Fall banding 2010: Week #1 in review

A week of scruffy birds

RRBO's 19th fall banding season got underway this week. First, a big thanks to local birder and RRBO volunteer Jim Fowler, who decided his songbird banding days are behind him, for donating his net poles to us. And to Robert Schubert, EIC student staffer, for cutting a whole batch more. We have a full set of straight poles to work with this season. Robert and Dana Wloch, one of my undergraduate research assistants, also helped out with getting the net lanes ready for banding. Many thanks!

The first week of banding usually starts slowly, as I tend to be putzing around pruning net lanes and putting up the final nets. This week there were 78 new birds banded, 4 recaptures, and 18 birds released unbanded (14 Ruby-throated Hummingbirds, the rest House Sparrows). This represented 25 species. Most were local breeders, but migrants included Least and Yellow-bellied Flycatchers; and Black-and-White, Nashville, Magnolia, and Chestnut-sided Warblers.

Most of the locally nesting species have one thing in common this time of year: they are in the midst of their fall molt. Once finished with nesting, adult birds replace all of their feathers. It occurs systematically, so they can still fly, but not quite as well. Thus a lot of adults tend to be a bit secretive.

Gray Catbirds are our #1 species. This adult female was originally banded in May 2008, and recaptured this week. What a mess.

Young birds (born this year and called "hatching year", HY for short) are also beginning to molt heavily now, replacing their juvenal* plumage with their first set of adult feathers. This HY catbird is actually one of the better looking individuals.

Most HY songbirds only molt body feathers, but some species also replace some flight feathers (wing or tail). Upon examination, it looked like this disheveled HY Song Sparrow lost its tail and was replacing it, versus a normal molt. The rest of the messy look was typical, though.

Indigo Buntings nest on campus, but I've never had a nest in the banding area until this season. This recently fledged bird was being tended by a male parent, or I might have had a hard time figuring out what species it was! When I catch a bird this young, I immediately run back to the banding lab, process the bird, and run back and return it where I found it. Once reunited with his offspring, the dad quit scolding me!

Up to about 5 or 6 years ago, Blue-gray Gnatcatchers didn't nest on campus. In fact, 20 years ago, I don't remember them nesting very frequently in the county. During the first Michigan Breeding Bird Atlas (1983-1988), breeding evidence was noted in only four quarter-townships in Wayne Co. Things have changed rather dramatically. During Michigan Breeding Bird Atlas II (2001-2007), 39 quarter-townships had breeding evidence, and for the last few years, three to five pairs have nested on campus. This HY bird, likely from a family that has been present this summer near the banding area, is only the 12th RRBO has banded since 1992, and only the second in fall.

Two interesting "abnormal" birds were banded this week.

This HY Eastern Kingbird, probably from a nest on campus, had fleshy tumors on the "shoulders" of both wings. The tumor on the left wing was small, but this one on the right wing was 14.2 mm. I see tumors of this sort from time to time. I suspect this was a feather cyst; a contributing factor for this condition may be malnutrition. This bird also had a prominent "fault bar" on the tail. This occurs when actively growing feathers stop growing for a period of time due to nutritional stress (lengthy discussion here). The bird flew well, but it's hard to say how much this will hamper it on its long fall migration.

American Goldfinches are abundant in one section of the banding area. They are just starting to fledge their young. This bird, however, was an adult male. Note that the first secondary feather on one wing was completely black on the underside, rather than having a white base. Usually when one sees birds with odd-colored feathers, the aberrant feather is white. Excessive dark plumage, or melanism, is less common, and I don't recall ever seeing single melanistic feathers or patches of melanistic feathers any birds, much less the many thousands of goldfinches I've handled.

This will be the fourth year of collecting fecal samples from Catharus thrushes to examine what kinds of fruit they are eating. It's the second year that Dana Wloch will be assisting by collecting and compiling samples from other bird species. This week resulted in 19 samples being "donated" by catbirds, American Robins, and a couple of Cedar Waxwings.

Welcome rain and the passage of a front this weekend should perk things up next week.

