Fall banding 2011: week 5

Well, things can sure change in a hurry. After probably the dullest first month in 20 years of fall banding came two of the busiest days in RRBO's history. The same stalled low pressure system that was responsible for days of rain and/or wind eased up just enough on Friday, Sep 9 to let us open our nets. Birds that had been pushed west by the weather systems in the prior days were all over the place. We caught 127 birds on Friday morning, and nearly all of them were warblers. It was raining at sunrise on Saturday, but stopped for two hours which allowed us to open nets. It was clear things were still hopping. We closed when it rained, and re-opened again. Although we were not open as long as Friday, we caught 134 birds, again mostly warblers.

Twenty were RTHU, which we released unbanded. Subtracting those and recaptures, 216 were new birds. Thanks to Darrin O'Brien and Dana Wloch, two of my most experienced banders, we worked out a system where birds were fully processed -- measured, aged, sexed, and weighed -- in less than two minutes and we were never away from the nets for more than 40 minutes.

In the fall, Bay-breasted Warblers usually don't show
much bay color on the flanks. This one has a hint.

The big story for the week has been Bay-breasted Warblers. Our fall average is just two, and our previous fall season high number is five. We have already banded 26 and seen many others. Tennessee Warblers are more numerous west of here in fall, but we've exceeded our fall average of nine with 11 so so far. These two species (along with Cape May Warbler), are generally thought of as "spruce budworm" warblers, since their populations can be tied with outbreaks of this insect on their nesting grounds.

Black-throated Green Warbler

When there are large pushes of birds due to weather systems, it's hard to attribute inflated numbers to actual increases in populations, but a few other species have more numerous than usual this season overall (not just on the two big days). Blackpoll Warblers are much more common; our fall mean is 23, and we've banded 43 so far. Our current total of ten Black-throated Green Warblers is well above our fall mean of two and high of six. We've netted and released 52 Ruby-throated Hummingbirds. Since they are not marked some may be repeats, but it isn't too unusual to catch three to five in one net. However, the most we've netted in the past was 50, and we usually get them into October.

Things tapered off after those two big days and have more or less returned to normal. I hope to have a post up about one of our special projects within the next week or so.

Fall 2011: Weeks 3 and 4

As you might imagine, banding has been largely at a standstill. Week 3 was very hot, limiting banding to only a couple of hours in the morning. Week 4 so far has been -- and looks to be -- completely rained out. A low pressure system (the remnants of tropical depression Lee) has been stalled just to our east, unable to move as Hurricane/Tropical Storm Katia moves up the Atlantic. Not much we can do but wait out the weather. Here are a few birds we banded when the conditions cooperated.

American Redstarts are quite numerous this fall. Most are young birds. Some young males and females can't be told apart. Male redstarts look a lot like females for an entire year. However, a few have more boldly colored orange patches on the sides, which you can just make out in this photo.

 

Wilson's Warblers are also common early migrants here. The young females show barely any trace of the dark black cap of males.

Yellow-bellied Flycatchers are a personal favorite of mine. It is really hard to capture their true lemony-olive color, but this photo comes close. Notice that their heads look too big for their bodies -- this can be a good field mark, especially when combined with the color.

I did take a look at the previous RRBO data and compared it to our August data to see if my hunch that birds seemed to have nested a little later, based on molt patterns, was correct. I mentioned this in my previous post. I examined all hatching-year birds banded in August 1992-2010. About 13% of those birds had not yet started their first post-juvenile molt. For August 2011, it was 26%. So it does seem that a lot of the juvenile birds we caught in August were a week or so younger than in previous years.

We hope to be able to resume banding over the weekend.

Fall 2011 banding: week 2

Another very quiet week, with not many migrants around. A higher percentage of the young resident birds that I'm banding have not yet started or are just beginning their post-juvenile molt than I usually see this time of year. This is the replacement of their juvenile plumage into their first winter adult plumage. It's usually in full swing right now. Same with the molt of adults, who typically molt all of their feathers after they are done nesting. The adults I've banded have just started this process.

The extent of this molt this year tells me that these species -- cardinals, catbirds, robins, and Song Sparrows mostly -- were a little later in fledging than usual. It could be that the big flood in May caused some birds to lose their first nest, and pushed breeding back a couple weeks. Or, good conditions this summer (warm, good amount of rainfall, lots of bugs) could mean some species attempted a third nesting.

