Tuesday, July 17, 2012

New AOU Checklist Supplement

It was about one year ago when the American Ornithologists' Union published their last supplement to the Check-List of North American Birds.  If you need a refresher, you can read about that supplement here.

The AOU has just released this year's supplement.  Here, I will summarize those changes most relevant to ABA-area birders.  If you want to read the full supplement, download the PDF here or read the proposals in their entirety here.

Two of these changes stand out, at least to me.  First is the split of Xantus's Murrelet, giving us Scripps's and Guadalupe Murrelets.  More fascinating to me is the taxonomic reshuffling of Falcons, Parrots, and Passerines with the findings that the three orders are relatively closely related!

More on these and other important changes:

1. Species Added
 Bryan's Shearwater has been added to the AOU list as this species has been newly described from an old specimen (other specimens have since been identified as this species).  It is considered accidental in Hawaii and not recorded from the ABA area, but this one is too interesting to leave out.

2. Splits and Lumps
 - Galapagos Shearwater has been split from Audubon's Shearwater (but has never been recorded in the ABA area).
- Gray Hawk has been split, but the break between Gray and Gray-lined Hawks is in Costa Rica, so the change doesn't affect the status of the birds in the U.S.
- Xantus's Murrelet has been split into Scripps's Murrelet and Guadalupe Murrelet.  Scripps's is the more northerly-breeding and generally the more commonly seen off the U.S. Pacific states.  Guadalupe is the more southerly-breeding, and though it does wander as far north as Washington (casually), it is found well offshore after breeding.
- Calliope Hummingbird is no longer in the monotypic genus Stellula, but is now included in Selasphorus.  This is an obvious relationship and a welcome change!
- Sage Sparrow is no longer in the genus Amphispiza with Five-striped and Black-throated Sparrows, but in its own genus, Artemisospiza.

3. Name Changes
- The genus Caprimulgus has been split so that ABA-area nightjars are now in the genus Antrostomus
- House, Cassin's, and Purple Finches have been moved out of the Old World genus Carpodacus and into their very own Haemorhous. More fun to spell, not so fun to pronounce?

4. Taxonomic Reshuffling
- The linear sequence of hummingbirds and wrens are changed
- Research has shown that Falcons, Parrots and Passerines are sister groups, so the three orders (Falconiformes, Psittaciformes, and Passeriformes) are now grouped together in linear sequence.

Sunday, July 1, 2012

Early Fall Birding

It feels a little weird to call it "fall birding" on July 1st, but with temperatures spiking over 115 recently*, it is much more pleasant to think of fall than summer.  Besides, as I have written before, something is always moving in the LCRV, and a few species begin to migrate south by mid-June, which is when the last of the spring migrants pass us by.

*Temperature range for today's outing: low 66; high 110

Today's birding trip with David to the Blythe area had many purposes.  Primary among those was just to get out birding, as I haven't had much chance lately.  Then there were the cuckoos, the shady forest birds known to be inhabiting the restoration sites in the Blythe area, representing potential ticks in La Paz and Riverside Counties.  Not to mention, of course, that they are all-around cool birds.  Finally, as always, there were migrants to track, and potential vagrants to find!

Today started where every good birding trip starts, 3:00 a.m.*  The plan was roughly to work out way south through western sites, then back north through eastern sites.  We started at Palo Verde Ecological Reserve (PVER), one of the Bureau of Reclamation's excellent riparian restoration sites.  It is particularly interesting being located in California, since most restoration sites (as well as remaining riparian habitat) fall in Arizona.  Along with Picacho State Recreation Area, PVER has some of the best landbird habitat along the California side of the lower Colorado River.

*I do not stand by this statement.

Dawn at PVER.  Tiny Bigfoot at the edge of the trees in the distance is a cuckoo researcher.
Breeding season at PVER.  Park in the parking area and you will be greeted by the cacophony of calls typical of an active Red-winged Blackbird colony.  Birds are abundant here, although most are blackbirds, cowbirds, and doves.  Several countersinging Blue Grosbeaks provided an easy Riverside County tick for me, but we were there for the cuckoos.  Sauntering along the road pictured above, it was not long before we heard the series of knocking calls typical of Yellow-billed Cuckoo.  Success!  Icing on the cake were flyby Long-billed Curlews and a single Whimbrel, and a female Indigo Bunting on our way out.

Today's INBU at PVER looked much like this one, but less thoughtful.
After a quick stop to check on a small heron colony and ogle fledgling Great Egrets, we were off to our next cuckoo stop, Cibola Valley Conservation Area!  I was glad to explore a plot I surveyed in 2011 that seemed great for cuckoos.  It took a bit of walking, but we finally heard a slow knocking, quickly answered by another bird hidden in the willows.  While walking out, we heard another bird knocking to itself.

