Thursday, October 29, 2009

Rankin Migration - 29 Oct. 2009

Blue traveled another 800 miles between Oct 21 and Oct 28 for a total of 5100 miles on migration. This week took him over the Venezuelan Andes and south into Columbia near Gaviotas. The GPS transmitters that these birds are wearing also record ambient temperature. When combined with lack of movement and decreasing battery power, low temperatures can be indicative of mortality. Typically temperatures are between 28 and 32 degrees C, so I was a bit alarmed when I saw temperature values below 10 degrees C. After checking altitude in Google Earth, I realized that Blue was in the mountains 2400m above sea level after having left the lowlands west of Lake Maracaibo (400m ASL) less than 8 hours earlier. The data show that he roosted overnight on a river bank…I think the sudden and temporary drop in temperature means he may have taken a bath first thing in the a.m.!.

The following GE terrain image will give you some perspective of his movements in the mountains.

and the following two photos are Panoramio images imbedded in GE and were very close to where he roosted.
Red added another 600 miles to the previous tally of 3900 miles for a total of 4500 miles to date. His most recent data point had him 39 miles NW of San Jose, Costa Rica.

Thursday, October 22, 2009

Rankin Migration - 22 Oct. 2009

Blue has logged over 4300 miles as of midnight Oct 21, a month after leaving his territory in Rankin Inlet where it is currently -11C with snow and a 20 mph wind – wind chill is -22C. His last data point had him a few miles east of Remolino, Columbia where it 25C with some scattered showers and a 2 mph wind. He left the Cuban mainland just west of Guantanamo Bay at about 0900Z on Oct 20 and (apparently) without stopping flew 702 miles across the Caribbean Sea arriving 34 hours later on the Columbian mainland at 1900Z on Oct 21. His 2 hr data points are very evenly space and show he was travelling at a relatively constant speed of just over 20mph, wind speed was apparently low (about 3mph from the NW).

Red has been sedentary since the last update, logging an additional 200 miles for a total of over 3900 miles…his data points are mostly clumped along the coast near Cuyamel on the Honduran side of the Guatemalan/Honduran border.


Saturday, October 17, 2009

Rankin Migration - 17 Oct. 2009

Blue has now logged more than 3000 miles and has continued to track SE. His last observed location was on South Bimini Island (part of the Bahamas) 56 miles ESE of Miami, Florida (quite a departure from other birds that have taken the Florida route). He stopped 3 times while in the West Palm Beach area, each occasion in a location significantly less populated than the surrounding urban landscape (a 25 square mile water catchment area, an up-scale acreage-type residential area and a golf course). He also used a natural area along the Fox River in other-wise highly populated region near Elgin, Illinois on a previous stop-over.

Red is 3700 miles into migration, and did cross to Cuba (the far western end near Cabo de San Antonio) before making the 125 mile ocean crossing to the Yucatan. He meandered southward generally along the coastline and his most recent data point shows him to be 17 miles WSW of Belize City.

Attached also are two photos from birds trapped on Padre Island – the first is of an adult female that first captured as a hatch year bird in 2000, and the second is of a blonde second year male.


Wednesday, October 14, 2009

Rankin Migration - 14 Oct. 2009

Blue has flown over 2500 miles, and despite an initially similar route to those taken by birds in 2008 (that took them westwards), veered eastwards to visit Chicago for a couple of days. He has tracked SE and now looks to be taking the Florida route.

Red has now flown over 3000 miles and was in the Dry Tortugas at last record and is likely currently on route to Cuba or directly across the Gulf.

Here are a couple of images taken during South Padre Island Peregrine Survey in Texas – the first photo is of a freshly eaten coot (a Hatch Year female with full crop was sitting not far away), the other is a pretty typical of the Padre Island habitat where many hundreds of peregrines stage on their way to South America.


Friday, October 2, 2009

Rankin Migration - 02 Oct. 2009

Both Rankin birds are now well into migration – As of October 1, Blue is in Minnesota and has flown over 2000 km since September 23 and Red is in Wisconsin with over 2700 km covered since September 22. Both have flown west of the Great Lakes and based on data collected in 2008, Blue may take a circum-gulf route perhaps via Padre, and Red at this point seems destined for Florida.
The above photo of red on territory was taken by Vincent L’Herault this summer.