Plard Floriane
Disentangling the spatial and temporal causes of decline in a bird population
Project Number: Parcs Data Center 43734 / 4D CH-7090
Project Type: |
Research_Project |
Project Duration: |
01/01/2020 - 09/12/2020 project completed |
Funding Source: |
other , |
Leading Institution: |
Vogelwarte Sempach |
Project Leader: |
Floriane Plard Swiss Ornithological Institute, Sempach 6204 Sempach
e-Mail: floriane.plard(at)ens-lyon.fr
|
Research Areas:
Disciplines:
Abstract:
The difficulties in understanding the underlying reasons of a population decline lie
in the typical short duration of field studies, the often too small size already reached
by a declining population or the multitude of environmental factors that may influence
population trend. In this difficult context, useful demographic tools such as
integrated population models (IPM) may help disentangling the main reasons for a
population decline. To understand why a hoopoe Upupa epops population has declined,
we followed a three step model analysis. We built an IPM structured with
respect to habitat quality (approximated by the expected availability of mole crickets,
the main prey in our population) and estimated the contributions of habitat-specific
demographic rates to population variation and decline. We quantified how much
each demographic rate has decreased and investigated whether habitat quality influenced
this decline. We tested how much weather conditions and research activities
contributed to the decrease in the different demographic rates. The decline of the
hoopoe population was mainly explained by a decrease in first-year apparent survival
and a reduced number of fledglings produced, particularly in habitats of high quality.
Since a majority of pairs bred in habitats of the highest quality, the decrease in the
production of locally recruited yearlings in high-quality habitat was the main driver of
the population decline despite a homogeneous drop of recruitment across habitats.
Overall, the explanatory variables we tested only accounted for 19% of the decrease
in the population growth rate. Among these variables, the effects of spring temperature
(49% of the explained variance) contributed more to population decline than
spring precipitation (36%) and research activities (maternal capture delay, 15%). This
study shows the power of IPMs for identifying the vital rates involved in population
declines and thus paves the way for targeted conservation and management actions.
Publications:
Plard F, Arlettaz R, Jacot A, Schaub M. Disentangling the spatial and temporal causes of decline in a
bird population. Ecol Evol. 2020;10:6906–6918. https://doi.org/10.1002/ece3.6244
PDF Publikation
Last update: 4/5/22
Source of data: ProClim- Research InfoSystem (1993-2024)
Update the data of project: CH-7090
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