***

*"Juvenal" is the term for a bird's first plumage; "juvenile" is a generic term for a youngster. For more on plumages and molts, extremely useful in aiding in ageing and identification of birds, Plumage and Molt at Audubon Guides, and Molt and Plumage Lab at Biological Ramblings. An excellent new book on the topic for birders, Peterson Reference Guide to Molt in North American Birds was published this year. I recommend it.

Banding recovery: Michigan robin in Mississippi

Hot on the heels of a report of an RRBO-banded robin found in Louisiana last month, is another southern recovery. This robin, first banded here on campus as a hatching-year bird on 30 September 2007, and was found dead 5 miles north of McLain, Mississippi on 8 March 2010.

Interestingly, we recaptured this bird on 11 October 2008, when we determined it was a female. The bird was molting wing feathers when it was recaptured, which birds typically do on the breeding grounds rather than during migration. Recaptures of passage migrants are quite rare, as well, so this was likely a bird that nested somewhere on campus or nearby.

This is the 9th robin banded on campus recovered outside of Michigan. Most of them (6) were originally banded in fall (the others in spring and summer), and recovered en route to, on, or en route back from their wintering areas. This map shows all 9 areas where the robins were recovered. The Ohio bird was found just a month after it was banded in fall, so it was likely still southbound. You can click on the markers for details.

This is certainly demonstrating a pattern of Michigan robins -- breeding or migrant birds -- wintering in the southeastern U.S.

A similar map and chart of all of our out-of-state banding recoveries is on the RRBO web site.

Banding in Mexico

My husband Darrin and I have just returned from a trip to the western state of Jalisco, Mexico (highlighted above). You might recall that last year we went to Nicaragua where we conducted bird and insect surveys and did some bird banding on a shade coffee farm. This Mexican trip was sponsored by Rocky Mountain Bird Observatory in Colorado, which has done a great deal of work in this area. Our trip supported conservation work in Jalisco, an area where there are many endemic bird species found nowhere else in the world.

While our itinerary took us to several locations, I'll focus here on a visit to the Las Joyas research station in the Sierra de Manantlán Biosphere Reserve, where we, too briefly, learned about and lent a hand in one of the longest-running and most intensive bird banding projects in Mexico.

The Sierra de Manantlán Biosphere Reserve covers 1400 km² (roughly 350,000 acres). It was established in 1987, after being acquired by the government to preserve a large population of a rare species of wild maize, Zea diploperennis. The 345 km² of tropical dry forest in the reserve is the largest of its type protected in Mexico, and the 50 km² of cloud forest portion is the largest protected on Mexico's Pacific slope. Much of the land in Mexico is owned communally under the ejido system. Because there are so many landowners, biospheres in the country are structured so that there is a core area in which little or no human impact is allowed, and a buffer zone where managed activities such as sustainable agriculture can take place. A general map of the area is here.

The Las Joyas field station is operated by the University of Guadalajara in the core zone, and is not open to the public. If you put these coordinates <19.586010,-104.274028> into Google Maps or Earth and zoom in on the marker, you can see the buildings as well as the remoteness. The station is quite rustic, with solar power and outhouses with composting toilets. We slept in a dorm, 4 beds to a room, with thin walls that did not keep out the night-time chill at nearly 2000 meters! We were also warned to use a flashlight and beware of mountain lions and jaguars if we went to the outhouses at night. Four other wild cats are also common there: bobcats, ocelots, margays, and jaguarundis. Alas, we did not see any of them.

In the center is the dorm at Las Joyas; outhouses at left and kitchen at right.

The area around the dorms was full of bird life. The most common species were many usually-hard-to-see Crested Guans (Penelope purpurascens), roosting in the trees and flying back and forth; multiple sallying Tufted Flycatchers (Mitrephanes phaeocercus); several male Brown-backed Solitaires (Myadestes occidentalis) in constant song; and a pair of uncharacteristicly cooperative Blue Mockingbirds (Melanotis caerulescens). Singing Quail (Dactylortyx thoracicus) and Long-tailed Wood-Partridge (Dendrortyx macroura, a Mexican endemic) also lent their voices to the morning chorus; we got great looks at the wood-partridges at the compost pile.

