Sunday, February 19, 2012

Beep.

Beep. 

Beep. 

Beep. 

Beep.

The radio receiver emits a series of steady pulses against a static background.  0.719 is sitting in a large Water Oak among twelve other Rusty Blackbirds.  The oaks surround a man-made pond, in a man-made environment consisting of two houses nestled on an open field, dotted with tall oaks and Loblolly Pines.  The birds sing together and sound like the turning hinges of an old iron gate.  Is their name derived from this sound?  Or is it inspired by the rust-colored feathers the males sport during the winter months?  Perhaps both.
Can you spot the RUBLs? 

Rusties like to be near water.  They largely depend on wetlands for their food during the winter months.  Invertebrates including insect larvae and worms, and vertebrates including minnows and the odd salamander, all high in protein, make up a large part of their diet.  When it gets cold or wet, the Rusties move into residential areas to eat pecans and acorns, which are higher in fat.

Over the last few decades the Rusty Blackbird has seen a marked decline in numbers.  Their population has dwindled since the 1960s and today, biologists are scrambling to determine why.  There are a number of theories that have been developed.  Many believe the problem lies on the wintering grounds.  Pesticides, mercury poisoning, loss of habitat, and an increase in natural predators are some of the factors being looked at.   

My job as a biologist with the Polistes Foundation in conjunction with the University of Georgia is to catch these birds and attach a radio transmitter to each individual so that I can track them in order to determine what they’re doing - where they’re going, what species they’re interacting with, and what they’re eating.  This research can give us insight into their personal lives and help determine what they need during the winter months, and whether or not they're getting it.
 
0.992, a female RUBL we captured after 0.719
The natural world is getting smaller and smaller  as urban environments and agriculture spread like a pernicious virus.  It’s as true here in Athens, Georgia as it is in the Amazon.  Wetlands, like the rainforests, are succumbing to bulldozers and dump trucks.  They are being drained and filled, or choked with silt and invasive plants.  And the species that depend on these habitats are disappearing. 

But we can't simply narrow it down to disappearing wetlands.  Many Icterid species use wetlands, like Red-winged, and Yellow-headed Blackbirds and their numbers (for now) seem to be stable.  So something else is acting on the Rusty Blackbird.  Perhaps it all comes down to flexibility. 
I ponder this as I watch 0.719.  Since 7:45 AM, he has been using the same residential area along with the rest of his flock.  It is now closing in on ten o'clock.  The sky is grey and a steady, misty rain falls.  Occasionally it pours, but it doesn’t last long.  The flock moves from tree to tree, settles to the ground along with Common Grackles, strutting around, picking at nuts, seeds, insects, and worms, before taking off into the trees once more.  Sometimes they’ll sit there for half an hour, preening and singing, before taking off in a ball.  0.719 eventually flies off with his flock, north into the thick of the wetland.  I move with them.

Why don't people take us "hippies" seriously?
At the end of the day, streaked with muck, with raspberry thorns embedded in my skin, and twigs in my hair, I walk back to my car.  I fold up the antenna and drive to the Kangaroo Express to get gas (I know).  At the pump a man pulls up behind me and gets out to fill his own tank.  He gives me a funny look. 

“Playing in the mud?” he asks.   

I look down at my filthy rubber boots and laugh.  I tell him I was tracking blackbirds.  I didn't include the “Rusty” part. Few people have any idea what a Rusty Blackbird is.  Fewer know that North America is home to over 716 species of breeding birds, and nearly twenty of those are Icterids including the traditional blackbirds like Red-winged Blackbirds, grackles, and cowbirds, as well as the orioles and meadowlarks.   

“Why would you bother doing that?” He presses.   Bother?  I silently scoff at his choice of words.   

I tell him they’re declining.  

“Like, endangered?” He asks.   

“Soon,” I reply,  “if nothing is done to help”.  

He laughed.  “Now, why would we want to keep a blackbird around?”  

I honestly didn’t know how to answer this question.  Not for lack of reasons.  I've tried many times to explain to the typical ignoramus who argued that "if you can't eat it, why keep it" that a world rich in biodiversity is a good thing.  There are many reasons why we should work to keep our many neighboring species around, but people on their way home from work don't like to stick around listening to a hippie blather on about why the planet needs saving.  

So, I simply said, “Why not?”

0.719 preparing to roost

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