Western Great Lakes Bird & Bat Observatory

Headquarters at Forest Beach Migratory Preserve

Citizen Science


By Kate Redmond

Shakespeare asked, “What’s in a name?” Because of their size and the fact that they will prey on small birds, older field guides call American Kestrels (Falco sparverius) Sparrow hawks, which is what its species name, “sparverius,” means. Like the Eurasian Kestrel, a rare visitor to North America, the American Kestrel is a falcon, but the Eurasian Sparrow hawk is in a different raptor family, the Accipiters.

American Kestrels have a huge range -- they are permanent residents across much of the United States, northern Mexico, and a pretty big chunk of South America (here’s their eBird footprint http://ebird.org/ebird/map/amekes), and they breed, but don’t overwinter, across the northern Great Plains and Rockies and in Canada well into the Arctic Circle. These remarkably adaptable birds are found in scrublands, grasslands, and agricultural areas and on woody edges from sea level to elevations of 14,000 feet, wherever there is hunting and nesting habitat. They are a common sight perched on telephone wires during Wisconsin winters -- often with a small rodent dangling from their talons.

Kestrels, our smallest falcons, are about nine to eleven inches long with wingspans close to two feet -- they’re roughly the size of Mourning Doves and are often mistaken for them. Kestrels are sexually dimorphic (“two forms”); males are more colorful than females, and females are about 10% larger than males. https://www.birdwatchingdaily.com/blog/2015/04/17/armchair-birding-compare-male-and-female-american-kestrels/. Both have a rust-colored back and a pair of dark markings called moustache marks on each side of their face. Two black spots on the back of the neck are thought to mimic eyes and may startle predators attacking from the rear. They are often heard before they’re seen; their most common call is series of loud klee-klee-klee or killy-killy-killy notes https://www.allaboutbirds.org/guide/American_Kestrel/sounds.

Their flight is swift, and their silhouette is described as “anchor-like.” Because they have less muscle mass, they are not as “bulky” as the larger Merlin and Peregrine falcons and so can survive with proportionately less food. They may grab insects out of the air, but they typically hunt from perches or while hovering, ambushing their prey rather than chasing it.

A kestrel’s diet changes with the seasons. Insects, especially dragonflies and large grasshoppers, provide the bulk of their food in warmer months, and they also catch beetles, caterpillars, earthworms, crayfish, frogs, bats, mice, and songbirds (and they’ve been seen taking birds as large as a flicker). Rodents, chiefly voles (Microtus), make up the bulk of their winter diet in Wisconsin. Kestrels generally eat smaller prey on the ground and carry their larger prey to a perch, and they will cache surplus food for later use, especially in winter. They sometimes hunt in family groups. They are preyed on by larger raptors like Red-tailed, Cooper’s and Sharp-shinned Hawks, and by crows, raccoons, skunks, and rat snakes.

Voles mark their comings and goings with scented urine, and researchers have found that these trails reflect ultraviolet light. Many references say that kestrels can spot these trails from above, allowing them to determine whether an area will be a productive hunting ground. Other researchers say that although gulls, shorebirds, Passerines (the perching/songbirds), and a few other groups of birds do have UV vision, raptors are not very sensitive to UV light and do not use it to find prey.

Unusual among hawks and falcons, kestrels are cavity nesters that use old woodpecker holes, natural hollows in trees, and even crevices in rock piles, as well as man-made nest boxes, and they will kick out any bird or squirrel that may already be in residence. They can be fairly tolerant of human neighbors -- I once saw a kestrel fly into a hole under the eaves of a building in the middle of a small town. Trees at the edge of a woodland are ideal sites.

Males defend territories during the nesting season and will chase raptors much larger than they are. He courts with aerial displays, flying into the sky and then plunging in a steep dive while vocalizing. The female responds by flying with slow, stiff, dove-like wingbeats, and the pair may exchange gifts of food, on the wing.

The male searches for potential nest sites and then takes the female around and shows them to her, but she makes the final choice. Inside the cavity, the nest is primitive -- often just a scrape on the floor. Both parents incubate the eggs, though the female pulls the lion’s share of the duty. The young fledge after about a month, but the parents continue to feed them for a few more weeks, and after that, young birds may congregate with young from other nests.

