Rosyfinch Ramblings
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February 2008
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Help Stop the Killing of Protected Raptors
Filed under: General, Birding & Outdoors
Posted by: Ken @ 6:42 pm

I just received this Audubon Alert, which deserves your immediate attention. Please respond by clicking the link below, to express your personal concerns to your elected US Representative:

“Last spring, citizens across the country were
appalled to learn that thousands of protected raptors such as
Cooper’s Hawks, Peregrine Falcons, and Red-tailed Hawks had been
killed in Oregon, California and Texas.

“The raptors were killed by hobbyists who breed
pigeons to carry a genetic trait that causes them to stop flying
and tumble in the air before righting themselves and carrying
on. These “roller pigeons” are flown in competitions and scored
by judges who rate the birds on the quality of the “roll” and
other factors. Of course, the pigeon rolling through the air
looks like crippled and vulnerable prey to a hawk, falcon, or
other bird of prey. Many of these pigeon enthusiasts have been
routinely killing raptors in an attempt to protect their roller

“The U.S. Fish and Wildlife Service estimates that as
many as 2,000 to 3,000 raptors were being killed on the
West Coast each year using methods including poisoning, beating
birds to death with clubs, and suffocation in plastic
. Even more troubling is the fact that the thirteen
men charged with these crimes received little more than a slap
on the wrist after pleading guilty. Currently, killing a
protected bird is a Class B Misdemeanor under the Migratory Bird
Treaty Act, which puts suffocating a Peregrine Falcon in the
same category as unauthorized use of the image of Smokey Bear.”

Take ActionPlease ask your U.S. Representative to co-sponsor HR 4093, the Migratory Bird Treaty Act Penalty and Enforcement Act of 2007 to ensure raptors and other migratory birds are given adequate protection.

“Representative Peter DeFazio of Oregon has introduced
legislation that would amend the Migratory Bird Treaty Act of
1918 so that the intentional killing of protected bird species
would be considered a felony, rather than the current Class B
Misdemeanor. HR 4093 would send a strong message to prosecutors
and courts that Congress takes these crimes seriously. It would
pave the way for significant fines (up to $50,000) and jail
sentences (up to 1 year) for the most serious bird-related

“We need your help to ensure passage of the
Migratory Bird Treaty Act Penalty and Enforcement Act of
. Representative DeFazio is currently circulating a
“Dear Colleague” letter seeking additional co-sponsors for this
legislation. Your Representative is a member of the Natural
Resources Committee, so it is especially important that you
contact him or her about becoming a co-sponsor.”

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How Many Rosy-Finches?
Filed under: General, Birding & Outdoors, NM & SW US, Sandia Crest
Posted by: Ken @ 4:32 pm

Waving Flag-- Rosies have returnedUpdate on the Rosy-Finches of Sandia Crest, New Mexico.  The flag is waving–
flocks of Rosy-Finches are still visiting the feeders at Sandia Crest House.

Flocks of up to 150 rosy-finches are still being reported at and around the feeders. So far this winter, 427 rosies have been newly banded, and about 400 more previously banded birds have been recaptured. About 90 percent of the recaptured birds are from the same season; some, even on the same day as first banded. However, each year, increasing numbers of trapped birds bear bands from previous winters. This winter, to date, there have been 40 such recaptures:

Recaptures BLRF BCRF GCRF Totals
Winter 2004/2005   5   5
Winter 2005/2006 7 4 1 12
Winter 2006/2007 16 1 6 23
Totals 23 10 7 40
BLRF = Black; BCRF = Brown-capped; GCRF = Gray-crowned Rosy-finches, respectively

As each winter season progresses, the percentage of recapture of same-season banded rosy-finches at Sandia Crest increases. An isolated population of birds could be compared to an unknown number of beans in a jar that could be shaken up uniformly. If we mark a known number of the beans as “banded,” we then may withdraw a random handful, count the total and the percentage that are “banded,” and extrapolate to determine the total number of beans in the jar. The larger the sample we examine, the greater our certainty about the total number of beans in the jar. Simple?

