Monday, August 24, 2020

Good news and pending news on southbound Swallow-tailed Kite migration.

Since we last wrote, we watched three GPS-tracked Swallow-tailed Kites head out over the Gulf of Mexico. So far, only two of them, Jeaga 1 and Sarasota, have made it safely to a shoreline.  

Jeaga 1, last over open ocean south of the Cayman Islands, made landfall south of Placencia, Belize, and has been spending her stop-over time ranging throughout the Toledo District of Belize.

Sarasota was pushed westward by tailwinds into the central Gulf but thankfully made landfall just north of Tampico, Mexico and continued to follow the Gulf coast south where he’s taking his time just south of the famous Veracruz hawk-watch location.

The good news for Jeaga 3 is that her GSM-GPS tracking unit produced excellent movement data after leaving Cuba. Unfortunately, 2 days later, she was still out over the Gulf of Mexico. Winds had derailed her southwestward flight to the Yucatan Peninsula, pushing her westward instead along a track very similar to those of Sanibel South and Sarasota. Two days after leaving Cuba, within 7 miles of the Mexican coastline just north of Tampico, Jeaga 3’s on-board “cell phone” connected with a land-based tower and uploaded her accumulated GPS data. At this point, she already had turned north, then northeast, and eventually back to the east, thus heading back out over the open waters of the Gulf of Mexico. She had been so close to land, but was now flying the WRONG way!

It might be helpful here to review some details about the solar-powered GSM/GPS transmitters these Swallow-tailed Kites are carrying. The GPS component of these solar-powered tracking devices are programmed to collect a highly accurate location fix (latitude x longitude accurate with 10 to 15 meters) every hour. This acquisition process, dependent on satellite communications just like any earth-bound GPS receiver (including the one that plots a moving map on your phone as you drive down the road), runs continuously regardless of where the bird is, even when far from a cell-phone tower. Months-worth of GPS fixes can be stored onboard. However, because the transmitter component of these devices communicates with international cellular phone networks, it is unable to upload the stored GPS data until the bird happens to fly within cell-tower range. Therefore, we may go for long periods not “hearing” from birds as they migrate over ocean and through remote areas. If something goes wrong during these times and the data-stream ceases, we have no way of knowing what happened. Some of the Swallow-tailed Kites we have tagged remain beyond tracking range for their entire wintering period, and we must wait in anticipation for their radios to resume transmission once they have begun migrating northward. Fortunately, once this happens, we receive all of the GPS fixes that have been received and stored while the transmitter has been silent. We are still hopeful that Jeaga 3 has made it to land, just beyond cell-tower range, and may soon begin uploading her stored GPS locations. 

As of August 15th, 2020, all but two of the 11 GPS-tagged Swallow-tailed Kites have left the U.S.A.

Ponchitolawa, tagged by colleague Dr. Jennifer Coulson of Orleans Audubon, still resides on the Pearl River in Louisiana, still fueling up for the migration ahead.

Sawgrass from Pinellas County, Florida, is now on the southern tip of Florida, about to cross the Gulf of Mexico.

Once Apopka was ready to start southward from his St. Johns River pre-migration location, he spent a night in the Okaloacoochee Slough State Forest, flew over the Florida Keys the next day, then crossed the Straits of Florida to Cuba.  After a night in near Havana, he headed due south, skipping Mexico’s Yucatan Peninsula altogether and making it all the way to Honduras! He must have well-prepared for this ~570-mile over-water flight because he kept moving south once over land.

Sanibel South made her way to the Gulf coast of Mexico and is following the path taken by Sarasota, now 400 miles farther south.

Suwannee and PBC-ERM male experienced what we would consider an ideal safe migration with quick flights to western Cuba, one night on Cuba, and west over water from the Guanahacabibes Peninsula the next day.  With a two-hour lead, Suwannee spent a night south of Tulum, Mexico, while PBC-ERM had made it to the island of Cozumel, Mexico for the night.  Neither wasted time once on land. PBC-ERM male is in Guatemala, and Suwannee is 300 miles ahead in Nicaragua.

After a night in Highlands County, Florida, Prichard crossed the Gulf of Mexico directly to the Yucatan Peninsula on 9 August, the fastest GPS track across open ocean for any of this year’s migrating kites.

Sending good vibes to our missing Jeaga 3, hoping that she is safe on land. Check back with us next week and we’ll bring you up to date.

