Monday, May 31, 2010

Eastern Bluebirds and Reporting Bands

Last week, J. H. and I finally braved the heat to band fledgling Eastern Bluebirds.  Unfortunately two of three boxes were already empty.  This fledgling was one of five young in the remaining box.

Bird longevity is short--a bird's average life span is less than two years (although wild birds are known to survive 10-20 years).  Furthermore, unlike most other vertebrates, a bird's survival rate does not seem to improve with age.  Birds are not skilled analytical thinkers--after all, they can fly away from most of their problems.  (This is not to say that birds do not learn at all; they just are not superior learners.)  The moral?  When you get to the reincarnation center, think twice about joining the bird line!

Less than 1% of banded songbirds are recovered. Since the 1960s, in both Europe and North America, band reporting rates have declined.  Robert A. Robinson, Mark J. Grantham and Jacquie A. Clark wrote a paper entitled "Declining rates of ring recovery in British birds" (2009 British Trust for Ornithology, Ringing and Migration 24:266–272). They suggest people spend less time outdoors and therefore find fewer dead birds and, when they do find bands, they do not know where to send the information.  I think Americans these days may be less likely, for whatever reasons, to cooperative with the Federal government. 

To counteract this trend, the US Banding Lab allows people to report bands electronically at http://www.pwrc.usgs.gov/bbl/homepage/call800.htmhttp://www.pwrc.usgs.gov/bbl/homepage/call800.htm and also by toll free phone: 1-800-327-BAND (2263).  Many of the larger bands now bear this telephone number.

Sunday, May 30, 2010

How to Upload Bird Songs into a Droid

I am not a computer wizard and I definitely take no responsibility for anyone following these
instructions.  You do so completely at your own risk. Nevertheless, I was able to upload the songs and photos of North American birds into my Droid.  These instructions will probably work for other smart phones and probably work on both a PC and a Mac.  I used a PC.

1. You need a copy of iTunes in your computer (there are PC and Mac versions; both are free).  Many people have iTunes in their computers. One problem is that you can not sinc two iPods from the same version of iTunes.  I was lucky that my bird calls were in Erika's iTunes on her computer.  None of our personal music was lodged there.  (You can probably load all your music plus the bird calls into the Droid.  I  did not want to try that.  By the way, the bird calls did not significantly affect the Droid's memory.)

2. The only item you need to buy is Thayer Birding Software's Guide to Birds of
North America
. Be sure to purchase the appropriate guide for your computer.  The link above is for a PC, the link below is for a Mac. If you have purchased this DVD, the Thayer folks give you permission to copy the calls to iTunes for personal use.  Instructions for transferring the Thayer files to iTunes is included in the DVD.

3. Download AutoMount into your Droid from the Droid Market or Google it on-line.  This is freeware.

4. Download DoubleTwist into your computer.  Be sure to use the PC or the Mac version. This is also freeware.

5. Run DoubleTwist.   When it asks what your phone is, connect the Droid to the USB port.  I just followed DoubleTwist's directions, and all the Thayer bird calls, along with photos of each bird, where delivered to my Droid. Be sure to open your music library and click the button that reads "sync mobile device."

6. Once the download is complete, unplug the Droid from the computer.  Go to Music on the Droid, and your bird calls can be selected.  You can even click an option to replay each call.

Hope this is clear.

Saturday, May 29, 2010

Rose-breasted Grosbeak

Yesterday was an odd morning at the Dundas banding site.  First, despite this being late May, when I should be encountering late migrants, I only caught this Rose-breasted Grosbeak and two Gray Catbirds.  Second, these three birds were all already banded by me during previous years (this year is my third at this location).  Finally, all three were banded on 19th of May but each on a different year--the grosbeak in 2009, one catbird in 2008, and the other catbird this year (just a few days ago)!

When I see Rose-breasted Grosbeaks, I am reminded of my favorite artist, Louis Agassiz Fuertes.  His later paintings are stunning (from the 1920s), although my favorite is a study of the Rose-breasted Grosbeak from his senior thesis in 1897.  I have not found this image on the net, although it can be found in A Celebration of Birds by Robert McCracken Peck published in 1982. The following links to Wikipedia and Cornell both contain other examples of his work. Fuertes, in his mid-50s, was killed at a railroad crossing in 1927.  Undoubtedly his best work was yet to come. There are times when we birders should keep our attention away from birds!

