Wednesday, March 25, 2015

Settling in. Pressing on.

Three satellite-tracked Swallow-tailed Kites have returned safely to the US, beginning to settle into their summer home ranges, while four others continue to press north. 
Tracks and locations of seven satellite-tagged Swallow-tailed Kites from 1 March - 16 March 2015.
Since back in Florida, Day has been traveling along a 17 mile corridor from Ormond Beach to south of Port Orange.

MIA is settling into his past summer territory in south Miami.

Gulf Hammock touched US soil on 8 March after a grueling 68 hours over water, fighting strong winds in the Gulf of Mexico. It pushed her farther west than she wanted to be, making landfall in Louisiana. She took some recovery time for rest and refueling before beginning to inch east to Florida.

Pace took a very similar path as Gulf Hammock, cutting the same “corner” crossing the Bay of Honduras. As of 16 March he was in northern Quintana Roo, Mexico and almost in position to make the cross-Gulf flight to the US.

At 500 miles south of Pace on 16 March, Palmetto was in Nicaragua on the same course as the two kites north of her. Her mate, Bluff was yet another 600 miles south of her just entering into the Darien of Panama.

PearlMS was last in Amazonas of Colombia and about to cross the high peaks of the Andes Mountains.

Tuesday, March 17, 2015

Windswept, but safe.

As predicted, Gulf Hammock, a female Swallow-tailed Kite tagged as an adult in 2011 in Levy County, Florida, was our next satellite-tracked bird to make it back to the United States. 
Gulf Hammock faced dangerous spring winds on her northbound gulf crossing. Pushed off course, she persevered, staying aloft for 68 hours until finally reaching Louisiana's coast.
Several weeks after leaving her Bolivian winter range and passing quickly through Central America, Gulf Hammock got a jump on most of her fellow kites by cutting across the Bay of Honduras to the Mexican state of Quintana Roo, on the eastern coast of the Yucatan Peninsula. It was a short trip from there to the northeastern tip of the Peninsula, where on 5 March at 9:00 a.m. EDT, she sailed northward out over the Gulf on strong tailwinds (see the wind map for 3/5/15 17:00 UTC). 

Gulf Hammock made exceptionally good time until the middle of the night, when she slammed into powerful headwinds of the approaching high-pressure system that completely halted her northbound progress. As shown by the track segment associated with the map for 3/6/15 06:00 UTC, she looped 90 miles out to the east, then back again nearly to her original position before taking up a northwesterly heading. 

From this point, Gulf Hammock consistently flew 90 degrees off the northeasterly wind for at least 44 more hours, eventually reaching Marsh Island on the coast of western Louisiana. 

In all, this Swallow-tailed Kite had spent 68 hours aloft over the Gulf of Mexico managing her finite energy supply and choosing a path that defied the Gulf’s deadly spring winds.

Thursday, March 5, 2015

Gulf Hammock nears a critical moment and shifting winds

We’re pleased to report that MIA and Day, two of our GPS/satellite-tracked Swallow-tailed Kites have made it safely to the US and have returned to their breeding territories.
Northbound migration of seven GPS/satellite-tracked Swallow-tailed Kites from 15 January to 1 March 2015. MIA and Day are the first to return safely to their US home range.

MIA moved quickly and steadily ever since leaving his winter range in southern Brazil. By 22 February he was on the northern coast of Honduras and took a 9-hour overwater shortcut to Dangriga, Belize. Pausing only briefly, he continued north and on the morning of 25 February launched from the tip of the Yucatan Peninsula, committing to nearly 500 miles of open ocean. He covered the distance in 24 hours, making land on Florida’s coast just north of Sanibel Island. He crossed to the eastern part of the state, spending a night in Davie, Florida, before continuing south to his summer home range in southern Miami. On 3 March MIA was spotted bringing Spanish moss to his old nest.

Day launched seaward on the same day as MIA, however she initiated her crossing much farther south from the northern coast of Honduras. Holding a tight northward heading, she sped midway between the Yucatan Peninsula and Cuba. Once through the Yucatan Channel, she turned abruptly to the northeast, setting her eyes on Florida’s southwestern coast. She completed her 830-mile overwater flight in an astounding 28 hours. Day reached the US just south of Sanibel Island, and over the course of 3 days, slowly made her way to her Daytona residence area.

We predict the next kite to make the over-water passage will be Gulf Hammock. Presently in Nicaragua, will she fly to Florida from northern Honduras, or will she stay over land until reaching the northern tip of the Yucatan? The strong, highly favorable southerly winds of the last week or so will turn into strong northerlies by midnight tonight (5 March). The circulation around this large high pressure system will gradually shift to the northeast and east, but winds will remain unfavorable for at least the next three days. This is bad news for Swallow-tailed Kites and birds of all species that are already out over the Gulf of Mexico and heading north. However, the large size of this system at least means that the headwinds are apparent to all the birds now staging on the northern coast of the Yucatan, thus discouraging them from beginning a northbound flight that very likely could be fatal.

