Legions of tiny black and white birds are moving south from Canada in droves.  Consider these reports (keyed on the map):

• Banders in Toronto, at Tommy Thompson Park along Lake Ontario (A on map), band over 200 of these birds beginning Oct. 16.
• At Prince Edward Point, Ontario (B on map) over 6000 are counted, and over 700 banded, beginning Oct. 19.
• Passage rates along the Chatham and Kent county lines in Ontario (C on map) are estimated around 300 birds per hour.
• Over 500 are banded at Long Point Bird Observatory, a peninsula in Lake Erie (D on map) beginning Oct 22.
• Over 1000 counted from the hawk tower at Holiday Beach, Ontario (E on map) on Oct. 30.

The species: one of the most familiar and beloved birds in eastern North America, the Black-capped Chickadee (Poecile atricapillus).

Chickadees are familiar because their range extends across most of Canada and the northern two-thirds of the U.S., where they are regulars at bird feeders.  And while they are resident where they are found, they also stage periodic irruptions, a phenomena more often associated with winter finches such as crossbills, redpolls, and siskins. Irruptions — birds moving south from mostly boreal nesting areas — are typically due to a lack of food, such as a failed conifer cone crop, in usual wintering areas.  That is also a factor in chickadee movements, especially following exceptionally good reproductive success resulting in “excess” numbers of young chickadees.

The map indicates that high numbers of chickadees are being seen along the northern shorelines of the Great Lakes. As one might imagine, such small birds are loathe to cross big waters, and they congregate and move along the coasts.  Still, there have been chickadee movements noted in the U.S., especially in update New York, eastern Pennsylvania, and Maine.

Holiday Beach, near Amhertsburg, Ontario, is less than 30 miles as the chickadee flies from my field site.  However, it’s south of me, and close to the mouth of the Detroit River where it empties into Lake Erie.  Chickadees have no doubt traveled along the Erie or Detroit River shorelines, reluctant to cross, when they end up being counted at Holiday. Being west of those waters, and away from shores, I tend to see little of these invasions. In 2001, the last time there was a large chickadee irruption, I did set a high season banding total, but it was modest. It is very near the end of my banding season now, and I’m just starting to encounter these migrant chickadees.  In the hand, they can be distinguished from residents by their bigger fat loads, and the simple fact that I haven’t already banded them earlier in the season, when I usually catch most of the local birds.

I like chickadees as much as anybody.  As an ornithologist, I am intrigued by their complex social structure, with well-defined flock membership and quite stable dominance hierarchies. As just a regular gal, I am charmed by chickadee acrobatics, energy, boldness, and all-round pizzazz.  As a bird bander, I am overjoyed that chickadee invasions do not extend to my field site.

It’s hard for me to imagine a worse situation than nets full of chickadees; even dozens of flesh-clamping cardinals or diarrhea-spewing robins seems more appealing.  All the bossy, determined fuss you see chickadees express in the field is magnified when they are in the hand. Observe how calmly this bird sits in my net.  You can see we’d been through all this before — I had banded this bird two days previously. Note that it is hardly tangled, an easy bird to remove from the net.  Note also the gleam in the bird’s eye, as it prepares to launch its assault.

The moment I reach into the net, it will explode in an indignant whirl of commotion, a virtual avian tempest in a teapot.  No other species squirms, wriggles, and hangs on to the net so tightly.  Most obnoxious is the constant barrage of pecking, with an outstanding affinity for locating cuticles and other soft, sensitive places. I’ve been bitten by dozens of species of birds, and although not the most painful, chickadee abuse is clearly the most annoying.

Chickadees remain miffed throughout the banding process. It’s really astounding how a 10-gram ball of feathers can make life so difficult. Inevitably when you open your hand to release them, they stick around for one final second — in order to offer one last good, hard peck.

I welcome chickadees: to the U.S. from their Canadian boreal birthplaces, to my yard and my feeders, but please, not into my nets.

Time to catch you up on my reading.  Topping the list is The Tapir’s Morning Bath by Elizabeth Royte. I thoroughly enjoyed this book, and it also gave me some serious food for thought on the direction of my own career.

The  book:
I often find reading about a far-flung place is more interesting to me after I’ve been there. TTMB is about the Smithsonian’s field station on Barro Colorado Island, in the Panama Canal, which I visited this summer. Plenty has been written about it — creation of the island, establishment of the field station, the many famous scientists who have worked there, and more papers, monographs, articles, and books about research results than you can shake a stick at.  Royte weaves this information throughout TTMB, but brings BCI to life by spending months living at the field station and working with the wide variety of researchers (some long established, some green grad students) working on BCI.

