Golden Eagles

Golden Eagle
Golden Eagle
Aquila chrysaetos
Courtesy USDA Forest Service
Dave Herr, Photographer

On a recent Christmas Bird Count, my team witnessed an amazing feat of flight. We parked in a subdivision cul-de-sac to walk into the sagebrush foothills. Overhead we saw two Golden Eagles meet in a talon lock and tumble towards earth. They disengaged moments before crashing and flew off in opposite directions. A minute later and we would have missed it all. So what were they up to? I am not quite sure.

Golden Eagles are supreme flyers. In both courtship and territory displays they steeply dive and swoop upward. During a pendulum display, they dive and rise in one direction then turn and retrace their path. Pairs often play with an object in the sky, repeatedly dropping and retrieving it. The talon lock display is rarely seen, but it too is used both for bonding between pairs and in territorial disputes. We saw the display in December and the birds separated immediately, so we probably witnessed a territorial defense. Golden Eagles require a territory anywhere from 20 to 200 square miles depending on prey abundance. As with most wildlife, loss of habitat is a prime threat.

Three quarters of recorded Golden Eagle deaths can be traced to humans. In treeless areas, power poles provide a convenient perch. When their 7 foot wingspan touches two wires, they are electrocuted. New designs and retrofits for power poles eliminate this problem and the resulting range fires, but many of the older designs remain. Wind farms also kill eagles, but again, new designs and more careful siting are helping to alleviate this problem.

The Golden Eagles’ favorite meal in the West is jackrabbit. However, they are opportunistic foragers and will dine on carrion. If the carcass they feed on was shot, they may ingest fragments of bullets or buckshot that contain lead. Lead poisoning is an excruciating way to die. Carcasses with lead fragments are eaten by many carnivorous birds and mammals who are then poisoned. This winter, 8 Bald Eagles died of lead poisoning at the Wildlife Rehabilitation Center of Northern Utah. We must remedy this problem so we can insure that our skies will always be graced by the grandeur of soaring eagles.

Our theme music was written by Don Anderson and is performed by Leaping Lulu.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:
Image: Courtesy USDA Forest Service, Dave Herr, Photographer
Text: Linda Kervin, Bridgerland Audubon Society

Additional Reading:
http://www.allaboutbirds.org/guide/golden_eagle/lifehistory

http://www.hawkwatch.org/component/content/127

http://www.peregrinefund.org/explore-raptors-species/Golden_Eagle#sthash.Gqowt1G0.gFqVfifi.dpbs

http://www.deseretnews.com/article/865596763/Lead-blamed-for-latest-bald-eagle-deaths-in-Utah.html

Shrikes

Loggerhead Shrike
Loggerhead Shrike
Lanius ludovicianus
Copyright 2013 Linda Kervin

The name songbird conjures up an image of a colorful singing warbler. But one family of songbirds, the shrikes, are fierce little predators. No bigger than a robin, shrikes mainly eat insects, especially grasshoppers and crickets, but they also prey on rodents, small birds, lizards, snakes and frogs.

Utah has 2 species of Shrike: the Loggerhead which resides here year round and the Northern which breeds in tundra and visits Utah in the winter. Shrikes prefer semi-open country that has some trees, shrubs or fenceposts where they perch to watch for prey and then swoop to kill with their thick hooked bill.

Shrikes are sometimes called butcher birds Continue reading “Shrikes”

Pinyon Jays

Click for larger picture, Pinyon Jay courtesy and copyright 2005 Marlene Foard - as found on www.utahbirds.org
Pinyon Jay, Tabiona, Utah
Courtesy and Copyright © 2005 Marlene Foard
As found on UtahBirds.org

Few birds have such a strong association with one plant that the plants name becomes part of the birds name. Sage grouse is one, Acorn Woodpecker another, but the Pinyon Jay is our topic today. Pinyon Jays are usually found in close association with pinyon-juniper forests throughout the Great Basin and the nutritious nuts of the pinyon pine are their preferred food. The blue and grey birds collect and cache pinyon nuts in summer and fall for later consumption. They have an uncanny recovery accuracy and excellent spatial memory, which allows them to rediscover these scattered caches and eat pinyon nuts all year. They do not recover all the stored seeds, however, and therefore aid in the dispersal of pinyon pines.

Pinyon Jays have a complex social organization and are highly gregarious. [Pinyon Jay Audio Courtesy Kevin Colver]

They spend their lives in large flocks of up to 150 or more individuals. Nesting is communal, although rarely are there more than 2 or 3 nests per tree. Breeding season is in late winter. Many birds spend their entire lives in the flock into which they were born.

