Sex-specific recruitment rates contribute to male-biased sex ratio in Adélie penguins

© 2024 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA..

Sex-related differences in vital rates that drive population change reflect the basic life history of a species. However, for visually monomorphic bird species, determining the effect of sex on demographics can be a challenge. In this study, we investigated the effect of sex on apparent survival, recruitment, and breeding propensity in the Adélie penguin (Pygoscelis adeliae), a monochromatic, slightly size dimorphic species with known age, known sex, and known breeding history data collected during 1996-2019 (n = 2127 birds) from three breeding colonies on Ross Island, Antarctica. Using a multistate capture-mark-recapture maximum-likelihood model, we estimated apparent survival (S^), recapture (resighting) probability (p^), and the probability of transitioning among breeding states and moving between colonies (ψ^; colony-specific non-juvenile pre-breeders, breeders, and non-breeders). Survival rate varied by breeding status and colony, but not sex, and pre-breeders had higher survival rates than breeders and non-breeders. Females had a higher probability of recruiting into the breeding population each year and may enter the breeding pool at younger ages. In contrast, both sexes had the same probability of breeding from year to year once they had recruited. Although we detected no direct sex effects on survival, the variation in recruitment probability and age-at-first reproduction, along with lower survival rates of breeders compared to pre-breeders, likely leads to shorter lifespans for females. This is supported by our findings of a male-biased mean adult sex ratio (ASR) of 1.4 males for every female (x^ proportion of males = 0.57, SD = 0.07) across all colonies and years in this metapopulation. Our study illustrates how important it can be to disentangle sex-related variation in population vital rates, particularly for species with complex life histories and demographic dynamics.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:14

Enthalten in:

Ecology and evolution - 14(2024), 2 vom: 15. Feb., Seite e10859

Sprache:

Englisch

Beteiligte Personen:

Morandini, Virginia [VerfasserIn]
Dugger, Katie M [VerfasserIn]
Schmidt, Annie E [VerfasserIn]
Varsani, Arvind [VerfasserIn]
Lescroël, Amélie [VerfasserIn]
Ballard, Grant [VerfasserIn]
Lyver, Phil O'B [VerfasserIn]
Barton, Kerry [VerfasserIn]
Ainley, David G [VerfasserIn]

Links:

Volltext

Themen:

Adélie penguin
Adult sex ratio (ASR)
Demographics
Journal Article
Recruitment
Seabird
Sex‐specific
Survival

Anmerkungen:

Date Revised 24.02.2024

published: Electronic-eCollection

Citation Status PubMed-not-MEDLINE

doi:

10.1002/ece3.10859

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM368748529