revisiting power lines

It may be a true anomaly that we found the Sora pair: foxes (and coyotes and badgers and raccoons and dogs and cats) are abundant out here, so scavenging rates must be pretty high. That said, the rate of birds dying across the country is pretty impressive right now. Obviously a lot of my friends do pay attention to birds, but 5 posts in 3 days about dead birds is a bit much* (highlights below).

One was a male Rose-breasted Grosbeak that hit a window in Illinois.
One was a hatch year Blackpoll Warbler that hit a power line in Mercer Co., NJ.
One was a Yellow Warbler that hit a window in Stillwater, OK.

It seems that life is throwing things at us again: on the 24th, a Marsh Wren, and on the 25th (today), a Mourning Dove.

These are suspicious. In spite of being on a road* these are unlikely to be roadkill. Both were found on our dead-end street. The street ends with big rocks and unpaved caliche, so folks hit the brakes pretty hard when they get to that point, not that they're going terribly fast with only two blocks of acceleration... That said, both the wren and dove were on the south side of the street; the side that nobody actually drives on because it is loose rocks, dirt, and caliche. So I doubt that these birds were roadkill. They were both beneath power lines, about half a block apart.

The Mourning Dove was a bit worse for the wear, so I left it in place (informal scavenging study?) but the Marsh Wren is now in the freezer - it was in excellent condition aside from a few missing feathers just above the right eye (point of strike?) and the beak being slightly misaligned. 

It's not that we have a morbid streak, it is simply that we process the information around us in different ways. A fleeting glance of "sad" and burying the creature does little for under-funded collections, and does zero for awareness of these species and their very simple threats.

Apologies for photo lack-of-quality (couldn't see the screen and was in a hurry in both cases):

Marsh Wrens winter in the reedy vegetation at Post Park - perhaps this would have been one of them.

Mourning Doves are residents of the region, but it is a sad image nonetheless:

A Killdeer that pales in comparison

Driving back from Post Park.

One roadrunner, two roadrunners....

Slow down to scan the trough - there was nothing there on the way down - is that a really pale Eurasian Collared-Dove? It's not unexpected, but it just doesn't seem right.

Far left side of the water on the ground - it has a pretty large head for a dove though.

With the power of a not-quite-point-and-shoot and some 8x42s...

Leucistic Killdeer (Charadrius vociferus) on Post Road, Marathon, TX 14 Sept. 2013 - photo by Heidi Trudell

Leucistic Killdeer. Melanism is extremely dark pigmentation, leucistic creatures are just shy of albinism - and this is a decent example. Well, if the photo were any better, it would be!

For more reading on leucism and melanism and albinism, check out the Sibley blog's excellent discussion of pigment variability! Also, wow. Lots of leucism.

* Apologies, this post was schedule for the 19th but didn't actually get published until the 24th!  Not quite sure what was going on there, but blogger has been acting up lately.

Migration is no fairy tale

In all causes of mortality, there are questions.

Why? 

How? 

...and often enough, the answers are simple.

Humans.

Birds have been documented at lighthouses - fluttering, trapped in the beam of light - since the 1800s.

Artificial light causes birds to become disoriented.

Glass is not a new technology. Prior to WWII, large panes of glass were expensive and of questionable clarity/quality. The following industrial boom, however, made sheet glass commonplace in architecture.

There's nothing like it in nature.  

Wind turbine technology went from the literal wind mill - for milling grain into flour, using broad, wooden, canvas, or metal blades - into 10x the height, 8x the width, and speeds ranging well into 100 mph range.

There has been no coevolution with this technology.

Cell towers have wires to anchor them. Power lines. Same story as above, but this time, a little closer to home.

Oversimplified? Very. But it does matter. Because there is no need for this:

Sora (Porzana carolina), power line kills, Brewster County, TX 17 Sept. 2013 - photo by Matt York

These are two Porzana carolina, or Sora. They were directly beneath power lines, not a stone's throw from a moist, Sora-friendly stopover point. Not terribly far from where this Redhead met power lines.

It is important to note - in all things - that birds are not helicopters. Hummingbirds are close to being an exception, but they are by far the outliers. Especially around water, where large, heavy-bodied birds are regularly traveling, it is hazardous to have power lines, cell towers, wind turbines, or large windows: even small, lightweight birds heading to or from the water need air space for takeoff and landing. Some airports are wedged into narrow corridors, but engineers would never dream of having massive aircraft land or takeoff from a runway boxed in at the ends by huge obstacles. The differences is that birds simply cannot perceive the obstacles and have no civil engineer to plan their routes. Since the dawn of their migratory patterns, changes in their habitats have been gradual. Only in a relatively short amount of time (it's all relative) have humans significantly, and quickly, altered their migration habitats in ways that are drastically different from year to year.