The banding "station" is a table set up along a trail. Ten nets are run two days a week all year long, manned by station regulars and students working on various projects. I was very impressed by the speed and skill of the student banders, as well as the many scientific publications which have resulted from work here.

At left, University of Guadalajara's Sarahy Contreras explains some background of the banding project at Las Joyas, in which she has been involved for many years.

We just didn't take enough pictures. The pace of bird captures was steady in the morning. The students or Darrin and I were nearly always off checking nets, extracting birds, and bringing them back to the banding table. We were happy to help out even as most of our group went off for a walk.

The most common North American migratory species were Wilson's Warbler and Nashville Warbler. Most of the birds were residents, though, and a lot of them were hummingbirds.

They had a whole range of tiny hummingbird bands arranged in mint tins, and an array of special banding pliers to put the bands on. Some species we had that day were White-eared, Magnificent, Rufous, and Berylline Hummingbirds, and Green Violetear.

Here are a few of the highlights for me:

Cinnamon-bellied Flowerpiercers (Diglossa baritula) feed on nectar. The long hook at the tip of the bill is used to hold flowers firmly, while they stab the base of the flower corolla with their pointy lower bill and extract nectar by inserting their tongues through the slit. This is done incredibly fast! This is a small bird, perhaps the size of a Magnolia Warbler.

Golden-browed Warbler (Basileuterus belli).

Dwarf Vireo (Vireo nelsoni). I think this was the only bird we heard in the field but only saw in the hand. It is a very poorly known species endemic to Mexico. It's nearest relative is the endangered Texas-breeding Black-capped Vireo (Vireo atricapillus) -- one of which we also saw at a lower elevation! Black-caps have a very restricted wintering range in western Mexico, and the bird we saw was banded, most likely at the same wintering site by Sarahy two years before.

We had 8 species of vireo on the trip, including Golden Vireo (Vireo hypochryseus) and Chestnut-sided Shrike-Vireo (Vireolanius melitophrys).

Of course, as in Nicaragua, I was happy to get an opportunity to handle a couple of south-of-the-border Catharus thrushes, related to the birds I study here at RRBO.

Here is an Orange-billed Nightingale-thrush (Catharus aurantiirostris). They are smaller than a Hermit Thrush, generally the smallest Catharus thrush we get here in Michigan.

And here I am with a Russet Nightingale-thrush (Catharus occidentalis).

On the trip, we saw many other spectacular species. Among my favorites were:
Citreoline Trogon (Trogon citreolus) -- endemic to Mexico.
Pale-billed Woodpecker (Campephilus guatemalensis) -- a relative of the extinct Imperial and Ivory-billed Woodpeckers.
San Blas Jay (Cyanocorax sanblasianus) -- endemic to Mexico.
Red-breasted Chat (Granatellus venustus) -- endemic to the Pacific slope of Mexico.
Red-headed Tanager (Piranga erythrocephala) -- endemic to Mexico.
Rufous-capped and Green-striped Brush-Finches (Atlapetes pileatus and Arremon virenticeps) -- both endemic to Mexico.
Rusty-crowned Ground-sparrow (Melozone kieneri) -- endemic to west Mexico.
Orange-breasted Bunting (Passerina leclancherii) -- eye-popping Mexican endemic.

Our small group tallied around 250 species. Many thanks to Arvind Panjabi, Sarahy Contreras, Eduardo Santana, and Siux Diaz for hosting this great trip.

Banding recovery: Michigan robin in Louisiana

We received a report of a young American Robin banded here on campus 28 October 2005 being found dead in Georgetown, Louisiana. There was no specific information on the date the bird was found, only "2009." Georgetown is in Grant Parish in north-central Louisiana, near the eastern border of the Kisatchie National Forest.

This is the 8th robin (out of nearly 3500) we have had recovered from out of state, and the third from Louisiana. Four more were also from the deep south, and one was from Ohio.

