Friday, May 28, 2010

No sign of Red...Blue still in the tropics

Blowing snow, poor visibility (fog) and gusts up to 50 mph have kept us from going out today - so I thought I'd get a note posted to the blog. Mark Prostor and I visited Red's territory on May 22, and found the resident female and an unbanded male. The nest ledge used last year is drifted in with about 12 feet of snow. To date, only about 1/3 of the sites in the study area (about 36 in total) are occupied.

Blue opted for the "safe, but longer" route having circumnavigated the Andes by bearing north until he reached the Venezuelan coast, then flying westward to Panama. His most recent location has him only 7 degrees further north than he was on May 13. Each degree of latitude is about 69 miles, so he is only 500 miles further north than he was 2 weeks ago despite having traveled more that 1900 miles.

At this rate, he will undoubtedly be one of the late arriving breeders (certainly later than he was last year) - but his timing may yet prove to be to his advantage. His territory remained unoccupied as of May 26.

Route to May 28

More next week...Alastair

Friday, May 14, 2010

Hmmm...decisions, decisions?

This week Blue traveled another 535 miles (since the May 7) for a cumulative distance of over 2800 miles thus far. Surprisingly he once again veered from the expected NW bearing to one that is now taking him NNE. If he maintains his current bearing, then it's possible that he may ignore the Andes and Panama altogether opting to take the Cuban route north as he did to come south. Alternately he could cross the Caribbean Sea from Venezuela or Columbia directly to Central America (Costa Rica or Nicaragua). Both have their risks and benefits - the former is ultimately a shorter route to Rankin Inlet, but it means crossing a minimum of 400 miles of open ocean. The latter offers the relative safety (in my mind at least) of the Central America land bridge, but is a significantly longer route to Rankin Inlet. Complex decisions when time is of the essence for those individuals breeding in the Arctic.

Route taken through May 13\

His last received data point indicated his position to be on the northern fringe of the Amazon Jungle straddling the border between Venezuela and Colombia (see image below)...

Blue's location on northern edge of the Amazon

...and that he roosted on a hill (red circles in lower left corner of the GE rendition below) overlooking the Orinoco River that divides Colombia and Venezuela . In the background, about 30 miles from the the river, you will a series of mountains...

GE rendition and most recent location (lower left)

...Panoramio photos show that the mountains include a well known table-topped mountain (Tepui or Tepuy) called Autana Tepui...I can think of worse places to stop.

View of Autana Tepui from village of Seguera

Autana Tepui

More next week from the Arctic.


Monday, May 3, 2010

Favorite things...

Blue has now completed a little more than 1/4 of his migration having flown 2300 miles in total. After arriving at Lake Tefe in Brazil on the Amazon River, he remained there for 6 days, then flew 190 miles taking the expected NW bearing toward Panama, which is still 1000 miles from his current location.

Route to May 7

Last week we saw Blue surprisingly retrace his route by flying south before turning north east toward Lake Tefe, which incidentally is very similar to the lake where Blue spent the winter.

Considering his dramatic change in direction, apparent preference for big lakes and the 6 day respite makes one question if he just "stumbled" across Lake Tefe.

Recall too (see April 24 post) that while wintering Blue repeatedly used a cell phone tower in a very urban setting...well the GE image with GPS locations and the photo below show that he repeated this behavior in the city of Tefe (click on each one to see and compare the full sized versions).

GE view of favored locations in Brazilian city of Tefe

Photo of Tefe (similar to GE image above)

Sure makes one wonder whether we're seeing random behavior or evidence of preference for a few favorite things.

Update on spring conditions...earlier (April 19) I posted some MODIS imagery from April 10 2009 and 2010 that show how spring conditions can differ from one year to next. The following 2 images (about 450 miles X 450 miles) below show snow cover in the region on the Hudson Bay near Churchill, Manitoba (red dot) on May 5th 2009 and 2010.

Churchill snow cover May 3 2009

Churchill snow cover May 3 2010

Sunday, May 2, 2010

Amazonia...and beyond

Blue flew an additional 580 miles between April 25 and April 30, his route has taken him to the center of the Amazon Jungle. Last October, he crossed the Caribbean Sea from Cuba and made landfall in western Venezuela - Peregrines typically perform a "loop migration", which suggests that he'll resume his path NW and through Colombia into Central do this, he must first cross the Andes.

Route up to April 30

There are very few Panoramio images posted in the immediate vicinity of the GPS locations , but the two below are typical of the region...

Tributary of Amazon River

It's a little surreal to think that in 4 or 5 weeks, (all things being equal) he'll be on territory near Rankin Inlet where it will be like this...

"Panorama Island" with Rankin Inlet in the background