I have heard and seen adult birds still tending their newly-fledged young. Here is a brand-new youngster I captured this week. Can you guess the species?

While it seems a little lost and forlorn, I found one of the parents in a nearby net. Although both sexes of this species look alike, they can sometimes be distinguished in the hand. The incubating parent (in most songbirds, just the female) develops a bare area on her belly called a brood patch. The area loses feathering and becomes vascularized in order to facilitate the transfer of heat from her body to the eggs and chicks. I was able to tell that this was the female parent of the chick above.

It's a Chipping Sparrow, a common nester here on campus.

Another frequent nester is the Baltimore Oriole. Because they migrate so early in the season, I sometimes don't catch any in the fall. I had three in one net this week, including this adult male. Orioles are pretty sassy. This one seemed astonished, and a little indignant.

Over the weekend, we had some north winds which brought in some migrants that were observed on our survey on Sunday. This week may bring a small uptick in captures if the migrants stick around, but the forecast is for more southerly winds and hot temperatures toward the end of the week. That could slow things down, but we'll see!

Fall banding 2011 begins

RRBO began the 2011 fall banding season on 12 August. The first week was a "soft" opening, when we put up only a portion of the nets each day, make adjustments, and handle all the young fledglings in the area with some extra TLC. We were also taking some extra time to prepare for a special project, which I'll write about in a future post.

Not too many migrants were present. We caught a Yellow-bellied Flycatcher on 15 August, which was an early date for a fall migrant in Dearborn. A Chestnut-sided Warbler captured on 17 August was the only other passage migrant netted this period. I like the inquisitive look it has.


What we did have was a lot of mosquitoes. This is the worst year for mosquitoes I can remember. In fact, so many come inside with me that they are as bad inside the banding room as many typical years outside.

The coolest bird we caught was not uncommon -- a male Northern Cardinal. But it was a bird we had banded on 19 April 2001 as a second-year bird. Thus, he is now over 11 years old, the oldest cardinal we have recaptured and the second oldest bird we have ever recaptured. While 11 years falls short of the record listed at the Bird Banding Lab web site of over 15 years, it was still good to see him. Over the years he has been recaptured 21 times, but the last time was in 2009.

This is our fifth year of studying the diets of fall migrant birds on campus. We're off to a good start with our sampling of seeds in the poop of various birds. These are all from robins and catbirds.

Just about every species of fruit that is currently ripe has showed up in the samples: grape, pokeweed, glossy buckthorn, dogwood, cherry, and nightshade.

Speaking of robins, three of the six robins we've caught so far have weighed less than 60 grams and have been fairly emaciated. By comparison, only six robins out of over 3500 previously banded here have weighed less than 60 grams, and the average weight for robins is about 78 grams. Generally, I only see birds like this when they are on death's door, and often after they have been exposed to lawn chemicals. I don't have an explanation for the lean condition of these birds, but we'll be monitoring future captures carefully.

Finally, it looks like it may be a very good year, the first in some time, for chickadees. Over the decade between 1992-2002, the resident chickadee population on campus was on the decline. Last fall, there was a large movement of chickadees in eastern North America. It was notable here, and I wrote about it after our last Winter Bird Population Survey season. Clearly, many chickadees chose to stay and nest here, as they were evident on our spring survey as well. We've already banded nine, which is our average over the past nine years. Our high was 52 in 2002. As you might imagine, they are quite the little fussbudgets. I'm happy that their numbers are rebounding, but not so sure I want to band a record number of them.

A Black-capped Chickadee was the first bird banded by RRBO during our inaugural fall season in August 1992. That's right -- this is RRBO's 20th fall banding season. Stay tuned for anniversary-year news.

Dearborn Goldfinch in Ontario

RRBO recently received notice that one of the 2500+ American Goldfinches banded here on campus was recovered elsewhere. Only about 1% of small songbirds banded are found away from the place they were banded, so a report of this kind is always interesting. Usually, birds are not found far away, and usually they are dead. This report indicated that the goldfinch in question, a hatching-year male we banded here on 19 October 2010, was captured and released by another bander north of Guelph, Ontario (about 175 miles from Dearborn, as the goldfinch flies) on 10 May 2011.This has happened only a few times for RRBO: a Yellow-rumped Warbler caught in Tallahassee, FL, a White-throated Sparrow on Ontario's Bruce Peninsula, and a Northern Waterthrush in Wisconsin. What made this American Goldfinch capture even more special was that it was captured by Antonio Salvadori.

