Paradigm Shifts in Habitat Ecology of Threatened Newfoundland Martens

Abstract

We evaluated multiscale habitat selection by threatened Newfoundland (Canada) martens (Martes americana atrata) across landscapes composed of a range of habitat types to test the hypothesis that martens preferred mature (61-80-yr-old) and overmature (.80 yr) conifer stands. At both the landscape and stand scales, adult ( L 1 yr) resident martens (n 5 58, 92 yr-specific home ranges) selected for, or used in proportion to availability, a broad range of habitat types, including recent cuts M 5 yr old, regenerating forest ,6.5 m, precommercially thinned stands, and mature and overmature forest. Marten home ranges were not dominated by mature and overmature forest; median availability of mature and overmature forest within individual home ranges was only 30% (range 5 11-76%). Age distributions were not different among martens with high, intermediate, and low quantity of mature and overmature forest in their home range; our data do not indicate that martens inhabiting ranges with little mature and overmature forest were compromising fitness. Habitat selection by martens in Newfoundland was more generalized than has traditionally been inferred, and we suggest that inherent landscape fragmentation, in combination with absence of many predators and competitors (i.e., ecological release), caused the Newfoundland marten to evolve to use a more generalized habitat niche than many mainland populations of American martens. We recommend that landscapes suitable for marten not exceed .29% younger aged forest. Maintaining resident martens in landscapes where forest harvesting is occurring requires prescriptions that recognize the highly fragmented nature of the natural landscape, the prevalence of mature and overmature forest, younger forests, avoided landcover types, and human access.

Can retention harvests help conserve wildlife? Evidence for vertebrates in the boreal forest

“…In Newfoundland, marten used a variety of habitat types, including recent clear‐cuts, mature forest, and regenerating stands (Hearn et al. ). Forest structural attributes may be a more important factor than successional stage in determining marten habitat (Chapin et al.…”

“…Marten use partially harvested stands in Quebec (Godbout and Ouellet 2008) and Maine (Soutiere 1979, Steventon and Major 1982, Fuller and Harrison 2005. In Newfoundland, marten used a variety of habitat types, including recent clear-cuts, mature forest, and regenerating stands (Hearn et al 2010). Forest structural attributes may be a more important factor than Fig.…”

Effects of natural resource development on the terrestrial biodiversity of Canadian boreal forests

“…In all studies where marten occupied managed boreal forest landscapes, patches of unharvested forest influenced home range location and movements by marten, except in Newfoundland (Hearn et al 2010), but the animals made use of regenerating forest stands (e.g., Thompson and Colgan 1987;Potvin et al 2000;Cheveau et al 2013). Managed landscapes with minimal old forests generally supported fewer marten than landscapes with a large proportion of old-forest patches (e.g., Thompson and Harestad 1994;Thompson 1994;Potvin et al 2000;Godbout and Ouellet 2008;Thompson et al 2008).…”

“…In Newfoundland, marten made use of all conifer forest types older than about 20 years and with heights greater than 3.5 m, probably as a result of predator release (Hearn et al 2010). Most often, however, in boreal forests, survival and fitness are lower in managed than in unmanaged forests (e.g., Thompson 1994;Andruskiw et al 2008;Johnson et al 2009).…”

“…Managed landscapes with minimal old forests generally supported fewer marten than landscapes with a large proportion of old-forest patches (e.g., Thompson and Harestad 1994;Thompson 1994;Potvin et al 2000;Godbout and Ouellet 2008;Thompson et al 2008). In Newfoundland, however, marten inhabited a landscape with less than 35% mature or older forests (Hearn et al 2010). Marten persistence in managed landscapes appears to be related to old-forest habitat remaining, prey abundance, sufficient structures, and predator release, although densities are generally highest in unmanaged forests (Thompson at al.…”