On The Wing

This week we installed the first of several stations aimed at detecting bats. Montana Fish, Wildlife, and Parks non-game biologist Kristi Dubois provided the initial monitoring equipment. Joining her for the installation were two members of the Northern Rocky Mountain Grotto, a Montana caving association. Many recreational cavers provide their time and expertise to monitor bat populations. Their commitment is partially in response to outbreaks of white-nose syndrome, a fungus responsible for the reduction of bat populations primarily in the eastern United States. Though caving activities were once thought to be responsible for the movement of white-nose syndrome, research now suggests that bat-to-bat contact is responsible for most transmission. Despite this finding, cavers continue to document bat populations and the dynamics of white-nose syndrome, and work with agencies to prevent the closure of cave systems. We have yet to document white-nose syndrome in Montana.

Very little is known about bat populations in Montana. The Montana Natural Heritage Program has initiated a statewide bat monitoring program to remedy this situation. Bat monitors like the one we installed provide information on species distribution, population status, overwintering behavior, and migratory phenomena. Collecting data now will help biologists monitor bat population response if the white-nose fungus makes its way to Montana.  Monitoring stations at MPG Ranch fit into this monitoring program. We hope to install stations at several elevations; the state currently lacks a high-elevation monitoring site.

For our initial site, we chose the pond/slough system on the Bitterroot River floodplain. This area boasts open water throughout the year. Initial data from other stations have revealed high levels of bat activity in the winter if open water is available. Given insect hatches from recent warm temperatures, Kristi thinks it’s likely we’ll detect bats right away.

William “Bat-boy” Blake helps pound in the posts that will hold the solar panels powering the bat monitoring station.

Debbie Leick helps Kristi Dubois program the unit so that it just records at night.

The crew finishes installing the charging station. The microphone that will record bat sounds is located to the left of the charging station, on a pole close to the water’s edge.

William Blake found this songbird band in a long-eared owl pellet collected in April of 2012. The band belonged to a hatch-year black-capped chickadee banded by the Avian Science Center at their Sheep Camp banding site on 9/9/11. They recaptured the chickadee on 10/13/11 and 10/20/11.

The owl above is most likely the hungry chickadee hunter. Photo by Nate Gordon

Raptor View Research Institute’s eagle trapping efforts have captured interesting photographs of golden and bald eagles from new “carcass cameras”. Cameras allow the trapping crew to monitor eagle traps and to identify birds with wing tags. This past week, the trapping crew caught an exciting glimpse of a female golden eagle recently trapped and outfitted with a satellite transmitter. Trapping, handling, and the burden of a transmitter, did not keep her from returning to eat at the bait within days of her capture.

We’ve noticed many other creatures making use of the deer and elk carcasses, including this ghostly great horned owl.  A great horned owl has snacked on the carcass over the course of several nights in the past week.

This picture appears to show both a golden eagle (foreground) and a great horned owl (background) at the carcass at the same time. What an uncommon combination!

To see birds on the carcasses you can browse the Eagle Research gallery here.

In December of 2011, Raptor View Research Institute placed satellite transmitters on one adult male and one adult female golden eagle on the MPG Ranch. Both eagles spent the winter roaming the Bitterroot Valley. When spring arrived, they headed north. The male settled on a breeding territory approximately 1,500 miles away, in the Wrangell Mountains. The female headed farther north, settling on a nest approximately 2,000 miles away in the southern Brooks Range. After the breeding season, we anxiously watched their movements to see when and if they might head back to the Bitterroot Valley. Both eagles left their breeding territories in October, and made a leisurely journey south. They were both just north of the Canadian border during the last week of October.  The eagles have since returned to the Bitterroot Valley, and have been within 50 miles (and as close as 5 miles) of their original capture location for the past two weeks.

Breeding territories of the male (blue star) and female (purple star) golden eagle captured on the MPG Ranch in December of 2011. The gold star represents their capture location and approximate current location, almost a year later.

Movements of the golden eagle male (blue line) and female (red line) during November 2012, with the original 2011 capture location on the MPG Ranch marked by the gold star.

On Friday, 9/21, participants in our Bird Migration Celebration field trip witnessed an unusual bird flying over our raptor observation site. One of the visitors first called the bird to the group’s attention. Raptor Counter Eric Rasmussen quickly got it in the spotting scope. Its flight pattern looked falcon-like. As it moved closer, Eric noticed its owl-like facial disk, unlike any hawk. But it also had an unusually long tail for an owl. Northern hawk owl!!

