Blue Jay

The phrase “naked as a jaybird” refers to something especially bared, and morphed from the original phrase “naked as a robin.” Blue jays are born without many feathers, naked, one might say. As the phrase morphed, so too did the preceding adjective, growing to include crazy, mean, and saucy as a jaybird. The slight is obvious in calling someone “crazy as a jaybird,” but the slight to the blue jay might be overlooked. With a reputation that precedes them, blue jays are often scorned by birders who call them thugs and overly aggressive at feeders.

Blue jays at feeder, photo by Jo Zimny Photos

Indeed, blue jays have been found to ransack the nests of other songbirds. At feeders, jays have been known to mimic the call of red-shouldered hawks, perhaps to scare other songbirds into thinking a raptor is near. They'll steal feed from squirrels, nuthatches, and woodpeckers, but it is a rather uncommon occurrence.

Blue jays are opportunistic. A majority of their diet consists of acorns, nuts, seeds, grains, and fruits. Insects become an important part of their diet during the breeding season. However, the birds do eat a broad diet including frogs, toads, bird eggs, nestlings, and rarely roadkill or deceased animals.

These birds belong to the corvid family, and accordingly are incredibly smart. Researchers trapping and marking blue jays have difficulty catching the same bird twice. Captive jays have used instruments to pull food from outside a cage to within it. Some blue jays have remarkably learned to pluck ants from a hill, wiping the formic acid of the ants onto their breasts and making the ants digestible. Additionally, blue jays will cache anywhere from 3,000-5,000 acorns each year—relocating a good majority of those acorns.

Oak savanna, photo by Joshua Mayer

Hugely important to the ecosystems of oak savannas and oak woodlands, blue jays have been considered a keystone species for the role they play in dispersing the acorns of oak trees.  If each bird “forgets” 5% of its crop, then an oak savanna will nevertheless have thousands of germinating oaks each year. Another mark of genius for blue jays is that they've been shown to discern fertile acorns with 88% accuracy. Other acorns may be infested with fungus, rust, or the acorn weevil, which lays eggs inside the growing acorn that will feed its larvae, which will eventually use long snouts to burrow a hole out of the acorn.

Photo by Stan Lupo

While oak trees arguably have their own role as a keystone species—allowing sunshine into the understory, fueling fire with combustible leaves, and providing food (acorns) for 150 species of birds and mammals—blue jays are bolted to that same role. Jays allow oak dispersal to an astounding level, as the birds will carry acorns over 2.5 miles away from the source tree.  In fact, after the last ice age, oak species dispersed into glacier-torn areas faster than wind dispersed seeds. It is thought that this is due to the dispersing behavior of blue jays.

“What about squirrels?” you might be asking. Squirrels also play an important role, but their dispersal is not as impressive as a blue jay's. The cached acorns of squirrels are most likely to be found within feet of the source tree. However, squirrels play a dynamic role in shaping the composition of the forest or savanna trees. Squirrels prefer to cache red and black oak nuts, while they prefer to eat white and bur oak nuts. This is because the red and black oak nuts are loaded with tannins, and store better for long periods. White oak acorns germinate in the fall and therefore don't keep as well as the red oak acorns. With fewer tannins, squirrels consume white oak treats immediately, and don't cache as many acorns from those white oak species. Even when white oaks are cached, the embryo is often excised.

Thus, blue jays may help to spread white and bur oak trees since they pick out fertile acorns and often find suitable sites for these acorns while burying them with a small amount of substrate. One study found that blue jays cached 55% of the acorns in a given area, while eating another 20% while they were gathering. Another interesting adaption from the blue jay is its ability to move multiple acorns per trip. The bird accomplishes this by storing some acorns in its “gular pouch” which can hold 2-3 acorns, stroring one or two in its mouth, and storing one on the tip of its beak.

Photo by Monica Hall

Blue jays live monogamous lives and run complex social circles throughout the year. It is thought that some birds recognize each other based on the markings of the face. Jays can be found in most forested habitats throughout Wisconsin, especially somewhere with oak trees. Here at Faville Grove, you can find these fascinating birds throughout the sanctuary, but they've been especially abundant in the ledge savanna where they've been plucking acorns.

Written by Drew Harry, Faville Grove Sanctuary land steward

Cedar Grove turns 70

I have been lucky to have been involved with Cedar Grove Hawk Research Station State Natural Area since 1985 when I worked with the DNR State Natural Areas program. It seems like only a few years ago that Cedar Grove turned 60 years old when Paul Smith, Outdoor Writer for the Journal Sentinel wrote an article on their first 60 years. 

