Windows on Duke's Campus are a Devil for Birds

Most birders come across a window strike victim every now and again and perhaps think of it as a tragic freak accident.  But did you know that collisions with windows are the second leading source of human-caused bird death in the United States?

Tufted Titmouse, a window strike victim at Duke University

It’s a serious problem, particularly for neotropical migrants, many of which have declined significantly in North America over the past century.  It isn’t possible to attribute population declines to collisions, but the annual death of an estimated 1 billion birds (*source below) certainly isn’t helping.  And with more and more buildings being constructed that means more windows and more chances for fatally concussed birds.  

The good news is that solutions are relatively cheap and easy.  Window panes can be coated with ultra-violet reflective films or stickers to make them appear visible to birds without ruining the view for people.  Mortality of nocturnal migrants can be greatly reduced by turning off lights and/or shutting blinds during peak movements.  This approach has been taken by major metropolitan areas, such as Toronto and Chicago, which have annual “lights out” programs.

Data on the scope of the problem here in the Carolinas is mostly anecdotal so far.  Around the campus of Duke University in Durham, NC a few birders have collected dozens of incidentally discovered carcasses to send to the natural history museum in Raleigh to be used as study skins.

An assortment of window strike victims found on Duke University's West Campus over the past year

I stumbled upon the first campus record of a GrasshopperSparrow outside Cameron Indoor Stadium over a year ago.  Luckily this bird was still alive, confused and fluttering against a ground-level window.  I was able to catch it, document it with an iPhone and release it unharmed. 

Grasshopper Sparrow, a window strike survivor at Duke University

The first campus Fox Sparrow record came a couple weeks ago, but this bird was less fortunate.

Fox Sparrow, a window strike victim at Duke University

Both these sparrow species are relatively rare around Durham and it is clear that buildings on campus are the cause of mortality not just to local residents, but also to passing migrants that may be drawn into the well-lit and reflective campus only to crash into invisible walls.  

a Hermit Thrush lies dead beneath Duke University's sparkling new Penn Pavillion

But it will take more than the tragic story of a few birds meeting an untimely end to sway the corporate administrators that crank the machinery running Duke’s multibillion-dollar empire.  Deliberate sampling, statistics and cost-benefit analyses are needed.

...which is exactly why carcass surveys began last week focusing on seven West Campus buildings. They will continue for 21 consecutive days of as part of a project led by Natalia Ocampo-Penuela, a doctoral candidate at Duke’s Nicholas School of the Environment, and Nicolette Cagle, a Nicholas School instructor.  Their Duke team will pool data with a consortium of 45 other North American colleges and universities investigating bird death from windows on their campuses.  The international team includes academic institutions in Mexico and Canada and is spearheaded by researchers at Augustana College in Illinois.  Duke is the only participant in North Carolina.  

Surveys at Duke will not only help quantify the magnitude of the problem nationally, but also help identify local campus hot spots for bird strikes where mitigation can have the greatest positive effect.  Data on the shape, orientation, surrounding land cover and window properties of these buildings will also help inform future architects about strategies for bird-friendly design.  Six of the buildings in the survey have received awards for Leadership in Efficient Environmental Design (LEED certification), but so far it doesn’t look like many are that actually that friendly to birds.

Did you know that last Tuesday night there was a big movement of migrating Yellow-bellied Sapsuckers, an uncommon woodpecker that winters in Duke Forest?  I do because surveyors found three dead ones around Duke buildings on Wednesday.  

Yellow-bellied Sapsucker, a window strike victim at Duke University

Durham’s first Ovenbird of the season arrived that night.  It may have crossed the Gulf of Mexico recently on its way to breeding grounds in Duke Forest or points to the north.  But it’s chance to breed this year were ruined by a window of the French Family Science Center at Duke.

Ovenbird, a window strike victim at Duke University

This kind of practical action-oriented conservation science that Ocampo-Penuela and Cagle are pursuing is exactly what these birds need.