It’s hard for me to actually tell you what this book is mostly “about,” which is to Royte’s credit. Engagingly, she accurately depicts the tedium, complexity, and discovery of field work (which, as a field ecologist, I love!) and the rich intellectual yet quirky world of scientists, all set against the backdrop of a tropical rainforest.  How the work of these researchers applies to conservation is a constant theme, skillfully explored by Royte, who inserts herself in the scene without forcing herself on the reader, as many authors are apt to do.  So, in turns, this book is about Barro Colorado and tropical forests, about the conservation of biodiversity, about how field work is done, about the world of science, scientists, and academia, and about people.  All without seeming preachy, dry, arcane, or scattershot.

Admittedly, I have a strong attraction to all these subjects, so perhaps I’m predisposed to liking a book like this.  But it would have been easy for an author to make a mess of it. I finished this book wishing I had written it.  And that’s one of my highest ratings.  It stays in the sidebar!

What made me think
One of the researchers on BCI was Bret Weinstein, and his philosophy (incredibly wise for a graduate student) was often highlighted by Royte.  Weinstein had a measure of disdain for the whole doctoral process, as do I.  Years ago, I saw one of my personal heroes, Paul Erhlich, give a talk in which he emphasized our urgent need to get out and DO conservation.  He indicated that our academic system needs revamping, that we spend too much time doing “knowledge for knowledge’s sake” rather than applied research, and that we jealously hoard our findings until we can publish them rather than share them and act collaboratively for the good of biodiversity. I heard this at a time when I was debating about entering a doctoral program, and it helped me decide to continue doing my field work rather than aborting it to spend several years jumping through hoops to get a PhD.  I felt I could do more continuing what I was doing than going back to school.

Of course, most scientists will say their research will aid in conservation.  Weinstein contends that really isn’t true.  “If they really wanted to conserve habitat, they’d work to redistribute the wealth and get slash-and-burn farmers,  ranchers, and loggers to stay out of the forest,” he says in TTMB. He goes on, adding another layer to Erhlich’s point, “Conservation is a political problem.  The powers that be won’t be dissuaded from destroying the forest by an explanation of its mechanisms.”  Ah, very true.  But what then?  Abandon research and a doctoral degree and become a politician?  No, Weinstein observes.  There is an advantage to having done research and having a PhD: you can talk about conservation and people will be more likely to listen.

I’ve been thinking about this a lot. My overall goal is conservation.  Given my background, skills, accomplishments to date, (and age!), how can I be most effective?  I especially love a book that gives me a new perspective, and the stories of the researchers on BCI depicted in The Tapir’s Morning Bath provide new insights that I will use as I reconsider the trajectory of my career.

You can read more about The Tapir’s Morning Bath, Elizabeth Royte, and the scientists she worked with at the book’s excellent web site at Booknoise, a showcase for promoting noteworthy books.

Hurricane Wilma, a slow-moving category 4 storm, is currently spinning over Cozumel Island off Mexico’s Yucatan Peninsula. It is expected to remain there for the next 24 to 36 hours. At this point, we are all familiar with the damage this hurricane can and will do. Homes and businesses will be destroyed. And it is likely that a unique bird will also be wiped out. This may prove to be the end of the Cozumel Thrasher.

The Cozumel Thrasher (Toxostoma guttatum) is endemic to Cozumel Island, and so few are thought to exist that it is categorized as critically endangered. It was fairly common on the island until Hurricane Gilbert hit in September 1988. After that, few birds were seen. Two researchers from the Universidad Nacional Autonoma de Mexico (National Autonomous University of Mexico) made 15 visits to Cozumel between 1994-1998, and found only three birds, two of which were mist-netted, the last in July 1995.

That October, powerful Hurricane Roxanne hit the island, and for years, there were few credible sightings of the Cozumel Thrasher. Then in July 2004, a single bird was seen by researchers, reigniting the hope that the species was hanging on in small numbers.

Hurricanes and Cozumel are no strangers. Thrashers obviously evolved with and adapted to these storms. It is theorized that introduced boa constrictors, now established after being released by filmmakers at the end of a shoot in 1971, have become important predators on nesting thrashers (as well as other animals on the island). This added pressure may have made the birds vulnerable to hurricanes, unable to successfully regain their numbers after especially strong storms.

