The research on the social system of an island population of the yellow necked mouse, Apodemus flavicollis (Melchior, 1834), has been conducted since 1994 on the Crabapple Island (Mazuria, Northern Poland). The data have been collected during trap sessions every six weeks from April to October. Each trap session lasted seven days (traps were checked at 07:00 a.m. and 07:00 p.m.). CMR (catch, mark, release) was used as the basic method to obtain information about sex, maturity and weight of individual animals. Yellow necked mice are shy and secretive animals and their above-ground activity is mainly nocturnal. Contrary to the bank vole (Clethrionomys glareolus) the second species on this island, they have low trapability and sometimes some of animals were absent from one or more sessions and then reappeared. It is known that the yellow necked mouse can climb trees. This suggests that it has a three-dimensional home range. To know more about this difficult species we started using ultraviolet reflective powder in 1997 to mark selected animals with different colors. This method - called ‘powder tracking’ - seems to be good for following movements of small mammals but it has not been used for this species under natural conditions. The dusted animals left trails visible in UV light at night. They were flagged and mapped during daytime. We have collected detailed information about spatial patterns of animal activity in different habitats without disruption caused by live trapping. Using of the same space by different animals in different seasons seems to be especially interesting.

References

1. Borowski, S. (1963). Apodemus flavicollis (Melchior, 1834) in the tops of tall trees. Acta Theriol., 6, 314.
2. Jike, L.; Batzli, G.O.; Getz, L.L. (1988). Home ranges of prairie voles as determined by radio tracking and by powder tracking. J. Mamm., 69, 183-186.
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4. Mullican, T.R.; Streubel, D.P. (1989). Tracing small mammal movements with fluorescent pigments. The American Biology Teacher, 51, 497-499.