As always, we are grateful to all the organizations and individuals who have made ARCI’s long-term studies of Swallow-tailed Kites possible, thus helping us understand how these amazing birds need our help. The ever-growing list of current contributors includes:

Audubon Center for Birds of Prey
bioGraphic
Caloosa Bird Club
Clearwater Audubon Society
CROW - Clinic for the Rehabilitation of Wildlife, Inc.
Florida Panther National Wildlife Refuge
Friends of Palmetto Bluff Conservancy
Friends of the Carlton Reserve
Friends of the Florida Panther Refuge
Friends of the Lower Suwannee & Cedar Keys National Wildlife Refuges
Halifax River Audubon
Jacksonville Zoo and Gardens
Lower Suwannee National Wildlife Refuge
National Audubon Society
Oklawaha Valley Audubon Society
Orange Audubon Society
Orleans Audubon Society
Palm Beach County Department of Environmental Resources Management
Palm Beach Zoo and Conservation Society
Palmetto Bluff Conservancy
Peace River Audubon Society
Sanibel-Captiva Audubon Society

Wednesday, August 19, 2020

Wow! Swallow-tailed Kites over the Gulf and through Cuba and…!

As of August 7th 2020, our GPS-tagged Swallow-tailed Kites have made leaps and bounds on their migration. Recall that Hurricane Isaias moved up the Atlantic coast, and the winds and pressure systems surely encouraged many Swallow-tailed Kites to take advantage of the tailwinds. All but two of the 11 tracked kites have moved south.

Ponchitolawa, tagged by colleague Dr. Jennifer Coulson of Orleans Audubon, is still foraging around the Pearl River in Louisiana, and Apopka is still along the southern reaches of the St. Johns River, in Brevard, County Florida.

Sawgrass from Pinellas County, Florida, has left the Savannah River near Augusta, Georgia and is now on the Altamaha River near Abbeville, Georgia.

Pritchard also left the Savannah River, spent a night south of Jacksonville, Florida, and is now in Highlands County, Florida.

After staying aloft for nearly five days over the Gulf of Mexico, Sanibel South has been moving slowly around Dewitt County, Texas.

Suwannee had spent a night in Florida’s Green Swamp, another in Picayune Strand State Forest in Collier County, Florida, and continues moving southward through the Everglades. We assume he will be crossing the Gulf of Mexico any time now. PBC-ERM Male is lingering on the southern tip of Florida’s Cape Sable, waiting to cross the Yucatan Channel.

Four kites have made the “leap” from south Florida!  Jeaga 2, followed just a day later by Jeaga 1, crossed south to Cuba spending two and three nights, respectively, before making quite different departures from the Island.  Jeaga 2 left for the Yucatan from western-most Cuba and made good time to an arrival just south of Cancun, Mexico. Jeaga 1 departed from the south-central Cuban coast heading southwest, crossed the Cayman Islands, and is on course over the Caribbean to make landfall between Belize and Honduras soon, if the wind doesn’t switch directions.

Jeaga 3 made a fast trip through south Florida and caught up with Sarasota on Cape Sable, Florida. They both left the southern tip of Florida within hours of each other, but their paths have been distinctly different. Jeaga 3 flew to western Cuba and spent one night on the Guanahacabibes Peninsula before departing for Mexico.  Winds derailed a direct flight to the Yucatan, so, just like Sanibel South, Jeaga 3 was pushed westward into the central Gulf of Mexico. Meanwhile, Sarasota crossed the Florida Keys towards the Yucatan Peninsula, but, just like Sanibel South and Jeaga 3, was pushed westward by tailwinds into the central Gulf.

Juvenile Swallow-tailed Kite photo by Marvin Smith
All this means three GPS-tracked Swallow-tailed Kites are now over open ocean, at the mercy of winds in this region of volatile weather!  As Sanibel South showed us, a kite can survive up to 5 days over water without food and rest, but the average maximum time over water has been three days.

If you’ve been following along with ARCI’s Swallow-tailed Kite migration blogs over the years, you have witnessed how these birds are putting a lot on the line as they make the attempt to cross at least 400 miles of ocean to reach the Yucatan Peninsula. However, they need the support of tailwinds and, as we all have learned, anything can happen.

Fingers crossed for all Swallow-tailed Kites to make it safe to land. More soon!

