Friday, January 29, 2010

Oriantha White-crowned Sparrows – on the move?

I digiscoped this White-crowned Sparrow from my office/bedroom window this afternoon. I was pretty intrigued by it. Most people wouldn't have paid much attention to this common wintering bird here. After all, the Tucson Valley Christmas Bird Count tallied 793 of them, and the Atascosa Highlands Christmas Bird Count had 651: it's not a rare bird. But this one is quite different that the five or so individuals that have been wintering in my yard this winter. I've been watching them, along with the single Abert's Towhee, two Violet-crowned Hummingbirds, and others in my medium-sized urban backyard.

Notice the prominence of the white stripes, the pattern in the face in front of the eye, and the bill color. This is a "Mountain" White-crowned Sparrow, also knows by the trinomial Zonotrichia leucophrys oriantha. Compared to other western North American subspecies, there is an extra little bit of black above and in front of the eye separating the white stripe over the eye from the the gray lores between the eye and the bill. Those white stripes are also broader, more striking. The bill is redder than the other yellow-billed forms. Compare it to this Z. o. pugetensis from Oregon (rather similar to our more common Z. o. gambellii) with its white supercilium continuous with the gray lores and yellow bill.

There are two very distinctive features of the the Mountain White-crowned Sparrow that are not visible from photos – or from specimens. The latter source of information (specimens) is where we got our master list of species of birds known from North America. It wasn't handed down by God, and so includes some errors – many of which still remain to be corrected.

First of all, we now know that Mountain White-crowned Sparrows have a radically different biogeography from other forms of White-crowned Sparrow. The biogeography includes their breeding range and habitat, migration route, migration timing, and wintering grounds and habitat. This is most evident here in southern Arizona in winter and spring: our common winter birds are virtually all Gambel's White-crowns, which depart for their breeding grounds in early April. Then suddenly in late April into mid-May there is another push of White-crowns, and they are all Z. l. oriantha then. They obviously winter south of here and migrate to their breeding grounds later. There are exceptions: one Mountain White-crowned Sparrow was identified on the Atascosa Highlands CBC, and in the winter of 1999-2000, an unprecented number of them wintered in southern Arizona (see that issue of North American Birds, which you can find at the Searchable Ornithological Research Archive [SORA]). These birds breed in the Intermountain West of North America. Gambell's White-crowns, in contrast, breed near edges of boreal forest of Arctic Canada and Alaska.

The other notable characteristic of Mountain White-crowned Sparrows that early ornithologists overlooked is their amazingly distinctive song. The example that was meant to be included on the CD set Bird Songs of the Pacific Northwest by Geoffrey A. Keller and Gerrit Vyn can be heard on the Cornell Lab of Ornithology's Macaulay Library website, catalog number 42273. (Incidentally, somehow the editors accidentally included catalog number 43976 on the CD instead, which is a White-crowned Sparrow from near coastal Charleston, Oregon that apparently learned an aberrant song through mimicry of either House Wren or House Finch; that particular cut is mislabeled in the CD booklet.) The fifth cut on the same CD set (also heard at the Maculay Library website, catalog number 130914) is what Gambel's White-crowned Sparrow sounds like – both in Alaska west of Fairbanks (where the CD bird was recorded) and here in Arizona where they winter.

It's only a matter of time before the American Ornithologists Union fixes this part of our checklist. It seems pretty clear to me that the form given the trinomial Zonotrichia leucophrys oriantha should actually be recognized as the unique species Zonotrichia oriantha.

Thursday, January 28, 2010

Photo Sheet from Chan Chich

Here's a photo sheet of the highlights from this year's Chan Chich Lodge tour. Click on it for a larger image.

Thursday, January 21, 2010

Our Last Day at Chan Chich Lodge

I led a very short night walk on a trail on our last night at Chan Chich Lodge, this past Friday night. Not surprisingly we didn't find anything until I got back to my room. A horrible, hissing noise led me to a pair of Virginia Opossums under a couch on the porch of the adjacent cabin. Who knows what sort of hanky panky they were up to.

When I went to notify the participants in case they wanted to see the animals, I discovered this Anolis laeviventris hunting by the pathway lights. All anoles are typically diurnal, but this one was taking advantage of the abundance of insect food attracted to the lights.

On our last morning, this past Saturday, we greeted a warm, foggy dawn at the suspension bridge a half mile down from the lodge.

This is where one of our group members forgot where not to stand on our first morning. He stood in a nest of the Red Imported Fire Ant (Solenopsis invicta), and this is what one looks like. They swarm up your legs very furtively and then being stinging all at once; you might find yourself taking your pants off in the middle of the road if you forget to watch where you stand.

