Recovery -- a rare event!

Since not very many banded birds are re-found away from the place they are banded, the majority of what we learn from banding birds comes from data we gather when we band them, and when we recapture birds on site. Nonetheless, every so often we hear about a recovery of one of our banded birds. These reports come from the USGS Bird Banding Lab, which administers bird banding in the U.S. We just got one this week, and it is quite special!

A Northern Waterthrush banded here on campus on 30 April 2007 was recaptured and released at Cedar Grove Ornithological Station in Sheboygan County, Wisconsin on 21 October 2008. The map below shows the location of Cedar Grove with a red marker, and our location in blue (click to enlarge).

How rare is this? Of the 32 recoveries that have been reported to us since 1992, this is only the 14th to have been reported outside the state of Michigan -- you can view an interactive map of all out of state recoveries here. Typically, these birds are found dead. The most common reason, if one is given, is that the bird has been killed by a cat. This waterthrush is just the third bird that has been captured and released by another bander. The others were a Yellow-rumped Warbler we banded in May 1997 that was recaptured in Tallahassee, Florida in March 1998, and a White-throated Sparrow banded in October 1999 that was recaptured on the Bruce Peninsula in Ontario in April 2006 (not a typo!).

But several more factors make the recovery of this waterthrush even more unusual.

1. The warbler and the sparrow are short-distance migrants, wintering in the U.S. The waterthrush is a long distance migrant. After we banded it, it probably nested in northern Michigan or Canada, then it likely spent the winter somewhere in the West Indies or perhaps Central America (you can view a range map here). Then it went north, nested again, and was headed back south along the western shore of Lake Michigan when it was captured at Cedar Grove.
2. Cedar Grove is a hawk banding station. For over 50 years, raptors have been banded at Cedar Grove, and small songbirds are only captured incidentally!
3. I've banded 167 Northern Waterthrushes during spring migrations, but only one has had a bill deformity...this one! So I happened to have photographs of it, which are below.

This slight deformity apparently did not hinder the bird prior to it being banded. It had a lot of fat, and at 22.1 grams, it was the second heaviest waterthrush RRBO has handled in spring, with the average being 18.0 grams.

Update: I've heard from one of the banders in charge at Cedar Grove. He told me that because they do not really "process" songbirds, the waterthrush was not checked for fat or weighed, nor was any abnormality noted. Bummer. I've caught only a few birds banded by other people (the last one was a Ruby-crowed Kinglet in 2005), but -- perhaps because I'm so astonished that it happens at all -- I give them a really thorough going-over.

The results are in: Fall 2008 banding summary

I have posted the fall 2008 banding summary on the RRBO web site. The numbers on the right sidebar are also updated. Also updated on the RRBO site are tables on the most commonly banded species and all the species banded on campus since 1992.

Just because the banding season is over does not mean I won't continue to post here at Net Results over winter. I have some posts planned on interesting bird tails, more on our thrush research, updates on publications, winter bird survey results, the Christmas Bird Count, and whatever else might unexpectedly come up. Please stay tuned.

The finale?

The last week or so has been a drag -- poor weather and poor health has kept me away from the nets for many days. The last couple of weeks of banding area always a challenge. Frosty nights mean frosty nets:
You can see the layer of frost on these closed nets. Often they are actually frozen shut, but even if they can be opened, it's like hanging out a bedsheet:

Not an effective way to catch birds! Nothing can be done but sit it out and wait for it to get warm enough for the frost to clear.

We did have our first Purple Finch of the season last week. Overall, about 80% of the birds we band in fall are young (hatch-year) birds. Young Purple Finches, male and female, have female-like plumage. So it's always cool to get a nice adult male like this one:

Purple Finches really are on the purple side of red -- a dark pink or raspberry color that distinguishes them from House Finches, which are red or orangish-red. Also note that Purple Finches really don't have much streaking on their sides. The abundant streaks of House Finches makes them look "dirty." Once you really get a good look at a Purple Finch, you'll see that it's easy to tell the two species apart. Banders have another clue: House Finches are pretty docile, but Purple Finches BITE!

We also had the last of the Orange-crowed Warblers. Other than Yellow-rumps, these are usually the final warblers to pass through.

Chipping Sparrows are very common on campus. This young bird was in our nets last week. It still has streaky juvenal plumage, especially the streaky cap. (And, no, I didn't spell that wrong. "Juvenile" birds have "juvenal" plumage.)

I've updated the stats on the sidebar again. I hope to be able to get in a few more hours next week as I begin removing the nets for winter. In many cases, I'd leave them up and see if I could extend the season, but a scout group will be coming in to put down landscape fabric and wood chips in the nets lanes. This will greatly reduce the pre-season net lane preparation for the next several years. I'm thrilled about it, so no complaints from me!

After it's all wrapped up, I'll update the stats and point you to the RRBO web site, where I will post a full summary of the fall banding season.

RRBO in the Metro Times

The Metro Times has come out with its annual Best of Detroit results. Readers are polled on their favorite things and places around metro Detroit, and the staff also gives its picks. The Metro Times picked the UM-Dearborn natural area as The Best Urban Getaway for 2008. The write-up notes:

"More than 250 bird species have been recorded by the Rouge River Bird Observatory, housed at the center. The observatory studies the role of this natural-amid-urban area as a stopover for migrating birds."

Many thanks to the Metro Times writers for the shout-out!

Week #9 in review

The composition of species indicates that we are in the final stretch for fall banding, and winter is knocking on our door. This week, our first American Tree Sparrow was banded.

And a favorite winter visitor, a Red-breasted Nuthatch. On campus, there aren't many conifers; in the banding area there are just two scraggly cedars. So it's always a treat to catch one of these cuties.

Of all the species we band, none is as indignant as the Tufted Titmouse. From the minute you start taking them out of the net to the second you let one go, they let you know how thoroughly offended they are at this whole banding process. There is a continuous barage of weird sounds, from evil hissing to extremely high-pitched, piercing whistles. Titmouse can make these noises while simultaneously pecking and biting. They are just 20 grams of pissed-off bird!

We banded four titmice this week (3 in one net). That's kind of unusual for us.

As you can see from the running stats on the sidebar, we are still well under the average capture rate for the season. Things have been picking up -- this week our capture rate was 48.7 birds per hundred net hours -- but still quite dismal. In general, this is probably not too surprising given the trends of the last couple of years. Following the terrible deep freeze of the spring of 2007, we had a poor banding season last fall, and this spring migration had the lowest numbers since I've been counting here on campus.

I've heard from some observers that did not see this trend. Typically, they have gone birding during peak times at known migrant traps such as Crane Creek in Ohio, or Tawas Point or Whitefish Point in Michigan. This doesn't surprise me much -- coastal areas and migrant traps can be expected to congregate birds that may be reluctant to cross, or have just passed over, an ecological barrier. This is, of course, why people like to bird at these places and why bird observatories and banding stations are often located at these sites. Migration ecology experts theorize that inland sites, such as the UMD campus, present a more accurate representation of stopover behavior, because birds use inland sites only if appropriate resources are available.

This brings up the interesting point that our monitoring efforts may produce results unbiased by the "migrant trap effect". Certainly it offers a contrast to other data. Sure, I am sometimes disappointed by the low numbers of banded birds. But I'm not in any sort of competition here. I always keep in mind that low data or no data are themselves valid results, and tell their own important story.