Tag Archives: ecosystem

A bird’s eye view: hindsight and foresight from long term bird surveys

The Hermit Warbler is a songbird that lives its life in two areas of the world. It spends its breeding season (late May-early July) in the coniferous forests of the Pacific Northwest (PNW) and migrates to Central America for the winter. Due to the long journey from the Central America to the PNW, it is dependent on food resources being available throughout its journey and when it arrives to breed. The environmental conditions across its range are tightly linked to habitat resources, and unfavorable climatic conditions, such as those becoming less frequent due to climate change, can negatively affect bird populations. Changes in bird populations are not always easy to notice, especially with small songbirds that live high in tree canopies. Studying birds for one or a few years may not be enough to signal the change in their well-being.

A Hermit Warbler singing on a lichen-covered branch in the forest canopy. Male Hermit Warblers will defend their territories ferociously against other males during the breeding season. H.J. Andrews Experimental Forest, May 2017.

Fortunately, long term data sets are becoming more available thanks to long term study programs. For example, the Willamette National Forest in Oregon is home to H. J. Andrews Experimental Forest (the Andrews). Designated by the USDA Forest Service Pacific Northwest Research Station, the Andrews forest hosts many forest research projects and has been monitored since 1948. In 1980, it was became one of the National Science Foundation’s Long Term Ecological Research sites ensuring that it will remain a resource for scientists for years to come. Bird surveys at the Andrews began 11 years ago, and researchers at Oregon State University are beginning to draw connections between changing climate and bird communities in relation to the forest’s structure and compositions.

H.J. Andrews Experimental Forest, where long-term bird study is launched in 2009 by Drs. Matt Betts and Sarah Frey. The forest sits on the moist foothills of western Cascades in Willamette National Forest.

One of these researchers, Hankyu Kim PhD student in the Department of Forest Ecosystems and Society, is using this data to study the Hermit Warbler and other bird species at the Andrews. Hankyu is interested in how and why bird communities are changing over time. With 11 years of bird observations and extensive temperature data, he is attempting to estimate how population of birds persist in the forests. To begin approximating how current climate effects birds, we need to have an idea about bird communities in the past. Past conditions can help us explore how birds might respond to future climate scenarios. Without the effort of many researchers before him to monitor birds, his investigation would be impossible.

Bird surveys are conducted via point counts. Researchers stand at a point count station for 10 minutes and count all bird species they see and hear. Listen to a hermit warbler and some other background birdsongs recorded at H.J Andrews in June 2017.

Hankyu realized the importance of long-term data after reviewing the 45-years of wintering waterbird surveys collected by the Birdwatching Club at Seoul National University, Korea during his time as an undergrad. The group took annual trips to the major Rivers and Coastal Areas, and in just a couple decades the members of the club had recorded declines and disappearances of some species that were once common and widespread. This finding inspired Hankyu to pursue graduate school to study unnoticed or uncharismatic species that are in danger of decline. Every species plays a critical role in the ecosystem, even if that role has not yet been discovered.

Tune in on Sunday May, 19 at 7 pm to hear more about Hankyu Kim’s research with birds. Not a local listener? Stream the show live or catch up when the podcast episode is released.

Want more about the Hermit Warblers in Oregon? Check out this video of Oregon Field Guide featuring Hankyu and some of his colleagues from Oregon State University.

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.

Aquatic Invertebrates: Why You Should Give a Dam

Rivers are ecosystems that attract and maintain a diversity of organisms. Fish, birds, mammals, plants, and invertebrates live in and around rivers. Have you considered what services these groups of organisms provide to the river ecosystem? For example, river invertebrates provide numerous ecosystem services:

Dragonfly larvae caught in in the waters of a small stream flowing into the Grand Canyon.

  • Insects and mussels improve water quality by fixing nutrients, such as those from agricultural runoff.
  • River invertebrates are food resources for fish, bats, birds, and other terrestrial organisms.
  • Grazing insects can control and/or stimulate algal growth.
  • Mussels can help to stabilize the bed of the river.

High school students are the best helpers for sampling aquatic insects!

And the list continues. These invertebrates have adapted to the native conditions of their river ecosystem, and major disturbances, such as a change in the flow of a river from a dam, can change the community of organisms downstream. If dams decrease the diversity of invertebrates downstream, then they may also decrease the diversity of ecosystem services offered by the invertebrate community.

Our guest this week, Erin Abernethy PhD candidate from the department of Integrative Biology, is investigating the community structure (or the number of species and the number of individuals of each species) of freshwater aquatic invertebrates downstream of dams. Specifically, Erin wants to know if invertebrate communities near dams of the Colorado River are different than those downstream, and which factors of dams of the Southwest US affect invertebrate communities.

Getting to field sites in the Grand Canyon is easiest by raft! It’s a pretty float, too!

Erin’s dissertation also has a component of population genetics, which examines the connectivity of populations of mayflies,populations of caddisflies, and populations of water striders. The outcomes of Erin’s research could inform policy around dam operation and the maintenance of aquatic invertebrate communities near dams.

“One must dress for sampling success in the Grand Canyon!” said this week’s guest, Erin Abernethy, who is pictured here.

Growing up, Erin participated in many outdoor activities with her parents, who are biologists. She became interested in how dams effect ecology, specifically fresh water mussels, doing undergraduate research at Appalachian State University. After undergrad, Erin completed a Master’s in Ecology from University of Georgia. She was investigating the foraging behavior of animals in Hawaii. This involved depositing animal carcasses and monitoring foraging visitors. Check out Erin’s blog for photos of these animals foraging at night! Erin decided to keep going in academia after being awarded a Graduate Research Fellowship, which landed her a position in David Lytle’s lab here at Oregon State. After she completes her PhD, Erin is interested in working for an agency or a nonprofit as an expert in freshwater ecology and the maintenance of biodiversity in freshwater ecosystems.

 

Tune in at 7 pm this Sunday February, 25 to hear more about Erin’s research and journey to graduate school. Not a local listener? Stream the show live.