European wildcat reproduction varied less with measured environment than expected—except in timing
WHAT THE EVIDENCE SAYS
An international dataset combined multiple survey methods across Europe. Confirmed wildcat litters ranged from one to six kittens, with an observed mean of 2.09, and litter-size estimates differed strongly among survey methods. No measured environmental or anthropogenic variable had a significant effect on litter size. Births occurred from March to October, with late-April and August peaks; higher-elevation records were later and more synchronized.
WHY IT MATTERS / OUR READ
The study is a reminder that monitoring method can dominate a demographic estimate. For population models, litter size and birth timing should carry method-specific uncertainty rather than being treated as fixed species constants.
CAVEATS / UNCERTAINTY
Survey methods were heterogeneous and produced different litter-size estimates. High-elevation samples were small and geographically concentrated in north-western Spain, so elevation and latitude could not be disentangled. Reproductive rate was estimated from only 14 females in one German forest area.
SOURCE
Mammalian Biology — primary study
View original evidence ↗
A continental dataset found no significant measured environmental effects on litter size, while births occurred later and were more synchronized at higher elevations in the available data.
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