CHICAGO AUDUBON SOCIETY Periodicals 5801-C N. Pulaski Road Chicago, IL 60646-6057

Navigating the world of and nature

VOLUME 26, ISSUE 6 NOVEMBER/DECEMBER 2012

very birder knows that involved just a single individual , but tropical hummingbirds use to capture arthropods. Do have a symbiotic relationship with certain it is frequently cited. Robert D. Montgomerie and temperate-zone hummers use the same? wildflowers. Browse through any textbook Catherine A. Redsell tracked the foraging activities The first method, hover-, looks like nectar- about biology, and you will almost of a female Broad-tailed Hummingbird for two weeks E ing: the bird holds itself in the air a few inches from surely find a section detailing the connection—com- in May in and around her nest in Rose Canyon in a spider web or a leaf and reaches for the prey with plete with photographs of the birds nectaring and Arizona’s Santa Catalina Mountains. The research- bill and tongue. This may be the most easily observed diagrams of bills, tongues, stamens, pistils, and corol- ers surveyed for nectar plants in the nearby landscape of the four methods. If you witness this behavior, you las. Because they are tubular and showy, and often might try to determine the bird’s target—sometimes red, the plants gain pollinators with long memories, it’s the spider, but hummers also parasitize from the who return to the same flowers again and again. And webs, taking insects the spider has already captured. because their bills are long and their tongues flexible Not all Sweetness (And, of course, female hummers often steal the and grooved, the birds have access to energy sources threads from webs as adhesive building material for not readily available to other animals. The birds and Light their nests.) A second method, hover-hawking, also probe the flowers to collect the nectar at the bottom involves hovering, but here the bird zigzags through of the corollas and come away dusted with pollen, by Jack Connor swarms of insects, picking them off one by one, which they carry from flower to flower. The birds are almost as a might. The final two methods are fueled; the plants are fertilized. probably the hardest to notice because both involve Hummingbirds and “hummingbird” plants make such the bird sitting quietly and mostly motionless, scan- an eye-catching ecology lesson that textbook authors ning for prey. In sally-hawking, the bird flies up to repeat it in book after book, and birders often fail to snatch a single flying insect and then returns to its see that it’s not the whole story. What’s easy to forget perch. In sally-gleaning, the hummer flies up to pick is the proviso that most texts generally mention in a an insect off a leaf and returns to perch. sentence or two but rarely illustrate: “Hummingbirds Stiles’ superb and lengthy article cannot be summa- supplement their sugar diets by feeding on small rized adequately in the space available, but here are a arthropods.” Most of us know this truth, but my sense few highlights: is that too many of us consider it a trivial point. How many birders have made a determined effort to watch More than half of all foraging efforts Stiles recorded how hummingbirds feed themselves away from flow- (both nectaring and predation) involved hunting for ers? And how important is that supplement, anyway? arthropods. Nectaring is actually the less-frequent activity. One problem may be that we don’t know what to look for. In a fairly lengthy library and Internet search, I Hummingbird stealing insects from spider web. Hawking is more frequent higher in the vegetation; Photo by Amber Coakley. found few illustrations of arthropod-hunting by hum- sally-gleaning and hover-gleaning are more common mingbirds (although it’s easy to find photographs and (in a one-kilometer-diameter circle around the nest) at lower heights. Foraging activity of all types is most drawings of the much rarer activity of hummingbirds and found none in bloom that were appropriate for intense early in the morning, when the birds are at being killed by praying mantises). The oldest explana- hummingbirds. Over several subsequent days, they their hungriest. tory images I could find dated to 1946 and appear recorded time budgets for the female’s activity for Spiders are a favored prey among many species; some in an article by German ornithologist Helmuth O. 10-minute intervals during each daylight hour (6:00 tropical hummers feed almost exclusively on them. Wagner titled, “Food and Feeding Habits of Mexican A.M. to 8:00 P.M.) and