Streams and rivers are a rich repository of minute traces of genetic material from all organisms that live in or near the water, from the tiniest microbes to fish, mammals, and trees. This environmental DNA (eDNA) can tell a detailed story about the life within and around the waterbody.
Brooke Penaluna and Richard Cronn, scientists with USDA Forest Service Pacific Northwest Research Station, have spent the past several years studying the potential uses of eDNA as a tool for understanding what’s living in Pacific Northwest streams. Through eDNA analysis, they have identified more than 900 taxa living in Fall Creek in western Oregon. And they were able to identify distinctions within species, giving a more nuanced picture of what’s inhabiting Northwest waters. Penaluna also found that the distribution of coastal cutthroat trout in 60 streams in Oregon and Washington was more extensive than previously thought.
Their methods show promise as a survey tool for public and private natural resource managers who are tasked with protecting endangered fish and other species, as well as monitoring the introduction of aquatic invasive species. The current survey method, in use since the 1960s, is electrofishing, which is more labor-intensive, can only be done in wadable water, and is potentially hazardous to stream life.
More work needs to be done to make eDNA analysis an efficient and costeffective tool in the field, but the possibilities are nearly endless.
Ecological disturbance is a key agent shaping the spatial and temporal landscape of food availability. In forests of western North America, disturbance from fire can lead to resource pulses of deadwood-associated arthropods that provide important prey for woodpeckers. Although the foraging strategies among woodpecker species often demonstrate pronounced differences, little is known about the ways in which woodpeckers exploit and partition prey in disturbed areas. In this study, we employed DNA metabarcoding to characterize and compare the arthropod diets of 4 woodpecker species in Washington and California, USA—Black-backed Woodpecker (Picoides arcticus), Hairy Woodpecker (Dryobates villosus), Northern Flicker (Colaptes auratus), and White-headed Woodpecker (Dryobates albolarvatus)—primarily using nestling fecal samples from burned forests 1–13 years postfire. Successful sequencing from 78 samples revealed the presence of over 600 operational taxonomic units (OTUs) spanning 32 arthropod orders. The nestling diets of two species in particular—Northern Flicker and Black-backed Woodpecker—proved to be much broader than previous observational studies suggest. Northern Flicker nestlings demonstrated significantly higher diet diversity compared to other focal species, all of which displayed considerable overlap in diversity. Wood-boring beetles, which colonize dead and dying trees after fire, were particularly important diet items for Black-backed, Hairy, and White-headed woodpeckers. Diet composition differed among species, and diets showed limited differences between newer (≤5 yr) and older (>5 yr) postfire forests. Our results show mixed evidence for dietary resource partitioning, with three of the four focal species exhibiting relatively high diet overlap, perhaps due to the pulsed subsidy of deadwood-associated arthropods in burned forests. Woodpeckers are frequently used as management indicator species for forest health, and our study provides one of the first applications of DNA metabarcoding to build a more complete picture of woodpecker diets.
For over 35 years, the Starkey project has conducted policy-shaping research on deer and elk.
With its game-proof fence and controlled access, the Starkey Experimental Forest and Range is truly a one-of-a-kind research facility. Combined with automated traffic counters, tractable elk that helped break new ground in elk nutrition, decades of telemetry data, and animal handling facilities and you have a world-class resource and research program referred to as The Starkey Project. A broad spectrum of federal, state, private, Tribal and university partners have collaborated, leading to widespread acceptance and use of results to tackle national issues in resource management. But key to Starkey Project success is the 30-plus year collaboration and co-leadership between the USFS Pacific Northwest Research Station (PNW) and Oregon Department of Fish and Wildlife (ODFW). How has this partnership, and the Project, been so successful? From the get-go, both agencies worked together to develop the facility, its technologies, and research agenda, while leveraging funding and equipment. Both PNW and ODFW support a full-time Starkey Project Leader, with scant turnover through the years. Jack Ward Thomas, Starkey Project Leader for PNW in the 1980s and early 90s, was instrumental in getting the fencing and supporting technologies established, working closely with Donavin Leckenby, Project leader for ODFW. Project staff have always been co-located to ensure the work remains tightly integrated. This long collaboration has been one of the closest and most successful research partnerships that we know of between federal and state agencies. Research results have been widely adopted for managing forests and rangelands of western North America.