You can view a table and an interactive map of all of the birds banded at RRBO that have been recovered outside of Michigan on the RRBO web site.

RRBO bird banding video

This video was produced in 2001. Although I enjoy having people see me so much younger and thinner, it could use an update as it was shot on film and the digital conversion isn't very high resolution. Nonetheless, it gives you an idea of how and why we band birds. We use this to introduce students, program participants, and visitors to the banding process.

Banding at RRBO from Julie Craves on Vimeo.

"Look what the cat dragged in"

Only about 1% of banded small songbirds are ever recovered away from the place they were banded (much of the value of focused banding studies is in initial captures and within-season recaptures). So when a bander receives notice that one of their banded birds has been found somewhere else, it's a pretty notable event. Especially remarkable is when a migrant bird is banded on its wintering grounds and recovered where it breeds (or vice versa).

Thus it was astounding to learn that a Bobolink banded in Bolivia by the Vermont Center for Ecostudies was recovered three years later in Vermont, just miles from the bander's home, 4300 miles away! This was the first time a Bobolink banded on its wintering grounds had been recovered on its breeding grounds (or vice versa).

Tempering that news was the fact that this bird, having managed to have survived at least three migratory journeys totaling 35,000 miles in flight, was delivered dead to a homeowner by a house cat.

Often, banders do not know the exact cause of death of a reported bird...usually the report is only coded "found dead." Sometimes the person who finds the bird is more specific. Out of the last 40 or so birds we have banded here at RRBO for which we have received reports, only around 30% were found alive. The majority of those found dead did not specify a reason. Of those that did, nearly 40% were coded "caught by or due to cat." They included these birds:

• A White-throated Sparrow banded on 26 October 1992 "caught by or due to cat" 5 May 1993 in Columbus, OH.
• A Song Sparrow banded on 3 April 1995 "caught by or due to cat" 17 Jun 1995 just south of North Bay, Ontario.
• An American Goldfinch banded on 10 May 2001 "caught by or due to cat" 12 May 2002 in Berea, KY.

(You can view a map and list of our out-of-state recoveries of banded birds here.)

The huge problem to birds and wildlife posed by outdoor cats is one that sparks a great deal of emotion. In fact, the blog post about the Bobolink pussy-footed around the issue to avoid the controversy. The bander pointed out that the fact that a cat brought home a dead bird is not concrete evidence that it killed the bird. However, it is generally believed that items brought home by cats are indeed prey killed by that cat, and numerous peer-reviewed scientific studies have used this behaviorial trait of cats to determine composition of prey items (see Barratt 1998, Churcher and Lawton 1987, and Woods et al. 2003 and the scores of references therein).

Don't get me wrong -- I love cats! I have two of my own, but they never go outdoors. Please, if you own a cat, keep it indoors. It is better for wildlife, and it is better for your cat.

For more information, you can see RRBO's keep cats indoors page, or visit the American Bird Conservancy's Cats Indoors! campaign web site.


Barratt, D. G. 1998. Predation by house cats, Felis catus (L.) in Canberra, Australia. I. Prey composition and preference, Wildl. Res. 24:263–277.

Churcher, P. B., and J.H. Lawton 1987. Predation by domestic cats in an English village, J. Zool. (London) 212:439–455.

Woods, M., R.A. McDonald, and S. Harris. 2003. Predation of wildlife by domestic cats Felis catus in Great Britain, Mammal Rev. 33:174–188.

Fall 2009 banding summary

I've posted a summary of the fall 2009 banding season at the RRBO web site. You'll find all the summary stats, a weather summary, top ten species banded, some commentary on deviations in numbers from previous averages, and notable within-season and between-year recaptures. There is also a brief explanation of how we calculate our capture rate, and our weather policy.

I've also updated our lists of the most commonly banded species. For the first time in RRBO history, American Robin unseated Gray Catbird at the top of the list.

Coming up, some results from our diet study.