followed all her movements Stiles even noticed some spiders retreating from their Hummingbirds,” published in The Wilson Bulletin. away from the nest as best they could. “During the webs when the birds hovered near, and he suggests 19 foraging bouts…that we observed,” they reported, Wagner studied the foraging behaviors of more than this might point to a competitive advantage for hum- “the hummingbird spent all her time either flycatch- a dozen species in Mexico during the 1940s. He illus- mingbirds with longer bills, which can still probe and ing, gleaning from leaves, probing among lichens on trates the techniques used by starthroats, sabrewings, grab without alerting their prey by the whir of their tree trunks, or flying between foraging sites.” Their violet-ears, and other hummingbirds to capture flying wings. conclusion: “[T]he bird must have subsisted only on insects from the treetops, over cornfields, and above arthropods for at least two weeks.” During the nesting season (at La Selva at least), forest streams. Several hummers are drawn in silhou- females spend three to four times more time search- ette flying up from tree branches to snatch insects A much larger study by J. V. Remsen, F. G. Stiles, and ing for arthropods than males do. In fact, the impor- from the sky, kingbird-style—a foraging technique P. E. Scott published in 1986 in The Auk examined tance of arthropod foraging may be one reason why that today would be called sally-hawking. He also the stomach contents of more than 1,600 individu- female hummers in many species—including several describes hummingbirds gleaning prey from bark, als of 140 species of tropical hummingbirds and North American species— have longer bills than leaves, and even water surfaces. found that 79 percent held arthropod remains. “The their mates. In all hummingbirds, females are the data indicate that most hummingbirds, at any given Based on his field observations, his work with captive sole caretakers of their nests and young, obligated moment during the day, are digesting arthropods [and hummingbirds, and the stomach contents of collected to gather all the food for their nestlings, which need suggest that] most hummingbirds feed on arthropods specimens, Wagner concluded that insects and spiders protein for growth. on a daily basis and probably at regular intervals were far more important in hummingbird diets than throughout the day.” Can observers equipped only with binoculars study is generally understood and that nectar was not as these phenomena? The answer is an unqualified yes. essential as many authorities believed. Hummingbirds Why don’t we notice hummingbirds hunting more Stiles depended extensively on his visual observations adapt their foraging to whichever sources are avail- often? Could it be that they spoil us—chasing each of birds in action in compiling his data, as did Wag- able, and arthropod prey often replaces nectar. “The other through our yards, preening in the open on leaf- ner in the 1940s, when binoculars were much weaker food of hummingbirds is determined primarily by less perches, or, best of all, zooming right up under instruments than they are today. habitat and season,” he wrote. “A given species may our noses to nectar at our feeders and garden plants? feed mainly on nectar or mainly on insects, depend- In those situations they make themselves hard to Searching for them out away from our feeders is one ing on the time of year. The majority of the hum- miss. Hunting for insects, however, they seem to keep key, of course. That involves a little extra legwork. As mingbirds in Mexico are not dependent on flowers.” a lower profile, noted often only by those who are is the case in many other birding challenges, however, most alert. the real challenge is mental: to learn how these birds Although few researchers have claimed that hum- truly live their lives, we must make the effort to look mingbirds can go without nectar indefinitely, a In a report published in The Condor in 1995, summa- past their flash and dazzle to the grittier reality just number of them have argued that arthropods are rizing his 18 years of hummingbird observations in beyond. more important in the birds’ diets than is generally the lowland forest in La Selva, Costa Rica, F. G. Stiles supposed. A 1980 study published in The Condor describes and illustrates four primary methods Courtesy of Cornell Lab of Ornithology. Chicago Audubon Society North Park Village 5801-C N. Pulaski Road Chicago, IL 60646-6057 www.chicagoaudubon.org 773-539-6793