As always, we are grateful to all of the organizations and individuals who have made ARCI’s long-term studies of Swallow-tailed Kites possible, thus helping us understand how these amazing birds need our help. The ever-growing list of current contributors includes:

Audubon Center for Birds of Prey
bioGraphic
Caloosa Bird Club
Clearwater Audubon Society
CROW - Clinic for the Rehabilitation of Wildlife, Inc.
Florida Panther National Wildlife Refuge
Friends of Palmetto Bluff Conservancy
Friends of the Carlton Reserve
Friends of the Florida Panther Refuge
Friends of the Lower Suwannee & Cedar Keys National Wildlife Refuges
Halifax River Audubon
Jacksonville Zoo and Gardens
Lower Suwannee National Wildlife Refuge
National Audubon Society
Oklawaha Valley Audubon Society
Orange Audubon Society
Orleans Audubon Society
Palm Beach County Department of Environmental Resources Management
Palm Beach Zoo and Conservation Society
Palmetto Bluff Conservancy
Peace River Audubon Society
Sanibel-Captiva Audubon Society
Sanibel-Captiva Conservation Foundation SCCF
Sarasota Audubon Society
Seminole Audubon Society 

Friday, August 14, 2020

And so it begins… Swallow-tailed Kites migrate south 2020 style.

If Sanibel South’s migration didn't produce enough nail-biting anticipation…we’ve got some stories for you soon!  To set the stage we are taking the timeline and maps back to last week.


From north to south:  

Sawgrass from Pinellas County, FL returned for the 4th year in a row to favorite pre-migratory foraging aggregations around the Savannah River south of Augusta Georgia.  This is 375 miles north of her breeding area.  

Pritchard is also on the Savannah River at the National Wildlife Refuge, which is 10 miles from Palmetto Bluff, South Carolina where he spent the summer.


Ponchitolawa, tagged by colleague, Dr. Jennifer Coulson of Orleans Audubon, is foraging around the Pearl River in Louisiana.


Sanibel South is taking time to regroup in SE Texas after five days over open ocean flying.  See her extreme migration here in our previous blog.


Suwannee is roosting within the Lower Suwannee NWR and feeding over adjacent farmlands west of Chiefland, FL.


Jeaga 3 has been enjoying the upper St. Johns River and joining hundreds of other Swallow-tailed Kites in a foraging aggregation at the Lake Apopka North Shore Restoration Area.  This is a historically known hot spot for pre-migratory kites.  


Apopka is along the southern reached of the St. Johns River in Brevard County Florida.


Three kites, Jeaga 1, Jeaga 2, and PBC-ERM male are all together in Palm Beach County on ERM lands.  


The Sarasota kite has just started to make his way south,
following the coastline of the western Gulf.


A lot is at stake for these birds to make the “leap” over open ocean to reach the Yucatan Peninsula.  They need the support of tailwinds, and with at least 400 miles to cross, anything can happen - as we soon shall see.


More soon!


As always, we are grateful to all of the organizations and individuals who have made ARCI’s long-term studies of Swallow-tailed Kites possible, thus helping us understand how these amazing birds need our help. The ever-growing list of current contributors includes:

Audubon Center for Birds of Prey
bioGraphic
Caloosa Bird Club
Clearwater Audubon Society
CROW - Clinic for the Rehabilitation of Wildlife, Inc.
Florida Panther National Wildlife Refuge
Friends of Palmetto Bluff Conservancy
Friends of the Carlton Reserve
Friends of the Florida Panther Refuge
Friends of the Lower Suwannee & Cedar Keys National Wildlife Refuges
Halifax River Audubon
Jacksonville Zoo and Gardens
Lower Suwannee National Wildlife Refuge
National Audubon Society
Oklawaha Valley Audubon Society
Orange Audubon Society
Orleans Audubon Society
Palm Beach County Department of Environmental Resources Management
Palm Beach Zoo and Conservation Society
Palmetto Bluff Conservancy
Peace River Audubon Society
Sanibel-Captiva Audubon Society
Sanibel-Captiva Conservation Foundation SCCF
Sarasota Audubon Society
Seminole Audubon Society
St. Petersburg Audubon Society
Sunrise Wildlife Rehabilitation
The Avian Reconditioning Center for Birds of Prey
Venice Area Audubon Society
West Volusia Audubon

Monday, August 10, 2020

Saved by the bugs? Sanibel South makes the longest over-water journey recorded!

Soon after we introduced you to Sanibel South in our last blog, she became the first of our tracked Swallow-tailed Kites to leave Florida for the winter. In fact, the start of her southbound migration has become one of the most exciting we have seen since our studies of Swallow-tailed Kite long-distance migration began in 1996.

As you may recall, Sanibel South started her southbound journey by first flying up to north-central Florida (Alachua and Gilchrist counties), where she joined daily foraging flocks of kites, which sometimes numbered in the hundreds, to feast on insects for a month. This strategy was soon to pay off as Sanibel South’s attempt to cross the Gulf of Mexico from southern Florida to the Yucatan Peninsula became one for the record books.

