Sweltering birds

On Tuesday (May 24) we trekked the Colima trek for the last time before the mountains get too hot for the summer; one Colima Warbler and a few dozen empids were our reward. Back in the Chisos Basin, we treated ourselves to lunch and saw one lonely Great Purple Hairstreak - it was our only butterfly for the day. Down at Panther Junction, at a private residence, we relished long looks at a very close Gray-cheeked Thrush (quite unexpected!) and some less-rare-but-equally-stunning passerines: Black-headed Grosbeak, MacGillivray's Warbler, Townsend's Warbler, etc.

As of Tuesday, we also ended up with a brand new nephew and the discovery that high fever in small dogs can cause seizures. It was an educational day all around.

Today, Saturday (May 28) it's 96 in the shade with a high of "only" 100 while the rest of the state is facing 105 on up. So it was strange to see another birder out in the midday sun; Byron Stone of Austin even kicked up a Sprague's Pipit at the motel pond. We relocated it twice, and saw a few more regional specialties for the day: Zone-tailed Hawk, Varied Bunting, MacGillivray's Warbler, etc.

Safe weekend, everyone!

Other updates

The Iron Mountain Fire seems to be an old memory; Marathon and Fort Davis and Alpine (and Marfa and Sanderson, for that matter) are all back in business with no road closures, no smoke and a burn ban that will cost you $500 if you don't have a permit for your welding, grilling, campfire, etc. Don't Even Think About It.

As for the Yellow-breasted Chat a few posts down:

"I am sorry to report that he did not make it. Very few cat caught birds ever do. I think it has to do with all the stress they go through, and they keep on fighting and their adrenalin stays up. Finally, at night they just give up. If they make it 48 hours, they usually survive. It is the first night that gets them. You cannot imagine how sick and tired I get of cat kills. ... I have seen hundreds, if not thousands over the past 23+ years." (from the wildlife rehabber)

the drying, the drought

"...this is one of the effects of an extended drought that most persons don't realize or notice directly." - Dr. Keith Arnold

There's still a Green-tailed Towhee and a White-crowned Sparrow on 'the back forty.' They should have left a long time ago. They have the energy to stay, but not to leave.*

Common Nighthawk - one - returned to town on May 19th. The evenings are silent and empty without them. Lesser Nighthawk - one - returned on April 17th. A few seem to be around. Where are the rest?

Bats had a good, strong, dense show early on. Since then, maybe one or two each evening. Perhaps that was migration.

Barn Swallows sit on the ground; they have no mud for nest building nor energy to do so. They wait for insects to come to them.

Western Wood-Pewees perch uncharacteristically low, barely above the ground.

Audubon's Yellow-rumped Warbler did not wake up this morning. Second, perhaps third adult bird I've ever knowingly picked up that died of natural causes. The keel, breast bone, photographed above, is a jarring reminder that fat stores = life. Lost muscle mass, emaciation, a beautiful bird with no life inside, that is the story of a severe drought. Native predators are coping. Unnatural predators are wreaking havoc.

Scott's Oriole (below) did not wake up this morning either. Third or fourth adult bird that I've ever knowingly picked up that died of natural causes.

It is fairly well known that birds lose a significant amount of weight overnight. The question of how much will definitely vary by species and a considerable range of external factors. I highly suggest reading up on this as a way of understanding what pressures birds face without ANY human/predator/artificial pressures.

This sort of widespread bird die-off is more common among insectivores who migrated too early and were caught in a freeze that killed off their prey. But this is drought.

* Now for a bedtime story. Emphasis/paragraph interruption is mine.

Moisture as a determinant of habitat quality for a nonbreeding Neotropical migratory songbird

Smith et al

Abstract.
Identifying the determinants of habitat quality for a species is essential for
understanding how populations are limited and regulated. Spatiotemporal variation in moisture and its influence on food availability may drive patterns of habitat occupancy and demographic outcomes. Nonbreeding migratory birds in the neotropics occupy a range of habitat types that vary with respect to moisture. Using carbon isotopes and a satellite-derived measure of habitat moisture, we identified a moisture gradient across home ranges of radio-tracked Northern Waterthrush (Seiurus noveboracensis). We used this gradient to classify habitat types and to examine whether habitat moisture correlates with overwinter mass change and spring departure schedules of Northern Waterthrush over the late-winter dry season in the tropics. The two independent indicators of moisture revealed similar gradients that were directly proportional to body mass change as the dry season progressed.