An amazing white-breasted robin finishes the season

This stunning and unusual American Robin with a white breast was the highlight of our final day of banding for the fall 2009 season today. Our short, final week was not particularly notable; I'll be posting a season summary in a few days. Meanwhile, let's check out this very cool robin!

American Robins with abnormal plumage are not terribly uncommon. There was the funky orange-faced bird I banded a couple of weeks ago. I band robins with one or a few white feathers at least once a season. In October 2007 I banded an adult female in which nearly all the gray feathers had a frosted appearance. I have found photos of quite a few robins that were the "opposite" of our bird, with pale backs but normal breasts (in Minnesota, Saskatchewan, Iowa, Pennsylvania, and Utah). However, I have never encountered or heard of a robin that had a completely white breast with a normal back, wings, and head like the bird we banded today.

Most of the gray plumage on this robin, which was a hatching-year bird (born this year), was normally-colored. It did have a few partially white feathers on each wing. Most of these feathers were short and/or deformed. On the left wing there was one slightly brittle short feather with a bit of white, and one mostly white feather next to it.

On the right wing, one primary was half white, stunted, and growing in this weird direction. About half of the tail feathers were also "messy" looking, due to some brittleness and twisting to them.

The only hint of orange pigment was on a few feathers under each wing.

This condition is usually called "leucism," which is an abnormal reduction in the deposition of pigment in the feathers. Some leucistic birds appear entirely washed out or pale if the reduction of pigment is roughly equal in all feathers (some authors now call this "hypomelanism"). More often, pigment is absent in only some feathers, and this is known as pied leucism, or "partial amelanism." Both the grayish-brown and orange/rust feathers on robins are colored by various types of melanin pigments.

There are a number of causes for this type of plumage abnormality. Some are environmental, including injury, disease, or malnutrition. Others are genetic. In the dozens of pied leucistic birds that I have handled, I have never noted the white or pale feathers being deformed in any way. This tends to make me believe that this robin's problems were genetic in some way. The bird appeared healthy otherwise.

This was the last robin -- the 391st -- of the season, and a pretty cool way to wrap up fall 2009.

Fall 2009: Week 11 in review

Things seemed more "normal" this past week, at least in terms of volume. Diversity slacks off this late in the season, with only a smattering of lingering migrants but more winter-type birds.

We banded an Eastern Phoebe on 25 October, a species we don't band too often. This was also the day we banded what will probably be our last Gray Catbird of the season, and when we caught our first Purple Finch of the fall (below).

It's always a treat to band a colorful adult male Purple Finch (the young males are not red and look like females). If the color difference between Purple Finches and House Finches doesn't tip you off, also notice the lack of brown streaking on the sides of the Purple Finch, and how straight the top of the upper bill is -- it is curved on House Finches (a male shown below). Should you have either species in your hand, House Finches are pretty docile, while Purple Finches are known for their biting!

On 29 October we had a nice surprise. We recaptured a Slate-colored Junco banded here as a young (hatching year) bird on 24 Oct 2007. Winter site fidelity is well-known in juncos, but given the number of them here during fall and winter, and the wide area on campus they occupy, it's not very often that we recapture one from a previous year. Also on 29 October, a Rusty Blackbird sang for me in the banding area. We no longer see many of this declining species (although it was the 10,000th bird banded at RRBO), so even though I didn't catch it, I was happy to see and hear it.

I also don't catch many White-breasted Nuthatches, but this one got snagged investigating a chickadee that was fussing in the net.

On 1 November, we broke our record for the most robins banded in a single fall season. We ended the day at 357. Our fall average is 172, and our previous high number was 354. This is only the fourth fall season that we have broken 300.

Will be winding down the fall banding season this week.

Fall 2009: Weeks 9 and 10 in review

Things have picked up the last two weeks, although the bulk of the birds have been American Robins. We're up to 295 banded this fall. At this pace, we may break our record of 354. Since we are working on determining what they are eating, this is the first year that I welcome them all!

I banded two interesting robins this week. One only had one leg. It looked like an old injury: the foot was gone, along with half the tarsus (the lower part of the leg). The other half of the tarsus was still attached under the skin, but apparently not by a tendon, as it moved and rotated fairly freely. It was all well-healed, and the bird was a healthy-looking adult.

