Maintaining the recovery of the formerly federally endangered Kirtland’s warbler (Setophaga kirtlandii) requires continual creation of early-successional jack pine (Pinus banksiana) habitat every ...year, which, in turn, requires a steady supply of commercial timber sales. However, dedicated Kirtland’s warbler habitat plantations are established at high stem densities (ca. 3600 trees ha−1) which can delay the production of marketable timber compared to a conventional forestry planting density (ca. 1900 trees ha−1). We used a retrospective approach to assess the impacts of tree density on Kirtland’s warbler occupancy, and an experimental approach to understand benefits and costs of pre-commercial thinning of Kirtland’s warbler habitat plantations. We observed an unexpected negative relationship between realized plantation density and maximum occupancy by Kirtland’s warbler singing males. We found that thinning of high-density jack pine planted for Kirtland’s warbler habitat resulted in increased diameter growth, increased live crown ratio, and a trend towards increased intrinsic water-use efficiency in the older age classes. These findings provide strong support for the importance of using adaptive management approaches to more rigorously evaluate the impacts of plantation spacing on Kirtland’s warbler productivity. Although increases in volume growth and timber prices following thinning are unlikely to ever recoup the costs of implementation, we argue that thinning could still be an important tool to accelerate the rate at which these stands attain marketability for the timber sales that are necessary to create a continuous supply of Kirtland’s warbler breeding habitat.
•Kirtland’s warbler occupancy did not increase with increasing stem density.•Kirtland’s warbler occupancy was influenced by stand age and habitat connectivity.•Plantations that had aged out of breeding habitat showed no evidence of stagnation.•Financial returns are unlikely to ever recoup the costs of pre-commercial thinning.
Initial movements of re- introduced wildlife populations can determine short-term restoration success. Managers need ways to encourage release site fidelity to mitigate suboptimal breeding, reduce ...mortality rates, and minimize human-wildlife conflicts. We studied initial movement ecology of elk (Cervus elaphus) fitted with GPS collars and re- introduced to the Missouri Ozarks in 2011 (n = 32), 2012 (n = 21), and 2013 (n = 31) for 6 mo post release. We assessed maximum displacement from the release site, range shifts, and range size across four sequential time frames (0–10 d, 11–31 d, 32–61 d, and 62–183 d). Compared to other elk restorations in eastern North America, site fidelity was high, with maximum distance from the release site 62–183 d post release ≤10 km for 94% of 2011 animals, 57% of 2012 animals, and 97% of 2013 animals. Elk range sizes were similar during the first 61 d post release but doubled in size 62–183 d post release to an average of 26.2 km2 (range: 4.0–218.8 km2). The average range overlap for individual elk in sequential time periods was between 23–26% across years, indicating elk used different areas over time. Release site had the greatest influence on initial movements; one site used in 2012 was associated with greater release site displacement and range sizes. Maternal cows also demonstrated higher site fidelity to the release site than nonmaternal cows. High site fidelity and small home ranges in elk recently restored to Missouri may be attributed to soft release, minimal human disturbance, quality habitat, and release groups of mature females.
The timing of births in ungulates has significant implications for juvenile survival and population growth. For North American elk (Cervus elaphus), typical parturition season ranges from late May to ...early Jun., and juveniles born outside of this peak characteristically exhibit lowered survival. We observed abnormally long parturition seasons in free-ranging elk populations in Missouri and South Dakota during 2012. Both populations exhibited late births; the last known births occurred on 26 Sep. in Missouri and 4 Sep. in South Dakota. Duration of parturition season was 112 and 119 d in Missouri and South Dakota, respectively. In Missouri, late births likely resulted from breeding by both yearling females and males. Late parturition in South Dakota may be caused by extended estrous cycles of elk that occurred on high quality range where few adult males were located.
Amino diacid 3, a highly selective competitive GluR5 kainate receptor antagonist, exhibited high GluR5 receptor affinity and selectivity over other glutamate receptors. Its diethyl ester prodrug 4 ...was orally active in two models of migraine: the neurogenic dural plasma protein extravasation model and the nucleus caudalis c-fos expression model. These data suggest that a GluR5 kainate receptor antagonist might be an efficacious antimigraine therapy with a novel mechanism of action.