This last morning we were all wiser but no less attentive to the birds above. We still managed some species that were new for the trip, including a pair of Cinnamon Becards, a Tropical Gnatcatcher way overhead, a Rufous Piha calling from somewhere in the canopy, and a Ringed Kingfisher on the bridge. A Yellow-olive Flycatcher that lives at the lodge compound finally showed itself for the 198th and final species that we recorded this week.

A real treat before we went to our rooms for final packing was this gorgeous Purple-crowned Fairy, rarely seen perched in the open for any length of time.

Here's our ride for the 20-minute flight from Gallon Jug to Belize City.

A view of Belize City on the flight back to Houston.

Friday, January 15, 2010

A Lovely Day at Chan Chich Lodge

Of all the birds one could hope to see at Chan Chich Lodge, Lovely Cotinga ranks near the top. And we saw this gorgeous male today, at close range, often in full sun, and for over 15 minutes while he digested his latest meal of lauraceous fruits.

What a beauty, and a rare one at that. Raul has been working here for many years and has only seen a few; the last one he saw was 3 years ago. I saw my very first one just exactly a year ago at Palenque ruins in Mexico. It occurs from Mexico to Costa Rica but is nowhere common.

We owe many thanks to the guides here at Chan Chich for this lucky sighting. First, for finding it (I'm pretty sure Marvin was the first to spot it three days ago), and second to Raul for going out of his way to accommodate a change in our schedule so we could try for it. The past two days Raul had re-found it only in the late afternoon, coming to this Nectandra tree (probably N. salicifolia).

While we saw Black-headed Trogon, Masked Tityra, and Crested Guan also eating the fruits, previous guests had seen Emerald Toucanet and Collared Aracaris here as well.

Yesterday evening we had a delightful evening of delicious appetizers and drinks at the setting of Laguna Verde. Ben Dodge, the manager of Chan Chich Lodge, greeted us, along with several other guests of the lodge.

Jim and Bill took a ride in a canoe, while the rest of us relaxed.

Appetizers included shrimp, mini chicken tacos, barbecued wings, and mini hamburgers. And Irma made really good margaritas.

This Ziba Scrub-Hairstreak visited the Hamelia flowers right outside the dining area on a couple days. It's finally warming up enough for butterflies to be active.

This tarantula was crossing the road as we were driving back from the Lovely Cotinga. It looks to be Brachypelma vagans, the Mexican Redrump.

If it weren't for the views and beauty of the Lovely Cotinga, the most notable sighting today was the brief views I had of what I first thought was a Rufous Mourner, then decided had to be a Rufous Piha. Then after consulting the books (and especially internet photos later on), I realized that the bird could only have been a Speckled Mourner. As far as I know, this species has never been sighted at Chan Chich, though a paper was published just 12 years ago that documented a record from Guatemala just 39 miles from here. In the spotting scope I saw unmistakably darker wing coverts that each had nearly circular, pale rufous terminal tip. And as far as I can determine, neither Rufous Piha nor Rufous Mourner should show that. It also wasn't big enough for Rufous Piha, nor showed the orbital ring and erect loral feathers of that species. But before we could all get good views of the front of the bird, it vanished across the road. In case anyone reading this can look for it, this was 0.6 mile west (toward the lodge) from the small bridge on the entrance road. This is a low spot in the road, with a small drainage crossing the road and an old logging road going north just west of this low spot.

Thursday, January 14, 2010

A Fourth Morning at Chan Chich Lodge on the WINGS Tour

Last night's drive to Gallon Jug and back was fun. We rode in the open back of a truck, using two spotlights to look for eyeshine in the trees and on the ground as we drove along. We saw one Kinkajou (an arboreal member of the family Procyonidae, the same as Raccooon), many White-tailed Deer, one Northern Potoo, and several Common Pauraques. I caught the eyeshine of this Common Pauraque as it must have opened one of its eyes as we drove past. When I got out to walk up to it to see what it was, it remained sitting there, apparently wanting to sleep.

I also spotted this Milky Treefrog, Trachycephalus venulosus, on a fence post.

This morning we started with actually seeing the Strong-billed Woodcreeper (its silhouette, anyway) in the predawn light around our cabins. We then moved into the woods where we all had great views of a cooperative Black-faced Antthrush. I then played iPod cuts of what is considered the same species from Panama and Peru – each sounding totally different. The bird didn't react to either, a convincing argument that this one should be split, already known as the Mexican Antthrush.

After breakfast we wandered down through one of the service areas. The wild Ocellated Turkeys have become accustomed to humans, and hanging out in cleared areas near buildings not only offers them forage but protection from the predators that are more likely to get them in the forest. Two days ago one wasn't so lucky, as an Ornate Hawk-Eagle nailed it just inside the forest from the lodge buildings. Some of the maintenance staff had discovered the bird on its kill and told us about it. Amazing bird. Here are some shots of the turkeys this morning.

We also had a lovely female Violaceous Trogon here.

