Long-term genetic monitoring of a reintroduced Eurasian lynx population does not indicate an ongoing loss of genetic diversity

Where reintroduced wildlife populations are considered as vulnerable this is generally due to limited founder size and isolation. While many of these populations show low levels of genetic diversity, little is known about the temporal patterns of genetic diversity loss and the role of initial founder effects vs. ongoing genetic drift. Here we analysed genotype data from 582 Eurasian lynx samples from the reintroduced Bohemian-Bavarian-Austrian population (BBA) over a time span of 35 years, representing approximately 13 generations. Two-wave reintroduction of lynx from at least two distinct West-Carpathian areas resulted in relatively high start-up of genetic diversity. After the initial decline when the population lost about a quarter of its genetic diversity compared to the Carpathian source population, the genetic diversity and effective population size remained almost unchanged over the next 20 years. Despite confirmed isolation of BBA and thus absence of gene flow, we detected relatively low inbreeding during the two recent decades within the slightly increasing population size, which may have prevented ongoing loss of genetic diversity. Given the current status of BBA, we do not support genetic reinforcement to maintain its long-term viability; but urge the importance of facilitating gene flow with neighbouring lynx populations through an improvement of landscape connectivity and by strengthening law enforcement as well as the prevention of illegal killings. A sound genetic monitoring alongside regular camera trap-based monitoring of population size, health status and reproduction is pivotal to decide on future conservation interventions.