Long-eared Owls

Written by Peter Pearsall/Photo by Peter Pearsall

Some may argue that humans never “find” owls; owls find us, and our interactions with them are nearly always on their terms. When we chance upon them in the daylight or listen in on their hooting, barking nocturnes, they are almost certainly aware of us before we perceive them.

The long-eared owl is a year-round resident of Malheur Refuge, but its nocturnal habits and cryptic coloration ensure that it is seldom detected by human observers. This medium-sized owl is active mainly at night, when it flies low over fields and grasslands in search of prey including small rodents, bats, birds and reptiles.

The “ears” of owls are in fact feathery tufts, not true extensions of the ears. It was once thought that these tufts aided owls in locating nocturnal prey by sound, but biologists today think that the tufts serve either to communicate non-verbally or as a camouflage mechanism, helping to break up the owl’s outline as it roosts by day in thick cover.

During the day long-eared roost in trees adjacent to hunting areas, such as in stands of willow or juniper. In winter long-eared owls are known to roost communally—sometimes a dozen or more (even up to fifty!) individuals have been found using the same general area. Long-eared owls usually roost close to the trunks of trees, and in Western junipers they effectively disappear behind the tree’s bushy gray-green boughs.

Long-eared owls are sporadic nesters at Malheur Refuge: some years several nests are reported, other years none. Availability of prey— particularly small rodents such as mice and voles—partially explains this. Another explanation relates to suitable nesting habitat. Long-eared owls in our region almost always appropriate abandoned black-billed magpie nests for their own use; the local abundance of breeding magpies may dictate how many long-eared owls nest in a given area. Ornithologist Robert Ridgway encountered long-eared owls regularly during his explorations of the West in the 1800s and noted the same magpie-owl relationship:

“Seldom, if ever, did we enter a willow-copse of any extent, during our explorations of the West, without starting one or more specimens of this Owl from the depths of the thicket. This was the case both near Sacramento and in the Interior, and in summer as in winter. In these thickets they find many deserted nests of the Magpie, and selecting the most dilapidated of these, deposit their eggs on a scant additional lining. This practice is so general, so far as the birds of the Interior are concerned, that we never found the eggs or young of this species except as described above.”

Keen of sight and hearing, often cryptically patterned and hidden by day, owls avoid detection because their lives depend on it. Many species rely on stealth to capture prey; most are equally reliant on camouflage to avoid becoming prey themselves. Thus, it is important to avoid causing undue stress to roosting owls: If you find one, it’s likely seen you first, and further pursuit could jeopardize its safety.

Double-crested Cormorants

Written by Peter Pearsall/Photo by Peter Pearsall

Double-crested cormorants (Phalcrocorax auritus), widespread across North America, are goose-sized waterbirds that feed predominantly on fish captured via surface diving. They are the most abundant of Oregon’s three cormorant species, found in both freshwater and saltwater habitats. Their common name refers to the twin white head plumes worn by adults during the breeding season.

Cormorants’ dark, prehistoric appearance and voracious appetites have long given them a malign connotation among humans, especially those that perceive the birds as a direct competitor for fish. The name itself comes from the Latin words “corvus” and “marīnus”, meaning “sea-raven”; for centuries the word “cormorant” was used to describe someone that was gluttonous or greedy.

In North America, prior to passage of the Migratory Bird Treaty Act in 1918, humans persecuted double-crested cormorants at will. The scourge of DDT in the 1950s took an additional toll, and by the 1970s populations of this bird had plummeted across much of the U.S.

Despite these setbacks, cormorants proved remarkably resilient and adaptable. Regulatory protection, coupled with the 1972 banning of DDT in the U.S., led to an incredible resurgence in double-crested cormorant populations: In the Great Lakes region alone, the breeding population went from around 200 pairs in the early 1970s to 115,000 by 2000.

Today, cormorants across the country are thriving, and their ever-growing need for fish is coming into direct conflict with the interests of commercial fisheries, aquaculturists, anglers and more. In some cases federally threatened and endangered fish species are also targeted by cormorants. Wildlife authorities at the state and federal level now find themselves in the ironic and unenviable position of needing to “control” cormorant populations to protect fish, including captive-reared fish destined for human consumption.

Thus the U.S. Fish and Wildlife Service, in cooperation with the U.S. Department of Agriculture’s Wildlife Services and state wildlife agencies, has developed policies aimed at addressing human-cormorant conflicts in the foreseeable future. These policies include authorizing an annual “take” of cormorants—by culling adults or oiling eggs—to reduce pressure on fish stocks without significantly affecting cormorant populations.

Read the latest updates on USFWS policy regarding double-crested cormorant management here.