Toni has been banding for nearly as long as I have been alive, founded the Guelph Banders Group, and bands at three locations. One is at his home in Guelph; another a property in Ermosa, just outside of Guelph; and at Colwyn Farm, northeast of Guelph near the town of Fergus. But here's the kicker. In 2008, Toni captured and released a Blue Jay banded in the east Dearborn yard of RRBO's Julie Craves and Darrin O'Brien. He caught the jay at his Ermosa, Ontario location. It's hard to imagine the odds of this occurring. I might expect that Black Swamp Bird Observatory would capture some of our birds, or vice versa, given their volume and location on the north shore of Lake Erie about 50 miles nearly due south of RRBO. So far, this hasn't happened. You can read more about other out-of-state recoveries of RRBO's birds on our recoveries page, and about Toni's banding history in this PDF from the Guelph Field Naturalists newsletter. Cross posted at the RRBO web site.

Update on the Ross's Goose

In my last post, I described the discovery of a Ross's Goose on 24 March 2011, a first record for Dearborn. The goose was banded, and we have just received the details from the Bird Banding Lab.

This was a nestling male banded on 7 August 2006 in Nunavut. This much I knew from reporting the goose on the Bird Banding Lab's web site. The location, it turns out, is McTavish Point. The geocoordinates are 67.75, -101.08333, which places it north of the Arctic Circle in the Queen Maud gulf region, where over 90% of the world's Ross's Geese nest.

This map (click to enlarge) shows the banding location with a red marker: this is 1900 miles in a straight line from Dearborn. I've also indicated the location of Akimiski Island in James Bay, Nunavut. Although we do not see many Canada Geese with orange neck collars around here any longer, this is where nearly all of them were banded (more on the Dearborn-Akimiski connection here).

Ross's Geese have undergone a substantial population increase in the last few decades, and while once exceedingly rare in the Midwest and eastern U.S. during migration and winter, they have been showing up in these regions with increasing frequency. The increase in Arctic-breeding geese (especially Snow Geese) has profound impacts on sensitive habitats. "Our" Ross's Goose was banded by Ray Alisauskas, a scientist with the Canadian Wildlife Service, one of the key researchers working on the status of Ross's Goose and Snow Goose and their impacts on Arctic ecosystems. (Thus answering the obvious question of who would be in such a remote place banding geese!)

Most of the specific information on the winter or migratory distribution of Ross's Geese based on band recoveries is from hunters. Presumably, a report like ours, from a live bird, is quite rare.

While not the flashiest bird, this Ross's Goose surely had one of the most interesting stories of any bird we have encountered!

Fall banding 2010 wrap up

I have summarized the fall 2010 banding season at the RRBO web site.

Click here for a detailed account of the season, including photos, a table, and some graphs. The page of our most commonly banded birds has also been updated. You can view overviews of previous banding seasons on this page.

Fall banding: Week #10 in review

Banding took place on five mornings this week, with several marred by the continued invasion of the banding area by deer. We banded 133 new birds of 24 species. The composition was decidedly autumnal: robins, sparrows, and kinglets dominated. An Orange-crowned Warbler and a lingering Blackpoll Warbler were the only warblers banded; Yellow-rumped Warblers remain conspicuously scarce.

There are many hundreds of Common Grackles and Red-winged Blackbirds in the area these days. Thousands are feasting on the sunflowers planted by Ford Motor Co. Large flocks, with a few Rusty Blackbirds mixed in, find their way to campus every day. They favor raiding the oak trees that are near, but not in, the banding area, so we usually don't catch too many. In fact, this was the first red-wing of the season:

This is an adult male. By next summer, the brown edging on his feathers will wear away, and he will have the jet black look we are more familiar with.

We have only banded about two dozen Brown Creepers since 1992. It is always a treat to get one of these delicate and sort of odd little birds.

We also don't band many White-breasted Nuthatches. In the fall, I'm twice as likely to catch a Red-breasted Nuthatch, even though we have few conifers and they tend to just pass through, than I am a White-breasted, although they are common residents.