Increasing threats to amphibian and reptile species raise the urgency of their conservation. However, relative to other vertebrate groups at risk, amphibians and reptiles have low and more variable social capital; they are not generally high-priority natural goods and services valued by people. Consequently, relative to other groups such as birds, mammals, and economically important fish, they garner fewer conservation resources. With increasing risks, their situation degrades. We examine five societal sectors with herpetofaunal conservation interests in the United States (local communities, people in defined geographies and jurisdictions, species and threat specialists and advocates, associated researchers, managers, and policy makers) to understand challenges of low and variable social capital for herpetofauna. With current trends of US public values changing from traditionalist consumerism of wildlife to mutualist coexistence philosophies, a refocus of outreach and inreach efforts could help reframe priorities toward species at greatest risk, rather than broad taxonomic biases. Integrated teams of engaged natural resource managers, researchers, and the interested public can help promote species- and issue-based programs to forestall losses, hence programmatically raising social capital. Heightened recognition of the importance of human relationships and herpetofaunal diversity among researchers, managers, policy makers, educators, artists, authors, citizens, and children could provide inertia to reframe conservation program effectiveness at local-to-national scales.
We evaluated commonly used methods for monitoring stream restorations to inform and improve restoration monitoring and evaluation, using a headwater stream in the Oregon Coast Range as a case-study example. In-stream restoration projects are seldom monitored both pre- and post-restoration. In addition, frequently used low-cost methods may not provide sufficient data to effectively assess trends in stream temperature. Here, we examined what can be learned from temperature loggers installed in the same locations over multiple years in a restored stream. In-stream structures were installed between 2007 and 2011 along a 10-km length of South Sister Creek, Oregon for the purpose of enhancing in-stream habitat. Summer stream temperature data were collected using Hobo Pro-V temperature-logging thermistors at four locations in 2006, prior to restoration, as well as in 2012 and 2013. In 2013, additional temperature loggers were placed within 80 m of the four original loggers to investigate within-reach variability. Although median stream temperatures were highest in 2013 at all four multi-year sites, 7-day maximum temperatures were 4 to 5 °C cooler in post-treatment years than in 2006. Inter-annual variability in stream temperature was more closely linked to inter-annual variability in air temperature and solar radiation than presence of in-stream structures. Thermal heterogeneity was greater in reaches with deeper pools than in bedrock-dominated reaches. Although in-stream structures can create cool microhabitats, they have little influence on mean stream temperature. Longer pre-restoration monitoring and sensor deployment in more varied in-stream habitats would improve our ability to evaluate restoration impacts.
The plains spotted skunk (Spilogale interrupta) is of conservation concern because of widespread population declines and is being considered for listing under the United States Endangered Species Act. Although the taxon is relatively rare and difficult to study, recent research and reports provided some information about spotted skunks in Arkansas and Missouri, USA. Using this information, we employed full and simplified multivariate species distribution models to evaluate cover type associations and identify regions of high predicted presence for plains spotted skunks. The simple model contained percent forest and percent development within 5 km, land cover category, and distance to water. Percent forest within 5 km was the most important variable based on permutation importance in both models, indicating that plains spotted skunk habitat may persist in contiguous forest at the landscape scale. Regions predicted to have high presence occurred in northern, western, and southern Arkansas and southern Missouri, totaling >300,000 ha. The resulting plains spotted skunk distribution map can be used for research and management efforts in areas of high probability of occurrence, and future statewide survey efforts may validate our results.
We quantified the population dynamics and life history diversity of seven brood years of coho salmon (Oncorhynchus kisutch) using a life-cycle approach. Four life history patterns, composed of fry, fry–nomad, parr, and yearling migrants indicated the importance of connectivity and access to a full range of freshwater and estuarine rearing environments through the year. Survival of each life history type varied annually with the yearling migrants contributing an average of 70% to the spawners in all but one return year. Fifty-eight percent of the spawners of the 2013 return year had an estuarine rearing strategy, primarily parr migrants that overwintered in the estuary. Fry migrants, thought to be surplus production, were consistently observed in the estuary and represented in the returning spawners. The annual contribution of alternative rearing strategies to the spawners may support the resilience and viability of the population. We recommend that life cycle models of coho salmon account for the contribution of estuary migrants to the productivity and persistence of coho salmon in support of management and restoration of populations.