No Allee effect detected during the natural recolonization by a large carnivore despite low growth rate ...

• Main Authors: Andren, Henrik, Hemmingmoore, Heather, Aronsson, Malin, Åkesson, Mikael, Persson, Jens
• Format: Dataset
• Language: English
• Published: Dryad 2022
• Subjects: FOS Biological sciences; Lynx; Lynx lynx lynx
• Online Access: https://dx.doi.org/10.5061/dryad.8kprr4xqb; https://datadryad.org/stash/dataset/doi:10.5061/dryad.8kprr4xqb

Eurasian lynx (Lynx lynx) have recently naturally recolonized southern Sweden. The first documented reproduction of lynx in recent times occurred in 2003, and the population increased from two to 48 family groups (the unit of measurement in Swedish monitoring) during its first 18 years (2003/04 – 2020/21). We did not detect any Allee effect, i.e., lower growth rate at low population density, during the recolonization of southern Sweden, although our population simulations revealed a non-negligible (30 %) chance that population observed development could include an Allee effect. The probable absence of an Allee effect was likely because colonizing females did not lack mating partners, as a larger number of wide-ranging males were established in the area before documented reproduction took place. Despite the absence of an Allee effect, the growth rate during recolonization was lower in southern Sweden (lambda = 1.20) than in central Sweden (lambda = 1.29). We have no evidence of higher mortality, including ... : We used data from the Swedish lynx monitoring system, available in the in the official carnivore database (Rovbase; rovbase30.miljodirektoratet.no). Lynx monitoring in Sweden is based on non-replicated counts of family groups. The monitoring is primarily conducted from December to the end of February and largely based on snow-tracking and identifying lynx tracks from two or more individuals, which are then assessed as a family group consisting of an adult female and young of the year. Simultaneous snow tracking or a distance criterion based on home-range sizes and movement patterns from radio-marked female lynx with kittens are used to separate observations of different family groups, to assure that counts of family groups are distinct. Additional observations that are used to confirm reproduction include camera-trap images of kittens, and any kittens shot in the early part of the hunting season (February) or killed in traffic accidents. Trained and authorized personnel from the Swedish County Administration ...