Yes indeed, for beans in a jar, that is. Now let’s try it on the rosy-finches. Let’s say that on two consecutive weekends in February the banders found that 25 of 36 and 21 of 32 were newly recaptured birds banded this winter. This comes to, roughly, 2 of every 3 birds trapped. Assuming that the researchers know that the 450 birds they banded this winter are out there, the total flock would be (if everything else is constant), about 1/3 more than the number banded, or about 600 birds. Now, lets get real…

Steve Cox, who, with Nancy Cox, leads the banding team at Sandia Crest, related a formula that can be used by banders to estimate flock/population size. It is a bit more complex:

N/M = n/R, then N = (M)(n)/R

Where N is the total population size to be estimated

M is the sample  that was captured, marked, and released

n is the number captured the second day

and R is the number of marked individuals that were recaptured on the second day.

Steve goes on to say,

“What the capture/recapture equation is saying is that the ratio of the total population to the total number marked on the first day is equal to the ratio of the total number caught on the second day to the number of marked individuals that were recaptured.
“(Example: M = 32 birds caught, marked & released on the first day, n = 40 birds caught on the second day, R = 20 recaptured, marked birds. Therefore N/32 = 40/20 and N = (32)(40)/20 or 640)

“You have to assume that the population is stable during the two events.”

Ah, but there’s the rub. Steve adds:

“However, this year I think the birds are not stable and the flock size is fluctuating week to week.  Added to this problem we have not had what I would call 2 consecutive days that are relatively the same (weather wise).  I believe that the weather is a very important  factor.  If it is really cold and windy the birds come to the feeders more often. On warmer days the birds are likely to be feeding somewhere else as well.  I have always assumed that they were somewhere else along the ridgeline.  Based on how much they fly, and the high fluctuation of birds, I now wonder if some might not be traveling to other close by mountain tops.  Another reason to get a few birds with transmitters on them.”

Transmitters— What a great idea! They could also solve the mystery of where these birds spend their nights. Steve and Nancy are working on that right now, and you may have the opportunity to assist them in getting the transmitters. Stay tuned.

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Rosy-Finches of New Mexico: Feb 24 Update
Filed under: General, Birding & Outdoors, NM & SW US, Sandia Crest
Posted by: Ken @ 8:41 pm

Waving Flag-- Rosies have returnedUpdate on the Rosy-Finches of Sandia Crest, New Mexico.  The flag is waving–
Flocks of Rosy-Finches are still visiting the feeders at Sandia Crest House.

USFS Volunteers today reported that the upper trails on Sandia Mountain had 14 inches of new snow on top of 2 feet and some drifts were as deep as 5 feet. The banders had a busy day today, as they had 83 recaptures. Nancy Cox said she spent much of her time looking up old band numbers. “We had several birds today that were from previous seasons but that we had already seen this season… we had a lot of help from two banders from Ohio today.  They were able to help hold birds for photo documentation…We also had birders from the Connecticut area and New Jersey Audubon.”  Another Brown-capped Rosy-Finch banded during the winter of 2004-05 was recaptured, the second one this winter. Nancy and Steve Cox provided an updated spreadsheet (link below) and this report:

“We processed 102 birds today.  Most of them were already banded birds.  We only banded 19 new birds (16 Brown-capped, 1 Gray-crowned Hepburn’s, 2 Gray-crowned Interiors). We recaptured 18 Blacks (all but 3 from this winter), 50 Brown-capped (all but one from this winter), and 15 Gray-crowned  (all from this winter, 11 Interiors and 4 Hepburn’s).  The 3 Blacks consisted of 2 that we first banded in the winter of 2006/2007 and 1 that we originally banded in the winter of 2005/2006. The Brown-capped recapture was one we originally banded on 12/5/2004.

“The road to the Crest had been closed yesterday. Today the road was plowed but they were icy in spots. The afternoon drive down was fine with only a few places where there was still some ice.”

Regular visitors to this blog may notice that now I am including regular
updates on the status of rosy-finch viewings at Sandia Crest, New
Mexico. Updates will continue until the last flocks depart. Then the
flag here and on will stop waving, and we will just have
to wait until late October or early November for it to flutter in
celebration of their return.