For more information about this project and instructions on what to do if you should find a window strike victim on Duke's campus, see their website: http://sites.duke.edu/birdcollisions/

If you find window strike bird anywhere in the world, you can report it to this new iNaturalist project: http://www.inaturalist.org/projects/bird-window-collisions

*Loss S.R., Will T., Loss S.S., and Marra P.P. 2014. Bird–building collisions in the United States: Estimates of annual mortality and species vulnerability. Ornithological Applications 116: 8-23. 

Los Angeles: Land of Woodpeckers?

Dear readers,

Here is the promised follow-up to my first post on Los Angeles birding about the area's wonderful woodpeckers.

You may be wondering how the desert wasteland I described in the last post is able to support wood-bearing trees, not to mention the advertised 'peckers. 

OK, I may have exaggerated the bleakness of the landscape a bit last time 'round.  There are actually plenty of trees in Los Angeles County and the woodpecker diversity surprised me.

Acorn Woodpecker, Los Angeles

One of the most ubiquitous is the charming Acorn Woodpecker, famous for caching acorns in tree-trunks. I don't know how they keep the squirrels at bay.  In the east, our Gray Squirrels would rob these poor birds blind as they do inevitably to just about all bird seed feeder-ers. 

Nuttall's Woodpecker, San Gabriel Mountains

And then there are the underrated Nuttal's Woodpeckers. I would say they are like the western equivalent of Downy woodpecker except that Downies are in California too (we saw one in the San Gabriel Mountains). 

Speaking of the San Gabiriel Mountains, the higher elevations are covered with some really pleasant parkland pine forests.  The trees seem to jut straight out of the bare rock in places and there's lots of space to stroll and see between the trunks. 

Up here we saw plenty of White-headed Woodpeckers.

White-headed Woodpecker, San Gabriel Mountains

And also the corvid that thinks it's a woodpecker, Clark's Nutcracker.

Clark's Nutcracker, San Gabriel Mountains

Or maybe it acts like a giant nuthatch?  Anyway I mentioned last time that it was a tossup between Corvids (the two scrub-jays, Steller's Jay, tame Ravens) and Woodpeckers for my favorite bird family of the trip.  And here I am blurring the lines again with this nutcracker!

But our best woodpecker moment came in one of those Los Angeles City Park, where we were able to sweep the North American sapsuckers.  In addition to the expected Red-breasted Sapsucker, this park also had a vagrant, like me, from the east: Yellow-bellied Sapsucker...

Yellow-bellied Sapsucker female, Veterans Memorial Park, Sylmar

...as well as its very similar western cousin, the Red-naped Sapsucker...

Red-naped Sapsucker male, Veterans Memorial Park, Sylmar

(come on, show us the nape!)

there's the red nape, Veterans Memorial Park, Sylmar

(...there it is).

And the cherry on top was a female Williamson's Sapsucker.

Williamson's Sapsucker female, Veterans Memorial Park, Sylmar

A big thanks to local birder named Doug, who found all these sapsuckers and then came out to the park to meet us and help track them all down! 

Thus far I've omitted the most common woodpecker, partly because I didn't get a photo of it, but mainly because it will help segue into the next post.  The Northern "Red-shafted" Flicker is dramatically different than our eastern "Yellow-shafted" version, what with it's rosier shafts.  But these two superficially different birds are considered to make up one and the same "species," with intergrade/hybrids not all that difficult to find. 

In this "sport" we call birding, points are awarded based upon contemporary lists of species.  It's a flawed system to be sure and one of the tragic consequences is that subspecies often get ignored.  And even when birders go to the trouble to try to pick out the ones that can be readily discerned in the field, it's often still a hedge against a potential future "split" that might one day turn into the beloved "armchair tick."

Western subspecies, those birds that clearly look different than the eastern versions with which I am familiar, but don't "count," will be the theme of the next post.

Stay tuned!