Thursday, May 27, 2010

Empidonax Flycatchers

Least Flycatcher

"Traill's" Flycatcher

On Wednesday the mosquitoes were out in force and I caught two Empidonax Flycatchers.  The genus Empidonax contains several of the most similar birds in North America--unless the birds are singing. They almost never sing while they are being banded.

The Least Flycatcher above can be told from the "Traill's" Flycatcher below because the Least is somewhat smaller and its bill is slightly shorter and stubbier.  Hard to tell in my photos, but the Least's eyering is usually wider and more complete.  In the field, the Least Flycatcher sings, "Che-bick!"

The "Traill's" is in quotes, because this name no longer refers to a species.  The old Traill's Flycatcher has been split into Alder and Willow Flycatchers.  Alder Flycatchers, who sing "fee-bee-o!", or, sometimes "free beer!," are found further north than are Willows, who sing "Fitz-bew."  Where their ranges overlap, the two forms do not interbreed, hence they are recognized as separate species.

When not singing, these two species are almost impossible to tell apart. Many bird books suggest that Alder Flycatchers have greener backs than the browner backed Willow Flycatcher.  If this field mark is valid, then my "Traill's" is probably an Alder Flycatcher.  (I have heard Alder Flycatchers singing in the summer in the eastern half of the nearby Cannon River Wilderness Area.)  Last year, however, when I sent the Bird Banding Laboratory a photo of a hand-held flycatcher that clearly showed a bird with a greenish tint to the back, they replied that a quiet bird, conservatively, is always a "Traill's" Flycatcher.

Just to make matters more confusing, two other Empidonax flycatchers are found in Minnesota, the rare Acadian Flycatcher (rare, at least, here) and the fairly common migrant, and fairly distinctive, Yellow-bellied Flycatcher.  Acadians sing "Pee-tsup" while Yellow-bellied Flycachers have a fairly distinctive yellow throat (and belly).  At least a half-dozen additional species in the genus Empidonax are found in western North America...

Monday, May 24, 2010

Chestnut-sided Warbler

As the lackluster 2010 spring migration plods along, yesterday I banded this female Chestnut-sided Warbler.  A friend visiting Ely, Minnesota, reports plenty of warblers in the North Woods.  Perhaps this year's warblers overflew central Minnesota.  I saw no warbler waves and only a smattering of species this May, and I have read similar reports from elsewhere in the region. One of the joys of birding is being in the right place at the right time; I guess a frustration is being at the wrong place at the wrong time...

Sunday, May 23, 2010

Brown-headed Cowbird

This female Brown-headed Cowbird is a obligate brood parasite, which means that she always lays her eggs in other species' nests.  Cowbirds do not build their own nests. They parasitize over 220 host species, ranging from kinglets to meadowlarks.  Yellow Warblers and Song Sparrows are particularly vulnerable to cowbirds.  Rare species, such as Kirtland's Warblers, are also adversely impacted by cowbird parasitism. Female cowbirds range widely and lay as many as 40 eggs per season. I do not know how young cowbirds learn how to sing and act like cowbirds instead of their host species. My cowbird information is gleaned from Lowther (1993).

Friday, May 21, 2010

Eastern Bluebird 2

I banded an adult Eastern Bluebird today.  J.H. has noted some mortality among his bluebirds during this cool, wet May and we have heard similar reports from other Minnesota bluebird trail owners.  In recent years, more bluebirds have fledged in our county (Rice) than any other in the United States.  This factoid could be due to there being more bluebird enthusiasts maintaining boxes here than elsewhere.

As I took the bird from the net, its mate attacked me.  I was disappointed that the male was not one of the young banded during the past couple of years.  I should not have been surprised, since adult males, after wintering with their young, aggressively chase them away during the next breeding season.  (Males will fight over mates or territories, as will females; indeed these fights can result in the death of one of the combatants!)

As is the case with many well-studied species, bluebird breeding behavior can be complicated.  Although pairs are often monogamous, males can be polygamous.  Females can be in separate cavities in the same territories or the male may have more than one territory, each with a female.  Also reported are records of one male with two females in the same nest box!  Polyandry is also known, where one female nests with more than one male.  About 20% of bluebird houses contain young not fathered by the "owner" of that box. Finally, the young of first broods occasionally help their parents feed the young of second broods. 

