Tag Archives: songbird

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. 

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.