Above: Broad-tailed Hummingbird, Oak Park, Illinois 2011. Photo Jerry Goldner. Right: Broad-tailed hummingbird with tail feathers displayed. Photo Jerry Goldner. Editor: Skipper Joy Wolters Layout Design: JustSayJoy.com

How Do Pigeons The Compass is the official publication of the Chicago Audubon Find Their Way Home? Society, a chapter of the National Unlocking The Secret Of How Birds Navigate Audubon Society. The Chicago Audubon Society, an Illinois non- By Justine E. Hausheer profit corporation, has been granted tax-exempt status by the federal he pigeon is far more says J. David government. The Compass and the mysterious than meets Dickman, a Chicago Audubon Society are not Tthe eye. Considered a neuroscientist at responsible for the accuracy of all nuisance by many, these birds are Baylor College information published or for opinions expressed in this publication. the stars of ongoing research into of Medicine Compass (ISSN 1097-7899) is birds’ sixth sense: navigation. in Houston, published bi-monthly by the Chicago who lead Audubon Society, 5801-C N. Pulaski, From the ancient Romans to the Chicago, IL 60646-6057. Distributed the research, Illustration by Shannon Rankin/Selflesh.etsy.com Allied forces in World War II, to membership ($5 allotted from published in Science. dues). Periodicals postage paid humans have long used pigeons to but actually macrophages, or white “These signals could be used at Chicago, IL. Postmaster: Send carry messages because of their blood cells that help the bird’s im- address changes to Compass, c/o like a GPS.” remarkable ability to find their way mune system. They’re loaded with Chicago Audubon Society, 5801-C N. Pulaski, Chicago, IL 60646-6057. home. Pigeons and many other Other creatures have internal iron because they recycle old red migratory birds are thought to use compasses—trout detect magnetic blood cells, says David Keays, lead Report sightings to: 773-539-6793 the earth’s magnetic fields to stay information through their nose, and researcher and a neuroscientist at Report injured birds to Chicago Bird the course, but scientists aren’t sure migrating loggerhead turtles pick the Institute of Molecular Pathology Collision Monitors: 773-988-1867 how our feathered friends detect up on both latitude and longitude— in Vienna, Austria. “We found them Website: www.chicagoaudubon.org and process magnetic information. but most navigation research has all over the bird, from the skull to Office Administrator: Skipper Wolters, 773-539-6793, [email protected]. New research is answering some of focused on birds. the wings,” he says. “They’re on these questions. patrol for pathogens.” Office hours: Monday–Thursday Until recently, scientists thought 10:00 a.m.– 4:15 p.m. In May scientists reported that that iron-rich neurons in pigeons’ The discovery means that scientists Closed Fridays and holidays brainstem cells associated with transmitted information about must continue the search for the OFFICERS the inner ear are activated when magnetic fields to their brains. But magnetic field-sensing cells. But President: Roger Shamley, 773-274-5362, a pigeon is exposed to magnetic another team unexpectedly dis- they aren’t flying blind: [email protected] fields. “The brain cells signal the proved this theory in April. The Dickman’s work hints Vice President: Chris Van Wassenhove, 773-477-4618, [email protected] direction, intensity, and polarity researchers discovered that the iron- that those just might be Treasurer: Bobbi Asher, 708-771-2085, of the earth’s magnetic field,” rich cells aren’t neurons at all found in the inner ear. p [email protected]. Secretary: Annette Prince, 630-841-7110, Golden-crowned a hummingbird, the [email protected] kinglet winters north- COMMITTEE CHAIRS Kinglet ward to Canada and Awards: Alan Anderson, 847-390-7437, Alaska. [email protected] Formerly breeding Birdathon: Joe Lill, 773-631-3154, almost exclusively [email protected] in the remote, boreal Education Chair: Roger Shamley, 773-274-5362, [email protected] spruce-fir forests Field Trips: Jeff Sanders, 847-657-6431, of North America, [email protected] this diminutive bird Stewardship: Dave Kosnik, 847-456-6368, has been expanding [email protected] its breeding range Nominating: Alan Anderson, southward into Golden-crowned Kinglet. Photo by Kelly Azar. 847-390-7437, [email protected] spruce plantings in second set of eggs while the male Program Chair: Joe Lill, 773-631-3154, [email protected] Golden-crowned Kinglet. Pennsylvania, Illinois, Indiana, takes care of the first brood. Despite Photo by Dave Rintoul. Editorial: Skipper Joy Wolters, and Ohio. They usually raise two having eight or nine young to feed, 773-539-6793, [email protected] large broods of young, despite the the male manages to feed them, tiny, continuously active short nesting season of the northern himself, and occasionally the incu- bird, the Golden-crowned boreal forest. bating female as well. AKinglet is most often found in coniferous woods. The female feeds her large brood Each of the Golden-crowned Despite being barely larger than only on the first day after they leave Kinglet's nostrils are covered by the nest. She then starts laying the a single, tiny feather. page8 2 Chicago Peregrine Program Monitoring Peregrines

