Lutra 52(1)_Kleef & Tydeman_2009

Natal den activity patterns of female pine martens (Martes martes) in the Netherlands

Maternal pine marten (Martes martes) den activity patterns at sixteen natal dens with kittens were studied in three separated forests in the north of the Netherlands from 1998–2007, using temperature recordings inside the den. All dens were old tree cavities of the black (Dryocopus martius) and the green woodpecker (Picus viridis). Temperature data indicated specific moments of arrival and departure of the female. Litter sizes varied from one to four kittens. Occupation of the dens ranged from 45 to 70 days and seemed to be affected by litter size. Attendance data were analysed on a daily basis and compared between two time intervals defined as pre-weaning and weaning periods. The proportion of time females spent at the den decreased (P0.0001) from the pre-weaning to the weaning period. The average time spent at dens varied from 9.1 to 13.8 hours whereas the average time spent away from dens varied from 5.3 to 6.1 hours. Attendance was affected by the age of the kittens and time of the day. Long away events did not start until the second week of kitten age. Den attendances appeared to be mainly diurnal and time spent at dens decreased as kittens grew older. Time spent away at dens (mostly nocturnal) increased due to an earlier departure while moments of arrival continued to be constant and were related to sunrise. Long away events were followed up by long home events and short away events by short home events. During the period of weaning the activity bouts, home as well as away, were no longer related to day or night.