Thursday, October 22, 2009

Following Raptors South - A Glimpse of Migration in Costa Rica

Many of us are deeply absorbed in the passing of migrants each fall. Here in New England, we treasure those crisp days bright with red-shouldered hawks and changing foliage. A kettle of 50 broadwings overhead may be all you need to get you through the week. But when they leave us in chilly New England, do you give thought to where they are heading? As I watch an osprey soar overhead in New Hampshire, I can’t help but envision its route…island hopping from Florida through the Caribbean until it reaches South America and shooting straight through Brazil. Or a merlin, forever in a hurry, tearing down the Atlantic coast and hugging the gulf until it settles somewhere in central Mexico.
HMANA’s website is a phenomenal resource for pulling together all the pieces of this puzzle. It is one of the best tools we have for understanding the big picture: what species are moving, how many, where they are going, and when they are moving. How great to be able to learn of raptor movements all over the continent with a few clicks of the mouse.

When we think about migration on a different scale, massive movements of raptors passing in the tens of thousands a day, we often think of Gulf coast sites or Veracruz, Mexico, well known for tallying an astounding 5 million raptors each fall! Well, I wanted to briefly highlight a migration monitoring site that doesn’t get much attention but has a lot to offer and is located in one of the most biologically and culturally rich sites in the world - the Kekoldi Hawkwatch in Talamanca, Costa Rica.
Here, tucked into the rainforests of the Caribbean lowlands inside an indigenous reserve, stands a canopy tower perfectly situated for monitoring migrants. All southbound birds are funneled through a narrow 5 km stretch between the Talamancan Mountains and the Atlantic coastline. In addition to millions of raptors, swallows and dragonflies cover the skies, warblers pour through in waves, intermingling with resident forest birds and common nighthawk counts have reached 20,000 in one day.

Since 2000, Kekoldi has been a volunteer-run site active during most fall and spring seasons. However, it struggles at times to find enough counters. This is unfortunate, given its biological significance and history of counting 2- 3 million raptors of 15+ species. I was lucky enough to spend two seasons at Kekoldi, assisting in the count and collecting data on Peregrine Falcon migration. The potential for research at this site is outstanding and it is critical to pursue for our understanding of raptor populations and movements in the tropics. Currently, HMANA is striving to assist the Kekoldi hawkwatch in adding data to the HawkCount database and by establishing continuous counts and so it can become a contributer of long term data.
To put this all into perspective, when we are swimming in broad-winged hawks up here in the northeast, the Kekoldi watchsite has already counted 200,000 Mississippi kites. As we welcome late season redtails and goshawks in mid-October, the skies above Kekoldi are covered in one million broad-winged hawks. By October 25th, a half a million Swainson’s hawks will be passing overhead. By the time November rolls around in New England, we are packing it in, or maybe withstanding the last few cold days, hoping for a golden eagle or two. But in Kekoldi, turkey vultures are just getting started and will total over one million by mid-December.

I think it’s important to keep these migration schedules in mind. It gives me a new perspective on migration and reminds me of the bigger picture. It also makes me value the count data I collect daily, and the feeling that I’m contributing to something larger.

Interested in visiting this secluded raptor hotspot? A HMANA tour to the Kekoldi Hawkwatch may be in the making for fall 2010. Stay tuned!

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