A critical 1st step in understanding the basic ecology of any predator is to delineate their suite of prey species. In this paper we provide data on the diet of 2 threatened snake species in British Columbia, the Western Rattlesnake (Crotalus oreganus) and the Gophersnake (Pituophis catenifer). By dissecting the gastrointestinal tracts of roadkilled specimens, we identified a total of 11 different prey types. Unlike what has been previously reported elsewhere for the 2 species, we found a strikingly high degree of overlap between the diets, as shown through Morisita's similarity index (Ĉ = 0.98). The Deer Mouse (Peromyscus maniculatus) was the most frequently identified prey type for both species, followed by shrews (Sorex spp.). Other prey species consumed by Western Rattlesnakes were approximately even in abundance and in low numbers. Gophersnakes had a wider range of prey consumed at moderate frequencies, including voles (Microtus spp.) and birds. We also detected prey in a relatively high percentage of our specimens, likely due to our method of analyzing roadkills rather than sampling live, free-ranging animals. These prey data contribute a better understanding of the natural history and conservation issues facing these 2 threatened snake species, providing insight into how they coexist in a habitat increasingly destroyed and fragmented by human development.

Torrent Sculpin (Cottus rhotheus) can play an important role in riverine ecosystems in the Pacific Northwest, but factors that influence their feeding ecology are not well understood. To better understand how environmental conditions may influence the diet of Torrent Sculpin in the Cedar River, Washington, we collected diet information from fish across seasons and habitats. Numerically, aquatic insects were usually the dominant prey type for each size class in each sampling effort. Overall, Torrent Sculpin prey on a wide variety of aquatic invertebrates but can also take advantage of other prey types, such as fry of Sockeye Salmon (Oncorhynchus nerka), juvenile Chinook Salmon (O. tshawytscha), and eggs of Largescale Suckers (Catostomus macrocheilus), when these prey become abundant. In February and March, predation on Sockeye Salmon fry was substantially higher in large, deep pools (>2.5-m depth) than in either riffles or slow-water secondary habitats. Besides fry of Sockeye Salmon, the only salmonid observed in the diet of Torrent Sculpin was juvenile Chinook Salmon. Sculpin (Cottus spp.) were an important prey type of Torrent Sculpin ≥100 mm total length (TL) in each sampling effort. This was especially evident during the summer when sculpin represented over 90% of the diet by weight of Torrent Sculpin ≥100 mm TL. Feeding strategy plots demonstrated that Torrent Sculpin exhibit an opportunistic feeding strategy for large-bodied prey (for example, fish, oligochaetes, and large plecopterans) and a more generalized feeding strategy for small-bodied prey (chironomids and small-bodied ephemeropterans). Prey size, abundance, and activity are likely important factors influencing prey selection in Torrent Sculpin. Because of their size, abundance, wide range in habitat use, and breadth of diet, Torrent Sculpin are an important species in the Cedar River food web.

Warner Sucker (Catostomus warnerensis), endemic to the lakes and tributaries of the Warner basin, southeastern Oregon, USA, was listed as threatened by the US Fish and Wildlife Service in 1985 because of habitat fragmentation and threats from introduced nonnative fish. To determine progress towards recovery and document factors that may prevent recovery, we evaluated the distribution, abundance, and movements of this species between 2006 and 2013. The species exhibits 2 distinct life-history types, a lake morph and a stream morph. The abundance of suckers in the Warner Valley lakes has decreased since the mid-1990s, and the lake fish assemblages were dominated by nonnative predatory fishes. The basin experienced drought conditions from 2007 through 2010, and the lakes partially dried which affected both sucker distribution and movement. During the drought, when lake levels were low and receding, we found little evidence of sucker recruitment in the lake populations. In 2011, stream discharge was high and the lakes refilled, and in 2012 we documented successful sucker recruitment. Warner Suckers in the tributaries were widely distributed and relatively abundant, and the stream habitat was in good condition. We did not document substantial downstream movement of suckers during the spring and summer months and found little evidence of mixing between the stream and lake populations. We documented the upstream movement of large numbers of suckers in 2 tributary streams during the spawning season. We also described associations between sucker distribution and habitat characteristics in the tributaries. Our analysis indicated support for the threatened listing and suggests that recovery efforts would be most effective by focusing on improvements to both upstream and downstream passage at irrigation diversion dams and on irrigation efficiencies.