Birds occupying drier habitats declined in body mass over the study period, while those occupying wetter habitats increased in body mass. Regardless of habitat, birds lost an average of 7.6% of their mass at night, and mass recovery during the day trended lower in dry compared with wet habitats. This suggests that daily incremental shortfalls in mass recovery can lead to considerable season-long declines in body mass. These patterns resulted in consequences for the premigratory period, with birds occupying drier habitats having a delayed rate of fat deposition compared with those in wet habitats.

Taken together with the finding that males, which are significantly larger than females, are also in better condition than females regardless of habitat suggests that high-quality habitats may be limited and that there may be competition for them. The habitat-linked variation in performance we observed suggests that habitat limitation could impact individual and population-level processes both during and in subsequent periods of the annual cycle.

The linkage between moisture and habitat quality for a migratory bird indicates that the availability of high-quality habitats is dynamic due to variation in precipitation among seasons and years. Understanding this link is critical for ascertaining the impact of future climate change, particularly in the Caribbean basin, where a much drier future is predicted.

---

So what does that all mean? It means, indirectly, that birds overwintering in dry places [here] may not have built up enough energy stores to migrate back north. Or if they have, by the time they get there they're not going to be able to compete as well as birds who wintered in areas with higher moisture. Or, perhaps, if birds who live in this area haven't had a good rain since September, there are few bugs to eat and a lot of competition. It means that 7.6% (this varies by species, I've seen 22% noted on winter studies) of their body mass goes away every night regardless of whether or not there's a bug to be eaten in the morning.

And in closing, this is a Western Tanager who was either roadkill or emaciated but who had been around long enough for me to not want to investigate further. One hopes that his kin have fared better.

Birding Marathon; look down!

Unfortunately the drought has put a phenomenal amount of pressure on all of the wildlife out here, but interesting things are turning up. The Varied Bunting pictures below were taken on Thursday, May 19 at a private residence in Marathon. This morning, Saturday the 21st, a tailless (??) Brown Creeper was seen on the north side of town, just to the NW of the 'Double Bacon' property line. No photos, alas. Everything is low. Everything is close to the ground, if not on it. The creeper was never more than five or six feet above the ground when we watched it. The Western Wood-Pewee in the yard rarely perches higher than the 4' fence posts.






























Varied Bunting (Passerina versicolor) by Cheryl Wallace

While many critters are being pushed closer to humans (and associated water sources), some simply are unable to survive. Two pristine specimens were picked up this morning, a male Audubon's Yellow-rumped Warbler and an adult male Scott's Oriole. While the Yellow-rump was suspiciously in front of a window, the window was covered with a screen and there wasn't so much as a ruffled feather on the bird. The Scott's could have perhaps hit a barbed wire fence, but it was also in perfect shape, just awkwardly posed in rigor. Both birds, when breast/belly feathers were ruffled for closer examination, showed muscle atrophy, no fat reserves and a sharply protruding keel/breast bone. Each bird relies on moisture, the warbler for the insects and the oriole for the nectar.

So whether the bird is dead or alive, unless it's riding a thermal, look down. Nooks and crannies and shady spots and wet spots and anywhere insect life may be, there's likely a bird nearby. Hopefully we'll get some rain soon and the warblers can go back to the treetops, but for now they're all grounded.

In the meantime... PICTURES!

The blog has been a bit strange lately, with a lot of travel, fire, and, well... here's the bird update in the meantime. It's been a busy week or three for the freezer* (salvage permits through Texas A&M).

Apologies for starting off a post with a decapitated Scott's Oriole (Icterus parisorum), but this is just chronological order for bird photos this month so far.

There is a responsibility when feeding birds, to ensure that they are reasonably safe from harm. So scattering seed in an area known to threaten birds would be unethical; in the middle of a road, for example. The 'Double Bacon' doesn't have any ground feeding options at all due to cats in the area and oriole/hummingbird feeding stations are quite high - it's an attempt to give birds the upper hand. The oriole above was killed directly under the [low] orange upon which it fed; (to be clear, it was not at the Double Bacon). The easy answer is to not feed birds at all if known threats are unavoidable.