Sora (Porzana carolina), power line kill, with Sibley's Western Guide, Brewster County, TX 17 Sept. 2013 - photo by Matt York

We are within the winter range for Sora; what we lack is habitat, and observable habitat. My only previous sighting for Brewster County was 23 October 2011, at Post Park. If my memory serves, it was an adult. These two, as illustrated in Sibley's book, were in the buffiness of youth. Juvenile plumage. Subtle coloration that matched the grass. These two were within 20, perhaps 15 feet of each other. An overcast morning, following an overcast evening after an overcast day. What are the odds? No, really. What are they? Sora are well documented as window kills throughout North America (Chicago, Toronto, NY, you name it - even Stillwater, Oklahoma) but to have two that apparently struck at the same time... were there 2 Sora? And both hit? Were there more? Was it 2 of 10? Surely 10 is too high a number - they're not particularly flocking creatures - but what do we know?

Two sora, three power lines, and a curiosity for what will be found in the future.

"I don't need a weapon! My friends are my power!" —Sora

If only. 

...if only.

* These two birds will go to the collections at Texas A&M University, per our permits. Call it science.

Fade to Black: Migration Continues

Heidi and I made it back to the Marathon Treatment Ponds this morning.

**Remember, this is on PRIVATE PROPERTY in which you have to drive through Private Property to reach it. We have been granted access.  Should you feel the urge, if you are out here, gently contact Heidi.  Our contact info remains on the side-bar.**

While there were sadly no ducks on the ponds beyond the "Mexican" Mallard residents, we did have Western Sandpipers (Calidris mauri), a Least Sandpiper (C. minutilla), and a calling, circling Baird's Sandpiper (C. bairdii).

All nice birds, but otherwise not much going on.  So we trekked south to check the mesquites for any warblers or other migrants.  Nothing much happening.

Walking back to the truck, which ultimately takes us back past the ponds, we had a quick glance at a fast-moving and different shape.

Black Tern (Chlidonias niger)

This is a young bird, what is often referred to a "1st Year" bird.  That is, it is in its first calender year of existence.  It hatched earlier this year from locations that could be as far north as the Northwest Territories, Canada.

Most Black Terns winter in South America, though some will do so as far north as the coast of SW Mexico.

Basically, this young bird has a long ways to go yet; well beyond north Brewster County, TX.



As we watched this entertaining and beautiful young bird, Heidi astutely pointed out that "it has yet to see the coast.."
Let's hope it does, but migration is no fairy tale.

Should this young tern make it back to its species' spring/summer breeding grounds, its plumage will be mostly black, with sooty-gray wings, and a section of white from lower belly to vent.  A gorgeous bird.



As members of Family Laridae go (Gulls, Terns, Skimmers), this is a fairly small species with an average wingspan of around 24 inches.



Those are, after all, mesquites in the background, not Sequoias.

Most terns are plunge-divers. They "plunge-dive" for food.  This young Black Tern kept diving down, but pulling up right before the water's surface.

Constantly.

This species also feeds on flying insects.



While not bad forage-value for sandpipers and dabbling ducks, these water-treatment ponds hold little-to-no food for a plunge-diving tern.



The distances some birds must travel during spring and fall migration are astounding.  Certain tern species are among the longest.

Here's a rough range map for the Black Tern:



Remember, this young bird dropped down to these treatment ponds after we already had been out there for perhaps 45 minutes.

It is on the move.



We were, of course, super-excited to see this individual in our corner of the Chihuahuan Desert this mid-morning.
However, again, this young tern has a long, long ways to go.

As we can all use a little bit in this life, and some more than others, we wish it:

Good luck.
Buena suerte.

Soon..

... there will hundreds at a glance.  Thousands.  Flocks so large on the trans-Pecos horizons it may look like wisps and puffs of smoke.

However, for now; well, as of a couple of days ago there is one.

This one:

Lark Bunting (Calamospiza melanocorys), male

In high-desert grasslands such as the Marfa Plateau or our Marathon Basin, the number of Lark Buntings can be staggering.  Large, seed-eating flocks questioning us with a call of "What?..What?"

My first returning Lark Bunting noticed was back on the 18th of July.  Yes, we also had a single group of seven fly over-head on August 10th.  That's been it.  The single male in mid-July may have been this particular male, photographed a few days ago in the same general area as seen over a month prior.

For a bird that spends much of its life in such large flocks, I wonder if a sense of liberation at being the "first" on a wintering-ground is felt or loneliness?  Both?  That question is ofcourse far more human than bunting, but still..

If it was a call to all or a call to none, no matter; it won't be terribly long.



He will also lose that dapper, black suit of feathers; his summer-breeding plumage.

Welcome back.

What?