Southern populations don’t necessarily migrate, but northern-breeding kestrels do, leap-frogging over resident populations to overwinter in the southern United States and in Central America. They are solitary in winter -- females head south first and claim territories in open areas on their wintering grounds, leaving the later-arriving males with the less-choice habitats. Males fly north first.

Kestrels have, as the TV stations like to say, “A Wisconsin Connection.” Wisconsin biologist Fran Hammerstrom, who studied Greater Prairie-Chickens for decades, decided to try to encourage kestrel nesting on the Buena Vista Grasslands by erecting 40 nest boxes in 1968. That project morphed into the Central Wisconsin Kestrel Research project, which she headed for the next 30 years, until her death. The project continues today.

It’s hard to imagine that populations of a bird that is so abundant and adaptable and that enjoys such a broad menu might be shrinking, but kestrel numbers on the East and West coasts are in decline. Data from the North American Breeding Bird Survey show an over-all drop in numbers of almost 50% from 1966 to 2010. The main challenge is the loss of nesting and hunting habitat due to urbanization, reforestation, and “clean” agricultural practices that remove dead trees and hedgerows. The use of pesticides that kill the rodents and insects that they depend on, deliberate killing, predation by Cooper’s Hawks, competition with starlings for nest boxes, and collisions with cars and with wind and communication towers also take their toll.

The National Audubon Society considers kestrels “climate threatened” http://www.audubon.org/field-guide/bird/american-kestrel, but others suggest that the falcons may benefit from climate change because it could make prey more available, cause the birds to nest earlier, giving them first crack at good nest sites and territories, and allow the young of the year to get more experience and conditioning before they migrate. What can you do for kestrels?

LINKS BBS and CBC maps   https://www.mbr-pwrc.usgs.gov/infocenter/i3600id.html

GOOD WEB SITE: http://www.hawkmountain.org/raptorpedia/hawks-at-hawk-mountain/hawk-species-at-hawk-mountain/american-kestrel/page.aspx?id=498

Calls - https://www.allaboutbirds.org/guide/American_Kestrel/sounds

http://www.audubon.org/field-guide/bird/american-kestrel To find out more and get involved with Central Wisconsin Kestrel Research, please visit the program’s website at: http://www.kestrelresearch.com


By Kate Redmond

   Seven things I didn’t know about Short-eared Owls (Asio flammeus):

  • They are a global species, missing from Antarctica and Australia but breeding in Europe, Asia, and the Americas, and wintering (but not breeding) in North Africa. They’re one of our most widely distributed owls.
  • They fly long distances, even over oceans, and sometimes land on ships at sea.
  • There are 10 recognized subspecies, including Hawai’i’s only native owl, the Pueo, whose ancestors probably flew down from Alaska.
  • If a female Short-eared Owl is flushed off her nest, she might whitewash her eggs as she leaves – the smell may camouflage the odor of the nest or discourage predators.
  • Their dining habits are gory. They remove the head and guts from their rodent prey and may pull the wings off of birds before swallowing them. 
  • Males perform a “sky dance” during courtship with aerial acrobatics, vocalizing (“barking”) and wing clapping. 
  • Their young are called “semi-altricial.” Helpless (but down-covered, not naked) when they hatch, they’re able to hike away from the nest by the time they’re about 15 days old and able to fly about 15 days after that. 

Because Short-eared Owls are found in a variety of open-country habitats with short vegetation like grasslands, tundra, dunes, marshes, hayfields, and shrubby fields, they’ve earned regional names like Prairie, Marsh, and Bog Owl. They breed in scattered locations in central and northern Wisconsin but are more commonly seen here in winter. If you’re looking for a place to take a winter walk, try the trails at Forest Beach Migratory Preserve, the northwestern part of Harrington Beach Sate Park, and the Schwengel Waterfowl Production area on Six Mile Road, northwest of Belgium. You might find some Short-eared Owls on the prairies.

