Golden Eagle Research Update

GBBO’s Golden Eagle investigations are continuing this year with another successful monitoring season of nest sites in Nevada completed. We are partnering with the Nevada Department of Wildlife, who has tagged several Golden Eagles with satellite transmitters to study their habitat use and home ranges in the Great Basin and Mojave Desert, as well as with UNR graduate student Zachary Ormsby, who is interested in how Golden Eagles fare in the urban-rural transition. As part of our expanded research of Golden Eagles, we are installing nest cams to determine what prey items the parents bring to their nests to feed their young. And in an exciting cross-over with another GBBO project, we have also started to use our Nevada Bird Count crews to collect monitoring data on black-tailed jackrabbits, which is one of the most important prey items of Golden Eagles. During prolonged droughts such as the current one, it is particularly important to know what prey items are used by eagles in order to optimize land management toward these prey species, which ultimately ensures survivorship in the long-lived Golden Eagle.

 

On Golden Eagles

GBBO is continuing to work with the Nevada Department of Wildlife and the U.S. Fish and Wildlife Service (FWS) to better understand the habitat requirements of Golden Eagles, and to generate guidance on how to best avoid and mitigate the potential impacts of renewable energy development.  

In 2015, GBBO will be collecting data to support a major habitat-quality modeling project overseen by FWS.  More specifically, we will be comparing the results of different nest survey types to generate “calibration factors” that will enable data from many different field projects to be more consistently and effectively integrated and analyzed. Additionally, we will be collecting data on nest distribution in previously unsurveyed parts of the state to validate predictions generated by the FWS model.  

In the near future, this work should allow land management agencies to make more informed decisions about the parts of the Nevada landscape that are especially important to Golden Eagles.

- John

Back in the Field!

Truckee River

Across the nation, bird biologists are gearing up for the upcoming field season, and GBBO is no exception.  Here’s a run-down of the field work that we’re starting up over the next couple of months.

We’ve mentioned before our efforts to monitor the populations of fish-eating waterbirds on Walker Lake and other terminal lakes in western Nevada, and this work is continuing. The ongoing drop in the water level in Walker Lake has led to increasing concentrations of dissolved solids, decimating the lake’s fish populations and the birds that depend on them. If ongoing efforts to secure more water for Walker Lake are successful, we hope we’ll be able to document waterbird recovery in the future.

Pine Nut Range

Also on the docket is our statewide Golden Eagle inventory project, in collaboration with the Nevada Department of Wildlife, where we’re working together to better understand how eagles are distributed statewide, so we can provide the Bureau of Land Management and other agencies with the information they need to protect Golden Eagles in the face of energy development pressure and other possible conservation challenges. 

Starting up is a new Elf Owl study in the Mojave and Sonoran Desert regions of California and Arizona. This will be our second Elf Owl project for the Lower Colorado River Multi-Species Conservation Program (LCR-MSCP).  The Elf Owl is a conservation priority species for this program, and our project is designed to better understand the habitat needs and preferences of this tiny owl, so that restoration activities along the LCR can be designed to provide maximum benefit. 

Elf Owl, copyright & courtesy of John Stanek

We are continuing to use the expertise and skills developed in designing and implementing bird surveys and monitoring projects to benefit management programs for stray dogs and cats in the US, and around the world.  Free-roaming cats and dogs can have negative impacts on wildlife and public health, and they also suffer from frequent abuse and neglect. Previous efforts to manage stray animal populations have often been ineffective because of insufficient monitoring, lack of analytical rigor, and a poor understanding of animal population dynamics. By providing consultation services to organizations that are seeking to better manage stray animal populations, GBBO is helping to rectify these oversights and ensure that stray animal management programs are effective.

The Lower Colorado River program continues this year – and, in fact, trail clearing starts up next week! Since 2008, we've been conducting area searches within riparian corridors in the river's historic flood plain as part of the LCR-MSCP.  We're surveying sites where riparian habitat has been restored, as well as those on federal, tribal, state, and private lands to obtain population size estimates, trends, and distributions for six LCR-MSCP species of concern (Gila Woodpecker, Summer Tanager, Arizona Bell’s Vireo, Sonoran Yellow Warbler, Gilded Flicker, and Vermilion Flycatcher) as well as many other riparian birds. Along with this population monitoring, we're also developing detailed habitat assessments for the first four of the above species.  More details can be found in our annual reports at http://www.lcrmscp.gov/steer_committee/technical_reports.html. 

In 2013, we began a new component of the project: monitoring potential impacts of saltcedar beetles on riparian birds of the LCR.  Here, in the center of the invasion by the saltcedar beetle, we are able to study the effects of defoliation as the impact unfolds. Impacts of defoliation may be sudden or they may occur over an extended period of time.  For example, sudden effects might result from nests being exposed to the sun (and thereby to higher temperatures), or by depressing insect populations through  sun exposure.  Alternatively, impacts might occur over time as suitable habitat becomes less and less available because of the lack of canopy cover and lack of recruitment of other suitable vegetation.  This season will be the second of the three-year project.

Last but not least – and near and dear to my (Jen's) heart! – is the Nevada Bird Count.  The NBC is a statewide bird monitoring program (with a few surveys dispersing out into adjacent states), that focuses on point count transects supplemented by area searches – and a whole lot of habitat assessments!  I just checked our database, and we have 892 transects set up so far; in 2014, we’ll be surveying a subset of these, along with a number of new locations.  The NBC acts as a sort of umbrella, encompassing a lot of different projects.  This year, we’ll be continuing our surveys at Warm Springs Natural Area, as well as those along the Truckee and Walker Rivers.  The Pine Nut Range is another big project area, where we’ll be investigating pinyon-juniper treatment areas as well as fire impacts from last year’s blaze.  We’re also going to be looking at bird communities in sagebrush and blackbrush habitats in the Great Basin and Mojave Desert, particularly in relation to linear disturbance factors like roads and powerlines.   Finally, we’ll be monitoring restoration areas at Pahranagat and Desert National Wildlife Refuges.   It’s going to be fun!  There are several more NBC-related projects in the hopper, too, so stay tuned!

Happy birding,

Jen, John, and Amy