Vol. 4, No. 4 October 2003
First Record of Cory's Shearwater in Costa Rica

For the third straight edition, Tortuguero is the site where a new avian species has been produced for the still-growing Costa Rica list. On 08 March 2003, an injured Cory's Shearwater (Calonectris diomedea) was found on the beach and brought to the Caribbean Conservation Corporation (CCC) for rehabilitation. Anna Thaler, who was at the CCC working on the bird banding program, wrote to say, "Unfortunately, it had a large wound in its neck from which it did not recover, and its skin was not optimal for creating a specimen, so we had to just bury it." However, before disposing of the bird, they did take a couple of photos, which show the bill color and the upperwing pattern, as well as give a feel for size. From what I can tell, everything fits quite nicely with the description of Cory's Shearwater given by Peter Harrison in "Seabirds, an identification guide." Since the bird was still alive when found on the beach, the assumption is that it most likely reached Costa Rica on its own and could be considered accidental (no pun intended). Though normally found in the Atlantic Ocean and the Mediterranean Sea, the range map in Harrison's guide does show the species entering the northern part of the Gulf of Mexico, which would put it that much closer within range of us.

Second Report of Swallow-tailed Gull in South Pacific

Back in the July 2000 GBN, I reported that Giovanni Bello had seen a Swallow-tailed Gull (Creagrus furcatus) near the mouth of the Golfo Dulce while working aboard the M/V Temptress. He saw it following the ship at night on two different occasions.

Three years later, we now have another report sent in by Erick Castro and reconfirmed verbally by Rudy Zamora:

"We left Playa Caletas (north of Corcovado NP) at 15:00 on 07 April 2003, and put to sea en route to Coiba Island, Panama, aboard the Pacific Explorer. We were told that we would be leaving Costa Rican waters at about 23:00.

"At 19:00, we were on the Sun Deck for the nightly recap and briefing for the next day's activities, when a bird appeared flying around the ship. Thanks to the experience of Stephen and Sio Weston, who had seen this species before, we were alerted to the possibility of it being a Swallow-tailed Gull. We got good looks at it in the ship's spotlight and were able to see all of the pertinent field marks.

"Consulting Harrison's "Seabirds" there was no doubt that our bird was an adult Swallow-tailed Gull in breeding plumage. All of the field marks coincided, as well as the fact that the bird was out fishing after dark."

Black Tern Seen in Sarapiquí

On 15 August 2003, Freddy Madrigal observed a Black Tern (Chlidonias niger) in breeding plumage near El Tigre de Sarapiquí, about two kilometers south of the entrance to La Selva Biological Station. For anyone familiar with the field where the Pinnated Bittern (Botaurus pinnatus) and Red-breasted Blackbirds (Sturnella militaris) have been seen, Freddy reported that "across the road about 150 meters from the main road there is another swamp; it was flying very low and circling the swamp for a while." The behavior is not uncommon for Black Tern, but it is curious that the bird was so far inland here in Costa Rica.

Regarding the El Tigre field, Jay VanderGaast reported from his August Field Guides trip, "we had a pair of Gray-breasted Crakes (Laterallus exilis) in the wet fields near La Selva on 05 August 2003 (though no bitterns, Red-breasted Blackbirds, etc.)." In brief visits to this field on 03 and 15 September 2003, I couldn't find either the bittern or the blackbird (though there were several dozen Red-winged Blackbirds (Agelaius phoeniceus) about). Likewise, on 13 October 2003, Robert Dean and Eduardo Amengual were unsuccessful in their search for these species. I suspect that the bittern may well be hidden away somewhere in the rather extensive grasslands, but do have to wonder whether or not the much more obvious Red-breasted Blackbirds haven't gone elsewhere.

Fall Migration Highlights

The annual autumn migration is in full swing as I write -- I can hear a Yellow Warbler (Dendroica petechia) chirping outside my window and a Swainson’s Thrush (Catharus ustulatus) is in the bird bath -- but thus far, here are some of the more interesting sightings that I have heard about:

Blue-and-white Swallow (Notiochelidon cyanoleuca patagonica): five seen on 29 August at Chomes by Jim Zook. In addition to their being at sea level, Jim realized that the birds he saw were rare migrants of the South American race because "their vocalizations were notably different, the wings and tail were longer, and it seemed to me that they had more extensive white in the face. I saw them flying and perched on the mud. There were three adults and two juveniles."

Snowy Plover (Charadrius alexandrinus): one seen on 11 September on the beach near the Limón airport by Daniel Martínez, Alejandro Solano, Daniel Solano, and Agustina Arcos.

Gray Kingbird (Tyrannus dominicensis): one seen on 13 September in Yorkin (on the Panama border, west of Sixaola) by Daniel Martínez, Alejandro Solano, Daniel Solano, and Agustina Arcos. Alejandro told me that he saw a Tropical Kingbird (Tyrannus melancholicus) that "didn't look right. We put the telescope on it and sure enough, it turned out to be a Gray Kingbird!"