Now for a roadkill fresh off of someone's bumper; an Empidonax flycatcher of uncertain ID, leaning towards Dusky Flycatcher (Empidonax oberholseri). The eye ring was not really visible, dessicated as the critter was getting, but everything else was favorable. See the next Empid ID challenge for more commentary!

Near miss with a bumper: female Painted Bunting (Passerina ciris), 'rolled' (uninjured on the road) on Hwy 385 between Marathon and Fort Stockton. She had no visible injuries, no broken wings, legs, etc, no blood anywhere, clear eyes and zero response when she was picked up in the middle of the road. Not having a box handy (shame on me!) I placed her under a bush; often enough, after a few hours the stunned bird is able to fly away. Generally being kept in a dark, safe, predator/car-free box is the preferred method in case complications arise. Rehabbers will love you for it.

This next little fellow, unfortunately, is a male Painted Bunting (Passerina ciris) who hit a French door. While generally the 'French door' modifications on sheet glass / glass doors can help, it's certainly not foolproof; birds will hit pretty much any glass surface as long as the surface is larger than the bird. There's a certain fondness for old timey glass that's slightly bubbly or warped on the surface because it tends to not reflect as well and also be in small enough pieces that there's more framework to support it. Those factors combined help reduce window kills.

Some day there will be a post on how to tell what killed a bird. While this is not that post, the bird above is a female Common Yellowthroat (Geothlypis trichas), killed by a cat. At first glance, such an intact critter would likely be a window kill, and that's not entirely ruled out. However, only having one or two tail feathers left would indicate that a cat got ahold of it; if not before death, after. It was either a short struggle, or none at all (there have been studies documenting cats and crows lurking around windows, waiting for birds to hit).

"A bird in the hand is worth two in the bush." Yes, but unless you have the Pyle guide to measure physiological aspects of the bird, Empidonax flycatchers are sometimes best left in the field. We suspect that the above creature was a Gray Flycatcher, (Empidonax wrightii), but it had more of a tangle with a cat than the previous bird, so field marks are a bit more mangled. In the field, we'd hopefully get a call note, a perching height/habitat preference, perhaps even characteristic tail wags. In the hand, this bird has ants.

Another flycatcher! This time, a Western Wood-Pewee (Contopus sordidulus), splendid specimen found as roadkill on a day when the smoke in town was so thick that Marathon felt like LA; couldn't see the mountains on ANY side! Flying low must have been an attempt to stay out of the smoke, or a conservation of energy... a lot of things have been flying low, or sitting on the ground (Barn Swallows, especially) while waiting for bugs to pop up. It's a rough drought.

The above three birds were picked up on Friday the 13th (Freezerday the 13th?)

The Yellow-breasted Chat (Icteria virens) above was lucky, in a way, to have been found alive. No tail at all, no rump feathers, no secondaries on the right wing (those are the ones that provide lift). Intact, hunting for insects, unable to escape a cat. So, rudder and lift-less, unable to escape from humans, we snatched him up and drove him to Fort Davis.

From the rehabber:
"Thanks for bringing him to me. He has some serious cat injuries which take a toll within the first 24 hours. He is feisty, and has eaten grapes, suet, soaked cat food, but his favorite is human fingers." [Note that the photo shows the chat latched on to a finger!]

No news, however, since the Sunday night e-mail.

Next up in roadkill: Blue Grosbeak (Guiraca caerulea). I suspect that our increased explorations along Hwy 385 will turn up quite a bit of freezer content. Roadkill itself makes more sense than window kills; there's momentum on all sides, unlike the static mirage of a window. It is generally unavoidable, though I bristle when people do not at least tap the brakes when approaching large, cumbersome, perched-on-the-ground Turkey Vultures who need to take off into the wind. Yes; most get out of the way in time. But give them the benefit of the doubt, for they DO shatter windshields.

I digress.

Last and quite diminutive, Audubon's Yellow-rumped Warbler (Dendroica coronata auduboni) is something I hadn't expected to be roadkill. But with their tendency to ground forage, perhaps I shouldn't be so surprised. The lovely male above was likely going to stick around and breed in this area, a very narrow sliver of Yellow-rumped Warbler nesting range... other than the chat (if you can really call it a warbler), there's not a whole lot of warbler breeding out here. At least we lucked out and got the eye-candy of yellow-rumps! ('Audubon's' Yellow-rumped Warbler is the showy, yellow-chinned western counterpart of the 'Myrtle' Yellow-rumped Warbler, who has a white chin, among other things.)