With a short neck and tail, Short-eared Owls appear to be all wing. In the summer, they might be mistaken for a Northern Harrier (a.k.a. Marsh Hawk), which lives in the same grasslands and hunts for the same food in a similar fashion (and sometimes steals prey from the owls). Short-eared Owls are brown and streaky; the undersides of their wings are light-colored, and they lack the harrier’s white rump patch. They are between crow-sized and Great Horned Owl-sized, but their bulk is all feathers. They weigh in at a pound or less. (Females are a larger and heavier than males.)    Like other owls, Short-eared Owls have a keen sensory repertoire. Raptors’ eyes are located on the front of their head, allowing binocular vision, and their eyesight is sharp.

Like the “horns” of a Great Horned Owl, their “ears” are actually feather tufts; the real ear openings are covered by skin and feathers, and as in many species, ear placement is asymmetrical, which allows owls to triangulate the location of their prey. Audio information is collected via the facial disk, a concave array of feathers around the bird’s eyes. Moving the facial feathers adjusts the amount of sound that is fed to each ear. They have a number of vocalizations (the young even call from within the egg), but their displays are visual, as befits a bird of open spaces.

In springtime, when the breeding season gets under way, and especially in winter, they may be communal, and groups of a dozen or more are common in winter.

During the summer, they hunt day or night, but on their wintering grounds, they are crepuscular – active at dawn and late afternoon/dusk. Voles are their main prey, and they also take mice, shrews, rats, rabbits, and muskrats. In summer, they’ll eat some insects and an occasional bat, and they’ll also hunt for grassland birds and for young gulls and shorebirds along the coast. They mostly hunt from the air, quartering back and forth over a field, sometimes hovering, carried in a stiff, bouncy, mothlike flight by their long, rounded wings. After a successful hunt, they carry their prey with their talons – unusual among owls.

Females make a rudimentary nest on the ground by flattening the grass and maybe laying down a few sticks, and they lay an average of five to seven eggs. The male feeds her while she incubates (their pair bond lasts for one season) and brings food for her to give to the young after the eggs hatch. If her nest is approached, she will try to intimidate or distract the intruder. Since they nest and often perch on open ground, they are vulnerable to attack by foxes, coyotes, dogs, and raccoons, as well as by other raptors.

Short-eared Owls are migratory. Birds from the north move into Wisconsin in winter as most of our breeding Short-ears fly farther south. Their populations reflect the highs and lows of their rodent prey, and they are also nomadic, abandoning areas where prey numbers are low. It’s tough to get an accurate fix on their status.

While they are not federally endangered, their numbers are declining in the southern part of their range in North America, and they are considered endangered, threatened, or species of special concern in most of the upper midwestern and Great Lakes states. In Wisconsin, they are a Species of Greatest Conservation Need (species that have “low or declining populations and are in need of conservation action”). Habitat loss and fragmentation and changing agricultural practices (including increased acreage dedicated to the production of corn for ethanol) are big factors, as they are for other grassland bird species. Their low flight puts them into the path of cars, and they have an affinity for airport runways.



nice pictures - https://wsobirds.org/apg-seow



By Jill Kunsmann

For a gardener, fall is always a bittersweet time of year. True, it’s hard to go “all negative” while the leaves are putting on their magical kaleidoscope of colors, and the return of the cool crisp air is a godsend after the withering heat and humidity of summer, but this year, fall had an added bonus in store for me! While cutting back perennials, I bent down to scoop up some fallen leaves but hesitated for just a second. That was most fortunate, for instead of leaves, I was about to scoop up a bat!

On his back, with wings spread and the sun shining on him, he blended perfectly into the brown mulch and yellow leaves that surrounded him. A closer look confirmed that he was still alive. I could see the rise and fall of his chest, but my assumption was that he was in the process of dying.

I’ve had lots of bats in my yard, but this was such a beauty – and so different! Without touching him, I could see that he had soft thick fur of a golden-red hue, and instead of the pointy ears of the little and big brown bats, his were gently rounded. I felt both admiration and sorrow for this creature. WGLBBO Director Bill Miller helped me identify it as an eastern red bat (Lasiurus borealis). Although they are widespread throughout eastern United States, it was the first time I had seen one.