Our next stop was at a most intriguing place, a Birding Site Without a Name in Imperial County, CA.  This is one of the earliest restoration plots along the river, and its character is very different from its younger siblings.  Dead and half-alive cottonwoods stand along the levee road adjacent to the river for the long stretch of this site, while healthier, bigger cottonwoods share the other side of the road with a mixture of Eucalyptus, Athel tamarisk, mesquite, and palo verde.  The site is narrow but long, with farm fields on the other side.  David and I birded this area once before, but approached from the farm field side and found it difficult and unsatisfying to bird.  Today, we discovered the access from the Levee Rd near CVCA, and were excited to see this habitat was not only very nice for migrating birds, but also very easy to bird.

"Palo Verde--Old Restoration Site"
The site is reminiscent of Parker Oasis on a grander scale.  I can imagine this spot being very good birding in winter or fall, but it could really have some amazing birding in spring, when birds gravitate to trees along the river as they work their way north.  Today, it was hot by the time we reached this spot, and birds had gotten quiet.  Still, I was surprised to pick up two Imperial County birds, Brown-crested Flycatcher and Lucy's Warbler!

Now on to fall migration.  La Paz County doesn't have a lot of shorebirding spots, but what it has is quality.  No mediocre sewage treatment plants around here.  The three main sites are the Parker Valley (pretty good), the Bill Williams Delta (great, as long as there are veg mats for the birds to loaf on), and Hart Mine Marsh (solid gold!).  Once the day had gotten too hot for landbirding, we cranked up the AC and rode on to Hart Mine Marsh.

Hart Mine Marsh, home to shorebirds, herons, rails and many other marsh fowl
Most of our notable birds here turned out to be ducks, which are likely oversummering birds.  In addition to the expected Mallards and Ruddy Ducks, there were Gadwall, Cinnamon Teal, a Northern Shoveler, and a Redhead.  Fall migrants were numerous: an avocet, a Greater Yellowlegs, 2 Willets, 3 Marbled Godwits, a Least Sandpiper, and 2 Caspian Terns.  Two Snowy Plovers were good to see, although we don't know whether these were early migrants or potential (failed?) breeders.  This was my first real taste of fall migration this season!  Still, the highlight here was an unusual short-tailed bird that crossed the road in front of us...

Photo of a (different) bobcat by David Vander Pluym

After this fine morning it was time to head home, but since the Parker Valley lies between Blythe and Lake Havasu City, there was still more birding to do.  Several flooded fields in the area hosted gobs of Cattle Egrets and White-faced Ibis along with a few Long-billed Curlews and Marbled Godwits.  We made a thorough check of the Twelvemile Slough Rookery, which includes nesting Cattle and Snowy Egrets and White-faced Ibis.  None of these are common nesting birds in the LCRV, and this may be the only active nesting location for Cattle Egret and White-faced Ibis.  All the more exciting to come here and count 950 Cattle Egret and 50 White-faced Ibis nests!  The Cattle Egrets were particularly exciting, most nests holding two near-fledging chicks at varying stages of awkwardness.

Cattle Egret awaiting its next meal

Each pair of white specks represents a Cattle Egret nest
Despite temperatures creeping into triple digits at this point, we decided to make a quick stop at 'Ahakhav Tribal Preserve to check on the Tropical Kingbirds.  This pair returned to the same spot where they raised two chicks last year, and had already been found nest-building in May.  More recently, incidentally, the pair at Pintail Slough returned to their territory as well.  Since we hadn't had any recent news on the 'Ahakhav birds, we wanted to find out how they were doing.  Long story short:  three chicks in a nest!

Tropical Kingbird broods its chicks
Next, our requisite shorebirding stop in the Parker Strip: Emerald Cove sewage ponds.  The habitat looks nice, but there was not a lot around today.  One surprise was a pure-looking drake Mexican Duck that stood out from all the other brown male Mallards in eclipse plumage.  Not only was he darker overall, but the clincher was his tail: medium brown, not white.

Finally, we had to make one last stop at the Bill Williams Delta, premier Arizona birding location for Just About Everything. Of course, it's not such a happening place in early July, but we did see two Black and three Caspian Terns and three Eared Grebes as well as the continuing Neotropic Cormorant.  As I said earlier, it is a very attractive place to shorebirds when there are vast veg mats for the birds to loaf and gather on.  Even before the summer bloom of these mats, though, we found shorebirds trying to use the available space:  40 Marbled Godwits were crammed onto a small spit of rocks jutting into the water, and the Caspian Terns were repeatedly trying to land among them (without success)!

Today was filled with some wild temperature extremes (44 degrees difference!), great birds, exciting migration, good food (burritos from Ruperto's in Parker), good company, and all you expect from a birding trip.  When all is said and done, I just have to say it was good to get outside.