Note the very gray cap contrasting with the darker nape, indicating this is a female.

We are still gathering good numbers of seed samples to determine dietary preferences of birds on fall migration. The composition is changing, with crabapples now showing up in samples as these fruits ripen. Earlier this season, I showed you that seeds are not the only thing we find that birds have consumed. This robin dropping contained a surprise. The dark seed is from Common Buckthorn, the light ones from Amur Honeysuckle. The other object is a jewelry clasp.


By this time of year, we usually spend quite a few mornings loitering around waiting for frost on the nets to melt, provided we have even been able to open them (they are rolled up when not in use, and can freeze shut). We had our first two frosty mornings of the season this week. It's hard to catch birds when the nets look like bed sheets.

The forecast is once again for mild weather, though, so we don't anticipate frost for the beginning of the week, although wind might be a problem. Somewhere, I have a photo of nets full of leaves....

Fall banding: Week #9 in review

This week had great days, and very boring days, kind of strange for this time of year. Over five mornings we banded 103 new birds and had 22 recaps -- a higher proportion of recaptures than recent weeks, indicating birds are sticking around a bit. We've recaptured 5 kinglets (both species); typically we only recapture two a season of these wandering sprites.

Warblers are lingering, with four species banded this week: Black-throated Blue (below, putting us at nearly double our usual fall average), Nashville, Orange-crowned, and Common Yellowthroat.
We've only banded a few Yellow-rumped Warblers so far, and really haven't seen a large influx of them yet.

As is typical of this time of year, it's Sparrowpalooza time. Six species of sparrows were banded this week.Field Sparrow.

Fox Sparrow.

White-crowned Sparrow (with young, hatching-year birds like this dominating).

And Song, White-throated, and Dark-eyed Junco.

Hermit Thrushes seem to be around in typical numbers after last year's diminished season total of 27. We've had 30 so far. Due to improved collection techniques, we have obtained seed samples from about 57% of the Catharus thrushes we've handled this year, up from the previous three-year average of around 44%. Already our overall collection of seed samples has revealed different proportions of seed species in the droppings of bird compared to the past few years. Fruit crops can vary from year to year based on weather, pollinator availability, and perhaps "built-in" cycles. Our long-term study of these dynamics will help us understand which species of fruits are consistently important, and which are only used in the absence of others -- important data for habitat management.

And finally, we are preparing for our annual fundraising campaign. The University does not provide any funding for RRBO. It all comes from outside sources, with a large proportion coming from individual donors. If you aren't on our mailing list, please consider adding your name. You can also cut to the chase, and donate today!

Fall banding: Week #8 in review

We banded all 7 days of week #8 (3-9 Oct), but several days were shortened by having to replace nets destroyed by deer. The deer herd on campus has gotten so large that we had to resort to surrounding the entire banding area in deer fencing several years ago. Due to budgetary constraints, we used relatively inexpensive plastic fencing which requires continual maintenance. Six got in earlier this week when a tree fell on the fence, causing considerable damage over several days.

Nonetheless, we banded 179 new birds of 30 species. Our best day was 5 Oct, when we handled a total of 63 birds. We breached our season high record for Blue Jays, which was set during our first season in 1992 with 19 birds. We're at 22 for the season now. Many banding stations east of us are having a banner year for kinglets, and it looks like we could be on track to break our own records as well, especially with Golden-crowned Kinglets.

This week was also the first strong showing of Hermit Thrushes. The most fecal samples I have obtained over the last three years for our dietary study was 41 from Swainson's, Gray-cheeked, and Hermit Thrushes combined. We're over that total already, with the bulk of Hermit Thrushes yet to come.

Speaking of thrushes, I recaptured a Gray-cheeked Thrush on 7 Oct that I originally banded on 1 Oct. It had a decent amount of fat upon first capture, and weighed 35.2 grams. When I recaptured it, it had piled on the fat and weighed 45.1 grams, an increase of 28% of its original mass in just six days. This is noteworthy, but not unusual for this species here. Gray-cheeked Over 25% of the Gray-cheeked Thrushes we've recaptured gained greater than 20% of their original mass, and about 10% of them gained more than 30%. This is especially interesting given that this species winters in northern South America. They have a long way to go, and it seems unusual for a bird to gain so much weight so early in their migration.