Pace slowed his progress in the rich Amazon region of Brazil. He tarried for 10 days between 16 and 27 February. He is now 50 miles into Colombia.

The remaining three birds are still in Brazil and slowly moving north. The breeding pair of kites Palmetto (female) and Bluff (male) are 260 miles apart with Bluff in the lead. PearlMS, the last kite to leave the US and also the northern-most wintering kite, started north on 24 February, the day before MIA and Day crossed the Gulf to Florida. PearlMS is in Rondonia, Brazil.

Thursday, February 19, 2015

A Crossing of Wingbeats

From South Carolina’s lowcountry to Brazil’s vast Pantanal, we have been following Palmetto and Bluff, the first-ever GPS/satellite-tagged breeding pair of Swallow-tailed Kites.
The paths of Palmetto and Bluff cross on the same day during the early leg of their spring migration. Until now, their migration paths have remained many days and hundreds of miles apart.  Palmetto and Bluff are the first-ever breeding pair of Swallow-tailed Kites to be tracked.  

Palmetto (female) and Bluff (male), tagged in 2011 and 2014, respectively, spend their North American summer in an area occupied by the Palmetto Bluff community, a historically and environmentally rich area cradled by the May River and the salt marshes and maritime forests of the southeastern coastal plain. As summer ends there and migration pulls them southward, Palmetto and Bluff, like all of the Swallow-tailed Kites that nest in the United States, settle over 5,000 miles away deep in the southern hemisphere. This far away land, however, is much like a mirror image of their northern breeding range. The Brazilian state of Mato Grosso do Sul, literally “thick forest of the south”, is crisscrossed with river floodplains, humid forests and vast marshes. The kites fly from the steamy, long days of one hemisphere to the steamy, long days of another – truly, an endless summer.

Since tagging Bluff in 2014, we have been learning how the nesting activities, migrations, and wintering destinations of these mates compare. During the breeding season, we saw contrasting movements and behaviors of the adults in their respective parental roles. Bluff, the male, did nearly all the foraging, while Palmetto, the female, spent most of her time incubating, brooding small young, and remaining near the nest until her young fledged and became independent.

By mid-June, Palmetto and Bluff successfully fledged one young. Late in the nesting cycle, Palmetto started ranging farther from the nest, using the area between Palmetto Bluff and the Savannah National Wildlife Refuge and lands along the New River in South Carolina. Bluff, however, lingered on his foraging range until 17 July, when he also headed to the Savannah National Wildlife Refuge and then north up the Savannah River west of Allendale, South Carolina.

Palmetto, newly outfitted with a GPS/satellite
transmitter and ready for release in 2011.
Starting south along the New River on 29 July, Palmetto flew 210 miles to central Florida to spend the night in the Green Swamp in Sumter County. Her last night in Florida, 31 July, was on the Babcock Ranch Preserve in Charlotte County. Continuing her speedy way south, she left Cape Sable at the extreme southern tip of peninsular Florida around 6 pm and arrived on Cuba, 30 miles west of Havana, in the middle of the night. She took the predictable westerly route through Cuba the next day, and made her way across the Gulf of Mexico to arrive in the state of Quintana Roo, Mexico, on 3 August before the sun rose. She exhibited true stopover behavior here, staying in one area for seven days, no doubt resting and feeding after her 200 mile overwater flight from Florida via Cuba. On 11 August, Palmetto proceeded south, taking a shortcut from Placencia, Belize, to Cuyamel, Honduras. She approached the Nicaraguan border via the Reserva Biologica Tawahka, Honduras, made her way safely through the narrow Isthmus of Panama and finally crossed the Andes in Columbia. She passed southeastward through the headwaters of the Amazon until she reached her winter range in Brazil on 17 September 2014.  

Bluff started south on 12 August, exactly two weeks after Palmetto’s departure. He moved quickly on his way to Florida, spending one night near the St. Marys River (the Florida-Georgia border) and one night south of Gainesville, Florida, before crossing southeast to the Lower Wekiva River Preserve State Park. On 17 August, he flew all the way to Okaloacoochee Slough State Forest west of Lehigh Acres, Florida, and was south of the Florida Keys by 1:00 pm the next day on his way to western Cuba. Flying through the night just off the island’s northwestern shore, Bluff continued another 130 miles across the Yucatan Channel, reaching Cancun, Mexico, at 11 pm the night of 20 August. By contrast, Palmetto had reached this coastline 17 days earlier and 175 miles to the south. By 29 August, Bluff had crossed from Nicaragua into Costa Rica close to the Caribbean shoreline, and by 9 September had crossed the Andes into Peru. He spent about a month meandering southward on his way to his winter range in Brazil. 

