Demographic responses to population recovery illustrated by 30 years of monitoring a once critically endangered parrot
Abstract
Understanding how demographic rates change during population recovery is critical for evaluating conservation success and determining when populations become self‐sustaining. However, documenting such transitions requires long‐term monitoring across substantial changes in population size— conditions that are rarely met. We leverage a 29‐year capture‐mark‐recapture dataset from the echo parakeet population ( Alexandrinus eques ), a vulnerable endemic parrot of Mauritius island that recovered from fewer than 20 individuals to over 500 during the study period. Using multistate capture‐mark‐recapture models, we analysed encounter histories of 2734 known‐aged wild individuals to estimate age and state‐specific survival probabilities while accounting for temporal variation, transitions between breeding states and controlling for unequal recapture probabilities. Demographic rates changed substantially during population recovery. Recruitment into the breeding population declined across all age classes as the population approached carrying capacity. Survival showed contrasting patterns: juveniles (<2 years old) exhibited a declining temporal trend (from 0.68 in 1994 to 0.57 in 2020), whereas adult survival remained stable across years, with breeding adults showing consistently higher rates (0.96–0.97) than non‐breeding individuals (0.76–0.90). Synthesis and applications . These findings highlight the dynamic nature of demographic processes throughout population recovery and emphasise the value of continued monitoring beyond apparent recovery to detect density‐dependent shifts in demographic rates of wildlife populations.
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BibTeX
@article{gelle2026demographic,
title = {{Demographic responses to population recovery illustrated by 30 years of monitoring a once critically endangered parrot}},
author = {Adrien Gellé and Malcolm A.C. Nicoll and Esther Kettel and Angelo Pernetta and Helen Gath and Jim Groombridge and Sion Henshaw and Carl Jones and Kevin Ruhomaun and Vikash Tatayah and Ken Norris and Simon Tollington},
journal = {Journal of Applied Ecology},
year = {2026},
month = aug,
doi = {10.1111/1365-2664.70523},
url = {https://hal.science/hal-05764999v1},
note = {CC BY},
}
RIS
TY - JOUR
TI - Demographic responses to population recovery illustrated by 30 years of monitoring a once critically endangered parrot
AU - Adrien Gellé
AU - Malcolm A.C. Nicoll
AU - Esther Kettel
AU - Angelo Pernetta
AU - Helen Gath
AU - Jim Groombridge
AU - Sion Henshaw
AU - Carl Jones
AU - Kevin Ruhomaun
AU - Vikash Tatayah
AU - Ken Norris
AU - Simon Tollington
PY - 2026
DA - 2026/08/03
JO - Journal of Applied Ecology
DO - 10.1111/1365-2664.70523
UR - https://hal.science/hal-05764999v1
AB - Understanding how demographic rates change during population recovery is critical for evaluating conservation success and determining when populations become self‐sustaining. However, documenting such transitions requires long‐term monitoring across substantial changes in population size— conditions that are rarely met. We leverage a 29‐year capture‐mark‐recapture dataset from the echo parakeet population ( Alexandrinus eques ), a vulnerable endemic parrot of Mauritius island that recovered from fewer than 20 individuals to over 500 during the study period. Using multistate capture‐mark‐recapture models, we analysed encounter histories of 2734 known‐aged wild individuals to estimate age and state‐specific survival probabilities while accounting for temporal variation, transitions between breeding states and controlling for unequal recapture probabilities. Demographic rates changed substantially during population recovery. Recruitment into the breeding population declined across all age classes as the population approached carrying capacity. Survival showed contrasting patterns: juveniles (<2 years old) exhibited a declining temporal trend (from 0.68 in 1994 to 0.57 in 2020), whereas adult survival remained stable across years, with breeding adults showing consistently higher rates (0.96–0.97) than non‐breeding individuals (0.76–0.90). Synthesis and applications . These findings highlight the dynamic nature of demographic processes throughout population recovery and emphasise the value of continued monitoring beyond apparent recovery to detect density‐dependent shifts in demographic rates of wildlife populations.
SN - 0021-8901
SN - 1365-2664
ER -