Tuesday, January 26, 2016

I Miss "My" Cooper's Hawk

The Cooper’s hawk would arrive every January to roost on our back gate, hunting.

A handsome bird was he and his flight a beauty to behold.  Incredibly swift, yet maneuverable, dodging branches till he snared his airborn prey.  He and his fellow accipiters are sometimes called “blue darters.”

He would often leave a half-eaten white-winged dove carcass inside the patio walls.  His calling card. Lois hangs hummingbird feeders on a juniper in the patio.  The Coop was the hummingbirds’ pal, holding at bay the larger birds that liked to raid the hummers’ nectar.

Now, for the third winter, the hawk hasn’t appeared on the back gate. Lois has to refifl the hummingbird feeders more frequently than she did when he hunted here.  

I can’t help but wonder if the no-show Cooper’s hawk is one more anecdote in the litany of natural examples of climate change and habitat disruption.  A New Mexico State University doctoral candidate doing research on the Coopers has found a surprising abundance of them in the Albuquerque urban area where he’s working. 

The researcher, Brian A. Millsap, told me, "I do think its possible Cooper's hawk population outside of Albuquerque in NM is declining. The Breeding Bird Survey (a nationwide annual monitoring program for birds coordinated by the U.S. Geological Survey) suggests that might be the case, with Cooper's hawks declining by over 1 1/2 percent per year over the past decade over most of NM (see: http://www.mbr-pwrc.usgs.gov/bbs/tr2013/tr03330.htm).  Of course this is a pretty coarse survey, so these results need to be considered with that in mind.  But my data from Albuquerque support this idea, because about half of the females fledged in town end up filling breeding slots elsewhere."

Millsap is the National Raptor Coordinator for the Division of Migratory Bird Management of the U.S. Fish and Wildlife Service.

Good science takes a while, and then it takes another while to penetrate the consciousness of the laity.  But birds and animals are equipped to intuit what it takes us months or years to observe and document. Perhaps the Cooper’s hawks know something we’re not even dimly aware of.

In the nearby desert I used to watch big grey owls — Great Horned, probably — gliding down the arroyos for two or three hundred feet,  barely  48 inches above ground level, hunting rabbits or other prey.  No longer.

In a few weeks the avid birdwatcher in the family, a granddaughter, will be visiting and we’ll head over to the Chiricahua mountains in Arizona.  I’ll ask her to keep a casual eye out for the owl and the hawk during her pursuit of more exotic species like the elegant trogon.  Perhaps she’ll tell me that they haven’t vanished at all, that my old eyes aren’t as sharp as they used to be, that my old feathered friends are still to be seen if you look hard enough.

But National Wildlife Federation scientists have already documented that climate change affects waterfowl around the world, changing their habitats, food sources and migration cycles.

They project up to 91 percent reduction in wetlands area in the Prairie Potholes region on both sides of the U.S.-Canada boundary in the Great Plains. This is one of the most important waterfowl breeding areas in North America. Populations of mallards, gadwall, blue-winged teal, northern pintails, canvasbacks, redheads and ruddy ducks are imperiled.

Science is only beginning to look deeply into how climate change can affect wildlife habitat. An Australian study found that current methods like wildlife reserves and bird sanctuaries may not be relied upon to sustain species as the climate changes. 

If only the scientists could interview “my” Cooper’s hawk, wherever he has gone.  Brian Millsap, for one, would love to hear his story.