We solicited and collated citizen-science volunteer observations of North American River Otters (Lontra canadensis) over 15 y in Humboldt, Del Norte, and adjacent counties in northern California. The occurrence of River Otter reproduction is thought to be an indicator of watershed and wetland health. We described when and where observers reported sightings of pups and litters. Citizen volunteers reported 3540 River Otter observations, of which 371 included required information about number and size of smaller pups. From these records, 148 litters were identified in 39 waterbodies. Five to 17 litters per year were reported. Average litter size was 2.0 (SE 0.1; range 1 to 4 pups). Litter size did not vary significantly among years or waterbodies, including coastal and inland sites. The number and size of River Otter litters reported did not increase (or decline) over the study period.

Collecting long-term population trend data on indicator species contributes to our understanding of overall ecosystem health. The Pigeon Guillemot, a burrow-nesting piscivore, was identified as one of many indicators of health in Puget Sound, Washington. We observed the local guillemot population size, burrow occupancy, chick diet composition (identified as single fish carried in adult bills), and prey delivery rates to chicks on Whidbey Island, WA, between 2009 and 2014. Observations were conducted by trained volunteers from the Whidbey Audubon Society and the former Island County Beach Watchers (now Sound Water Stewards) who counted adults, verified burrow occupancy, and recorded prey delivery frequency and composition. Using the maximum counts across all Whidbey Island colonies, the index of abundance observed annually was an average of 991 individuals. A mean of 240 occupied burrows were observed each year. The peak rate of prey delivery occurred between the weeks of 12 July and 2 August, annually. Types of delivered prey consisted of 57.6% gunnel or prickleback (Pholidae or Stichaeidae), 25.6% sculpin (Cottidae), and 16.5% other or unknown prey. These data serve as a diet and reproductive baseline for assessing changes over time.

We conducted an inventory of Wolverines (Gulo gulo) in southwestern British Columbia in winter 2012, using a multi-method approach of non-invasive genetic tagging and camera trapping. We detected a minimum of 4 females and 2 males at 5 hair-snag stations within an area of approximately 225 km², which exceeded expectations based on predictions of low habitat quality and density from a broad-scale provincial model. Results were consistent with known adult intrasexual spacing patterns, suggesting that individuals were unlikely to represent members of a family group; however, overlap of territories could be a possible explanation of our results given the presence of potentially high-quality habitat features in our study area. Another possibility is that Wolverine density is higher in this part of the province than predicted by the model, potentially due to differences in food supply and key landscape features between this area and the areas where the model was developed. Further research is recommended to allow us to distinguish among competing hypotheses and fill data gaps on Wolverine ecology in this poorly studied coastal-transitional mountainous ecosystem.

Between-year breeding dispersal has not been previously documented in White-headed Woodpeckers (Picoides albolarvatus). Therefore, resightings of color-banded adults on previous years' breeding territories have been considered a means of estimating annual adult survival. From 2013 to 2015, I observed 2 cases of between-year breeding dispersal by adult color-banded White-headed Woodpeckers in central Washington. Mean dispersal distance was 6.9 km, and both adults were successful in fledging young in their new territories. Without extensive searches outside of previous years' territories, such dispersal events could have been classified as mortalities leading to annual survival estimates that were biased low.

The natural history of the American Robin (Turdus migratorius) is well described throughout its continental range. Its diet is described as consisting primarily of invertebrates and fruits. The few records of vertebrate prey species are considered unusual food items. Documentation of American Robins preying on amphibians is rarer still, and of those records only anurans have been documented west of the continental divide. On July 2015, an American Robin was observed predating a plethodonid salamander in the northwestern foothills of the Olympic Mountains of Washington State. Previous studies have posed that plethodonids are an unlikely food for thrushes despite their abundance because of the typically fossorial or moist habitat requirements of plethodonids, which restrict their foraging ability. We believe this is the 1st account of predation of a plethodonid salamander by the American Robin in western North America, and one of few across the entire range of this well studied bird. This observation will expand the understanding of the American Robin's varied diet and hopefully stimulate other reports of atypical prey items in the future.

A single incident of attempted predation of a Harbor Seal (Phoca vitulina) pup by an American Mink (Neovision vision) was observed on Blakely Island, Washington in 2015. San Juan County Marine Mammal Stranding Network members responded, investigated the event, and performed a necropsy on the seal. Predation is the most parsimonious explanation for the attack due to the American Mink's opportunistic predatory tendencies and the vulnerability of the moribund Harbor Seal. With both the American Mink and Harbor Seal populations documented as abundant or at carrying capacity, respectively, mink predation on vulnerable Harbor Seal pups could increase or influence Harbor Seal haul-out behavior.