The pine marten (Martes martes) population in a wooded coastal dune area in the Netherlands

Author: Leo Heemskerk

https://doi.org/10.63269/SJL5809

Abstract: This article presents the findings of a long-term study on the population structure, social organization and spatial behaviour of pine martens (Martes martes) in a forest area in the Noordhollands Duinreservaat, a coastal dune reserve in the Netherlands. A rich dataset of the pine martens inhabiting the area was generated by using camera traps to record the individually unique bib patterns of the martens. Based on the data collected, a database was compiled that allowed analysis of where, and when, the individuals were registered. A total of 9892 images of pine martens were recorded, and in 78% of these cases, the pine martens could be individually identified. In the four-year period between 2020 and 2023, a total of 64 individuals were recognized in the research area, which covered about 1500 ha. Many of these individuals were followed for long periods of time and each had its territory or at least a home range, with a high population density of pine martens of 2.2-2.8/km2. On average, two different pine martens occurred at each camera trap location. At one location, seven different individuals were seen. However, at two locations no pine martens were registered. Recording the date and time of the recordings provided insights into the martens’ activity patterns and allowed the creation of an extensive annual overview on a two-weekly and half-hourly basis. The individuals observed could be classified as kittens (first calendar year), territorial males, territorial females, and non-territorial (sub)adults. These non-territorial animals were females in their second or third calendar year and males in their second, third and one even in its fourth calendar year. By deploying camera traps, 32 subadult pine martens, which had a home range, but no territory, were monitored during these four years. Several were born in the research area, appeared on video for the first time with their mother and were followed in subsequent years. This provides insights into the social behaviour of pine martens in a family context. Usually, two female partners live in the territory of an adult male, together with several (sub)adult pine martens, each with their own home range within the boundaries of the territorial male. The number of (sub)adults in each adult male’s territory can vary from year to year. Social interactions were filmed, including growing young males playing with their mother’s new generation of kittens.