Since retiring in 2011, I have helped lead annual Natural Resource Foundation tours to Cedar Grove. On October 10, I was outside of the banding building with six people on a Natural Resources Foundation tour and was surprised to see Paul Smith walk up to us. The first thing he said was, “I just heard a merlin.” A tour visitor replied, “We just released a merlin.” Paul is visiting the research station on three days this year and is planning to write an article on Cedar Grove turning 70.

Photo provided by Cedar Grove Ornithological Research Station

Dan Berger and Helmut Mueller started the banding station in 1950 and caught two red-tails that year. Dan passed away in 2018 and Helmut and Nancy now visit for only a day.

The oldest bander at the station now is John Bowers, 82 from Cedar Grove, who has been volunteering for the past 31 years. When he greets an old visitor he always says, “I have not seen you since the last time I saw you.”  John arrives every day from August 15 to November 15 at noon and heads home after supper. Besides trapping and banding, he enters all the banding data on the “confuser” (computer). In the past 30 years John has volunteered on about 2,670 days and has only missed 30 days.

Tom Meyer and Rick Hill now supervise the banding with two interns this year, Savanna Steward from California and Danny Erickson from Waukesha County, along with many dedicated volunteers.  

This year Tom Meyer reported that Cedar Grove has three records or highlights for 2019: In addition to turning 70, they banded their 44,000th raptor, and now have HOT WATER!

Last year 685 raptors were banded. When I spoke with Rick Hill on November 7, they were banding a northern goshawk, the 700th bird of the year and the third goshawk of the morning. Banding highlights this year included banding a Swainson’s hawk and a broad-winged hawk. Normally broad-wings feed on small mammals, amphibians, and insects. Few saw-whet owls were caught this year due to the many nights of rain when they closed the mist needs. Running totals for this fall include Sept. 27, - 300 birds banded, Oct. 8 - 400, Oct. 16 - 487, and Oct. 26 - 600.

Check out the Cedar Grove Facebook page that includes information on birds banded at Cedar Grove and recovered another year at Cedar Grove or at other locations. Steve and Laura Holzman with Fish and Wildlife Service from the state of Oregon spend a week of their vacation every year at Cedar Grove banding raptors. They complied the species recovery maps.

Map provided by Cedar Grove Ornithological Research Station

Graham Steinhauer, Brand Smith and I were visiting the Western Great Lakes Bird and Bat Observatory a few miles south of the banding station and stopped in to say hi. Graham was handed a red-tail to release and John Bowers then informed us they were closing the road to remove ash trees and if we did not leave in five minutes, the private access road would be blocked for five hours.

Red-tailed hawk, photo by Tim Eisele

Tim Eisele won the “door prize” at the Goose Pond Volunteer Picnic, which was a visit for two to Cedar Grove. On October 16th Tim and Linda Eisele, Jim Otto, and I headed to Cedar Grove. The winds were out of the northwest, the ideal direction; however, the wind gusted over 20 miles per hour and the strong winds impacted the number of birds coming in. About 340 hawks passed over the banding station that day and only 16 were captured; 10 red-tails, 5 sharp-shins, and 1 Cooper's hawk. Usually they catch 10 percent of the birds they see. A merlin came in and perched 25 yards from the banding site. I thought this would be an easy one to catch, but the merlin had just caught a song bird and was not interested in being banded. On October 23, they counted 400 raptors flying past and 43 left with with “jewelry” leg bands.

On October 25, Brand Smith, our American Kestrel volunteer coordinator, took our bird volunteers Dory Owen, Mary Manering, and Sharon Weisenberger to spend some time at Cedar Grove. They had a great time and released three red-tails and five sharp-shin hawks. It is amazing to see the birds coming in at a high rate of speed, the banding operation, the small field station, and visiting with the banders.

Mary Manering watching Brand Smith releasing a red-tailed hawk. Photo by Dory Owen

Mary Manering ready to release a sharp-shinned hawk. Photo by Dory Owen

Savanna, a Cedar Grove intern, ready to release a red-tailed hawk. Photo by Dory Owen

Sharon Weisenberger holding a sharp-shinned hawk. Photo by Dory Owen

Check out Jacqueline Komada’s Friday Feathered Feature post from last year on Cedar Grove.