The other robin had orange, rather than white, facial markings (below, with a normal robin up top for comparison). This picture doesn't quite convey just how bold and orange this bird looked. Although I can't recall ever having banded one quite like this, it's not too unusual to get robins with this orange color in place of buff or white on some of the wing coverts.

As for warblers, we are down to the usual Yellow-rumped Warblers, the occasional Nashville Warbler, and some Orange-crowned Warblers. The duller Orange-crowns, like the one below, look a lot like Tennessee Warblers. Orange-crowned Warblers have longer tails, and yellow undertail coverts.

The bird below is a little brighter. The long-tailed look is quite evident here.

For comparison, a Tennessee Warbler banded earlier in the season, a very yellow individual. Slightly different angle, but note the shorter-tailed look.

I also recaptured a Blackpoll Warbler on 22 October which I had banded 10 days earlier. It was very fat to begin with, and positively rotund upon recapture (it weighed 20.2 grams). This represents a late fall departure date for Dearborn.

Other late dates include a Common Nighthawk in west Dearborn on 20 Oct; four Chimney Swifts over campus on 21 Oct; Northern Rough-winged Swallows near the Rouge River, also on 21 Oct; and a Green Heron on campus on 22 Oct.

We have a week or so to go for fall banding before we wrap things up for the season.

Fall 2009: Week #8 in review

The brown birds of fall have arrived. Here's our first Winter Wren of the season. This species has a very broad range across the Northern Hemisphere. In England, it known simply as the "Wren." In Germany, it is called "Zaunkoenig," which translates to "King of the Fence." An evocative and accurate description for these little balls of fiesty attitude! We often seem to catch them early in the morning. Extracting from a mist net what amounts to an energetic and slippery ping-pong ball in dawn's dim light is one of banding's challenges.

Another brown bird of fall is the last of the Catharus thrushes to migrate through, the Hermit Thrush. This is my favorite of the thrushes in my study, although I like them all. They can be very common this time of year, although so far they have not reached a peak here by any means.

Our #1 species right now is the American Robin. Early October is the peak of migration for them, and the time when large numbers in wandering flocks are descending on campus. Because migration has been relatively slow this fall, I've been coming in on my days off whenever the weather is okay. The first net run or two in the morning can be loaded with robins. I had to drag my good friend Jim "The Big Bwana" Fowler out of banding retirement earlier this week to help out in case I got swamped with robins.


Dana Wloch is the UM-D student in charge of identifying and compiling all the seeds found in the droppings of robins and species other than Catharus thrushes, so she's pretty happy with all the robins right now.

The other group of brown birds that are abundant this time of year are the sparrows, especially White-throated Sparrows. They have certainly arrived, but not yet in the numbers I expect. The non-brown sparrow that is conspiciously scarce so far is the Dark-eyed Junco. We've only seen a few so far this fall. That should change in the coming week.

Fall 2009: Week #7 in review

Things picked up this week, although overall the weather was quite uncooperative, with rain or wind cutting down our hours substantially. We began the week with a Detroit Audubon Society field trip, which occurs around this time every year. It's an informal morning of talking about RRBO's research, answering questions, discussing the species that we bring out to show the group after they've been banded and just before they are released. This year there was a nice variety of birds. The photos below were taken by Bill Rapai, of Grosse Pointe Audubon.

Orange-crowned Warbler

Gray-cheeked Thrush. Speaking of which, one was
recaptured twice this week that ended up gaining
a whopping 12.8 grams over 11 days -- that's a
gain of 40% of it's original mass! I have had other
over-achieving Gray-cheeked Thrushes over the years,
including one that gained 16 grams. I don't have an
answer why this particular species would pile on so
much fat at this relatively early stage in their
migration (they winter in northern South America). In
these situations, I usually recapture them more than
once over 10 days or so in which weather doesn't seem
to be a factor in delaying their departure. They are
often recaptured the first time quite fat, and just get
fatter every time I catch them.