This is a very large leafcutter ant colony on the Silvester Village Road, at least the visible portion above ground. Their vast fungus garden, which they feed with the leaf pieces that they excise from the surrounding vegetation, is much bigger and located entirely underground.

On this same road we saw some new birds for our list, including White-bellied Wren, Greenish Elaenia, and Green-backed Sparrow, and the rest of us caught up on King Vulture when an adult and immature soared right overhead. Our list is up to 172 species in four days here at Chan Chich.

We also had a lengthy, memorable encounter with a Thrushlike Schiffornis (or the Un-thrushlike Non-manakin, as I like to call it). It was catching caterpillars on the low vegetation next to the road only about a yard away from us, then hopping up to tenderize them on its perch before swallowing it. It consumed two while we watched it, completely unafraid of our presence.

A nice flower on this road, attractive to Stripe-throated Hermits, is this gentian in the genus Lisianthius.
On our way back, I stopped to take a photo of this epiphytic cactus that has spread all over the roof of this outhouse.

Wednesday, January 13, 2010

A Week at Chan Chich Lodge

I'm about 2/3 of the way through a week-long birding tour here Chan Chich Lodge, near the Guatemalan border in NW Belize. It's been great.

It's shocking the level of comfort and quality of dining one can find here in the middle of the Central American rainforest. Here's a view of the cozy little lodge, built into the central plaza of a small Maya ruin (small compared to the big cities of Chichén Itzá, Calakmul, or Tikal, but still nothing to sneeze at).

With a staff that treats you just right, several experienced local guides to keep us up on recent sightings – some who have been here for the full 20 years of the lodge's existence – and some fantastic birding just outside our cabins, there are few places that can match this for a short birding and natural history holiday.

Today was an especially easy day. We started with hearing the local Strong-billed Woodcreeper who has been giving one or two song phrases each morning about 20 minutes before sunrise right over our cabins. We also saw a couple Common Pauraques, which have been silent all night during the new moon and most active just before sunrise.

We then went by bus to Laguna Seca, a lovely lake with blooming water lilies and surrounded by untouched forest. Here is a Northern Jacana living up to its nickname of lily trotter.

A Crimson-patched Heliconian was one of several butterflies we saw today, our first fully sunny day after the latest powerful cold front managed to knock our overnight lows to about 53°F this past Sunday. But the temperatures haven't reached their tropical heights yet, and today was about as perfect as it gets.

At the Escarpment, some 500 feet higher than the surrounding area, we watched the sky for raptors rising on the morning thermals. Activity was good well into the late morning, and we saw Great Black-Hawk, Black Hawk-Eagle, Ornate Hawk-Eagle, Short-tailed Hawk, King Vulture (at least a couple of us), and several Double-toothed Kites, including this immature which perched right above the parking area.

We also had a fantastic encounter with a Royal Flycatcher here, watching it catch butterflies from the edges of the road. I didn't know they were such a butterfly specialist.

On our way back as most were drowsing during the slow, bumpy ride back to the lodge (it's only 14 miles, but the limestone roads don't let our driver go very fast), I startled everyone by screaming out "White Hawk!" as one flew right across the road in front of the bus and vanished in the forest. We walked around for about five minutes, got a glimpse of a Ruddy-tailed Flycatcher, and were about to give up hopes of seeing the hawk when it occurred to me that it might come into a recording. It turns out I had two cuts on my iPod – one from Bolivia and one from Costa Rica. The one from Bolivia, a repeated whistle, had no effect. But the one from Costa Rica, sounding very different from the Bolivian recording, soon elicited an identical vocal response from our bird which promptly flew in and landed right over the road. What a gorgeous sight, surely one of the most lovely raptors in the world. We had our fill of the bird through our scopes as it ignored us, left it to its victory, and headed to our late lunch. What a morning! And I learned how different the southern South American birds sound from these. They look very different too. Hmmm. Why are they considered the same species?

Some other highlights from the past few days:

White-whiskered Puffbird, surprisingly numerous here. This one was foraging with it's partner from the cable supports of the suspension bridge a half mile down from the lodge yesterday morning. They usually stick tight to the forest understory.

Tody Motmot behind the upper plaza ruins. Quite a special little bird.

Ruddy and Tawny-winged Woodcreepers, unusually approachable at an army ant swarm. They pick up various invertebrates that are flushed from their hiding places in the leaf litter as the ants swarm across the forest floor. It's very fortunate to find such an ant swarm, as you'll rarely ever see these species away from them. We had another such swarm yesterday that was also attended by a Northern Barred-Woodcreeper as well as both Hooded and Kentucky Warblers.

This strange little plant is Helosis cayennensis, a completely parasitic plant in the family Balanophoraceae. One species in this family has the smallest flowers of any angiosperm.

Who knows what we'll see on our last two and a half days? Tonight we're going on a night drive in hopes for a nocturnal animal or bird.