting for both autosomal and sex-chromosome-linked inheritance is identifiable, that is, the two effects can be distinguished, and provides accurate inference on the variance components.

Estimating migratory connectivity of birds when re-encounter probabilities are heterogeneous (pages 1659–1670)

Emily B. Cohen, Jeffrey A. Hostetler, J. Andrew Royle and Peter P. Marra
Article first published online: 8 APR 2014 | DOI: 10.1002/ece3.1059

Understanding the biology and conducting effective conservation of migratory species requires knowledge of migratory connectivity, the geographic linkages of populations between stages of the annual cycle. Unfortunately, we are lacking this information for most migratory species. We demonstrate the use of available large-scale banding and re-encounter data to estimate migratory connectivity for North American breeding birds in a multistate recapture and recovery model that accounts for re-encounter probabilities.

Understanding the biology and conducting effective conservation of migratory species requires an understanding of migratory connectivity – the geographic linkages of populations between stages of the annual cycle. Unfortunately, for most species, we are lacking such information. The North American Bird Banding Laboratory (BBL) houses an extensive database of marking, recaptures and recoveries, and such data could provide migratory connectivity information for many species. To date, however, few species have been analyzed for migratory connectivity largely because heterogeneous re-encounter probabilities make interpretation problematic. We accounted for regional variation in re-encounter probabilities by borrowing information across species and by using effort covariates on recapture and recovery probabilities in a multistate capture–recapture and recovery model. The effort covariates were derived from recaptures and recoveries of species within the same regions. We estimated the migratory connectivity for three tern species breeding in North America and over-wintering in the tropics, common (Sterna hirundo), roseate (Sterna dougallii), and Caspian terns (Hydroprogne caspia). For western breeding terns, model-derived estimates of migratory connectivity differed considerably from those derived directly from the proportions of re-encounters. Conversely, for eastern breeding terns, estimates were merely refined by the inclusion of re-encounter probabilities. In general, eastern breeding terns were strongly connected to eastern South America, and western breeding terns were strongly linked to the more western parts of the nonbreeding range under both models. Through simulation, we found this approach is likely useful for many species in the BBL database, although precision improved with higher re-encounter probabilities and stronger migratory connectivity. We describe an approach to deal with the inherent biases in BBL banding and re-encounter data to demonstrate that this large dataset is a valuable source of information about the migratory connectivity of the birds of North America.

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