I've been training a new bander this season, Guadalupe Cummins. She is an environmental science graduate student here at UM-D, and I'm trying to convince her to work on a project having to do with birds. She began extracting birds and banding them on her own this week.

"Probie" and a goldfinch.

Speaking of student projects, we have now collected over 100 samples of bird droppings from robins and catbirds to examine for seeds (and far fewer from thrushes). Robins are especially productive, although sometimes they don't wait until they are in a bag to provide a donation. I carry little glassine envelopes to collect any errant seedy blobs, so long as I can attribute them to an individual bird. This activity has been the source of a lot of amusement and a variety of suggested names and titles. I'll leave you with the winner.

Julie Craves, the Number One of Number Two.

Fall 2009: Week # 6 in review

Another slow week has gone by. We finally broke 400 new birds banded this week, after 28 days of banding. This time of year, we can expect to band 400 birds in a week. Other folks in the western Great Lakes have also complained about this being a really lousy migration so far. The culprit: the jet stream has for the most part been stubbornly parked at a high latitude, through the middle of central Canada. It's been in this general position since mid-August, a highly unusual situation. Migration is strongly influenced by weather systems, and weather systems are influenced by the jet stream. Rather than going into this here, I'll put some links together in my next post.

We did have a few mildly interesting days. The predominant warbler has been the Blackpoll, followed by Magnolia (below) and Nashville.

This is the time of year when we get very large flocks of blackbirds, mostly Common Grackles and lesser numbers of Red-winged Blackbirds, along with some Brown-headed Cowbirds and (if we're lucky) Rusty Blackbirds. So far, it has only been grackles, and they seem to have arrived/gathered a little early this fall. They mass on the oak trees, ripping off acorns, and carpet the forest floor flipping through the leaf litter. Because of their weight, grackles don't "stick" in the banding nets very well, but it isn't unusual to catch a whole batch of them if they are moving through the net lanes. This is never very fun. They can (do!) pinch quite hard with their sharp bills. They also have very strong feet and it can be uncomfortable if they grab on and get a toenail stuck in your cuticle.

I happen to think that grackles are pretty handsome, but right now they are molting. The one below is a young bird, molting from its dull juvenile plumage into the more typical glossy garb. Judging from the color, this is probably a male. The wing feathers are also molting, or I'd be able to tell which gender by the length of the wing -- males are larger than females.

Speaking of toe nails, here's a robin with pale nails; they are usually dark-colored. We see a number of birds lacking pigment in their nails every season. Often it is Gray Catbirds and robins for some reason.As you'll see in my next post, the jet stream and weather systems are finally on the move. So long as we can avoid rain and wind, things should pick up next week.

Fall 2009: Week #5 in review

It was another quiet week. There was an influx of migrants on Sep 15, and some obvious large movements of American Robins and Blue Jays beginning on Sep 17. Some new species were recorded this week. Philadelphia Vireos have a very tight fall migration window right around September 15. We saw our first on Sep 12, and banded two on the 15th.

The 16th saw our first White-throated Sparrow of the season, and more were around on Sep 20. Sep 19 we had our first Gray-cheeked Thrush. Cape May Warblers seem to have had a good year. We banded two nice-looking hatching-year males, one of which is shown at the top of the post.
Two older birds were also recaptured this week. The first was a female Northern Cardinal first banded as an adult on April 13, 2003, making her at least 7 years old. We had recaptured her a number of times in 2003 and 2004, but this was the first recapture since then.

Next was a Gray Catbird that had been banded as an adult, in its second year, on May 17, 2005, making this bird at least five years old. We have captured it several times each year, often in breeding condition -- this was a male.
And here's my ID tip of the week (don't get your hopes up that I'll have one weekly!). The bird above is a Chestnut-sided Warbler. Like many (most that I see) individuals of this species in the fall, there isn't any chestnut on the sides. However, the color of the back and top of the head are very distinctive. To me, it's just like the color you get when you use a fluorescent yellow highlighter on newsprint. What do you think?

