Sunday, April 25, 2010

A brief rest and then...

Blue has now covered just under 1500 miles of the approximately 8500 miles it will take to get to Rankin Inlet. His route north remains somewhat similar to that taken south (purple = southern route, blue = northern route).

Route up to April 25

Acquiring 12 locations per day (1 fix every 2 hours) tells us a great deal about active and sedentary periods...for example, this peregrine habitually travels at a approximately 30 mph, starts out at about 10 a.m. on migrations days, and usually stops to roost between 8 p.m. and 9 p.m. So...generally active for about 10 hours and sedentary for about 14 hours per day. Of course, there is some variability; here's a brief synopsis of activity between the 20th and 24th...

20 - 21 = sedentary
22 = 400 miles
23 = 285 miles
24 = 229 miles

Locations on the 20th and 21st were concentrated among 4 or5 areas of about 8 square miles each that appear to be fenced and are apparently (Panoramio images) grazed by livestock (cattle and/0r goats) .

Goats

Cattle

The area appears to be quite arid, and some watering holes like the one below are artificial. These locations are probably permanent and are undoubtedly very attractive to many bird species in the area.. It's likely that Blue hunted these watering holes before resuming migration.

Livestock watering hole

...more soon, Alastair.

Saturday, April 24, 2010

Panoramio tells the tale

In mid-March, whilst wintering in Brazil, Blue began spending many hours each day and night in a very urban location as shown in the GE image below - to me it looked like he may be using the trees around which the GPS locations were scattered, but I couldn't tell from GE what was so special about the few trees he seemed to have selected when there were so many others just like it to choose from?

The "Roost" location

I e-mailed the GPS locations to my colleague, Mark Prostor, to get his thoughts on what might be so attractive to the peregrine. He took a look at the locations in GE and then started looking for Panoramio images close by...he found one of the swimming pool below(and bottom left corner of the GE image above), and pointed out the GPS fixes were located at the cell phone tower that can be seen in the top right corner of the pool photo.

The Pool

It also be came apparent after a few weeks that GPS locations would periodically be situated in the surrounding soy bean fields like the one below located half a mile from the cell tower.

Soy bean field

Looks to us like the cell phone tower served as both safe overnight roost and strategic location from which he could hunt prey in the nearby agricultural lands.

Alastair



Wednesday, April 21, 2010

Red's fate to be determined

Red's PTT stopped transmitting on Dec 24, 2009. So...in early January thanks to Oscar Beingolea who traveled 700km from Lima, Peru, and spent several days in the field searching Red's home range in an effort re-trap him and remove the PTT, we gained some insight that was otherwise not possible.

Although Oscar could not locate the peregrine or the PTT, he visited several locations that had been used repeatedly by Red, and told us some things not apparent from our limited perspective gained solely from Google Earth.

In one case, viewing the GPS data in Google Earth showed repeated use of a location that was devoid of any structure all, and not something at all that one would predict as typically "used" by peregrines. Oscar soon discovered that a small village with a new water tower had been constructed there at some point after the satellite imagery used by GE, making it "appear" that the peregrine was perching in an unlikely spot.

In another instance, Red abruptly stopped using what had to that point been a heavily-used overnight roost. We had high hopes that the peregrine would be found at or near that location. On his first visit Oscar discovered a small plot of land left fallow and surrounded by Algarrobo trees. Here is how Oscar described what he and two of his colleagues (Fernando and Pedro) found...
"...something has not been right with his "favorite place", since we could find no evidence of the falcon's presence at the place he likes. Last time we were there, we could see that two trees had been cut down next to the main tree standing there. We were not sure about how long ago had been they cut down. There weren't any small branches around suggesting they had been used for charcoal already, but how long ago?.

The weather is extremely hot and its is not rare that the trunks are left drying outdoors till they are needed. That first day at the "place he likes" we found no logging activity around the cut trees, other than a stump 50 cm tall and some other small pieces on the ground.
Well, today at "the place he likes", we met some loggers that were cutting the trunks into smaller pieces, less than 12 meters away from the main standing tree. I'm sure that is enough to scare away any falcon. Furthermore, when I asked to the loggers how long ago had they cut down the trees they told me "15 days ago". Alastair, that cut is really fresh and must have scared the falcon from the place he likes. They had probably have even cut HIS FAVORITE TREE..."
The "Favorite Place"

Once back in Rankin Inlet next month, Red's breeding site will be one of the first places I check ...I'll let you know what I find.

Alastair

Monday, April 19, 2010

Blue headed for Rankin Inlet


After spending the Arctic winter on the Paraguay/Brazil border, Blue began the first leg of long inward migration back toward his breeding territory near Rankin Inlet this week. His return route (in blue) is so far quite similar to that taken south (in purple) 4 months ago. Last year he was on territory before the end of May. For his timing to be similar, he has about 40 days to travel more than 8500 miles. I'll be on the ice of the Hudson Bay by then, and will hopefully get the chance to actually watch him arrive knowing exactly how far he has flown in an effort to get an opportunity to produce more young. In the meantime, his most recent location has him 400 miles NW of his wintering territory.

This spring is already quite different than last. The first of the 2 images below show snow cover over the southern portion of the Hudson Bay and James Bay on April 10, 2009, and the second shows snow cover on April 10, 2010.

Snow Cover April 10, 2009

Snow cover April 10, 2010