Category Archives: animal and rangeland sciences

Putting years and years of established theory to the test

A lot of the concepts that scientists use to justify why things are the way they are, are devised solely based on theory. Some theoretical concepts have been established for so long that they are simply accepted without being scrutinized very often. The umbrella species concept is one such example as it is a theoretical approach to doing conservation and although in theory it is thought to be an effective strategy for conserving ecosystems, it is actually very rarely empirically tested. Enter Alan Harrington, who is going to test its validity empirically.

Alan is a 2nd year Master’s student in the Department of Animal and Rangeland Sciences working with Dr. Jonathan Dinkins. Alan’s research and fieldwork focuses on three species of sagebrush- steppe habitat (SBSH) obligate songbirds: the Brewer’s sparrow, sagebrush sparrow, and sage thrasher. Being a SBSH obligate means that these three birds require sagebrush to fulfill a stage of their life-history needs, namely during their breeding season. However, by studying these three species, Alan is aiming to tackle a broad conservation shortcut as he is trying to figure out whether the umbrella species conservation approach has worked in the SBSH where conservation is guided by the biology of the greater sage-grouse (GSG), which has been termed an umbrella species for sagebrush habitat for many years.

An umbrella species, a close cousin to keystone or an indicator species, is a plant or animal used to represent other species or aspects of the environment to achieve conservation objectives. The GSG is such a species for the SBSH. However, the SBSH is an expansive habitat found across 11 western US states and two Canadian province that covers several millions acres of land. Hence, the question of whether one species alone can be used to manage this large habitat is a valid one. Furthermore, SBSH has been declining dramatically over the last decades. In fact, it is one of the fastest declining habitats in North America. This decrease in available sagebrush habitat has led to the decline in GSG populations since European settlement and the GSG requires SBSH to fulfill its life-history needs. Thus, populations of other birds that require the SBSH have been declining too, like sagebrush-obligate songbirds.

Alan using binoculars to survey for songbirds to determine their abundances.

The state of Oregon, like many other western US states, are concerned about protecting SBSH and GSG because they are both quickly declining and songbirds are extremely sensitive to changes in the environment responding quickly to them. Within the last 10 years, the GSG was petitioned to be listed under the Endangered Species Act by several expert groups due to the severity of the decline. Both times, the petitions were designated warranted however were precluded from listing. This issue of declining SBSH and declining GSG populations is made more complicated by the fact that most SBSH also doubles as rangeland for grazing cattle or SBSH is often used for agriculture. Thus, the petitioning for trying to get the GSG listed as endangered caused stakeholders in Oregon to get involved in this situation since the listing of the GSG as endangered could result in very radical management changes for the SBSH, limiting agricultural and land use of this habitat.

Map of Alan’s study area.

As you can see, the topic is not a simple, straightforward one, however Alan is already two years into getting the data to answer some of his questions. Alan’s fieldwork takes place in eastern Oregon in a study area that is 1.4 million acres big. Naturally, he doesn’t survey every single foot of that massive area. Instead he and his lab mates (three of them work together during the field season to collect data for all of their projects) have 147 random point locations, which are located within five Priority Areas of Conservation (PAC), designated by the Oregon Department of Fish & Wildlife as core conservation areas based on high densities of breeding GSG. The field season is from May to July and Alan often puts in 80-hour work weeks to get the job done. For his data collection, Alan does random nest transect surveys at each of the 147 locations for the three sagebrush obligate songbird species, as well as collecting abundance data on any songbird he sees at each random point location. These two methods are also done for GSG UTM locations so that Alan can compare data between them and the songbirds. On top of this, Alan received a grant from the Oregon Wildlife Foundation to purchase iButton temperature loggers to deploy into songbird nests. Along with trail cameras, these will help Alan identify events indicative of nest success or nest failure.

Alan will start his first round of analyses this winter and he’s looking forward to digging into the data that he and his lab mates have worked hard to collect. Ultimately, Alan hopes that his research will make a difference, not just for the sagebrush steppe habitat, his three songbird species, or the greater sage-grouse, but also within other ecosystems. The umbrella species concept is used in all aspects of ecology and so hopefully his findings will be applicable beyond his field of study. 

To hear more about Alan’s research and also about his journey to OSU and more on his personal background, tune in on Sunday, November 24 at 7 PM on KBVR Corvallis 88.7 FM or stream live. 

If you can’t wait until then, follow Alan’s lab on Twitter!

