Comparison of sites used by translocated and resident American martens (Martes americana) in northern Wisconsin

Tanya R. R Aldred, Purdue University

Abstract

The American marten (Martes americana), also known as Waabizheshi (Ojibwe), is an ecologically and culturally significant carnivore species in the Great Lakes region of the United States. Despite past reintroduction and restocking efforts, their population has not increased significantly and it remains a tribal and state-listed endangered species in Wisconsin. I studied the habitat of sites used by translocated and established resident martens in northern Wisconsin. The purpose of this research was to determine if there were differences in microhabitat characteristics between translocated and resident martens at resting and foraging sites. I compared microhabitat characteristics at sites where martens rested and hunted small mammal prey in northern Wisconsin during the winters of 2009 and 2010. I also compared small mammal prey biomass at foraging sites between translocated and resident martens. Martens were backtracked and locations where they rested and captured prey were recorded. Potential hunting sites were located >300 m from the kill site, within the same isopleth of an individual's home range and in the same cover-type. No significant differences were detected between the microhabitat characteristics at 54 rest sites of translocated (21 rest sites) and resident martens (33 rest sites). However, comparison of microhabitat characteristics at 18 kill and 18 potential hunting sites (9 translocated: 9 residents) revealed that total log volume was higher at resident kill sites (30 m3/ha) compared to translocated (14 m3/ha) kill sites. At potential hunting sites I found total log density was higher at resident (369 logs/ha) sites compared to translocated (169 logs/ha) sites. For translocated martens snag density was higher at kill sites (111 snags/ha) compared to potential hunting sites (30 snags/ha) of translocated martens. For resident martens, average log length was greater at the broad and local spatial scale of kill sites (451:425 cm respectively) compared to potential hunting sites (392:335 cm respectively). Finally, average log height was higher at kill sites (21cm) compared to potential hunting sites (13cm) of resident martens. For the comparison of small mammal prey biomass at kill and potential hunting locations, average weights and minimum number known alive of all small mammal species were calculated over the two year study at 13 kill sites and 13 paired potential hunting sites (6 translocated: 7 residents). For translocated martens prey biomass was similar at kill sites (4.17 g/trap night) compared to potential hunting sites (5.37 g/trap night), and resident marten prey biomass was similar at both kill (4.93 g/trap night) and potential hunting sites (5.97 g/trap night) indicating that translocated and residents hunt and kill prey in areas of similar prey biomass. Paired t-tests indicate there were no significant differences in total prey biomass between kill sites and potential hunting sites of translocated or resident martens. Welch 2-sample t-test results display no significant differences in prey biomass between kill or potential hunting sites for translocate and resident martens. Similarly, results of t-tests comparing individual small mammal prey biomass species were not significant. Results suggest that translocated martens are resting in areas with similar microhabitat characteristics and structural complexity to those found by resident martens. Analysis of kill and potential hunting site suggests that resident martens may be more experienced and familiar with finding higher quality foraging habitat than translocated martens in northern Wisconsin. However, overall results demonstrate that structural characteristics of coarse woody debris are an important element of habitat used by martens which is consistent with literature and that habitat quality is an important factor for successful translocation. Small mammal prey biomass comparisons suggest that translocated and resident martens are killing prey in areas of similar prey densities. This is likely because martens are generalized predators and when they are translocated to new habitat they are still able to capture and hunt for small mammal prey as effectively as resident martens.

Degree

M.S.

Advisors

Zollner, Purdue University.

Subject Area

Wildlife Conservation|Wildlife Management

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