Eventually I hope to have full posts up, one post per critter or two, with the various angles of wings/tails, etc for future reference. For some reason the color of down feathers strikes me as especially interesting because white/gray/black down seems to be somewhat randomly scattered through the critters, but my work with dead birds is still relatively* limited. (Relatively, considering some folks spend their lives preparing specimens and working in/around collections!)

Also, let it be known that Matt has found a good majority of the critters in this post. Between the two of us, a dead bird out here doesn't stand much chance of escaping an 'afterlife' in scientific/academic data!

Drought?

Drought.
It's in the fields. It's in the meadows. It's in the mountains. It's in the basins.

Its in our lives.
Not all. Parts.

Yesterday morning I noticed something differently aglow in the after-dew of early morning. Perched in a pinyon. Later in a tamarix.


















Attempting what all have come to be in this part of the Earth; dried off and warmed up.

Butterflies have been very, very scarce with this drought. An early-season flight of a few species and then nothing. As common as rain drops in this fire-happy area.
This a butterfly. A real beauty. One of the larger, perhaps largest of the western butterflies.


















Two-tailed Swallowtail (Papilio multicaudata)

There are moments in our lives when some … thing(?)… attempts to cross our minds with certain reminders.
Its up to us to be observers. The less-observant will likely miss it. They often do. A few always.
What, then, are we told? Well there are many things, observer.


















One..
“Hang on. Shi…Stuff happens. It’s going to be alright. Work on remembering this.”

















Again, we need not name this Orator. Its all around us, observer. Names are unnecessary, human things. Names start wars, observer. Unnecessary.


















Those who work so hard to name It, and that only, miss everything. Unnecessarily.


















“Hang on.



















Stuff happens.


















It's going to be alright.

Work on remembering this.


















You are not alone, observer." - Butterfly

For a moment that morning, in spite of all that's around me, I ask no one and everything,
"What drought?"

photos by Heidi Trudell

Hwy 90 between Sanderson and Marathon CLOSED

At this time due to firefighting operations on Schwartz fire. We've learned that firefighters are going to back-burn north of Hwy 90 to reduce fuel load .

noon update from Marfa Public Radio

Post Park - more migrants!

Edit: Iron Mountain fire update "The Iron Mountain Fire has consumed 15,675 acres. Officials are calling that fire around 25% contained."

This morning we were joined by a lovely couple from Maine who had birded south Texas before, but were new to the Big Bend region. While there were a good number of migrants, there were also a few 'first of season' (FOS) critters in attendance as well. Interesting/migrant/FOS birds are in bold. It's been a slow spring, but at least it's finally here!

Marathon - Ft. Peña Colorado Pk (The Post)

Species list:

3 Scaled Quail
1 Pied-billed Grebe
20 Turkey Vulture
1 Osprey
1 American Coot
1 Killdeer
3 Spotted Sandpiper
15 White-winged Dove
4 Mourning Dove
1 Yellow-billed Cuckoo FOS
6 Golden-fronted Woodpecker
1 Ladder-backed Woodpecker
1 Olive-sided Flycatcher
1 Western Wood-Pewee FOS
1 Gray Flycatcher
1 Dusky Flycatcher
1 Empidonax sp.
8 Vermilion Flycatcher
1 Ash-throated Flycatcher
1 Cassin's Kingbird
6 Western Kingbird
2 Bell's Vireo
3 Warbling Vireo
3 Northern Rough-winged Swallow
1 Violet-green Swallow
4 Barn Swallow
1 Cave Swallow
1 Verdin (heard only)
3 Cactus Wren
1 Marsh Wren
1 Black-tailed Gnatcatcher
1 Hermit Thrush
1 Gray Catbird
2 Northern Mockingbird
1 Yellow Warbler
1 Yellow-rumped Warbler (Myrtle)
10 Yellow-rumped Warbler (Audubon's)
1 Black-throated Gray Warbler
20 Wilson's Warbler
1 Yellow-breasted Chat
1 Rufous-crowned Sparrow
4 Canyon Towhee
4 Chipping Sparrow
10 Clay-colored Sparrow
1 Lark Sparrow
1 Lincoln's Sparrow
6 White-crowned Sparrow
4 Summer Tanager
1 Western Tanager
2 Northern Cardinal
1 Black-headed Grosbeak
15 Blue Grosbeak
2 Indigo Bunting
3 Painted Bunting
1 Red-winged Blackbird
3 Bronzed Cowbird
5 Brown-headed Cowbird
2 House Finch