tion of Peregrines. Over 20 years of Peregrine Falcon on the Federal banding has allowed us to look at Endangered Species List. During the dispersal and longevity of the this same time period, the Peregrine peregrines found in Illinois and the Fund was established. It oversaw the Midwest. reintroduction of Peregrines in the east using a process called hacking, Historically, an estimated 400–500 a delicate method of releasing birds pairs of Peregrines once nested in back into the wild. the Midwest and eastern United States. But by the 1960s, the spe- The Midwest launched its own Photo courtesy of cies had been extirpated (wiped release programs in the 1980s under Peregrine Falcon. The Field Museum. out regionally) and few were seen the coordination of the Raptor Photo by Jack Ballard. during migration. Once a feder- Center in Minnesota. The Chicago onitoring our state’s ally endangered species, Peregrine Peregrine Program began in 1985 Illinois-based birds have originated over 20 pairs and their Falcons had all but completely as a cooperative effort between from nest sites located in Indiana, M territories is definitely a disappeared from the Midwest by the Chicago Academy of Sciences, Minnesota, Iowa, and Wisconsin. team effort. Over the last 20 years, the 1960s, due to the use of DDT. Lincoln Park Zoo, Illinois Depart- When population levels in the Mid- Mary Hennen and her fellow team The primary cause was the buildup ment of Conservation, and Illinois west finally began to rise, the focus members on the Chicago Peregrine of organo-chlorines—DDT and its Audubon Society. of Peregrine programs shifted from Program have helped to success- byproducts—in the birds. These releasing birds to monitoring nest- fully reintroduce these beautiful accumulated chemicals caused From 1986-1990, the Peregrine Pro- ing pairs. Illinois' peregrine popula- birds back into the Midwest. The addling of eggs (causing an egg to gram released a total of 46 Pere- tion has gone from extirpation in team currently monitors nest sites, become infertile), abnormal re- grines from four different hack sites. the state by 1951, to a single breed- tracks parent identification, as well productive behavior in adults, and The goal was to help re-establish ing pair at the Chicago-Wacker site as watches over offspring as they thinning of shells, which led to egg Peregrines on a regional basis in the in 1988, to 12 breeding pairs in over hatch, mature, and fledge (take their breakage. Midwest, with the hope that some first flight). Through these obser- birds would return to Illinois to 23 different territories by 2011, to a vations, scientists can determine In 1972, the government banned breed. This regional falcon dispersal current level (2012) of 25 territories. how well their efforts are working the use of DDT in the United can be seen through the identity of For more information, go to to create a self-sustaining popula- States, and a year later, placed the our adult Peregrines. Over the years, fieldmuseum.org.

An Arresting Photograph Faux Feathers: Blurs the Lines Between Incredible Hunk of Hematite Mimics Bird Wing Animal and Mineral By Julie Leibach o, it’s not what you think. In fact, the aerodynamic N object isn’t even organic, let alone avian. Bearing a resem- blance to bird wings, it’s a hunk of hematite, a mineral formed from iron and oxygen. Photographer Rosamond Purcell shot this speci- men for A Glorious Enterprise, a 464-page tome commemorating the bicentennial of the Academy of Natural Sciences in Philadelphia, America’s oldest natural history museum. Aptly christened “Bird Wing” by museum curators, this chunk of hematite represents one of about 466 mineral specimens collected by William Sansom Vaux (his name- sakes include the Vaux’s ). A Quaker and lawyer by training, Vaux was also a passionate mineralogist, particularly drawn to aesthetically appealing specimens—especially hematite. He procured this shimmery, dusty-rose piece from the English Midlands, once a hotbed for quarrying. Upon his death in 1882, Vaux left a 6,000-piece mineral A hunk of hematite. This image is one of many that feature specimens from Philadelphia's collection to the Academy. Academy of Natural Sciences and appear in the book entitled A Glorious Enterprise. Photograph by Rosamond Purcell. Courtesy of Audubon Magazine.

page 38 ringing Th B e Benef its 1-800-342-3782 Of Over 95% of our products are Na manufactured in our factory tu in Chicago. re T o Y our House

Bright lights from buildings, along with reflective or transparent window and lobby glass, are hazards for birds migrating through Chicago.