The source for most of this information is: Gowaty, Patricia Adair and Jonathan H. Plissner. 1998. Eastern Bluebird (Sialia sialis), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu.bnaproxy.birds.cornell.edu/bna/species/381

Thursday, May 20, 2010

Lincoln's Sparrow

Lincoln's Sparrows are usually difficult to observe.  Usually they remain hidden, low in bushy tangles.  Occasionally, however, they visit feeders and can be seen on lawns.  The best field mark is the tan wash behind their breast streaks.  This sparrow was named by Audubon in 1833 for Thomas Lincoln who accompanied Audubon to Labrador when the bird was discovered.

Lincoln's Sparrows breed across Canada, the Arrowhead of Minnesota, and in the Rocky Mountains. Most winter in Mexico, the Pacific Coast or the southwest of the United States. Because of their elusiveness, not too much is known about their breeding behavior or genetics.  I occasionally band them during the spring and fall migrations.

Wednesday, May 19, 2010

Yellow Warbler

Today, 19 April 2010, I caught three Yellow Warblers, one male and two females.  To my delight, the male was already banded, by me at the same location, on 13 May 2008.  Thus this male was at least 3 years old--well short of the 10 year, 11 month oldest banded Yellow Warbler on record (a bird both banded and retrapped in New York).  The closest my banded Yellow Warbler spent the winter is the coast of central Mexico, and probably further south--yet it returned to my banding station!
For the beginning birder, female Yellow Warblers are a bit more difficult to identify than the male.  As you can see in the top photo, males sport fairly distinctive chestnut stripes down their breasts.  Females are similar to a number of other yellowish warblers, but none of the other birds have yellow in their tails (see photo below). An exception is a female American Redstart, but I hope you will not be confusing redstarts and Yellow Warblers.
I was curious about catching the male and two females at the same time.  Occasionally, male Yellow Warblers are polygamous, and males with two mates defend larger territories than those with one female.  Rarely male Yellow Warblers simultaneously maintain two territories, each with a single nesting female.  Some males trespass into neighboring territories and attempt to mate with females mated with other males, resulting in nests containing young with different fathers.  On the other hand, Yellow Warblers will occasionally maintain mates in successive years.

Much of this information has been gleaned from Lowther, P. E., C. Celada, N. K. Klein, C. C. Rimmer and D. A. Spector. 1999. Yellow Warbler (Dendroica petechia), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu.bnaproxy.birds.cornell.edu/bna/species/454.

Tuesday, May 18, 2010

Feeding Orioles and Hummingbirds

Ruby-throated Hummingbirds have appeared at my hummingbird feeder.  I fill it with a 4 to 1 ratio of boiled water and sugar.  I do not add food coloring.  When I catch hummingbirds at the banding station, I must release them unbanded.  Hummingbird bands have so little space for numbers that the Bird Banding Laboratory only issues bands to researchers with specific hummingbird studies.

Hummingbird enthusiasts should watch for vagrant species in the fall.  A friend in South Dakota, where only Ruby-throated Hummingbirds are expected, discovered both Rufous and Calliope hummingbirds at his feeders!  His whole yard is planted for hummers and he inspired me to always include Salvia flowers in the garden.  Besides the normal red annual Salvia, this year Erika and I planted a purple perennial species.

My colleague John H. feeds Baltimore Orioles with a feeder that holds both sugar water and grape jelly.  He goes through so much grape jelly each summer that we joke he should invest in grape jelly futures.  His neighbor suspects local food stores raise the price of grape jelly due to the summer demand by oriole feeders!  (John has not had much luck attracting orioles with orange halves at the feeders.)  The photo below is of a female Baltimore Oriole.

Sunday, May 16, 2010

Gray Catbird

I was all set to write about catbirds (I banded this one on Friday) and other birds that mimic when I saw a link on the South Dakota bird listserv on that very subject!  This video really says about the same thing as I was going to write about: http://www.youtube.com/LabofOrnithology#p/u/12/KRgvpjcSNcM

The basic premise is that the larger your mimicking repertoire, the bigger the stud you are.  At least if you are a male catbird trying to attract females to mate with you. (I wonder it is similar for human males and the number of songs in their iPods?)