But now, as Palmetto and Bluff head north, we are seeing something new. A week ago, Palmetto, who had wintered 300 miles south of her mate, passed within 40 miles of his range and continued northwest. She slowed down in Rondonia, Brazil, just long enough for Bluff to catch up. On February 14th, between 3pm and 5pm eastern, they were within 5 miles of one another. Considering how independent their southbound migration and wintering season had been, it was interesting to see how closely they passed to each other. One reason simply may be that the kites’ migration corridor, for all its length, is relatively narrow. But the identical breeding schedule and locations of these two individuals could be another reason why they were in such close proximity during this time. We look forward to seeing how closely their paths come during the remainder of their northbound flight. It’s also fun to wonder how many other kites bound for nest territories in southeastern South Carolina may be nearby.

Sunrise at Palmetto Bluff, South Carolina. 

Friday, February 13, 2015

MIA races for the Andes, Bluff still in idle

All but two of our seven GPS/satellite-tagged Swallow-tailed Kites are moving their way north to the U.S. Their locations spread almost 2,000 miles across Brazil, Peru and Colombia. The four birds that wintered the farthest south in Mato Grosso do Sul, Brazil, have leap-frogged the others and are now ahead of the pack. 
Swallow-tailed Kite Northbound migration 2015. Tracks show movements from 1/20/15 - 2/9/15.
© Avian Research and Conservation Institute
MIA is in the lead in Putumayo, Colombia. His views are about to change from expansive green rainforests to the peaks of the Colombian Andes.

Several hundred miles behind are Day and Gulf Hammock in Loreto, Peru, a sparsely populated region covered with wide river flood plains. The prey diversity of this rich rainforest is advantageous to the migrating kites. Notice how the tracks of MIA, Day and Gulf Hammock look like curly straws in this area – they obviously couldn’t resist slowing down here to plump up on some high calorie road food.

Pace and Palmetto are 115 miles apart in Mato Grosso, Brazil. As Palmetto pressed north, she passed within 20 miles of her mate, Bluff, who has yet to leave his winter range. This is the first nesting pair of Swallow-tailed Kites that has ever been tracked with GPS/satellite-transmitters; make sure you keep an eye on them!

PearlMS remains in Rondonia, Brazil. Day passed right through her winter range on 22 January. Wonder if they foraged together for a day?

Fly on!

Thursday, January 22, 2015

2015 northbound migration begins!

For new followers, this blog is the first in an annual series in which we will describe the northbound migration of seven satellite-tracked Swallow-tailed Kites: Palmetto, Bluff, Gulf Hammock, Pace, Day, MIA, and PearlMS. All of these birds made it safely to their South American winter range last fall.  Now we will watch as they make their way back to their nesting areas in the southeastern U. S. 

This magnificent odyssey takes them across the Andes Mountains and several hundred miles of open ocean, where the late-winter weather can quickly turn perilous. The most dangerous leg is when they fly northward over the Gulf of Mexico. Rather than jump from the Yucatan Peninsula to western Cuba or the southern tip of Florida, the reverse of their southbound track, they generally head northward from the tip of the Yucatan Peninsula on the first good tailwind. If all goes well, they will reach land somewhere along the Gulf coast and turn toward the place where they nested last year. 

Because Swallow-tailed Kites cannot maintain continuous flapping flight, they are unable to make way against headwinds. Instead, they circle over the water waiting for the winds to change and carry them to land anywhere from southern Florida to the east coast of Mexico. We have learned from our telemetry research that many Swallow-tailed Kites die during their northbound migration because they cannot remain aloft for more than four days. In 2013, three of the 11 kites we were tracking by satellite perished while crossing the Gulf when unusually large high-pressure systems spawned strong northerly winds that persisted for over a week.

From the expansive family-owned cattle ranches of the Brazilian Cerrado, two of our seven GPS/satellite-tagged Swallow-tailed Kites have started their 5,000-mile journey back to the southeastern U.S.
The Swallow-tailed Kite northbound migration begins. Tracking data from 1 Dec. 2014 to 20 Jan. 2015. 

As in the last two years, MIA has made the first move.  He wintered the farthest south of all of the tracked birds and started north from the state of Mato Grosso do Sul, Brazil, on 8 January.  He is already 200 miles past PearlMS, who wintered the farthest north in Rondonia, Brazil.

Day is also making her first moves towards the U.S., having departed her winter range on 16 January.  She shared the same roosts and foraging grounds with Palmetto and Pace, which are still within their 100 square mile winter range near Santa Rita do Pardo.

Palmetto’s mate, Bluff continued moving south during the winter months.  Don’t be fooled by the green track. This is a 600-mile southbound move he made in early December.  Currently, Bluff is 300 miles north of Palmetto.

Gulf Hammock still occupies the lush forests in the state of Santa Cruz, Bolivia.

Any guesses on which of the remaining Swallow-tailed Kites will start north next?

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.