Swallow-tailed Kite foraging in Alachua County, Florida.  Photo by Adam Kent

Swallow-tailed kites are truly creatures of the wind. Typically, the eastern portion of the U. S. population, i.e., the ~65-70% that nest in Florida, Georgia, and South Carolina, prepares for southbound migration by moving into position in southern Florida, where they feed in flocks on flying insects by day and roost communally at night. As individuals achieve the body condition needed for their impending journey, they stage along the southwestern coast of Florida (seaward of Big Cypress Swamp and the Everglades) while awaiting favorable tailwinds that will help carry them across 450 to 600 miles of the Gulf of Mexico. As you can imagine, crossing such a vast expanse of open ocean is dangerous for any bird, but especially for a large soaring species that, like most raptors, relies mainly on upwardly rising thermals generated by heated land masses to stay aloft. Over-water wind direction and speed are critically important to migrating Swallow-tailed Kites because, unlike migrating songbirds and seabirds, they are not built to sustain self-powered flight for extended periods. To complicate matters further, weather patterns over the Gulf of Mexico are exceptionally volatile. A favorable wind on the tail of a kite heading out to sea can become a deadly headwind within a few hours or less, leaving a kite at the mercy of aerial currents that will keep places to rest, eat, or drink beyond their reach for several days. 

Winds across the Gulf of Mexico. Maps by https://earth.nullschool.net/
 

From our long-term research, we know that, despite their astounding aeronautical prowess over the sun-soaked southern landscape, none of the Swallow-tailed Kites we have tracked survived over the Gulf of Mexico for more than 3 to 4 days and nights. Remember that the thermals that support the Swallow-tailed Kites’ endlessly energy-efficient soaring over land cannot be as frequent or powerful over the ocean. As we monitor the tagged kites during these dangerous times, seeing prolonged downwind flight far from shore followed abruptly by radio silence reminds us of the harsh consequences of the Swallow-tailed Kite’s physiological limits.

However, In the last few days, Sanibel South has miraculously raised the bar for those that will follow. After spending the night of July 24th in the Ten-thousand Islands National Wildlife Refuge (near Chokoloskee, Florida), she took a tailwind offshore around 10:00 a.m. and flew southwestward across the lower Florida Keys and out over the cold, deep waters of the Yucatan Channel for 260 miles, right toward the northeastern Yucatan Peninsula. With her speed and direct trajectory, it was not alarming to see her bypass Cuba. About half the kites we have tracked have done so, reaching the eastern shoreline of the Yucatan peninsula within 12 to 20 hours.

This time, though, as occasionally happens, the weather had a different plan. With 200 miles to go, a strong wind started blowing directly toward the west, and Sanibel South hitched a ride, blasting right past the Yucatan, flying downwind for another 800 miles before almost reaching the eastern shore of mainland Mexico.   

Almost. Had she flown another 50 miles, Sanibel South would have reached the coastal wetlands, farm fields, and forests of the state of Tamaulipas by mid-day on July 28th. Instead, as you can see on the map, she flew an 80-mile ellipse to the northeast (looking for land she might be able to reach…climbing for a better view?), ending up back on her original westward course at 10:00 p.m. that night. From there, she headed northwest until sunrise, when she probably could have seen the Mexican coastline less than 25 miles away. But instead of flying toward shore, she took up a northeasterly course, paralleling the coastline for 350 miles before finally coming ashore near Freeport, Texas, just after midnight on July 29th (almost 1:00 a.m. July 30th).  She crossed the narrow strand of beach 106 hours after leaving the southwestern coast of Florida behind.  

 

Southbound migration across the Gulf of Mexico of Sanibel South, a Swallow-tailed Kite tracked by GPS in 2020 by ARCI.

This over-water flight of at least 1,755 miles (an average of 16.6 miles per hour) is the longest ARCI has ever recorded in 25 years of remotely tracking migrating Swallow-tailed Kites. Having witnessed so many Swallow-tailed Kite over-water migratory flights ending in death after three to four days, we believe Sanibel South must have been unusually fit. Perhaps she owes her success to the masses of insects she had been eating before leaving Florida.

Sanibel South understandably is taking her time and refueling in south Texas.

Let us hope the rest of the southbound Swallow-tailed Kites have the resources they need to get across the Gulf of Mexico, and to make the return trip in the spring. 

We look forward to sharing more of their stories as the migration season unfolds.

You can be part of our Swallow-tailed Kite Population Monitoring Survey by reporting your sightings here: http://arcinst.org/2020-stki-population-survey

For great live wind maps, click here: https://earth.nullschool.net/