Dave Menke, Photographer” alt=”Click for larger picture, Pinyon Jay Courtesy US FWS
Dave Menke, Photographer” src=”https://wildaboututah.org/images/fws.menke.pinyon-jay.250×164.jpg” width=”250″ height=”140″ align=”right” border=”0″ />
Pinyon Jay
Gymnorhinus cyanocephalus
Courtesy US FWS
Dave Menke, Photographer

Pinyon Jays are not migratory, but they tend to be nomadic; traveling to wherever there is a good crop of pinyon nuts. They will also eat a wide variety of seeds, insects and berries to supplement their diet and can be found in adjoining sagebrush, ponderosa pine forest and riparian habitats. The conservation status of Pinyon Jays is considered vulnerable. Destruction of pinyon-juniper forests for grazing and changes in fire regimes have resulted in loss of habitat. And what is a Pinyon Jay to do without its pinyon nuts?

Thank-you to Kevin Colver for the use of his bird recordings.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:
Pictures: Courtesy and Copyright © 2005 Marlene Foard, as found on utahbirds.org
Also Courtesy US FWS, Photographer David Menke
Bird Recordings: Kevin Colver
Text: Linda Kervin, Bridgerland Audubon Society

Additional Reading:

Gymnorhinus cyanocephalus (Pinyon Jay), Fire Effects Information, USDA Forest Service, http://www.fs.fed.us/database/feis/animals/bird/gycy/all.html

Avian Cognition Laboratory, Northern Arizona University, http://www4.nau.edu/acl/index.htm

Pinyon Jays, Utah Bird Profiles, UtahBirds.org, http://utahbirds.org/birdsofutah/BirdsL-R/PinyonJay.htm

Pocket Gopher

Click for a larger view of Northern Pocket Gopher, Thomomys talpoides. Courtesy NPS, Gillian Bowser, Photographer
Northern Pocket Gopher
Thomomys talpoides
Courtesy NPS
Gillian Bowser, Photographer

Pocket Gopher

While hiking mountains meadows in spring, you will likely encounter earthen tubes that meander across the soil surface. These are remnants of the winter tunnels of pocket gophers. Often called ropes, these dirt cores result from pocket gophers burrowing for food all winter long. They dig under the snow, backfilling their tunnels with dirt. Another surface clue to pocket gophers’ presence are the hills of soil that they push to the surface. The tunnel opening in the hill is closed with an earthen plug.

Pocket gophers are superbly adapted for their subterranean lifestyle. Their eyes and ears are tiny. In compensation for poor eyesight, they have long whiskers or vibrissae on their snout. The vibrissae are very sensitive to touch and allow them to navigate in their dark tunnels. In reverse, they rely on their stubby, hairless tails to guide them as they run backwards.

Click for a larger view of Pocket Gopher Surface Mound with Open Entrance Hole. Courtesy Lyle Bingham, Photographer
Pocket Gopher Mound
with open entrance hole
Courtesy
Lyle Bingham, Photographer

These little rodents have formidable tools for digging. Their front claws are long and stout and powered by impressive shoulder muscles. As with all rodents, the incisor teeth grow constantly, offsetting the abrasion of biting through hard soil and roots. Cleverly, the lips close behind their front teeth which keeps their mouth clean of dirt. These gophers really do have pockets: fur-lined cheek pouches which they use to carry food to the storage areas of their burrows.

Pocket gophers are vegetarians, eating roots and bulbs below ground and stems and leaves above. Their plant diet and tunneling cause many farmers and homeowners to consider them a terrible nuisance, but pocket gophers also contribute to a healthy ecosystem. One pocket gopher will move up to 4 tons of soil each year, alleviating soil compaction. They bring fresh mineral soil to the surface and fertilize belowground with their droppings and leftover stashes of vegetation. Their tunnels provide habitat for other animals that live underground. Many mammals, birds and snakes dine on pocket gophers.

If you find a gopher mound, try watching quietly. If you are really lucky, as our Wild About Utah web guru, Lyle Bingham was, you may see one pop its little head out for a quick look around.

Credits:

Images: Courtesy NPS, Gillian Bowser, Photographer
Text: Linda Kervin, Bridgerland Audubon Society http://www.bridgerlandaudubon.org
Video:


YouTube Video Courtesy:
About Exploring the Nature of Wyoming
University of Wyoming Extension

Additional Reading:

Northern Pocket Gopher — Thomomys talpoides. Montana Field Guide. Montana Natural Heritage Program and Montana Fish, Wildlife and Parks. Retrieved on April 30, 2013, from http://fieldguide.mt.gov/detail_AMAFC01040.aspx

About Exploring the Nature of Wyoming, University of Wyoming Extension, http://www.youtube.com/watch?v=frfxuO6oYkA

Wiscomb, Gerald W., Messmer,Terry A., Pocket Gophers, Wildlife Damage Management Series, Utah State University Cooperative Extension, http://extension.usu.edu/files/publications/publication/NR_WD_005.pdf

On Being Misunderstood:: Pocket Gophers, The Metropolitan Field Guide, http://www.metrofieldguide.com/on-being-misunderstood-pocket-gophers/

Pocket Gophers, Living with Wildlife, Washington Department of Fish & Wildlife, Washington State, http://wdfw.wa.gov/living/gophers.html