The fact that two previous hurricanes had such apparent devastating impacts on Cozumel Thrasher populations does not bode well for this species, considering the strength of Wilma and the amount of time it is expected to lash the island. We might not know for years whether or not the thrashers are gone. For generations they were able to cope with nature’s blows, but our carelessness once again may have created a situation from which the birds cannot recover. Already, it is a great loss.

That what we have we prize not to the worth
Whiles we enjoy it, but being lack’d and lost,
Why, then we rack the value, then we find
The virtue that possession would not show us
Whiles it was ours.
— Willliam Shakespeare, Much Ado about Nothing, Act IV, scene 1

Any day now, American Tree Sparrows (Spizella arborea) will arrive to spend the winter.  They share honors with Red-bellied Woodpeckers and Ring-necked Ducks in being comically misnamed. American Tree Sparrows (tree sparrows for short, although they should not be confused with Eurasian Tree Sparrows, Passer montanus) breed across great expanses of northern Canada (click on Cornell map below), often north of the treeline, where they nest on or near the ground.  In winter, they are also most often seen on the ground, frequently underneath backyard feeders, or balancing daintily on the dried seed heads of wildflowers and grasses.

They are, using an old-fashioned term once applied to birds deemed beneficial to humans, “good neighbors,” consuming seeds of some of the weediest weeds: ragweed, lamb’s quarters, crab grass, knotweed, pigweed, and even Phragmites.  One very old account estimated that American Tree Sparrows consumed 875 tons of weed seeds over the course of a winter in Iowa alone.  In the early part of the twentieth century, much was made of the value of tree sparrows to farmers because of the “vast quantities of obnoxious weed seeds” the bird consumed.  The contributor to the American Tree Sparrow section in Bent’s Life Histories series went into some detail on this point, then concluded, “In the summer the tree sparrow is of no economic significance, as it nests beyond the reaches of civilization.”  She quickly redeems herself by adding, “But whether or not we can evaluate the species in cold dollars and cents, it will always be welcome as a gentle, cheerful little creature in our winter fields and gardens.”

With their chestnut caps, tree sparrows resemble Chipping Sparrows (S. passerina), and are sometimes called “winter chippies,” but at least here in Michigan it is not too often that these two species are in the same place at the same time. Chipping Sparrows depart south for winter as tree sparrows arrive, and return north as tree sparrows are heading back to Canada.

American Tree Sparrows are fairly well known for their fidelity to wintering sites, but much of the literature on the subject is old, and studies were in less-developed areas, which could be more appealing to the birds.  How faithful might they be to an urban bird feeder, especially given the option of many other feeders in the vicinity?

I started banding this species in my back yard the winter of 1997-98.  This is admittedly not a very high-volume effort — we are able to attempt to catch birds only on weekends with decent weather. Still, I’ve banded over a hundred tree sparrows, and 17% have returned in subsequent years, some for three to five years in a row.  Considering that the majority of small songbirds, in particular migratory species, don’t live two years, that seems pretty remarkable.  I think the rate would be higher, except the last few years my husband and I have had less time to band in the yard, and there have been fewer tree sparrows around.

Some authors have hinted populations of tree sparrows may be slipping. Due to the remoteness of their nesting areas, population trends can be difficult to accurately discern, and are based primarily on winter bird counts here in the U.S.  One of those counts is Cornell’s Project FeederWatch, which noted a shift in the areas where tree sparrows spent the winter, (as shown in this series of maps) as opposed to a true decline.  My own long-term winter surveys show a 95% decline from 1993-2004, but habitat at my site has been maturing, so it may not be as attractive to tree sparrows as it used to be.  I’ve also done analyses on a couple of local Christmas Bird Counts; they also show declines. But over the 30 years of those counts, the count circles have undergone extensive development, and there is less sparrow habitat available.

Which of these factors — shifts in distribution, habitat change, or habitat destruction — is causing the apparent declines in tree sparrow numbers?  Or is climate change playing a role, causing them to stay further north in winter, or impacting food resources on the nesting grounds?  Is it a combination of these factors? Or are populations actually stable?

Audubon knew these birds as “Canada Buntings,” and referred to them as “sweet little creatures.” I look forward to the return of these hardy souls, so charming and unassuming, such heroic exterminators of malicious weeds.

calls like clear sweet bells
flock of graceful tree sparrows
enlivens winter

I’m not easily grossed out, but I figure that it’s probably best if human waste is not discussed on public blogs, at least those that are not dedicated to some sort of medical topic.  And for sure photographs of human feces should hardly be necessary to illustrate any post on any topic, including exotic maladies.  Yet here I am, violating the boundaries of good taste. (I have miniaturized and tried to be as unoffensive as possible.)

