Saturday, February 6, 2010

How to detect ruffled feathers

One of my favorite non-bird books is The Songs of Insects, a fabulous guide to dozens of species of crickets, cicadas, and katydids. Photographer Wil Hershberger's web site has a page where he notes the presence of two small filoplumes on the napes of songbirds he'd photographed. Filoplumes are specialized feathers, long and hairlike, that are most numerous at the base of wing feathers. Special sensory cells at the base of filoplumes transmit information on the position and movement of wing feathers during flight. According to the Manual of Ornithology: Avian Structure and Function, many passerines also have filoplumes sticking out of their crown and nape, "perhaps warning the bird when wind disrupts the smooth outer surface of the plumage."

I found this incredibly intriguing, and when I had the time, I looked for these plumes on the birds I banded. Sure enough, there they were! I was able to find them on a variety of species, both male and female, and could even see them on some older head shots I had taken during previous fall banding seasons. Although not particularly easy to photograph (especially with one hand!), here is a little slide show of some of my shots. Look at the back of the neck -- you might have to slow the speed down a bit or pause on some photos. (Note: apparently some Firefox users cannot see the Flickr slide show, a known bug with Flickr. If you have a Flickr account, it might help to log in.)



Species in order: Yellow Warbler (male then female), Orchard Oriole, Black-and-white Warbler, Brown Thrasher, White-throated Sparrow, Tennessee Warbler, Magnolia Warbler, Rose-breasted Grosbeak (male then female), Black-thr Green Warbler, Connecticut Warbler, Golden-winged Warbler, Nashville Warbler, Purple Finch, Wilson's Warbler, Baltimore Oriole, Common Yellowthroat. Created with Paul's flickrSLiDR.

A 1989 paper (pdf) in the Condor, the journal of the Cooper Ornithological Society, described the presence of these protruding filoplumes on the napes of many passerine species. The authors noted that species which lacked these plumes had dense, stiff feathering on their napes, while species that displayed the filoplumes had softer and more flexible feathering in this area. They also concluded that these plumes served to detect disturbances in the feathers in an area that birds could neither see nor reach. The looser plumage might have less insulative properties to begin with, and unnoticed disheveled plumage might make a bird even more vulnerable to heat loss. A quick shake or perhaps scratch of the head, or facing into the wind can smooth the feathers once again, correcting the situation.

It's hard to believe I handled tens of thousands of birds -- with part of the routine being close scrutiny of plumage -- without making particular note of this interesting characteristic!

Monday, February 1, 2010

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.

Saturday, January 23, 2010

Peregrine wintering in Dearborn

Wintering Peregrine Falcons are not unusual in Dearborn. Most years we have at least one sighting, and one has wintered every year for the past five years. Since Ford began planting sunflowers and other crops at their local properties, this has been the most common place to find them (Merlins, too). The Ford Rouge Plant has also been another Peregrine "hot spot."

This winter we have a Peregrine in a new location. On January 4, Dearborn police officer and long-time RRBO volunteer Mike O'Leary found a Peregrine at the Village Plaza, the tallest building on the west side of Outer Drive just north of Michigan Avenue. The "A" marker on the map below is the intersection of Michigan and Outer Drive. The red arrow points to the Village Plaza building. Enter off Michigan Avenue, past the sub shop, via the street marked in green on the map.

The Peregrine has been hunting around the building and the adjacent golf course. It likes to hang out on the concrete ledge on the southwest corner of the building. The arrow in the photo below shows where it especially likes to sit.

Believe it or not, the bird is in this photo at the tip of the arrow. While it was clearly identifiable with binoculars, a scope is needed for a good photo. Although the falcon was seen yesterday (January 22) by Mike, my husband Darrin and I -- ready with camera and scope -- did not see it this morning. When we get a shot, I'll post it here, and update the latest date seen. If you happen to go by and get a look, let me know in the comments.

Updates: A day or so after I posted this, Mike let me know that he was passing the Village Plaza when he saw the Peregrine heading west along Michigan Avenue. He followed it all the way into Inkster, when it easily passed Mike's car, going an estimated 65 MPH! Apparently, it hunts rather far afield!

7 Apr: Still present.
6 Mar: Still there!
30 Jan: Seen again today at the Village Plaza.
13 Feb: Now more often hanging out on the Michigan Avenue side of the building (see comments).

Monday, January 4, 2010

Dearborn CBC, 2010

RRBO has been coordinating the Dearborn portion of the Detroit River Christmas Bird Count (CBC) since 1995. The count is held each year on New Year's Day.

After last year's exciting count featuring winter finches, this year's count was very dull, with the second-lowest number of individuals in 14 years. The low numbers of raptors, Mourning Doves, and House Sparrows, and absence of any blackbirds, compared to recent years was due to most of the productive Ford properties being planted in hay and harvested this year, leaving them in barren stubble with no or few birds.

The best of these fields are the ones that are directly adjacent to a tree line where birds can roost or go for cover, with the original field at on the south side of Hubbard at Southfield being the one that has traditionally had the most birds. Here is what the field looked like this summer, after the grain was harvested and the hay bailed. This is looking west towards the Ritz Carleton hotel:

Whatever waste grain may have been left behind had long been picked over, leaving nothing for birds to eat. There is a coyote living in a den in the small nearby woodlot that I've seen several times. Here it is on count day, in the lower right.