Yesterday two friends and I did a Big Day in Rice Co.  We began at 4:30 AM and birded until 8:30 PM.  We listed 129 species of birds, including 19 warblers.  Highlights include a Hooded Warbler, Cerulean Warbler, and Eurasian Collared Dove.  It was a fun but exhausting day.

Friday, May 14, 2010

American Redstart

Today I banded two after-second-year male American Redstarts.  Redstarts have an uncommon molting pattern.  After they hatch, they molt into a plumage that is very similar to females (see bottom photo), except that the males have a slightly orange tinge to their yellow sides.  The males remain in this plumage through the following breeding season (their second year), after which they molt into their distinctive black and orange plumage.  They retain this new plumage the rest of their lives.  Thus, the next spring, black and orange birds are older than two calendar years.
I wish I were better at working with Photoshop.  I'll have to admit the photo above was manipulated--I erased my hand, which was holding on to this bird's feet.  I think the photo is, nevertheless, rather intriguing.  On the next photo, notice the bristles at the base of the bill.  Birds with rictal bristles can usually be predicted to feed on flying insects.  However, when researchers taped down rictal bristles, the birds' flycatching abilities did not diminish.  Placing birds in wind tunnels, ornithologists discovered that the bristles protect the flycatchers' eyes from the birds' prey and other airborne debris (Handbook of Bird Biology: Cornell Laboratory of Ornithology).
I took the following photograph of a female American Redstart last year near Dundas, Minnesota.  Note the yellow sides.  A first or second-year male would have a much deeper, almost orange tinge to his sides.

Thursday, May 13, 2010

Wood Thrush

On Wednesday I banded only a House Wren and this Wood Thrush.  This thrush's call is one of the magical sounds of the Eastern forest--click here for a sample.  This species is one bird I band more often in Minnesota than in northeastern South Dakota. Spring banding continues to be frustratingly slow. Yellow-rumped Warblers are an example of this poor spring in Northfield.  In late April and early May 2009, I banded well over 75 of these common warblers.  This year I have ringed less than a half dozen.

Perhaps the last week of rain has impeded the migration.  To date, I have banded only three warbler species, all dutifully reported in this blog.  In South Dakota, May rains almost always brought migrants to the banding station.  I hypothesized that most Dakota migrants took off from Nebraska or Iowa and overflew South Dakota unless they hit bad weather--a situation similar to migrants crossing the Gulf of Mexico.  In Louisiana, trans-gulf migrants do not make landfall until several hundred miles inland--unless there is weather, in which case they fall out along the coast or even on oil rigs over the water.  I figured perhaps the Dakota prairies presented a similar barrier for woodland migrants.

Tuesday, May 11, 2010

Bird Colors

I have read numerous variations in Arctic tales about how the loon and raven got their colors. In one of these, initially birds were white. Raven and loon find a pail of black paint. Raven does a fine job decorating loon.  When it is loon's turn to decorate raven, however, raven is so fidgety that loon loses his patience and dumps his black paint all over raven.
Why are birds colored as they are?  Camouflage, certainly, but there is more to color than that. Biologists painted the white spots behind kingfisher bills and found that the birds could no longer aim properly for their prey.  The kingfishers were using the white spots as sighting mechanisms. [I would be interested to know if anyone has a citation for this fact.]
Often, however, why bird color has evolved is not clear.  The catch-all explanation is that bird colors attract mates. However, when researchers painted blackbirds' red epaulets black, the manipulated males found mates but had trouble maintaining territories (Searcy and Yasukawa 1983. Sexual Selection and Red-winged Blackbirds. American Scientist 71:166-174).

Monday, May 10, 2010

Ovenbird

I mentioned in one of my early blog entries that Erika maintains that my favorite bird is the last one I've seen.  That bird would be this Ovenbird I banded yesterday afternoon.  The Ovenbird qualifies as a best bird on a number of counts.

1. The Ovenbird, a rather aberrant warbler, struts along on the forest floor calling "teacher, teacher, teacher," a habit that definitely appeals to a retired biology professor.

2. After I saw a satellite photograph of deforestation in the Yucatan Peninsula, where many Ovenbirds winter, I have worried about the Ovenbird's future.  Due to deforestation in Mexico contrasting with the jungle of Guatemala, you can actually see the border between Mexico and Guatemala from space.  (See, for example, http://geology.com/world/guatemala-satellite-image.shtml.) Ovenbird populations are also declining because of fragmentation of North American forests. Fortunately Ovenbirds, both as migrants and breeders, are still fairly common in Minnesota.