Total species reported: 57

Post Road:
Greater Roadrunner
Red-tailed Hawk

Other things of interest:
Monarch
Black Swallowtail
Blue spp (none cooperated!)

Whiptail spp

Marathon area fires

There are no road closures that we know of for this batch of fires:

Iron Mountain fire is *just* north of Marathon/Hwy 90; it is spreading east toward Hwy 385.

Schwartz fire is east of Marathon, north of Hwy 90 and spreading slowly west toward Hwy 385.

Gage/Holland fire is a bit west of Alpine, not sure which side of Hwy 90 it's on.

Marfa Public Radio link with audio update

Photo 1, facing west, taken at the prairie dog town 10 miles north of Hwy 90 on Tuesday afternoon shortly before 3 pm. Photo 2, facing east, taken near the prairie dog town, same time/date.

Brewster County Birding Karma

This is our preliminary 'weekend' report (our weekend is Tues/Weds), with notable sighitngs in bold. While Rose-breasted Grosbeak was reported from Rio Grande Village as well as Christmas Mountains Oasis, we missed them along with Crissal Thrasher. But for very little effort we racked up a good number of critters. So, so many critters.

Report Details
Date range: May 1, 2011 - May 7, 2011 Total # of Species: 92
Total # of Checklists: 8
Location(s): Big Bend NP--Rio Grande Village; Big Bend Ranch SP - Barton Warnock Visitors Ctr. (Brewster Co.); Brewster; Christmas Mountain Oasis; Terlingua- Ghost Town area


Summary
May 1 May 2 May 3 May 4 May 5 May 6 May 7
Number of Species -- 6 63 77 -- -- --
Number of Individuals -- 3 40 1 -- -- --
Number of Checklists -- 2 5 1 -- -- --


