Monday, September 22, 2014

Riding the coastline, lifting on wind

Three of our satellite-tracked Swallow-tailed Kites made it to Brazil!  Their GPS data indicate that Day and Palmetto have almost caught up to MIA, who has been far ahead of the other migrants since leaving Florida on 30 July. Two more of our tagged kites, Gulf Hammock and Bluff, are in Peru. Pace is making his way through Panama and PearlMS has passed overland through eastern Mexico.

Tracks of seven tagged Swallow-tailed Kites on their southbound migration from 7 Jul - 9 Sept 2014
Raptors often follow coastlines and mountain ranges during migration, probably as an aid to navigation, but also to exploit the lift produced when winds are deflected upward by ridges. 

Satellite-tracking reveals how Swallow-tailed Kites use coastlines and mountain ranges as migrational aids.

These images show the tracks of six tagged Swallow-tailed Kites moving south along the coastal plain of southern Costa Rica and northern Panama. Note how close their tracks are as they parallel the nearby coast, and how the kites make use of the coastal mountain range to remain aloft using as little energy as possible.  

Can you imagine how many other migrating Swallow-tailed Kites and other species of birds are using these areas?  We hope our tracking information can be used by governments and conservation groups to help protect these valuable migration corridors and to keep them safe for the countless numbers of birds that rely on them each year.

Thursday, September 11, 2014

A snapshot at summer's end

A snapshot of the locations of seven satellite-tagged Swallow-tailed Kites on their southbound migration. 

PearlMS has lingered in the floodplain of Louisiana’s Atchafalaya River for 7 days.  He spent most of his pre-migration on the Pearl River.

Pace is stopping over in the Sian Ka’an Biosphere Reserve of Quintana Roo, Mexico.

Bluff crossed from Nicaragua into Costa Rica, staying close to the Caribbean shoreline.

Gulf Hammock is 150 miles south of Bluff near the Caribbean coast of Panama.


Palmetto, Day and MIA have safely crossed the Andes and are making their way southeastward through the headwaters of the Amazon.

Tuesday, September 2, 2014

PearlMS sets forth...heads west?

PearlMS begins his southbound migration heading west to circumvent the Gulf of Mexico. 
The last of our seven GPS-satellite tagged Swallow-tailed Kites has begun his southbound migration...heading west. Ten days later than last year, PearlMS left his summer range near the Pearl River in Mississippi on 27 August, and began flying westward around the Gulf of Mexico.  His first stop, 120 miles away, was the rich lowlands of Bayou Nezpique, near Jennings, Louisiana, where he remained as of 31 August. 

During either their spring or fall migrations, Swallow-tailed Kites like PearlMS from the western subpopulation (Alabama, Mississippi, and Louisiana) may fly south directly across the Gulf of Mexico, or they may head west and travel entirely overland, following the Gulf coastline through Louisiana, Texas, and Mexico. 

By comparison, Swallow-tailed Kites that nest in the eastern portion of the species’ U.S. range (South Carolina, Georgia, and Florida) cross the Gulf of Mexico during their spring and fall migrations, but their routes differ depending on the season. Migrating southward at the end of the nesting season, they fly from southwestern Florida to the northeastern Yucatan Peninsula of Mexico either directly or with brief stops on Cuba. When they return in the spring, they depart from the Yucatan Peninsula and make landfall somewhere along the northern Gulf coast, from Louisiana to Florida. 


Jennifer Coulson of Louisiana Department of Wildlife and Fisheries
Photo by Tom Coulson
If you have followed our blogs, you know that PearlMS is one of three kites tagged in Louisiana and Mississippi by our long-time colleague Jennifer Coulson.  Dr. Coulson has studied Swallow-tailed Kites in this region for many years.  

Learn more about her work here: http://www.jjaudubon.net/research