My best day at Cedar Grove was on a Natural Resources Foundation field trip last year. It was a busy day for everyone. My “job” was to record the banding data in the record book. When we left at 5:00 p.m., 312 hawks were spotted and 56 were banded. Birds seen (and banded) included northern harriers 4 (0); bald eagle 1 (0); sharp-shinned hawk 160 (42); Cooper’s hawk 9 (2); red-tailed hawk 7 (1); merlins 128 (11)  and peregrine falcon 1 (0).  

Cedar Grove Research Station is not a membership organization but receives donations to pay the interns and operate the station. Mist nets are expense and only last a few years. They have over $3,000 of mist nets up every day.

If you would like to visit Cedar Grove, check out the Natural Resource Foundation field trips.  We anticipate heading over to Cedar Grove one or two days with Madison Audubon volunteers/members in the future. If you have questions about Cedar Grove, call Mark at 608-333-9645 or email him at goosep@madisonaudubon.org.

Written by Mark Martin, Goose Pond Sanctuary Co-Manager

Foster's Tern

This summer, a great blue heron spent what seemed like its every waking (and sleeping) moment on a wood duck box on the Hwy 89 pond. Every walk around the pond yielded a surprise when a tall figure against the backdrop of prairie, pothole, and aspen turned out to be the heron, again perched on the wood duck box.

There was one instance where this heron departed from its usual routine, as far as we saw it. While the interns and I were on North Shore Road, we witnessed the heron land in the pond. We observed the bird with binoculars for a minute, before it quickly stabbed a bullhead out of the water, gulped it down after a couple of tries, and then returned—where else—to the wood duck box.

In his regular perch. Photo by Drew Harry

I was surprised by the size of the fish in the pond. Yet years past have seen egrets, pelicans, and great blue herons raiding this resource.

I was also surprised, on July 19, when I witnessed a Forster’s tern flying over the 89 pond. This is an endangered bird in Wisconsin that nests in colonies, so my sighting was unlikely to be breeding individual of the immediate area. However, my sighting occurred right around the time when young are fledging, and after this period, parents often disperse more widely to forage for minnows in lakes, rivers, and ponds.

Foster’s tern at Hwy 89 pond. Photo by Drew Harry

In the area of Faville Grove, one nearby location stands out as a potential breeding location for Forster’s terns. The Chub and Mud Lake Riverine Marsh to the north, in Dodge County, covers nearly 7,000 acres of wetland habitat and harbors the appropriate riverine marsh habitat often preferred by Forster’s terns. Portions of this area were never platted during the Public Land Survey, because they were presumed to be a lake. For Wisconsin’s second Breeding Bird Atlas, a number of probable breeding pairs were found in this area.

Faville Grove likely holds wetlands too small and isolated to host breeding Forster’s terns. These birds look for extensive wetland marshes, often nesting on well-concealed islands of vegetation to avoid mammalian predators. Raccoons, skunks, opossums, and weasels, could all decimate the eggs of a colony of Forester’s terns, so nest site selection is key for these birds.

For this reason, only a few colonies in Wisconsin traditionally produce offspring. These areas include Big Muskego Lake, the upriver lakes of the Winnebago Pool, Rush Lake, and the western shore of Green Bay.

It’s interesting to note that many wetlands in the immediate vicinity of Faville Grove contain islands of potential habitat for Forster’s terns. Due perhaps to the unique chemical makeup of these low-lying areas, most boggy lowlands are surrounded by a “moat” of open water, which typically rings the entirety of the wetland.

Wetland “moat” at Faville marsh. Narrow areas of water are likely due to erosion. Native vegetation will replace agricultural field and hold the soil in place in the far upper left of this photo, credit Rob Couey

There are a number of explanations for this moat, including runoff from uplands that increases decomposition and fires running into the edge of the wetland and increasing decomposition. The result is an open island of wetland vegetation with portions dominated sedges and cattails—seemingly perfect habitat for Forster’s terns. Farm field erosion can complicate dynamics of this moat, however. Runoff and siltation from upland areas can fill in this moat, and allow predators to access the island, while also making it more likely that it dries down during summer and fall.

Overall, the Forster’s tern is a chance occurrence at Faville Grove, but we’re happy to support their post-breeding foraging efforts. These birds have migrated through southern Wisconsin at this point, and are likely somewhere in Central or South America. These birds will return in late April, looking for the perfect island of wetland vegetation.