Save the Eagles Day

Written by Peter Pearsall/Photo by Peter Pearsall

Today is National Save the Eagles Day, recognizing a lasting commitment made by scientists, lawmakers and the public to protect America’s wildlife and wildlands from human-caused harm. The bald eagle—national bird of the United States, found across the country—was once an endangered species. In the 1950s, bald eagle populations had dropped to just 412 breeding pairs in the lower 48 states. The culprits? Habitat loss and the widespread use of an insecticide known as DDT.

Developed in the 1940s-50s to combat mosquitoes and fleas during World War II, DDT was later sprayed on agricultural fields to kill crop pests. Environmental exposure degraded the insecticide into other chemicals, some of which interfered with calcium carbonate production in shell-based organisms such as crustaceans, mollusks, and egg-layers like birds. Small amounts of these chemical byproducts were retained in prey animals’ bodies, accumulating in predators until they reached harmful levels. The result for eagles and other predatory birds was eggshell thinning: eggs would break under the weight of the incubating parent, killing the nascent chick.

The precipitous decline of eagles, brown pelicans, peregrine falcons and other prominent birds during this period led to the United States’ banning of DDT in 1972, followed by the passing of the Endangered Species Act a year later. Coupled with habitat restoration and captive breeding programs, these efforts brought bald eagles and other species back from the brink, and today they are thriving. Their story reminds us that while humans are capable of inflicting great and sometimes unwitting harm on the natural world, we are also capable of righting those wrongs.

The bald eagle is resident throughout North America and can be found in almost every region of Oregon. With their distinctive white head and yellow beak—and incongruous, tittering call—these enormous birds stand out. The bald eagle’s wingspan can reach up to eight feet across, and its disheveled stick-built nest can weigh more than a ton. Listed as an endangered species until 2007, bald eagles are increasing in number across the country, becoming almost plentiful in some areas. At Malheur Refuge, bald eagles are most numerous in the winter, when they congregate near Malheur and Harney lakes to prey on waterfowl.

2020: A Look into the New Year at Malheur National Wildlife Refuge

Written by Jeff Mackay, Malheur National Wildlife Refuge Deputy Project Leader/Photo by Peter Pearsall

At the close of 2019, a promising snow pack on the Steens Mountains is building and Department of Interior agencies have an approved budget for the Fiscal Year.  While an adequate snow pack is yet to be seen, a budget will enable us clearly to continue working with our partners to accomplish Refuge goals and deliver conservation in the Harney Basin.

What does 2020 hold for the Refuge?  Here’s a vision into a few key elements planned for the New Year…

Staffing

The Refuge work force should grow as we plan to fill five vacant core positions: Project Leader, Administrative Officer, Mobile Heavy Equipment Operator (MHEO), Senior Firefighter (Engine Captain) and Forestry Technician (Fuels Specialist).  The Administrative Officer (AO) position has been vacant since April and Refuge Administrative Assistant Suzanne McConnell has been serving as the Acting AO skillfully accomplishing the full suite of administrative duties. The Project Leader (PL) position has been vacant since August when Chad Karges retired.  I have been serving as the PL and will continue in that role until the position is filled which perhaps will occur this spring. The MHEO position which serves as the Buena Vista Sub-station Manager has been vacant since fall 2018. Refuge Maintenance Mechanic (MM) Kenneth Berry has been serving as the Acting Sub-station Manager.  The Engine Captain and the Fuels Specialist positions have been vacant since fall 2018. We are fortunate to have a strong interagency relationship with the Burns District Bureau of Land Management and the Malheur National Forest and personnel from both agencies have served on work details to help cover the duties of these two important positions during this past fire season.  Filling these five vacant positions will return the Refuge to minimum staffing capacity and enable the Refuge to better achieve desired conservation outcomes.

Malheur Lake Restoration

In early 2020 Aquatic Health/Fisheries Biologist James Pearson will complete the Malheur Lake ecosystem model as part of his Doctoral graduate degree program at Oregon State University.  Currently Malheur Lake exists in a chronic turbid state prohibiting the growth of aquatic plants which provide important feeding and nesting habitat for wildlife. Through execution of certain large scale management actions we believe Malheur Lake can be restored to a healthy clear water state.  The ecosystem model will be used to analyze the influence of various system drivers on the ecological state of Malheur Lake enabling a focus on manipulation of key components. Complimentary to running the model, Habitat Biologist Edwin Sparks will oversee pilot projects to evaluate survival of planted emergent marsh vegetation (hardstem bulrush) in Malheur Lake.  Through a series of planting trials conducted in Malheur Lake, Ed will evaluate factors such as bulrush plug size, water depth, water and soil characteristics, and predation (by carp, muskrats, and waterfowl) on the survivability of planted hardstem bulrush. Model outputs and results from the vegetation planting project will help inform decisions on a suite of management actions leading to restoring a clear water state in Malheur Lake.  Restoration of Malheur Lake to a functional marsh ecosystem is years away, but by continuing to work with our partners in the Harney Basin Wetlands Initiative, we envision a clear path forward that will achieve our desired outcomes while maintaining an awareness that the path may meander as we continue to learn and understand the secrets of Malheur Lake. 

