Grizzly Bears (Ursus arctos) are protected in the contiguous United States under the federal Endangered Species Act. The conservation strategy for the species encourages population connectivity between isolated Grizzly Bear Recovery Areas through Demographic Connectivity Areas. Another goal is reestablishment of a breeding population in the Bitterroot ecosystem through natural immigration. Using the locations of 362 verified Grizzly Bear den sites and Maxent as a resource selection function, we predicted 21,091 km² of suitable denning habitats. Terrain features, distance to roads, and land cover best explained suitable denning habitats in northern Idaho and western Montana. The results support the demographic model for population connectivity, and independent of other factors there is suitable denning habitat for hundreds of Grizzly Bears in the Bitterroot analysis area. We suggest additions to the Bitterroot Grizzly Bear Recovery Area, and that more effective motorized-access management be applied to demographic connectivity areas.

At northern latitudes, bats often use roosting structures provided by people. Conventional thinking suggests that bat boxes should be entirely black to absorb heat and assist bats with thermoregulation. However, with long periods of summer daylight in subarctic Canada, we suspected that risk of overheating might occur in black boxes. We investigated whether roost temperatures exceeded 42°C, the upper limit of the thermoneutral zone in Little Brown Myotis (Myotis lucifugus), and whether replacing the black roof with a white one, akin to a sun hat, would alleviate the risk of overheating without compromising roost temperatures especially at night. We also investigated whether bats used the boxes. The internal temperature of black boxes exceeded 42°C on some days in 2 summers. Substituting the black roof with a white one consistently reduced the maximum daily roost temperature to below 42°C, but this was also accompanied by a slightly lower minimum roost temperature at night and a cooler roost temperature regime overall. The reduction in maximum daily roost temperature by the white roof was more pronounced on days with higher maximum daily ambient temperatures. At 5 sites with paired white-roof and black-roof boxes, 4 had bat use of both boxes and 1 had no use of either box. Bats used 10 of 19 (53%) black-roof boxes in 2019, and 16 of 21 (77%) in 2020. Replacing a black roof with a white one can mitigate risk of overheating for boxes in subarctic latitudes, and likely through a range of temperate latitudes. However, completely black boxes are still necessary to enhance the thermal environment for roosting bats through most of the summer. We suggest that providing bats with roosting options, such as paired black-roof and white-roof boxes immediately adjacent to one another, is a better habitat enhancement option than just single black boxes.

Anecdotal and quantitative evidence of the Cougar's (Puma concolor) ability to swim across large bodies of water remains limited in the scientific literature. Here we report a 1.1-km swim by a dispersing male Cougar from the Olympic Peninsula to Squaxin Island in Puget Sound, Washington. We then predict the total number of islands in the Salish Sea that may be accessible to Cougars via swimming, using this Cougar's movement as a potential upper threshold distance, and present sightings records from islands in the Salish Sea to confirm or refute our results. We estimated that 3808 of 6153 islands in the Salish Sea could be accessible to Cougars with ≥1 or more 1.1-km swims, and we confirmed Cougar presence on 18 of those islands. Four islands with confirmed sightings required swims closer to 2 km. Increasing the threshold distance to 2 km yielded an additional 775 potentially accessible islands, including the 4 not captured by the 1.1-km threshold. Cougars are an umbrella species used to identify wildlife corridors across their range. We believe that improving our understanding of Cougar swimming abilities will aid us in determining the extent of habitat connectivity existing in the Pacific Northwest, where current habitat fragmentation characteristic of the Anthropocene may threaten Cougar metapopulation connectivity important to maintaining genetic health of the species.

We describe a mass mortality event at a school in Medford, Oregon in which the remains of over 5600 Vaux's Swifts (Chaetura vauxi) were found at the bottom of a chimney. The use of operating chimneys by migratory aggregations of this species poses the risk of significant mortality. We offer suggestions to reduce the risk of Vaux's Swift mortality caused by operating chimneys and illustrate how community involvement can contribute to mortality reduction.

The potential for trophic cascades triggered by recent range expansion of the Barred Owl (Strix varia) to the Pacific Northwest has caused concern among conservationists and managers. Barred Owl predation of small forest carnivores is a particular concern because these carnivores typically have low population growth rates relative to their body size owing to long interbirth intervals, which may result in sensitivity to increased mortality. The Western Spotted Skunk (Spilogale gracilis) is a common small carnivore in forests of the Pacific Northwest that may be a prey item for Barred Owls, and previous research suggests that avian predation can be a primary cause of mortality for congeneric spotted skunks (Spilogale spp.). We report a confirmed predation event of a Western Spotted Skunk by a Barred Owl and 3 additional predation events that we suspect were due to Barred Owls based on circumstantial evidence. During a Western Spotted Skunk research study, we recovered the radio collar of an adult male skunk from the top of a tall snag and located intestines and avian feces at the base of this snag. DNA metabarcoding revealed that the avian feces contained Western Spotted Skunk and Barred Owl DNA. Barred Owls are a novel predator of the Western Spotted Skunk in forests of the Pacific Northwest and may have both direct and indirect negative impacts on Western Spotted Skunk populations.

Bobcat predation on nesting Ospreys, here documented in California, is a rare occurrence. An increase in potential predator populations in recent decades may have contributed to the event described here.

This note documents changes in both substrate used for nest sites and distribution of nesting Ospreys in the San Francisco Bay area over the last 2 decades. Ospreys shifted from use of natural to artificial structures for nesting, as well as shifting nesting distribution from a fresh-water reservoir to the San Francisco Bay estuary. Changes in predator populations, prey, and availability of nest sites may be influencing these changes. The shift from use of natural to artificial structures for nest sites by Osprey mirrors a pattern observed in other western states.

Reported herein is the description of atypical head coloration on a male Evening Grosbeak (Coccothraustes vespertinus). This coloration is unique in that feathers on the posterior of the crown lack the typical dark melanin pigmentation, allowing the underlying vivid yellow (carotenoid) pigmentation that is usually revealed on the male's eyebrow stripe to also be revealed here. The non-melanic form of melano-carotenoid schizochroism is a likely explanation for this crown color variation. Given the importance of crowns and their coloration during mate selection among various avian species, their importance for Evening Grosbeaks is worth further investigation.

Reported herein is the demonstration of flock and pair bonds by members of a Wild Turkey (Meleagris gallopavo) rafter. This demonstration was observed following the fatal vehicle strike of one of the rafter's members.

In late May 2021, I spotted a Bighorn Sheep lamb (Ovis canadensis) stranded in a cliffside hollow in the Rock Creek drainage near Philipsburg, Montana. For nearly 3 months, a ewe returned to nurse the lamb. In early August, the lamb likely fell to its death.