Written by Drew Harry, Faville Grove Sanctuary land steward

Not-So-Spooky Bats

With Halloween just around the corner, let’s talk about a furry, flying critter with an unfairly ghoulish reputation: Bats.

Hoary bat, one of Wisconsin’s eight native bat species. Photo by Daniel Neal, Oregon State University FCC

Of the 5,416 mammal species on Earth, about 1,200 of them are bats. This makes bats the most diverse mammal group second only to rodents. We have eight native bats here in Wisconsin, and they are all insectivores that prefer to eat beetles, stinkbugs, leafhoppers, and moths. Many of these insects are agricultural pests, and through their pest reduction services, bats have a huge positive impact on farmers. Flies and mosquitoes that directly impact humans are also on the menu.

Bats have been heavily persecuted by humans because of common myths associated with them, a fear of their unknown habits, and their general appearance. Let’s dispel some of those harmful bits of misinformation, shall we?

1. Myth: Most bats have rabies. Fact: Less than one percent of bat individuals have rabies.

2. Myth: Bats like to land in your hair. Fact: Bats may fly around you at night, but that’s only because insects are attracted to the heat and carbon dioxide that humans give off. Their goal has nothing to do with your hair. 

3. Myth: Bats will suck your blood. Fact: Only three species of bats in the world feed on blood, and they all live in Central or South America.

4. Misconception: Bats are ugly. Counter argument: To each their own on this one, but I can say with confidence that not all bats are ugly. There’s a reason that some species of bats, like this cutie below, are called flying foxes.

Young flying fox. Photo by Australian Bat Clinic and Wildlife Trauma Centre

There are four major threats to bat populations including bioaccumulation of pesticides, hibernacula disturbance, wind turbines, and white-nose syndrome (WNS). WNS is by far the most pressing issue. 75-100% of all bats in a hibernaculum (usually a cave or mine) are expected to die if the colony becomes infected with WNS. WNS is caused by a fungus. How it causes such high rates of mortality is somewhat unknown, but it is generally accepted that WNS causes bats to awaken from their hibernation period costing them precious energy. 

Map by White-Nose Syndrome Response Team

Each species of bat emits their own distinct frequency while searching for food. Scientists developed bat survey equipment with this auditory footprint in mind. The machine “listens” for bats, determines what species was present, and adds the associated coordinates to create a bat survey map. Mark Martin, Sue Foote-Martin, and Brand Smith started conducting bat surveys at Goose Pond Sanctuary and Schoeneberg Marsh in 2008. Bats found on past surveys in our area have included big and little brown, hoary and eastern red bats.  A silver-haired bat found on the recent Schoeneberg Marsh count is new species to the bat list. 

This baseline data is valuable in determining what bat species are declining most heavily. On August 6, 2019, Tanner Pettit (summer Goose Pond intern) and I replicated a bat survey from 2016. Note that the time of year, time of night, water levels, and wind speeds are all similar between the two surveys. Each symbol on the map represents one bat encounter. The results were sobering.  

Results of the 2016 Bat Survey. Map by WDNR Bat Program

Results of the same survey done in 2019. Map by WDNR Bat Program

Andrew Badje, DNR Conservation Biologist, downloaded the 2019 bat data for Goose Pond and Schoeneberg Marsh and said, "On that note, 4 species/survey is a great result, for the WNS world we currently live in.” Bat counts have also been conducted at Goose Pond and have found similar results.

Little brown bats in a hibernaculum. Photo by Petroglyph FCC

Bats are sometimes grouped by habitat preference. Tree bats usually roost in small groups under bark or in tree cavities. As the name implies, cave bats usually roost in caves or mines. The largest known bat colony is called Bracken Cave in Mexico, and it hosts 20 million bats annually. This makes it the largest concentration of mammals ever discovered. Because cave bats pack themselves closely together for warmth and to conserve space, they are particularly susceptible to diseases like WNS.

Little brown bat with white-nose syndrome. Photo courtesy of USFWS National Digital Library.

As you can see from the bat survey map of Schoeneberg Marsh above, bats of all species have declined sharply except for big brown bats since 2016. While big browns are cave bats, their larger body size probably helps them survive the winter better than smaller bodied bats. Solutions for WNS like vaccines and hibernacula climate control are in the works, but our window to save bat populations is rapidly closing. 