There were two highlight birds this week. First up was a young male Yellow-bellied Sapsucker banded on 4 Oct. This is only the fourth we've banded here since 1992. They are not uncommon here, but usually hang around above net-level.

The other bird was banded today (10 Oct) -- a Palm Warbler of the eastern or "Yellow" race, which nests east of Ottawa and usually migrates east of the Appalachians. We banded one in 2003 (photos and more info on the RRBO web site) and 2008 and have two spring sight records.

Yellow Palm Warblers, in addition to being slightly larger than the western form that typically migrates through Michigan, have very yellow underparts, with little contrast among the throat, belly, and undertails coverts. Overall they are more washed with yellow, including a yellow supercilium.

Western Palm Warblers, especially in fall, are pretty dull. Here is one from earlier this month:

Even in spring plumage, western birds have brownish chest -- you can see how it contrasts with the throat and undertail coverts in this spring bird in Florida (photo by Len Blumin):

Today's bird was a young (hatch-year) bird that was as bright or brighter than the 2003 bird, which had a short wing measurement and no chestnut color in the crown, indicating it may have been a female. Today's bird had many concealed chestnut crown feathers over a large area and a longer wing, making it a male.

I've updated the Palm Warbler page at the RRBO web site with some new photos later in the week. We average about nine Palm Warblers a fall season, and we are a few bird over that total so far this year -- maybe we'll have a few more individuals to show the range of western Palm Warbler plumages in fall.

Fall banding: Weeks 6 & 7 in review

The last two weeks were characterized by some odd weather. Week #6 (19-25 Sep) featured a return to summer, with very warm weather and substantial south winds, not so good for migration. Last week (26 Sep-2 Oct) began with more of the same, and ended up with an ubrupt change to more autumn-like conditions, although wind and rain were involved. Thus, five full and two partial banding days were lost to weather.

For the period, we had 189 birds of 35 species. The wide diversity of warblers typical of mid-September began to give way to the birds of fall: White-throated Sparrows, Hermit Thrushes, more American Robins. Blue Jays are migrating right now, and we've been catching more of them. It's pretty easy to tell a young blue jay from an adult. As in quite a few species, there is a difference in the shape of the outer tail feathers. In young birds, the first set of tail feathers is usually more pointed:

In older birds, these feathers tend to be blunter:

In theory, this can help you age the bird. In practice, if a young bird loses its tail feathers, they will grow back with the adult form. So if a jay has adult-shaped feathers, you need to have at another characteristic to verify the age. The primary coverts (the feathers that cover the bases of the outer flight feathers) and adjacent alula of young jays are dullish blue-gray or brownish-blue:

In adults, they are brighter blue, and usually barred:

These photos aren't the greatest to illustrate this -- in a lot of jays the differences are pretty obvious, while these individuals were not the best examples.

We had nine recaptures of birds we previously banded. The highlight was the Indigo Bunting that turned out to be oldest Indigo Bunting ever reported recaptured by a bander in North America. There were four birds from last year (Downy Woodpecker, Black-capped Chickadee, American Robin, Song Sparrow), and three from 2008 (Hairy Woodpecker, 2 Gray Catbirds), and a Northern Cardinal from 2005.

On Sunday, September 26 we hosted an informal bird program for a Detroit Audubon Society field trip. A nice group showed up, and they got to see a variety of species. Most of the warblers were banded after the group left, unfortunately! Birds banded were: Blue Jay, Black-capped Chickadee, Philadelphia Vireo, Red-eyed Vireo, Swainson’s Thrush, American Robin, Gray Catbird, Nashville Warbler (below), Magnolia Warbler, Cape May Warbler, Blackpoll Warbler, Wilson’s Warbler, Common Yellowthroat, Lincoln’s Sparrow, White-throated Sparrow, Indigo Bunting, Northern Cardinal, and American Goldfinch.

Super senior P. cyanea

One of the most interesting birds banded this season was not an unusual species, but an unusually old bird. Most small songbirds do not make it through their first year -- they have about an 80% mortality rate. If they make it through their youth, many only live 2 or 3 years. Resident birds tend to live longer than migrant birds, and the farther a bird must migrate each year, the more hazards it faces, and the shorter the typical lifespan.