Fall 2009: Week #4 in review

I don't have much to say about this week. It was pretty boring. We've had some nice groups of warblers, usually consisting of a dozen species, right behind the EIC. Not many have materialized in the banding nets, however. I think this may be the slowest start to a fall season ever. I've updated the stats in the sidebar, and leave you with a photo of a pair of Black-throated Blue Warblers banded this week. We need some good weather fronts to get things moving, but nothing looks promising over the next 5 days or so.

Fall 2009: Week #3 in review

In contrast to last week, this week was gorgeous. A high pressure system remained stalled over the region, creating beautiful weather but a doldrum of sorts for migrants. Last weekend saw some movement, and early in the week, which meant we had our first observations of Cape May Warbler, Magnolia Warbler, Black-and-white Warbler, Chestnut-sided Warbler, and Blackburnian Warbler. We banded several other new arrivals, including Nashville Warbler, Tennessee Warbler, Ovenbird, and Wilson's Warbler. As the week progressed, things just petered out.

Ovenbirds are a personal favorite.

The air is filled with the (obnoxious, if you ask me) begging calls of young American Goldfinch, a species that is among our latest nesters. We've started catching families. The adults are just now beginning their fall molt, and their old feathers are extremely worn.

The white wing bars on this adult male goldfinch have worn nearly completely off. Dark pigments make feathers stronger, and the pale areas often wear away first.

I've also netted a lot of hummingbirds this year; one day this week I released eleven. I presume many are the same individuals, but between mulitple birds in the nets at the same time and plumage differences, I know there were at least seven different ones out there one day. Hummingbirds require special bands and permits, so I just release the birds when I catch them.

A molting adult male hummingbird ready to zip off. Only a few of the 40 I've caught so far have been adult males or this one!).

The most disappointing news of the week was finding out that the massive construction project next door at Henry Ford Community College will not be complete for at least another month. This loud, dusty project is directly adjacent to my site, and the bulldozers, piledrivers, and other big noisy machinery get going just after sunrise. I believe this is having a negative impact on my banding activities. The resident birds seem to be used to the commotion, but when the hubbub gets vigorous, the migrants seem to move away from it all. Although the very large underground retention basin, capped with a parking lot, is supposed to be complete by October 15, this is a three year project and will continue the next two summers. Arrgg!

The big dig next door. If this view isn't enough, for the next couple of months, you can have the excitement of following along on a web cam.

Fall 2009: Week #2 in review

This week was largely a washout. Even during dry periods, the generally damp weather has really encouraged the mosquitoes, which are worse this year than I can ever remember them being. Yuck!

The first boreal-nesting migrant was banded this week, a young female Canada Warbler on 25 August. A couple more Baltimore Orioles were in the nets, thus breaking our previous fall record of 14 banded; we now stand at 16. I've banded five Yellow-shafted Flickers so far, which is above-average. They are fairly heavy and so do not "stick" in the nets very well. But they seem to love digging around in the new wood chips, so I expect we may set a record for this species this year as well.

Young (hatching-year) female Canada Warblers can be pretty dull.

Most notable bird banded this week, in my opinion, was an adult Red-eyed Vireo netted on 25 August. It was a recapture, and had originally been banded, also as an adult, in August 2003. This means this bird is at least 7 years old. We've had returns of other Red-eyed Vireos before, but prior to this bird the longest period between recaptures was less than 5 years. You can take a look at RRBO's age records on this page. It lists a variety of species with at least two years between captures. According to the Bird Banding Lab's longevity records, the oldest Red-eyed Vireo is estimated at 10 years, 2 months old.

What makes this particularly remarkable is that Red-eyed Vireos winter in South America, making the minimum distance traveled between Dearborn and the northern coast of Colombia about 2200 miles one-way.


Range map for Red-eyed Vireo, from Cornell's All About Birds, a recommended resource.

This bird, then, has flown at least 36,000 miles on migratory flights!

Looks like the weather will be much improved next week. With reports of migrants in the region already trickling in, things should start to get interesting soon.