Also, check out this recent publication that Alan played a big role in devising and writing while he was at the University of Montana in the Avian Science Center. The project tested auditory survey methodologies and how methodology can help reduce survey issues like misidentification and double counting of bird calls/signals. 

Core Strategies for Conservation of Greater Sage-Grouse

Greater sage-grouse (GRSG) is a North American bird species that nests exclusively in sagebrush habitat. In the last century, natural populations of this species have significantly declined largely due to human influenced habitat loss and fragmentation. This has prompted multiple petitions to the U.S. Fish and Wildlife Service (USFWS) to list GRSG under the Endangered Species Act (ESA), which would require mandatory restrictions on critical sagebrush habitat. This means that land managers of sagebrush areas would face land use restrictions for natural resource extraction and development, the bulk of the economy in Wyoming.

Wyoming Basin study site with associated GRSG Core Areas in blue. These Core Areas were designated as part of the GRSG Core Area Protection Act, Wyoming’s GRSG conservation policy aimed at protecting at least 67% of male GRSG attending leks. This policy is focused on directing development outside of these areas by setting strict conservation measures inside the Core Areas. Overall, the policy has remained effective in protecting at least 2/3 of GRSG habitat and has been identified as having the highest conservation value to maintaining sustainable GRSG populations.

 

Scent station and associated trail camera set-up in Natrona County, WY. Scent stations were randomly placed throughout the study site along roads and stratified between Core and Non-Core Areas. Mammalian predators are known to use roads for easy travel. These scent stations will help gather occupancy data of mammalian predators (Photo Credit: Eliana Moustakas).

Wyoming is a stronghold for GRSG, with the most birds, the most leks (male mating display grounds), and the largest contiguous sagebrush habitat in North America. Since GRSG declines have led to its possible endangered listing, Wyoming Governor Dave Freudenthal launched an effort in 2007 to develop stronger policies for GRSG that would protect the species and its habitat while also sustaining the state’s economy. A public forum followed, including representatives from state and federal agencies, non-governmental organizations, and industries, and in 2008 a conservation policy called the Greater Sage-Grouse Core Area Protection Strategy was developed to maintain and restore suitable habitat and active breeding GRSG pairs. The plan aims to protect at least 67% of male GRSG attending leks, and is focused on directing development outside of Core Areas by setting strict conservation measures inside Core Areas. By protecting sagebrush habitat and allowing development and mining in Non-Core Areas, Wyoming can continue to expand its natural resource economy and play a critical role in GRSG conservation.

In 2010, the USFWS concluded that GRSG were warranted protection but left them off the ESA list because threats were moderate and did not occur equally across their range. The status of GRSG was reevaluated in 2015 and the USFWS determined that GRSG did not warrant protection, claiming that the Core Area Strategy was sound framework for a policy by which to conserve GRSG in WY. However, recent monitoring of GRSG has shown that populations are still in decline in some Core Areas and in populations across their range. Our guest this week, Claire Revekant, a second year Master’s student in the Department of Animal and Rangeland Science, is trying to understand if avian and mammalian predator abundance differs between Core and Non-Core Areas.

Golden eagle using a utility pole to perch. Raptors and corvids are known to use  structures to perch and nest.

 

Working under Dr. Jonathan Dinkins, Claire estimates associations between human influence areas and habitat variables on the abundance of predatory birds and occupancy of mammalian predators. For example, raptors and corvids have been documented to perch and nest on fences and other human structures, and roads have been found to be used as travel paths for mammalian predators. Claire’s hypothesis is that predatory animals will be higher in Non-Core Areas where human-influenced environments serves as areas of food subsidies. Identifying areas of predator abundance and relating those areas to human features and habitat variables may help policy makers prioritize plans to mitigate human influence and protect sagebrush habitat.

Badger captured by trail camera at scent station in Lincoln County.

While her research is focused on predators of GRSG, Claire’s work for GRSG conservation contributes to the conservation of other sagebrush-obligate species (species that relay on sagebrush for all or some parts of their life cycle). By protecting the ecosystem for one “umbrella” species, other species may also benefit. Throughout her career as a wildlife biologist, Claire has been involved with numerous projects where she has handled and monitored several species. From learning to band raptors as a child to monitoring seabird productivity as an intern at the Monomoy National Wildlife Refuge, Claire has developed a passion for research. She told us that she can’t remember a time when she had a different dream job. Tune in tonight Sunday November, 11 at 7 to hear more about Claire’s research and her journey to graduate school on 88.7 FM KBVR Corvallis, or stream the show live.