Crest House Sighting Logs for this and prior winters

Rosy-finch and Rio Grande Nature Center banding schedule

Updated table and link to spreadsheet of all banding results

 Narrative Reports from visitors and banders: Correspondence Page

ID Tips: the four rosy-finch races at Sandia Crest

Check Weather, Webcams and Road Conditions


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Will the Rosies wait for Easter?
Filed under: General, Birding & Outdoors, NM & SW US, Sandia Crest
Posted by: Ken @ 10:02 pm

Waving Flag-- Rosies have returnedUpdate on the Rosy-Finches of Sandia Crest, New Mexico.  The flag is waving–
Rosy-Finch flocks are still visiting the feeders at Sandia Crest House.

This time of year we are frequently asked whether the rosy-finches will still be there when the enquirer is planning a visit to family in the Albuquerque area at Easter time. The answer differs from year to year. On average, the median date for Easter is April 7. Easter may fall anywhere between March 22 and April 25, inclusive, but, believe it or not, according to Matthew Skue at, the most likely date is April 19.

This year, Easter falls on Sunday, March 23. Such an extremely early date means that birders will have a good chance of seeing at least one of the three species at the Sandia Crest House feeders this Easter. In 5 of the past 8 winters, flocks have persisted until March 25th or later. Stragglers were reported as late as early April in 4 of the past 5 years. The average departure date for the rosy-finch flocks is March 27th.

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The Moon and Migration
Filed under: General, Birding & Outdoors, Florida & SE US
Posted by: Ken @ 10:44 am

Cloud cover permitted us only a few glimpses of the full eclipse of the
moon on the night of February 20. I tried to photograph it, but with
poor results. While I was watching the moon “ride” through the clouds,
I missed a tremendous photo opportunity. A passenger jet making its
downwind approach to the Fort Lauderdale Airport passed directly over
the moon’s face. Unfortunately, I was viewing this through binoculars,
not the SLR viewer of my camera. Unbelievably, another jet did the same
thing about 30 minutes later, and I missed that shot as well. This is
my best image of the eclipse, so you may guess how bad the others were!

Lunar eclipse Feb 20 2008

The ancients had numerous theories about where birds spent their time after they disappeared in the fall and returned each spring. The moon figures prominently in both one of the oldest theories and in our present understanding of migration. They hibernated, hiding away in a torpid state, or, as some maintained, underwater or in the mud of marshes.  Aristotle believed they transmuted back and forth between other species that were present only in the winter. Another belief was that they spent their winters on the moon.

Even many of those who recognized that birds escaped the winter by moving to lower elevations and to warmer climates had trouble imagining how the very small ones could ever have enough energy to carry out such an enormous effort. They theorized that small birds hitchhiked on the backs of larger ones. Nowadays we can actually witness the nocturnal migration of small birds by simply watching them cross the face of the moon. There is experimental proof that some birds rely on the stars for navigation, but the timing of flights in some species, such as Red Knots, is linked to the phase of the moon.

An excellent source of information about migration is this USFWS brochure: Migration of Birds, Circular 16, which is downloable as a PDF file.

For every species, there are many unanswered questions about the details of their migration. Some information can be gathered readily, such as dates of arrival and departure from various locations. Some birders are experts at identifying certain species by the sound of their calls as they pass overhead in the night. Banding and recapturing banded birds provides objective data about the movement of individuals. Color-tagging and fitting birds with radio transmitters allows tracking and observation of behavior. Isotope studies of feathers can sometimes tell where the bird was located when the feathers formed. Radar reveals the the staggering biomass of bird flights during migration. Here in South Florida the Key West weather radar clearly tracks birds to and from Cuba and other points, north and south. The National Weather Service Web site  has very technical instructions on how to capture images from prior time periods, but this Badbirdz Web site does it for you.

Badbirdz carries on the tradition of Noel Wamer, who provided us with wonderful screen captures of radar loops during migration until his untimely death only a few months after we moved to Florida in 2004. The Badbirdz motto is “Keeping Noel’s dream alive, one migrant at a time.” The following is an image of a wave of birds moving towards Cuba last November:. You can view loops that cover the entire period from sunset to sunrise on November 3-4 here.

November 2007

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