I moved to a different section of the garden to give him peace and quiet in his final hours, but not before I put up a little sun shield for him. When I checked a few hours later, he had turned himself right side up but was still huddled up on the mulch. Throughout the day, he remained in the same position … and then it was dark. At first light the next morning, I raced out to see what his status was, only to discover he was no longer there.

After a little research, I began to piece together a scenario for the bat other than my imagined swan song. The eastern red bat, described as one of the most beautiful of North American bats, usually roosts among foliage in trees and shrubs, choosing a site that is free of branches below to leave a clear flight path. In the fall, the bat migrates south to warmer climates, where they may enter short bouts of torpor in leaf litter or hanging in deciduous trees.

Undoubtedly, I had knocked this low-hanging bat from a branch as I charged through my garden chores, and since it was chilly, he was content to curl up in the warm leaf litter and bark mulch he landed on. Although the eastern red bat has a broad range east of the Mississippi River, it is a Species of Special Concern in Wisconsin. Learning about a species’ habits is critical for us to participate in their conservation. For additional information on this fascinating species, click HERE.


Seed Collection

 Volunteers helping Josh Sclicht to seed collect at Forest Beach Migratory Preserve

October is known as the “Harvest Month,” and that is no exception for the OWLT stewardship team. On a fine but breezy morning, Josh Schlicht, OWLT Stewardship Coordinator, met a group of volunteers assembled at FBMP who were eager to assist in an inaugural seed-collecting program at OWLT properties.

Josh, a wildlife ecology and biology major from UW-Stevens Point, had a contagious enthusiasm for the project at hand, and soon volunteers were organized with brown paper bags – each labelled with the species to be collected. Instructions were “to leave 25-30% of the seeds on the plants for birds and other wildlife to eat.” That has been part of the focus at FBMP – to create a patchwork quilt of plants that would nourish and restore migratory birds during a stopover and provide food and shelter for other animals. (See the success story of Black-throated Blue Warbler in this newsletter.)

Purple coneflower, penstemon, golden Alexanders, blazing star, nodding onions, and brown-eyed Susans were on the docket for this day. These would be added to a growing collection of over 50 species that are being carefully spread on trays to dry and will go through a stratification process at 30–38° Fahrenheit.

According to Wikipedia, “In horticulture, stratification is the process of pretreating seeds to simulate natural conditions that a seed must endure before germination. Many seed species have an embryonic dormancy phase, and generally will not sprout until this dormancy is broken.” OWLT carries out these necessary procedures at the Kratzsch Conservancy, one of the Land Trust’s properties.

As seeds were collected by the volunteers, questions were answered and knowledge shared. Josh enumerated a number of compelling reasons why OWLT has begun seed collecting at its properties. “It’s important to increase diversity at land trust properties,” he said. “Through scattering seeds, new plants can be introduced to spots that are currently a mono-culture – or to sites that are battlefields combatting invasives. Aggressive natives like cup plant and saw tooth sunflower help combat invasives and are often deployed to control canary reed grass, Canada thistle, and Queen Anne’s Lace.”

As the seed bank grows, hopes are to have enough surplus to begin sharing with other land trust organizations and perhaps, in return, receive seeds of native species not present on OWLT properties.

But it’s not enough simply to have a large storehouse of seeds to sow. To reclaim land for natives, there needs to be a burn that will knock down the invasives long enough to give the new natives a chance to germinate, and many sections of the properties have regularly scheduled burns.

According to Prairie Moon Nursery, a long-term management plan that includes regular controlled burns is pivotal to the success of establishing a prairie. “If a planting is not periodically burned, a thatch layer can build up over the years, causing some native species to grow poorly – or die out. Burning in March or April gives the native plants a competitive edge over weeds.”

Once a burn has been completed, new prairie plant seed can be introduced by drilling holes or casting over open ground as a cover crop.

The efforts to establish and maintain native plants and prairies on land trust properties requires vigilance, determination, expertise, and many hours to accomplish. This first year of seed collecting was certainly successful, and as OWLT looks to 2018, it is hoped that many more volunteers will join those who are already active in supporting this important initiative.

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