A few fields did have sunflowers in them, but they had also been picked clean. We had very large flocks of blackbirds this fall in the sunflower fields. Here is a brief video I took in October:


A few fields were planted in a wildflower mix. Although some of the choicest plants, such as the bluestem grasses, had been de-seeded, there was still a lot of good seed left. We had most of our small birds in these fields.

The Ford Rouge Plant had not been harboring much waterfowl up to the count, since the Detroit River is still open. Among the usual suspects there was a new species for the Dearborn portion of the count: Bonaparte's Gull. This was also our first January record for this species. A few do winter in the Great Lakes, but most are found in the Gulf states or southern Mississippi River in winter.

On campus, several Golden-crowned Kinglets, and Fox and Swamp Sparrows were good finds. Elsewhere, in an undisclosed location, a Northern Saw-whet Owl was located. They are not too uncommon here in winter, just hard to find.

Afterwards, most local counters gathered on campus to exchange intelligence, warm up with a cup of coffee, and have some pizza. Below, clockwise from lower left, are Greg Norwood (territory = campus and Rouge River channel), Tom Carpenter (Rouge Park), Gary Hutman (Rouge Park), Rick Crossland (rover), me, and Jim Fowler (Ford Rouge Plant, Detroit River, compiler). Other participants missing from the photo are listed on the results page.

The majority of participants on the Dearborn count are Dearborn residents, and my own Dearborn neighborhood is well represented. Here are the Springwells Park birders: Cathy Carroll, Gary Hutman, my husband Darrin O'Brien, and yours truly.

For a complete list of the bird species seen and other stats, as well as the results of all previous years, head on over to the Christmas Bird Count page on the RRBO web site.

Sunday, December 27, 2009

Rockwood CBC: Lots of Refuge properties

Dawn at Humbug, looking from Jefferson Avenue toward the Trenton Channel Power Plant.
Since 2004, RRBO has been participating in the Rockwood Christmas Bird Count (CBC) by surveying the Humbug unit of the Detroit River International Wildlife Refuge (DRIWR). Last year I gave a little background on this count and our coverage of Humbug. This year, my husband and I once again counted at Humbug, but we also made whirlwind stops at five other units of the DRIWR that are within the Rockwood count circle. Several are fairly new units that are under restoration and the USFWS wanted to see if waterfowl were using them. Since the units are not open to the public and we have a special use permit for various projects, we offered to give them a look. Although it rained on Christmas Day, the next day most standing water had refrozen, limiting waterfowl use. That was probably not a bad thing. If the water had been open, we'd still be counting. As it was, this was more of a reconnaissance mission. Now we know the logistics, and can make recommendations on how the units should be covered in the future. We ended up walking over ten miles, but only tallied 44 species, owing to our quick work at most of the units and drive time between them. It was nice to see a total of 10 Bald Eagles at 4 of the 6 units. A Killdeer at the Humbug unit was probably our best bird. Great Blue Herons are always found in good numbers at Humbug, since there is always some open shallow water there due to discharge from the Trenton power plant just north of the property. We had 49 herons at Humbug, close to our record of 53 in 2004. We had another 19 roosting around the old quarry pond at the Gibraltar Bay unit on Grosse Ile (more on the units below). Sparrows in general seemed sparse, although we had two Fox Sparrows at the Brancheau unit. All of our 148 American Robins were at Humbug, feeding on Common Buckthorn, honeysuckle, and perhaps some rose hips. We completely missed any blackbirds, Carolina Wren, Cedar Waxwing (also missed by all other teams on the American portion of the count), and, sadly, American Crow. Very few crows were found on the count; this species does not seem to be recovering from West Nile Virus. Here is a run-down of the units. 
  • The Humbug Marsh unit is in Gibraltar and Trenton. At least half of the northernmost section was rehabilitated over the summer, and was either unvegetated or iced over, making that part quick work. I've attached a number of photos to this route, so hover over the map, and click on the first icon on the right to go into slideshow mode. We had 29 species here.
  • The Gibraltar Wetlands unit is very near Humbug, behind the high school at Jefferson and Woodruff Road in Gibraltar. Since it was frozen and we only had a few birds there, I did not include this in EveryTrail.
  • The Gibraltar Bay unit is the former Grosse Ile Nature Area (and a one-time Nike missile site) at the south end of Grosse Ile. We mostly went for waterfowl. 22 species.
  • The Fix unit was the furthest south we traveled, and is adjacent to the Fermi nuclear power plant in Monroe Co. These old farm fields have been planted with prairie and grassland vegetation, but were unvegetated this winter. We had 15 species here, including our only Winter Wren. More info here.
  • Walking a muddy dike at the Fix unit, with the cooling towers of the Fermi nuclear plant as a backdrop.
     
  • The Brancheau unit is north of Fix, on the other side of Swan Creek. These fields will also be planted for wildlife. A pump system has been installed to bring in water from Lake Erie so the fields can be managed for waterfowl or shorebirds. 17 species.
  • The Strong unit is just south of Pointe Mouille State Game Area. It also has old farm fields, and a large wetland bordered by dikes. The main dike is tall and grassy, with fields and woods on one side, and the wetland on the other. In many places Phragmites makes it hard to see into the wetland. We had our Fox Sparrows here, along with most of our American Tree Sparrows. We also had a Sharp-shinned Hawk, less common than Cooper's Hawks here in winter. 24 species.
The final dike walk of the day, this one at the Strong unit.
Realistically, covering all these units effectively takes more than one group of people. In the future, we will probably continue at Humbug and then concentrate on Gibraltar Wetlands and Gibraltar Bay.