Each year Chicago Bird Collision Monitors recover more than 7000 birds that have suffered roug W ht Iron & T ubula collisions in the downtown area. r Fe PLEASE RECYCLE ede r P Our aluminum martin ol houses are manufactured es • Q from 100% recycled aluminum. uic With your participation our rescue and prevention k C onn ect TM Ho efforts can be expanded and more birds can be saved. oks & Han gers • Baffl es • Bird Houses & Feeders and more! YOU CAN HELP: Join a morning rescue team. Monitor a building where you live or work. Transport birds to wildlife rehabilitation centers. Support collision prevention work. Assist in public outreach and awareness programs.

For more information: Please watch for our Annual Appeal 2012 www.birdmonitors.net mailing coming in late November. This is one of our most important fundraisers 773-988-1867 of the year. All donations are extremely important to our goals and programs. We thank you for your past support and hope you Reminder to our readers: will be able to help us again this year. The Compass can be read and enjoyed in color on our website, chicagoaudubon.org. Just click on the word “Compass” in the top row of links on the homepage to visit our archives. Don’t miss these wonderful birds in living color! For historical value, we have added a link to the very first Chicago Calendar of Events November/December 2012 Audubon newsletter. This link is sitting on top of Clymene Moth. the Archive list. Enjoy! Photo by Roger Shamley. Birdwalks, Workdays, Special Events

Important Notice to our Readers Chicago Audubon Membership Form WOODED ISLAND BIRDWALKS. other management activities. Meet at JACKSON PARK. EVERY the Tower Road parking lot, east of the There has been some confusion You may charge your membership WEDNESDAY AT 7:00 A.M. AND lagoon bridge. For further information, about the difference between a online using our secure website, EVERY SATURDAY AT 8:00 A.M. please call Dave Kosnik at 847-456- National Audubon membership and chicagoaudubon.org, or call the office These wonderful walks continue 6368. Everyone is welcome! a Chicago Chapter membership. A at 773-539-6793 and charge your throughout the year. Bring binocu- National membership by itself does membership over the phone, or mail in lars, field guides, and dress for the MONTROSE POINT MAGIC not financially support the Chicago this form. weather. Many species are seen. Meet HEDGE STEWARDSHIP Audubon Chapter. National Name: at Clarence Darrow Bridge, just south WORKDAYS. Volunteers needed to Audubon and the Chicago Chapter of Museum of Science and Industry. help with weeding, mulching, plant- (and all other chapters) have entirely For details and directions, contact Pat ing native shrubs and trees. We have separate budgets (except for a small Address: Durkin at [email protected]. also been establishing a prairie. For yearly stipend from National). In Everyone is welcome! information about work dates, to sign

other words, the Chicago Chapter up, and for directions, please contact has always carried the burden of SKOKIE LAGOONS WORKDAYS. David Painter at 773-383-0721 all costs of producing and mailing 10:00 A.M. MONTHLY, EVERY or email at [email protected]. this newsletter and other types of Phone: SECOND SATURDAY. These work- Everyone is welcome! mailings that we have been sending days are continuous throughout the to both the Chapter members year. The Chicago Audubon Society CHICAGO URBAN CHRISTMAS and the National members in this Email: sponsors regular monthly workdays at BIRD COUNT. SUNDAY, area. Because of this separation Skokie Lagoons every second Saturday DECEMBER 16. Compiler Jeffrey in budgets and because we need of the month. Activities include buck- Sanders, [email protected]. local support, we are asking that thorn cutting, brush pile burning and you consider becoming a Chapter Minimum yearly membership: $25 New Members at $65 or above receive a nice hat. member at this time. Chapter membership will not only help with We accept Visa, MasterCard, and Discover. our immediate need to reduce costs Y Y related to the newsletter, it will give Name on card: direct financial support to our local programs and goals and enrich the To our readers and their families energy and support of the Chapter Card number: and friends, our best wishes for membership base. If you would like to become a Chicago Audubon the coming holidays and for a Chapter member, please fill out the Expiration date: Wonderful and Happy New Year! form to the right and send it to our office at: Chicago Audubon Society Chicago Audubon Society does not ❄ ❅ ❆ ❅ ❄ 5801-C North Pulaski Rd rent, lease, trade, or otherwise Chicago, Illinois 60646 disclose any membership information whatsoever.

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