Highest Count for a Species Show Sample Size
Species Name May 1 May 2 May 3 May 4 May 5 May 6 May 7
Mallard (Mexican) -- -- -- X -- -- --
Scaled Quail -- X X X -- -- --
Green Heron -- -- -- X -- -- --
Black Vulture -- -- -- X -- -- --
Turkey Vulture -- -- X X -- -- --
Northern Harrier -- 1 -- -- -- -- --
Common Black-Hawk -- -- -- X -- -- --
Gray Hawk -- -- -- X -- -- --
Zone-tailed Hawk -- -- 1 X -- -- --
Red-tailed Hawk -- -- 1 -- -- -- --
American Kestrel -- -- 1 -- -- -- --
Killdeer -- -- X X -- -- --
Solitary Sandpiper -- -- -- X -- -- --
Eurasian Collared-Dove -- -- 2 -- -- -- --
White-winged Dove -- -- X X -- -- --
Mourning Dove -- X X X -- -- --
Common Ground-Dove -- -- -- X -- -- --
Greater Roadrunner -- -- X X -- -- --
Elf Owl -- 1 -- -- -- -- --
White-throated Swift -- -- -- X -- -- --
Lucifer Hummingbird -- -- 2 -- -- -- --
Black-chinned Hummingbird -- -- 5 -- -- -- --
Golden-fronted Woodpecker -- -- X X -- -- --
Ladder-backed Woodpecker -- 1 1 X -- -- --
Gray Flycatcher -- -- X X -- -- --
Dusky Flycatcher -- -- X -- -- -- --
Black Phoebe -- -- -- X -- -- --
Say's Phoebe -- -- X X -- -- --
Vermilion Flycatcher -- -- X X -- -- --
Ash-throated Flycatcher -- -- X X -- -- --
Western Kingbird -- -- 1 X -- -- --
Loggerhead Shrike -- -- -- X -- -- --
Bell's Vireo -- -- X X -- -- --
Plumbeous Vireo -- -- -- X -- -- --
Common Raven -- -- X X -- -- --
Northern Rough-winged Swallow -- -- -- X -- -- --
Barn Swallow -- -- 2 X -- -- --
Cliff Swallow -- -- -- X -- -- --
Verdin -- -- 1 X -- -- --
Cactus Wren -- -- X X -- -- --
House Wren -- -- 1 -- -- -- --
Black-tailed Gnatcatcher -- -- -- X -- -- --
Swainson's Thrush -- -- 2 X -- -- --
Hermit Thrush -- -- -- X -- -- --
Gray Catbird -- -- -- X -- -- --
Northern Mockingbird -- -- X X -- -- --
Curve-billed Thrasher -- -- X X -- -- --
Nashville Warbler -- -- 2 X -- -- --
Yellow Warbler -- -- X X -- -- --
Yellow-rumped Warbler -- -- X X -- -- --
Townsend's Warbler -- -- -- X -- -- --
Black-and-white Warbler -- -- -- X -- -- --
American Redstart -- -- -- X -- -- --
Ovenbird -- -- -- X -- -- --
Northern Waterthrush -- -- -- X -- -- --
MacGillivray's Warbler -- -- -- X -- -- --
Common Yellowthroat -- -- -- X -- -- --
Wilson's Warbler -- -- X X -- -- --
Yellow-breasted Chat -- -- X X -- -- --
Green-tailed Towhee -- -- 2 X -- -- --
Canyon Towhee -- X X -- -- -- --
Chipping Sparrow -- -- X X -- -- --
Clay-colored Sparrow -- -- X X -- -- --
Brewer's Sparrow -- -- X X -- -- --
Vesper Sparrow -- -- X X -- -- --
Lark Sparrow -- -- X X -- -- --
Black-throated Sparrow -- -- X X -- -- --
Lark Bunting -- -- 3 X -- -- --
Savannah Sparrow -- -- X -- -- -- --
Lincoln's Sparrow -- -- -- X -- -- --
White-crowned Sparrow -- -- X X -- -- --
Summer Tanager -- -- -- X -- -- --
Scarlet Tanager -- -- -- 1 -- -- --
Western Tanager -- -- 3 X -- -- --
Northern Cardinal -- -- X X -- -- --
Pyrrhuloxia -- -- X X -- -- --
Black-headed Grosbeak -- -- 2 X -- -- --
Blue Grosbeak -- -- X X -- -- --
Lazuli Bunting -- -- 1 X -- -- --
Indigo Bunting -- -- X X -- -- --
Varied Bunting -- -- 3 -- -- -- --
Painted Bunting -- -- X X -- -- --
Red-winged Blackbird -- -- X -- -- -- --
Yellow-headed Blackbird -- -- 1 -- -- -- --
Brewer's Blackbird -- -- X X -- -- --
Brown-headed Cowbird -- -- X X -- -- --
Hooded Oriole -- -- -- X -- -- --
Bullock's Oriole -- -- X X -- -- --
Scott's Oriole -- -- 1 X -- -- --
House Finch -- -- X X -- -- --
American Goldfinch -- -- 1 -- -- -- --
House Sparrow -- -- X X -- -- --


Northern Harrier - adult male, VERY late!
Common Black-Hawk - in the nesting area at RGV
Gray Hawk - pair calling over RGV store and Daniel's Ranch
Zone-tailed Hawk - at least 3 individuals in the region
Elf Owl - heard only at CMO
Lucifer Hummingbird - displaying at CMO
Black-and-white Warbler - still haven't left?
American Redstart - young male
Ovenbird - out in the open acting like a pipit, palest crown markings we've ever seen
Northern Waterthrush - waggling through flooded campground
MacGillivray's Warbler - wins the least cooperative bird of the trip award
Green-tailed Towhee - EVERYWHERE, very strange!
Lark Bunting - still. not. gone.
Scarlet Tanager - startled us by cooperating near Daniel's Ranch
Lazuli Bunting - two males and a female at RGV, female at CMO
Indigo Bunting - quite common around RGV
Varied Bunting - CMO, most cooperative sightings of this spp to date
Painted Bunting - worse than Wilson's Warblers!

Eventually we'll get the numbers deciphered from notes, but the sheer number of Indigo and Painted Buntings was mind-boggling. Now we know why the rest of west TX has no other birds; they're still hanging around BBNP!