Refuge Management Direction

In 2013, the Refuge Comprehensive Conservation Plan was approved providing current management direction for various Refuge operational programs.  In 2020 we will continue to irrigate meadows and maintain ponds providing important wildlife habitat for migrating and nesting birds. Refuge maintenance staff, Maintenance Supervisor Edward Moulton, MHEO Bill Modey (Double O Sub-station Manager), MHEO Orritt Hoffman (P Ranch Sub-station Manager), and MM Kenneth Berry are invaluable for achieving the desired habitat management outcomes as they maintain water management infrastructure, manage water diversions, and oversee the Refuge vegetation management (haying) program.  Additionally, maintenance staff maintain Refuge roads allowing visitor access throughout the public use areas. Speaking of visitors, recently, Wildlife Refuge Specialist Carey Goss oversaw the installation of new directional and interpretive panels replacing old outdated signs. The new signs will enhance visitors experiences by providing interpretive information and updated and expanded directional information. Additionally, Carey will continue to work with Refuge volunteers and partners from Friends of Malheur Refuge and Portland Audubon to deliver the Refuge information and the environmental education programs.  Refuge Wildlife Biologist Melinda (Alexa) Martinez will continue to implement the Refuge inventory and monitoring programs. Working with the Refuge science partner from Portland Audubon, Alexa will continue to execute high priority wildlife surveys. A new survey of colonial nesting waterbirds (pelicans, terns, grebes, ibis, egrets, herons, cormorants) on Malheur Lake is planned this year using an Unoccupied Aerial Vehicle (UAV or “drone”). The use of UAV methodology is expected to reduce disturbance to nesting birds while enabling biologists to gather important data. Refuge Law Enforcement Officers John Megan and Brett Dean will continue to assure the protection of Refuge resources as well as continue to provide for staff and visitor safety.  Refuge Fire Management Officer Shane Theall along with Fire Operations Specialist Danny Yturriondobeitia and Rural Fire Protection Association Liaison Jacob Gear will continue working with partners to deliver the wildfire suppression and prescribed burn programs. Both programs are important for protecting and managing valuable wildlife habitat as well as protecting Refuge infrastructure and assets.

We look forward to sharing 2020 with you and hope that you will have an opportunity to visit Malheur Refuge.  Plan to spend some time at the Refuge Headquarters where you will find Refuge staff to answer questions unless of course if they are out completing field work.  We encourage you to wander through the Refuge Museum and visit the Cranes Nest Nature Center before making the short hike on the Marshall Trail.

Happy New Year!

Malheur Moth Inventory: The Never-ending Story

Written by Dana Ross/Photos by Dana Ross

A moth inventory can be virtually impossible to complete. Whereas common and widespread species are nearly always captured within the normal course of a sampling regime, it is the rarer species that require significantly more effort to detect and yet add enormously to the total checklist. Each moth species has specific resource requirements and is influenced by various environmental and ecological conditions. Thus, any species may be relatively more or less abundant in a given year. Rare moths (those that are infrequently sampled) may be those whose larval host plants are also rare or whose habitat is limited. They may also be species more prone to succumb to natural enemies or suffer from interspecies competition. Finally, species on the edge of their range tend to be uncommon.  

A species accumulation curve (x-axis = cumulative # of samples; y-axis = cumulative # of species) can suggest when an inventory is approaching a point of saturation, that is, of having documented nearly every species at a given site. And yet with additional effort through time and space species will continue to be added, if at a much slower rate. The challenge is to adequately sample the diversity of plant communities throughout the entire season of moth activity–functionally April through October at the Malheur refuge–such that a baseline of both the common species and the majority of the uncommon to rare ones are detected.

To date, a grand total of 66 black light trap moth samples have been taken from a variety of refuge plant communities. So far, sampling has occurred only during late April and intermittently from mid-July through mid-September. This means that, at the very least, the vast majority of spring-flying moths (May-June) await discovery. To that end, moth sampling will take place in late May, 2020 thanks to funding through the Pacific Region Inventory & Monitoring Program.

For those of you who would like to know more about the impressive moth diversity of the Pacific Northwest, I highly recommend spending some time browsing Pacific Northwest Moths. For a broader look at what we have throughout the United States and Canada, visit the Moth Photographers Group or Butterflies and Moths of North America.