Dispersal in a gradient of habitats: Activity by juvenile North American red squirrels (Tamiasciurus hudsonicus) in varying-age forest stands

作者：Larsen Karl W^*

来源：Ecoscience, 2009, 16(1): 75-83.

DOI：10.2980/16-1-3157

• forestry
• habitat suitability
• natal dispersal
• red squirrel
• succession
• Tamiasciurus hudsonicus
• track counts

Understanding the subtleties of the dispersal process, such as how dispersers investigate or avoid different habitat types, is critical to gaining insight into colonization rates and other population processes that occur across landscapes. In central British Columbia, Canada, I examined red squirrel (Tamiasciurus hudsonicus) dispersal activity in second-growth pine (Pinus contorta) stands of varying ages. The main objective of the study was to determine whether i) the dispersing animals directed more attention towards relatively older seral forest stands that more closely approximated their natal habitat (mature forest stands) or ii) they did not discriminate against younger forest stands, at least during the exploratory foray phase of dispersal. To counter the difficulty in monitoring dispersers over a large number of sites placed across the landscape, track counts were used to index dispersal activity. Dispersal activity became noticeably greater in pine stands once they reached 14-18 y of age, whereas younger stands showed relatively little activity. Average tree height and cone production in the second-growth forests increased with age, so both of these characteristics along with others (such as conspecific sign) constitute attributes of the stands that the animals potentially were keying into. To elucidate the relative importance of these potential cues will require further study.

• 出版日期2009