The northern hawk owl flew right over the observers, made a few passes at the great horned owl decoy, and then continued flying south.

This observation represents a first for the Bitterroot Valley. In Montana, most northern hawk owls breed in the northwestern part of the state, in and around Glacier National Park. People occasionally see them in other areas, but usually in low numbers in the non-breeding season.

Many thanks to field trip participant Nathan DeBoer for photos of the northern hawk owl.

We are hosting four field trips related to a Bird Migration Celebration organized by Five Valleys Audubon, the National Audubon Society, and other partners. Today we hosted our first field trip, an excursion to the Bitterroot River floodplain. Participants helped the Avian Science Center trap and band songbird migrants. We caught many interesting species, including the savannah sparrow, white-crowned sparrow, orange-crowned warbler, yellow-rumped warbler, and the ruby-crowned kinglet.

The MPG Ranch will host three additional field trips related to bird migration: songbird banding with the Avian Science Center on 9/26, and raptor counting with Raptor View Research Institute on 9/21 and 9/27. See the Bird Migration Celebration website for more information on how to register for these and other field trips.

Last week Debbie and Nathan installed three acoustic monitoring stations on the ranch. These devices will record the call notes of migratory birds as they fly south at night. We will use special software to analyze the sound files and make species identifications. Debbie and Nathan placed a station near each of our bird-banding sites, installing one near the floodplain, one near a mid-elevation shrubby draw, and one near the summit of Mt. Baldy. We will compare the species detected along this elevation gradient. We will also compare the species captured in mist nets during the day (and presumably using the ranch as stopover habitat) to those that simply pass over.

In the future, we will use acoustic monitoring stations to detect other species of interest, including common poorwills, common nighthawks, and flammulated owls.

Many pairs of Lewis's woodpeckers call the MPG Ranch home. Lewis's woodpeckers are unusual in the woodpecker world. They feed on flying insects instead of drilling into wood for food. They also eat available fruits like hawthorn berries, serviceberries, and elderberries. Lewis's woodpeckers have an unusual coloration. Their plumage combines dark green back feathers with rosy-pink breast and face feathers. To find Lewis's woodpeckers, look for a large, dark bird fly-catching from snags along the river. 

Lewis's woodpeckers rely on large snags to house their cavity nests. Right now, most of the nests on the MPG Ranch have fledged their young. Family groups stay close to the nest snag for a few days, and the young loudly beg for food. They take advantage of the floodplain dragonflies and fruits before their migration in late August.

Megan Fylling, a graduate student at the University of Montana, monitors the Lewis's woodpecker nests on the ranch and other areas throughout the Bitterroot and Clark Fork River watersheds. This Ravalli Republic article highlights her research.

An adult Lewis's woodpecker and recently hatched young reside in a cottonwood cavity. Male and female Lewis’s woodpeckers are identical, and both incubate eggs. So we do not know if this is mom or dad on the nest.

Three days later, three featherless young huddle in the nest. Despite their youth, these nestlings already make plenty of noise begging for food.

Would you like to see songbirds up close? On Wednesday, July 18, the MPG Ranch will host a songbird banding session in partnership with UM's Avian Science Center, Five Valleys Audubon, and Bitterroot Audubon. This field trip is part of the Avian Science Center's Bird's-Eye View education program. Banding will take place from 8 until noon along the Bitterroot River floodplain, part of the Bitterroot River Important Bird Area. Participants will learn how scientists capture and process songbirds, why healthy riparian areas are important to songbirds, and how the MPG Ranch works to improve songbird habitat. And you'll get to see many elusive songbirds up close- including species like the yellow warbler, lazuli bunting, cedar waxwing, gray catbird, and house wren. Would you like to join us? Contact me for more information!

Debbie Leick confirmed that short-eared owls nest on the ranch. Several people have glimpsed short-eared owls this spring, but brief encounters and the presence of similar sized long-eared owls made identification uncertain.

On a songbird survey, Debbie saw an adult short-eared owl dive-bomb a coyote. Later, when she returned to the area, she found a ground nest tucked into the bitterbrush. The nest contained four downy owlets and one unhatched egg.

Short-eared owls usually live in open habitats and hunt during the day more than most owls. Like many ground-nesting birds, their nests are vulnerable to predation by coyotes, foxes, and birds of prey.