Indigo Buntings nest over much of the eastern U.S., and winter in the West Indies and Central America, and are therefore considered long-distance migrants. This male Indigo Bunting was first banded as a "second year" bird on 23 August 2003. Thus, it was hatched in the summer of 2002. We recaptured it in May 2006 and May 2007 when it was in breeding condition. This many round trips is pretty remarkable itself.

We caught him again this past week, on 29 Sept. Based on the way age calculations of recaptured birds are made, this makes this bird 8 years and 3 months old -- which happens to be a longevity record for this species in North America, according to the longevity records kept by the Bird Banding Lab. The previous record was an 8-year-old bunting in West Virginia -- a record that stood for the last 48 years.


You can take a look at some of the other birds we have recaptured years after their original banding on this page at the RRBO site. Note that on that page, the "age" indicated is the period that has elapsed between captures, not a calculated age.

Fall banding: Week #5 in review

This past week things picked up nicely, bringing us what we expect at this point in migration, a nice diversity and good numbers of birds. We missed a day and a half to rain, but banded 183 new birds and handled 31 recaptures, one of which was a Gray Catbird first banded in 2005. There were 37 species, including 15 species of warblers. We are already at or above our fall season average for Black-throated Blue, Blackpoll, Magnolia, and Nashville Warblers, and American Redstart. The most special warbler of the week was this great young male Hooded Warbler. It is the third ever banded for RRBO, and only the second fall record for Dearborn.

We banded two other unusual birds this week. The first was this dark, heavily marked form of the Veery, matching descriptions of the Newfoundland race.

The other surprise was this European Goldfinch. RRBO has done a lot of research on this species. While not a first for Dearborn, it was interesting nonetheless. This individual was not a wild vagrant from Europe, but an escaped or released cage bird.

We banded four species of vireos this week: Warbling, Red-eyed (we're already at our fall average), Philadelphia, and Blue-headed. I think Warbling Vireos look angry, while Philadelphia Vireos, like the one below, look "cute."

Blue-headed Vireos are one of my favorite species. We don't catch a lot of them, and they are just so handsome.


Actually, photographing any vireo is a challenge. They are all fuss and squirm. My general rule is that I only take a few quick shots of any bird I handle. If I can't get a good one, my loss. I don't have a lot of great vireo portraits because they are so uncooperative, most pictures end up like the next two.

We've been getting a lot of great samples for our study of what fruits birds eat in the fall at our site. This is the fourth year I've collected droppings from Catharus thrushes. I often find (in addition to the seeds, pulp, and berry skins I'm looking for) small hard parts of insects. Most often it is sections of millipedes, parts of beetles, and, frequently, ant heads. I guess thrushes aren't particular about the type of Hymenoptera they eat -- this head of an Eastern Yellowjacket (Vespula maculifrons) stared out at me from a sample provided by a Gray-cheeked Thrush.

Dana Wloch, one of my undergraduate research associates, is in charge of identifying and categorizing the samples from all other bird species. This is mostly robins and catbirds, but this week we've gotten samples from Rose-breasted Grosbeak and Red-eyed Vireos. Seems like yellowjackets are on the menu, as this head and a couple legs came from one of the vireos.

I've been asked how birds manage to eat bees and wasps without getting stung. Usually, they wipe the insect on a branch or the ground and get rid of the stinger. A more lengthy answer can be found in my February 2007 column in Birder's World magazine.

And another new bander has joined the team. Welcome to Sara Cole, a senior at Wayne State University. Here is Dana showing Sara how to age and sex her first bird, a Common Grackle.

It was a fun week. More birds coming up.

Fall banding: Weeks 3 & 4 in review

Weeks 3 and 4 (August 29 to September 10) were nothing much to write home about. We banded 117 new birds and handled 27 recaptures of 23 species. Looking back on the first month, it seems to be shaping up to be an above-average season for House Wrens, Red-eyed Vireos, and American Redstarts.

How can anybody get tired of seeing an adult male redstart?


In the fall, you see many more female-plumaged redstarts than these gorgeous males. Some are adult females, many are young birds, both males and females. Male American Redstarts do not get their bold black-and-orange plumage until their second full molt (for birds born this year, that will take place next fall). Still, young male redstarts are often a little more orange than yellow and can sometimes be differentiated from the even duller females. The young male below was especially bright.