A chain link fence is being replaced on our campus, including a section with a gate that leads to my field site. Lines of red spray paint on the ground traced the intended route of the fence, while utilities were glaringly marked with both fluorescent green spray paint and a row of perky blue flags.  Nevertheless, yesterday one worker pulled up a flag, carefully set it aside, and proceeded to drill a post hole with great precision right into a gas line.  Our entire side of campus had to be evacuated.

Today I noticed the three guys who had so stunningly misconstrued the cautionary cues had been replaced by three new fellows.  One, in fact, emerged from the woods ahead of me as I was returning from the field to our lab with the morning’s first batch of birds to be banded. It seemed to me to be only a marginal improvement to go from nitwits
who had drilled into a gas line to guys too lazy to walk 30 yards to the nearest building to take a leak.  At least this dude’s casual bathroom habits wouldn’t cause an inconvenience like the broken gas line, I thought to myself.  Oh, how wrong I was.

We were greeted on our next trip out to the field by a huge pile of crap right next to one of our bird banding nets. No coyote leaves a heap like this, or a napkin from Subway (motto: “Eat Fresh”) next to it. I resorted to sticking a (the?) discarded gas line flag into it because we were too busy to do anything but try to avoid it.  As you can see if you click on this photo, it is square in the path to the net. This strapping young man apparently needed to grasp the net pole, ignoring that it was not a natural forest object and in the center of an obvious trail, in order to achieve good form so he could pass yesterday’s lunch. I’m sorry to say that by the time things slowed down with the birds, the fence installers had departed. I had no opportunity to pick up the load in a shovel and place it on or near their truck, while sweetly inquiring, “I believe this is yours?”

Instead, I was left to dutifully document the doody.  Not for the blog per se, but to accompany a couple of important letters.  First, one to the owner of the fence company — let’s call it “Acme Fence and Stool” — advising him that perhaps his firm should add being toilet trained to a list of qualifications for employment.  And another to our vice chancellor, congratulating him on finding a contractor that was not only low-bid, but clearly made up of “special needs” employees, scoring points for the University.

I realize that fence installers may not be the sharpest tools in the shed, but is this really the level to which our labor force has stooped (or squatted)?  This incident was just so egregiously pathetic I was left not enraged, or disgusted, or even particularly surprised.  It just completely bums me out that there are so many mindless, oblivious cretins walking around.  Readers, do not assail me with similar stories!  I don’t want to know how many MORE idiots there are out there like this carefree defecator. If you can find a silver lining in this crappy situtation, however, please leave a comment.

Large aggregations of insects — a crop of periodical cicadas, overwhelming hatches of mayflies, or the sudden synchronous appearance of many colonies of winged ants — are most often a summertime phenomenon. But fall can be an excellent time to observe — even without intending to — equally impressive bunches of bugs.  Within the last few days in my region, the annual assemblege of Eastern Box Elder Bugs (Boisea trivittatus) has begun.

Despite the ubiquity of Box Elders (Acer negundo) around here, I don’t see boatloads of Box Elder Bugs most of the summer.  As the name suggests, they feed primarily on Box Elders, but will also utilize other maples. Box Elder Bugs (let’s call them BEBs) are Hemipterans, or true bugs, with piercing mouthparts. They suck juices from young leaves and stems, but really prefer the newly developing seeds of A. negundo. Since Box Elders are dioecious (male and female flowers are on separate trees), large populations of BEBs really only occur on female Box Elders, which have all the seeds. BEBs rarely do any damage to trees.

Mature BEBs are about 12 mm long. BEBs overwinter as full-grown adults, so now is the time of year when they begin looking for sheltered places in which to hibernate. First they gather en masse on or near tree trunks. Then they may fly up to two miles prospecting for a cozy, dry location to pass the winter months. In nature, rock piles or loose bark might do the trick, but buildings also offer excellent refugia.  BEBs wedge their way under shingles, into vents, and various other cracks and crevices. If it has been a warm, dry summer — like this one in the Midwest — there might be thousands of BEBs on the sunny sides of buildings, just taking a break from their search, or looking for entry into an appropriate hibernacula.  When they get into residential buildings, people get all freaked out, although they are completely harmless to humans.