Written by Graham Steinhauer, Goose Pond Sactuary land steward

Blue-headed Vireo

The world over, how many birds have blue heads? Most of those birds, one might imagine, are located in the tropics—nestled away in exotic rainforests. A quick “blue-headed” query into eBird reveals blue-headed wood-doves, coucals, hummingbirds, sapphires, bee-eaters, parrots, macaws, and racquet tails, among a legion of other blue-headed birds. Most of these birds are indeed tropical, ranging from West Africa to Colombia to Caribbean endemics.

One bird with a blue head can be found in Wisconsin, among nine or so others, breeding in the northern mixed conifer forests in summer, and migrating through southern Wisconsin in October and early May. The blue-headed vireo makes a relatively early migration through the southern part of Wisconsin, typically in late April to early May. Abundant caterpillars on leafing out trees provide a rich source of protein, and the bird’s preference for nesting in conifer trees is due at least in part to the available foliage to conceal nests for this early-arriving species.

Blue-headed vireo, photo by Melanie

In many ways, the blue-headed vireo is anomalous among passerines. Its Latin name (Vireo solitarius) hints at its former common name (Solitary vireo), and these birds live up to their solitary reputation, with males defending wide-ranging territories of northern forestland, up to 15 acres at a time. Additionally, males will build many nests as part of their courtship behavior, with the female finally choosing the male with the best-built nests and most well-defended territory. Perhaps due to the male’s outstretched territory and nest building, the female actually weighs more than the average male, which is rare in songbirds.

Another distinguishing characteristic is the blue-headed vireo’s call note while on the nest, allowing researchers easier detection of these birds on their breeding grounds. This bird’s typical song slightly resembles the red-eyed vireo, but Roger Tory Peterson has called it “more deliberate, softer, and sweeter.” Learning the intricacies of vireo song and plumage can be a launchpad into advanced birding, and as this article writes, the red-eyed vireo—which ceaselessly sings all summer long in eastern forests—is the basis for differentiating vireo songs.

While breeding bird survey routes in northern Wisconsin have shown slight increases in the abundance of blue-headed vireos, their outlook is not all positive. Numerous factors will threaten this bird in the coming decades. At the forefront is climate change. National Audubon’s new Climate Report shows dire predictions for hundreds of North American bird species. An interactive online tool allows you to see the impacts to birds in your zip code, and a look at the blue-headed vireo shows a huge range reduction and movement north (below, photo courtesy of Audubon.org/climate/survivalbydegrees).

This map from Audubon’s Survival by Degrees website shows the blue-headed vireos habitat loss and gain in North America, under a 3 degree warming scenario. Provided by National Audubon Society.

While today, these birds find breeding habitat in the southern Kettle Moraine at 43 degrees north, a predicted warming of three degrees Celsius will result in blue-headed vireos moving at least 17 degrees north—if they can even make it that far.

Another concerning focus of the conservation of blue-headed vireos is the proliferation of an invasive species, the hemlock wooly adelgid. Introduced from East Asia, this bug sucks sap from trees and kills its host within 4-10 years. This bug has devastated eastern forests with hemlock, however; Wisconsin is at the western edge of the range of hemlock, and has yet to report any incidence of hemlock wooly adelgid.

Map of eastern hemlock’s native range, courtesy of USDA Plants Database

The map above shows the range of eastern hemlock in the United States. The gap in the species range across the Midwest may inhibit the spread to Wisconsin, in addition to the Great Lakes buffering its spread. Yet, populations of this bug have been found in western Michigan.

In Wisconsin, hemlock has been increasing since the cutover at the start of the 20th century. The graph below shows the volume of hemlock in the state increasing since the 1980’s, and a continued increase of up to 40% is projected for the next few decades, which could benefit blue-headed vireos.

Graph from WDNR Division of Forestry Report, October 2017

While other coniferous trees may harbor blue-headed vireos, it may be of no consequence unless greenhouse gas emissions are curtailed.

Blue-headed vireo, photo by Skip Russell

Here at Faville Grove, I saw a number of blue-headed vireos in the Ledge Savanna South just last week. I got fantastic up-close looks at these birds as I stood on the quartzite outcrops of the ledge, and the vireos foraged through a hickory tree just a few feet in front of me, apparently gleaning insects. This bird is a true delight on its spring and fall migration (it has a blue head!) and would be a somber loss from our mixed conifer forests of the north.

Written by Drew Harry, Faville Grove Sanctuary land steward

Cover photo by John Sutton