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We present updated distribution information for the Pacific White-sided Dolphin (Lagenorhynchus obliquidens, PWSD) in the southeastern Bering Sea, including Bristol Bay. The northern extent of this dolphin's range currently includes Bristol Bay and a 150-km swath north of the Aleutian Island chain, and presence in the Bering Sea has been described as rare. Our review of National Marine Fisheries Service marine mammal survey data (1991 to 2010) and sighting reports from sources such as the Platforms of Opportunity Program, whaling and fisheries catch records, and naturalist reports (1975 to 2016) found numerous sightings (n = 191) and year-round presence within the current range. We also found 18 sightings, 2 of which were bycatch in commercial fisheries, that occurred north of the existing range and in all seasons. Based on these results, we suggest PWSD presence in the Bering Sea is not rare, occurs year-round, extends farther north than shown on current range maps, and that site-fidelity may occur in areas near and within Bristol Bay.
On the basis of annual observations collected over 35 y, we chronicled the trends in abundance of Mule Deer (Odocoileus hemionus) and White-tailed Deer (Odocoileus virginianus) in semi-open montane habitat in the Devona district of Jasper National Park (JNP), Alberta, 1981–2016. During 722 d of observations conducted in winter over this period, we recorded a decline in Mule Deer and the incursion of White-tailed Deer into the park. Of a total of 429 deer sighted, White-tailed Deer increased from an average of 0.08 sightings/d to 0.73/d, whereas the native Mule Deer declined from 0.42 sightings/d to 0.01/d. Over the same time span, sightings of all deer increased from 0.51/d to 0.74/d. Although the ultimate cause of the opposing population trends of the 2 deer species is not certain, we review the proximate causes discussed in relevant literature, and we compare the results of our census to a list of deer killed by vehicle collisions on JNP roads and highways. As a measure of the presence of Gray Wolves (Canis lupus) in the study area, we recorded the largest size of wolf packs sighted each year and found no trend over time. The question of whether wolf predation on the 2 deer species could account for their opposing population trends remains to be investigated.
We sampled the water chemistry and otolith chemistry and structure of juvenile Cutthroat Trout collected in the Marys River and adults collected in the Willamette River to evaluate the potential to identify life-history variation in this population. Differences in water chemistry between the Marys and the Willamette Rivers during the sampling period were reflected in otolith chemistry. We differentiated 2 life-history patterns: juveniles whose mothers appeared to be resident in the Marys River, and juveniles that likely had fluvial mothers from the Willamette River. Otolith elemental composition of both juveniles and adults showed maternal effects on core chemistry, movement, or changes in elemental incorporation related to changes in ontogeny, growth, or seasonal changes in temperature. Water and otolith edge 87Sr/86Sr were consistently lower in the Willamette River than in the Marys River. Mean otolith 87Sr/86Sr during early life provided evidence that some adults reared in tributaries and migrated into the Willamette River later in life, whereas core 87Sr/86Sr for some juveniles shows that they likely originated from outside of the Marys River or are offspring of mothers that migrated into the Marys River to spawn. Based on otolith annuli, growth rates during early life were generally higher for adults than juveniles; these differences could reflect inter-annual, habitat, or life-history differences. Otolith 87Sr/86Sr and structural analyses hold promise for elucidating origin and life-history patterns of Willamette River cutthroat populations.
Estimating marten (Martes spp.) survival rates in managed forests is important for comparisons with vital rates in unmanaged forests, and data across populations in different forest types are needed in meta-analyses. We estimated survival rates of a Pacific Marten (Martes caurina) population from 1993 to 1998. This population experienced no fur trapping and occurred in an atypical habitat of sparse tree-canopy cover, small tree diameters, and many natural openings and logging clearcuts. In the beetle-damaged, salvage-logged Lodgepole Pine (Pinus contorta) forest, downed wood and snags were removed and slash piles were accumulated to mitigate logging effects. The average annual probability of adult (≥1 y) survival was 0.684, sx̄ = 0.104 (n = 53). The overall adult survival did not differ between years or between the sexes across years. Average annual survival of young (<1 y) was 0.753, sx̄ = 0.118 (n = 26). Seasonal survival of adults (0.945, sx̄ = 0.027) and young (0.974, sx̄ = 0.026) was highest in winter (December through February), and lowest in summer (June through August; adults = 0.853, sx̄ = 0.035; young = 0.902, sx̄ = 0.046). Adult winter survival was significantly greater than summer survival; and for adult females, winter survival was greater than in the other seasons (other seasons range = 0.862 to 0.903) and greater than male winter survival (0.918, sx̄ = 0.039), because there were no known female losses during the period (survival = 1.0). Based on evidence at field recovery sites and laboratory necropsies, predators were associated with 74% of all recovered marten carcasses, including Coyote (Canis latrans), Bobcat (Lynx rufus), American Badger (Taxidea taxus), and raptors of unknown species. Slash piles were used by marten, but the mitigation experiment was discontinued after logging. We suggest that slash piles may have helped sustain the local population of marten in the short term.
Northwestern Deermouse (Peromyscus keeni) is distributed on several islands of Haida Gwaii, British Columbia, but its absence from Langara Island has puzzled biologists who wondered whether the introduction of rats (Rattus spp.) contributed to its extirpation. An often-cited reference to naturalists' visits to Langara Island in the 1930s, before the introduction of rats, noted that deermice were common, but details of observations were lacking and specimens were not mentioned. Scrutiny of the literature and archived field notes, and inquiries with museum curators, yielded no evidence for the historic presence of deermice on Langara Island. Details pertaining to 1 specimen taken on Langara Island during rat-eradication activities, in 1994, plus 1 encounter with a live deermouse in a seabird burrow in 1966 provide the only records of the occurrence of Northwestern Deermouse on Langara Island.
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