Although I have an enormous geriatric female Box Elder in my yard, I have few BEBs, and none have ever sought sanctuary in my house.  They have, however, begun to accumulate on the outside walls of our campus parking structure.  Many will crawl under light fixtures and signs, to emerge on warm winter days to bask a little before retreating once again. On these brisk winter afternoons, I welcome the sight of these handsome little bugs, with their pleasing geometric pattern of black and red. Their tentative exploration of a January thaw provides a reminder of the richness and plenty of summer during a time of year when that fecundity seems furthest away. I like to think that perhaps, like me, they turn themselves to the winter sun, and imagine the lush abundance of a summer past, and one yet to come.

Lo! on the topmost pine, a solitary cicada
Vainly attempts to clasp one last red beam of sun.
— Japanese poem

I actually got a call the other day from a man complaining about the sounds of cicadas and katydids.  He explained that since a nearby forest had been cut down for a subdivision, there had been an increase in loud insects in his neighborhood.  He wanted to know how to get rid of them. 

He played a tape recording of an insect (he thought it was a bird, which I presume he was equally ready to oust) which he said called all night long.  Blasting over the phone was the unmistakable pulsating song of one of the dog-day cicadas, Tibicen pruinosa (you can hear this call, along with many others, on the Cicadas of Michigan web site).  Cicadas do not call at night, although I think the guy was unconvinced.  I explained to him about the great diversity of these insects, and something of their life cycle. Although I tried to reassure him that the calls would diminish greatly the next few weeks, to cease all together when autumn really hit, he still tried to get me to recommend something that could be sprayed on all the trees to evict the offending insects.  I suggested instead that perhaps he should consider relocating to an even more developed area where there were no trees or green space and therefore, no annoying insect sounds.

I found this disgusting.  We want to live in the "country," but we don't want to deal with wild animals that find our garbage or disturb our gardens. We don't want to listen to singing birds that have the gall to try to establish a territory, in a place where generations have sung, at dawn; or to noisy insects, especially those louder than leafblowers or hedge trimmers or lawnmowers, or those that can be heard even when our house is closed up tight with the air conditioning on.  We complain about woodpeckers trying to homestead on our structures, after chopping down those unsightly dead snags where they would prefer to nest.  We complain about flying insects after evicting the swallows from under our eaves, because they could "spread disease." We wonder where the butterflies have gone, after spraying with insecticides and pulling out all that messy goldenrod we think makes us sneeze, restoring "order" to "our" property. 

We want to "get away from it all," but the sprawl we create insures that all we said we wanted to get away from is once again hard up against our back doors, and what we thought we wanted to escape to, we have sterilized and tamed into a bland, dysfunctional parody of nature. 

I find it thoroughly depressing that a fellow citizen of my planet would want to silence cicadas. Perhaps he thought my blunt suggestion about moving to a concrete landscape was rude.  I hope that it made him think.  I try to tell myself that no matter how hopeless and frustrating the situation seems, my obligation, as a person who values, treasures, and understands biodiversity, is to try to educate others. I'm feeling a sense of urgency, and wondering how much more often the enlightenment must be conveyed by forceful eye-opening rather than gentle awakening.

Here’s a startling update to the deer overpopulation thread.  A paper in the latest issue of Conservation Biology described how Black Bears (Ursus americanus) have been extirpated from an island in the Gulf of St. Lawrence by the introduction of White-tailed Deer.

Anticosti Island, Quebec is a large (7943 sq km/3000+ sq mi) island that once supported an abundant population of bears, but no deer.  About 220 deer were introduced on the island in 1896, and by the early 1930s numbers had reached greater than 50,000; currently there are between 60,000 and 120,000 deer on Anticosti.  By the time the population reached a high density, the deer had severely reduced or even extirpated the deciduous shrubs on the island.

Bears do not digest foliage very efficiently, and must consume large quantities of berries in order to accumulate enough fat to hibernate through the winter.  Berries were once abundant on Anticosti, but a recent survey found an average of only 0.28 berries per square meter.  The deer, which prefer deciduous shrubs to conifers, have overbrowsed all the berry-producing plants.  In particular, shrubs of the Rubus family (raspberries, blackberries) are browsed before they can even reach fruiting height.  Bears need at least 66 berries per square meter to even maintain body mass.  Thus, bears cannot even be re-introduced onto Anticosti, as it is no longer able to support them.

An astounding and sobering example of the effects of deer overpopulation!

Cote, S.D. 2005.  Extirpation of a large black bear population by introduced white-tailed deer. Conservation Biology 19:1668-1671.

This port-a-john on campus was getting a lot of business. From incoming freshmen.