3. The first bird I ever banded was an Ovenbird near Washington, DC, in about 1967.  Furthermore, during my South Dakota tenure, an Ovenbird I banded in Aberdeen on 4 May 2003 was recovered near Davidson, Saskatchewan, on 16 May 2005--a distance of about 527 miles.

Sunday, May 9, 2010

Swainson's Thrush

The spring migration continues to unfold slowly, with few birds at the banding stations.  Yesterday at dusk, a time when thrushes often visit the water feature, I ringed this second-year Swainson's Thrush.  You can identify the species by its tan spectacles.  Many birders are unaware that western races of Swainson's Thrushes have russet-colored backs.  The bird in the photograph has an olive-colored back, as would be expected in Minnesota.

The bird's age is known by the tan spots on its secondary coverts, just visible in the far right, lower corner of the photograph.  These coverts are left over from the bird's speckled juvenile plumage.  Older birds will either have molted into unspotted feathers or the tan spots will have worn away. 

This species winters from central Mexico to northern South America.  Erika and I saw them in the winter in the jungles of eastern Peru and Ecuador.  They breed in the northern Rocky Mountains and across Canada (and northern New England and northern Minnesota).  A Swainson's Thrush that I banded in Aberdeen, South Dakota, on 19 May 1985, was recovered on 11 April 1988 in Guatemala.

Thursday, May 6, 2010

Chipping Sparrow

Yesterday I caught a Chipping Sparrow that I originally banded on 7 May 2009.  Surely birds' ability to return to their nesting territory each spring is one of nature's wonders.  Ornithologists tell us that birds rely on multiple clues for navigation, including the sun, stars, and the earth's magnetic field.  Nevertheless, it is amazing that a small bird like a Chipping Sparrow can make it back to the exact field where it bred last year. (This species usually winters north only to the southern United States.)

Chipping Sparrows, encountered from western pine forests all the way to the urban sprawl of the east, may be one of the most common birds in North America.  Many of us probably hardly give the Chipping Sparrow a second look, but, as you can see from this photo, this species is an exquisite little bird.

Monday, May 3, 2010

Nashville Warbler

This morning we caught our second warbler species of the year, a male Nashville Warbler.  The chestnut crown feathers are seldom seen in the field.  This species is often attracted to the water feature. 

This species was first described by Alexander Wilson in 1811 near Nashville, Tennessee, but this warbler is common, either as a breeder in the north, or as a migrant elsewhere, across much of North America. Two disjunct breeding populations exist, one in the east, and the other in the Pacific Northwest. The western birds are brighter and males of both races are brighter than females.

Sunday, May 2, 2010

Tricky Sandpipers

This morning I ventured out to one of our local sewage treatment pools in search of shorebirds.  I came upon this dowitcher, and all day I have been debating its identity.  Long-billed and Short billed Dowitchers are notoriously difficult to tell apart.  To me, this one seems to have the front end of a Short-billed Dowitcher--note the spotted rather than plain or barred sides of the neck.  But the lower underparts are definitely dark reddish--indicative of a Long-billed Dowitcher.  In the field, because of that dark reddish color, I identified this bird as a Long-billed Dowitcher. A friend once told me that you see Long-billed Dowitchers when you are wearing long pants, and Short-billed when you are wearing shorts.  In other words, Long-bills migrate earlier in the spring than do Short-bills.  I was wearing long pants, but I COULD have gone out in shorts...
This Semipalmated Sandpiper was a little easier to identify.  Note its very short black bill and black legs.  Also, the breast appears to be whitish, without streaking.  I have not observed many Semipalmated Sandpipers near Northfield.

Saturday, May 1, 2010

Yellow-rumped Warbler

Finally May has arrived and this morning the trees were full of Yellow-rumped Warblers!  We banded one that visited our water feature.  We are quite pleased with our stream, although we suspect we got a bit carried away by its length.  We are sure a shorter one would also be very attractive to thirsty migrants.  Over the years, we have enjoyed many migrants, sometimes in great numbers.  I hope to share photographs of many of those with you as the spring progresses.