Although it's a little hard to see in the photo above, the uppertail coverts are also quite dark and they contrast with the grayer-colored back. The orange patches at the base of the wings are...orange.

Meanwhile, in the young probable-female below, the patches are dull yellow, and so are the patches on the tail.


The tail-fanning is a characteristic behavior of this species, earning it the name "candelita," or "little flame" in some Latin American countries where it spends the winter.

Speaking of tails, Palm Warblers are beginning to come through.


Tail-pumping is a very distinctive trait of this species. They do not, however, do this in the hand.


And let's welcome our first new bander of the fall 2010 season, Carmen Volante. Carmen is a senior here at UM-D and is shown here on the left with one of our veteran banders Andy Dettling, and Dana Wloch, the undergraduate research associate in her second year of looking at robin and catbird diets.

The middle week in September coming up is often our best week for diversity of birds, especially warblers. We'll see what we come up with!

Fall banding 2010: Week #2 in review

Warblers welcome!

Week #2 was abbreviated due to my participation on a state advisory panel. The modest totals for the week were 59 birds of 21 species, plus recaps and another batch of hummingbirds released unbanded. Returns of birds banded in previous years included a female American Robin from 2007, and a Gray Catbird from last fall.

The best part of early fall is the nice variety of warblers that start to come through. Later, we'll have higher numbers of some species, or more diversity of birds overall. But this early in the season there is a nice parade of often-subtle, but always pretty, warblers. Here are a few from this week:

Blackburnian Warbler.

Chestnut-sided Warbler. Am I the only person who thinks the green looks like the color you get when you use a yellow highlighter on newsprint?

Black-and-white Warbler.

Wilson's Warbler. Audubon called this species "Wilson's Flycatching Warbler" and you can tell they do some aerial flycatching by the "whiskers" around the bill, known as rictal bristles. They help trap small flying insects.

Tennessee Warbler. More of a gleaner, it lacks the long rictal bristles of the Wilson's Warbler and uses its sharp bill to probe leaves for insects.


One thing we note when we band Tennessee Warblers is the presence (and size) of a white spot on the outer tail feather. About 30% of adult and 20% of hatching-year birds have this spot at our site, and usually if it is present in hatching-year birds it is smaller than this.

Other highlights this week included our first Swainson's Thrush, one of my focal species in my study of use of resources during migratory stopover.

The biggest thing I got in the nets was a female Cooper's Hawk. This is only the third Coop we've caught at RRBO, since they are generally too large and heavy to stay in the nets; and the first female, which are larger than males.

I've been grabbed by little male Sharp-shinned Hawks, which are only about the size of a flicker, and they have needle-sharp talons than can hardly be felt going in...but can be a real problem when the bird starts tugging to get them out! This big female Coop had talons to be respected and very long legs. It's times like these I'm glad I always carry too many bird bags. I handed her a wad to grab onto until I could secure her legs. Really, you can never let go of the legs when handling a hawk, so banding one is much easier as a two-person job. As luck would have it I was working alone and nobody was even in the building to snap some photos. Everything went without mishap as she was quite calm and cooperative, but I wished I could have photographed her eyes -- she had the very green-gray eyes of a young bird (soon to turn yellow and eventually red). That and the fact that her back feathers had extensive rufous tips may indicate she was hatched locally and not a migrant from farther away.

With hawks you worry about the feet, with Rose-breasted Grosbeaks you worry about getting bitten. That bill is very strong and while I've never had one draw blood, they pinch so hard you get left with a divot on your finger that lasts for hours. Plus, they just have nasty dispositions. This adult female didn't nip me, since I've handled enough of them to know not to be careless and always put them in a distinctive colorful bird bag so I don't get surprised when I reach in.

The weather forecast for at least the beginning of next week sounds like a return to summer; not very conducive to migratory movement. We'll see what ends up in the nets.

A reminder that we are moving the RRBO web site in the next few days. Please use this URL to access the current/soon-to-be-replaced site, it will continue working: http://www.umd.umich.edu/dept/rouge_river and use my long University address (jcraves AT umd DOT umich DOT edu) or gmail address (jac DOT rrbo AT gmail DOT com) to contact me. Don't use the jac AT rrbo DOT org until further notice.

I'll be posting frequent updates here -- I'm very excited about the new site and can't wait to hear what you think!