A yellow-breasted chat uses the shrubby habitat in lower Whaley Draw.  Debbie Leick recognized the bird on June 1rst and then spotted it again the next two days. Debbie was able to see and photograph a standard US Fish and Wildlife Service metal band on the chat's right leg. We suspect that this individual may have been banded last year by the Avian Science Center on our northern floodplain.  Yellow-breasted chats are more common in eastern Montana than in the western half of the state.  We hope this one has a successful breeding season.

On April 27, 2012, I discovered two long-eared owl nests, one in lower Tongue Creek and one in Sheep Camp. Long-eared owls roosted in both drainages throughout the winter. I could see at least one fuzzy owlet in the Tongue Creek nest, but I was unable to see anything but a sitting female in the Sheep Camp nest. Both owls laid their eggs in old black-billed magpie nests, located in the center of heavily browsed maples. A few more days of leaf growth on these shrubs would have prevented me from finding the nests.

The fuzzy grey feathers at the bottom left of the visible owl belong to at least one owlet.

The Tongue Creek female displayed a defensive posture, hissing and puffing out her wings.

The Sheep Camp female sits calmly on her nest. I saw fresh bear scat near the base of this shrub.

In a joint project with Raptor View Research Institute, two satellite transmitters were placed on male, and female adult golden eagles on the MPG Ranch. Since mid-December, the female golden eagle has traveled a wide loop around the Bitterroot Valley. She spent roughly a week near the ranch, then made her way south along the western edge of the Sapphire Mountains. On December 30th, she reached her farthest southern point, near the branching of the East and West Forks of the Bitterroot River south of Darby. This location is almost 60 miles from the point of her original capture. She stayed in this general area until January 14, when she made a big movement north, this time on the west side of the Valley. She is currently in the foothills of the Bitterroot Mountains west of Stevensville. We were surprised to see that she seems to avoid the low-elevation valley bottom. Calving season has begun in the Valley, which may attract her to the lowlands.

During the summer of 2011 the MPG Ranch hosted a project by the University of Montana's Avian Science Center (ASC) to capture and band songbirds on the northern floodplain. The ASC documented several new species on the property, including a breeding pair of yellow-breasted chats and an incidental black-billed cuckoo. The  final report includes capture information and a comparison between bird captures at the MPG Ranch and several other riparian sites in the region.

Photo: Yellow warbler by Kate Stone

In the past week, flocks of American tree sparrows have returned to the ranch. Like the northern shrike, rough-legged hawk, lapland longspur, and the snow bunting, American tree sparrows breed in the far north and fly south to overwinter in Montana. They are recognized by their rusty-red cap and eyestripe and their bicolored bill. American tree sparrows forage in small flocks, searching shrubs and the ground for seeds, berries, catkins, and insects. On the MPG Ranch, you are most likely to see American tree sparrows in areas with shrub cover, including the Bitterroot River floodplain and shrubby draws. They will move from shrub cover along the floodplain to feed in nearby fields of crested wheatgrass and weeds.

Riparian areas and wetlands occupy less than 4% of Montana’s land surface, yet they support more than 80% of Montana's bird species.  Through a partnership with Bitterroot Audubon, the MPG Ranch recently constructed four, quarter-acre exclosures on the floodplain of the Bitterroot River. The purpose of these exclosures is to prevent ungulates like deer, elk, and moose from browsing the riparian vegetation that provides essential bird habitat. Heavy browsing in the past has limited the establishment and regeneration of important floodplain species such as cottonwood, aspen, and willow. MPG Ranch staff and Bitterroot Audubon volunteers will monitor the birds and vegetation within and around the exclosures. The exclosures will also serve as a demonstration to other landowners interested in protecting riparian vegetation on their own property. 

The MPG Ranch hosted a field trip for Bitterroot Audubon and interested landowners on Saturday, October 8. The twelve participants viewed the exclosures, discussed the importance of riparian vegetation to birds and other wildlife, and observed more than 25 bird species. Several of these species, like the ruby-crowned kinglet and the white-crowned sparrow, do not breed on the floodplain but are currently using it as migratory stop-over habitat. 

We've observed a surge in migrating raptors in the past week. From 9/16-9/22, we counted 324 raptors migrating over the ranch. The most abundant raptors were the sharp-shinned hawk (90 counted), American kestrel (56 counted), and Cooper's hawk (40 counted). William from Raptor View Research Institute was able to capture this male prairie falcon.

Migration is happening! The MPG Ranch is hosting several fall migration projects with research partners like Raptor View Research, the Avian Science Center, and the Owl Research Institute. During the first two months of September researchers have documented several new species on the property, including the ferruginous hawk, flammulated owl, cordilleran flycatcher, American redstart, and the ovenbird.