Delayed dichromatism in waterfowl as a convenient tool for assessing vital ratesuse asterix (*) to get italics

Adrien Tableau, Iain Henderson, Sébastien Reeber, Matthieu Guillemain, Jean-François Maillard, Alain CaizerguesPlease use the format "First name initials family name" as in "Marie S. Curie, Niels H. D. Bohr, Albert Einstein, John R. R. Tolkien, Donna T. Strickland"

2024

<p>Monitoring the number of individuals is by far the most popular strategy for studying the environmental factors that determine population dynamics and for measuring the effectiveness of management actions aimed at population recovery, control or eradication. Unfortunately, population size monitoring is inefficient in identifying the mechanisms underlying demographic processes and, in particular, in assessing the extent to which population growth rate is influenced by changes in adult survival rather than variations in reproductive parameters. In many waterfowl species, sexual dichromatism is observed in adults, while immatures of both sexes display a plumage pattern similar to that of adult females. In these species, the apparent proportion of males increases as the female-like immature males gradually take on the plumage of adult males. The difference between the apparent sex ratio before and after the young reach sexual maturity then provides information about the age ratio of a population. Using winter counts that distinguished between female-like and male-like individuals of two non-native populations of Ruddy duck, a species that exhibits such a plumage pattern, we present a non-invasive method based on the apparent sex ratio to split population growth rate into adult survival and recruitment rates (the latter also referred to as productivity). This method can correctly detect annual changes in vital rates, supporting the assumption that counts conducted in an appropriate time window reflect the age structure of a population. We exemplify how the respective contributions of survival and productivity to the population growth rate are essential for understanding the processes behind demographic dynamics. Finally, we point out some best practices to correctly apply the "apparent sex ratio" method described here.</p>

https://doi.org/10.5281/zenodo.11471723You should fill this box only if you chose 'All or part of the results presented in this preprint are based on data'. URL must start with http:// or https://

https://doi.org/10.5281/zenodo.11471723You should fill this box only if you chose 'Scripts were used to obtain or analyze the results'. URL must start with http:// or https://

alien species - demography - fecundity - harvest - intrinsic growth rate - Oxyura jamaicensis - reproductive success

NonePlease indicate the methods that may require specialised expertise during the peer review process (use a comma to separate various required expertises).

Biological control, Conservation biology, Demography, Life history, Population ecology, Statistical ecology

Andy Green ajgreen@ebd.csic.es, Todd Arnold arnol065@umn.edu, Dave Koons David.Koons@colostate.edu, Gunnar Gunnarsson gunnar.gunnarsson@hkr.se, Pär Söderquist par.soderquist@hkr.se, David Koons suggested: Rob Wilson rwilson43@unl.edu

e.g. John Doe john@doe.com

No need for them to be recommenders of PCIEcology. Please do not suggest reviewers for whom there might be a conflict of interest. Reviewers are not allowed to review preprints written by close colleagues (with whom they have published in the last four years, with whom they have received joint funding in the last four years, or with whom they are currently writing a manuscript, or submitting a grant proposal), or by family members, friends, or anyone for whom bias might affect the nature of the review - see the code of conduct

2024-06-07 17:39:34

Huihuang Chen