Orange-crowned Warbler (Vermivora celata): one seen on 21 September near Purisil on the road to Tapantí NP, during the monthly outing of the Asociación Ornitológica de Costa Rica. As reported by Daniel Martínez, "the bird was in a eucalyptus tree at the edge of a coffee plantation. The vent was yellow and it had noticeable streaking on the breast -- probably a female -- it behaved like a Tennessee Warbler (V. peregrina)."

Blue-headed Vireo (Vireo solitarius): one seen on 23 September at the Rain Forest Aerial Tram during the monthly bird count by Alejandro Solano.

Bobolink (Dolichonyx oryzivorus): two seen on 30 September at Finca Las Concavas by Daniel Martínez and Alejandro Solano. Daniel reported, "One bird in non-breeding plumage flew out from the grass near the lake to another pasture, where it perched a moment, then flew off with another similar individual, calling as they went."

Lincoln's Sparrow (Melospiza lincolnii): one seen in mid-October on the beach at Tortuguero by Adolfo "Fito" Downs, who wrote that "it was standing on the sand! I studied it for about 20 minutes. It seemed that it was tired or lost because it didn't move until I was about four meters from it."

Bamboo Bonanza for Acanthidops bairdii

In late July, while birding along the road to Providencia de Dota (km 76 on the PanAm Highway south, across from Los Chesperitos restaurant), Jim Zook discovered that the bamboo was in seed and Peg-billed Finches (Acanthidops bairdii) were everywhere. He even found an active nest of this usually fairly uncommon species.

The last time that there was a major flowering/seeding episode of bamboo on Cerro de la Muerte was in 1990. Highlights of that memorable period were the discovery of the first Peg-billed Finch nest ever recorded and an abundance of Barred Parakeets (Bolborhynchus lineola).

This time around, Peg-billed Finch nests seem to be common (Julio Sánchez has found at least three), but Barred Parakeets have offered little more than the occasional fly-by. There appears to be at least one pair of Slaty Finches (Haplospiza rustica) taking advantage of the seeding bamboo, but they are infrequently seen as they prefer to stay well inside the cover of the dense forest. And disappointingly, the much-hoped-for Maroon-chested Ground-Dove (Claravis mondetoura) has not so much as uttered a single syllable.

[Incidentally, prior to the bamboo going to seed, during his March tour, Jay VanderGaast observed a Bat Falcon (Falco rufigularis) perched on a bare tree at the junction of the highway and the Providencia road. Although this is a much higher elevation than the field guide indicates for this species (2850m vs. 1675m), on 28 November 2001, I also saw a Bat Falcon at a similar elevation on the gravel road going into Cuericí, where the locals said the bird was regularly seen.

And as long as I'm on the subject, Paul Coopmans reported a high-elevation sighting of Barred Forest-Falcon (Micrastur ruficollis) during the April Birdquest tour. "Excellent views of a responsive bird at dawn on Cerro de la Muerte. We were at an elevation of about 2800m, unusually high for this species."]

Buffy-crowned Wood-Partridges Below Km 80

Thanks to Marino Chacón of Savegre Mountain Lodge, I finally got to see Buffy-crowned Wood-Partridge (Dendrortyx leucophrys). On 24 August 2003, Marino took Robert Dean to a spot about three kilometers down from the PanAmerican Highway, on the road to Savegre (San Gerardo de Dota). Marino had apparently heard the birds calling in the area some time earlier, but on that particular morning it took some work to find them. However, after about an hour of playing tape and walking trails, they finally saw a bird right in the middle of the path.

A few days later, while visiting Savegre with Paul Murgatroyd, I asked Marino if he could take us to the site. On the morning of 29 August, we set off up the road and eventually stopped at a house, where Marino spoke with a woman, apparently asking permission to bird on private land. Passing through a barbed wire fence, we entered a mostly wooded area with two trails running parallel to each other on a hillside. Marino began playing a tape of the wood-partridge call and we soon had a response from the slope above us. In his zeal to show us the bird, Marino told us to stay put while he bushwhacked around and up to flush the bird down towards us. The plan nearly worked, except that the bird ended up dashing off to our left, giving me only a glimpse of a fleeing silhouette -- not the kind of thing you really want to put on a life list, nor would I have.

Moments later, a second bird called from below the trail we were on, but from within such dense cover that it was impossible to see. After more than half an hour of effort, Marino suggested that we try another spot across the road.

This second site is actually a place that is open to the public and has a small restaurant and a nice-looking trail system. We stood behind the restaurant as Marino played the tape and almost immediately got an answer from near the edge of the woods. At his suggestion, we went in the upper of the two trails behind the restaurant, and hadn't gone but a few paces when he motioned for us to stop and look down to our right. There in a small opening, not more than a meter in diameter, was a covey of at least six wood-partridges! We had fairly brief, but excellent, looks through the bins before they scattered into the surrounding underbrush.

If you're going down the road to San Gerardo de Dota, this spot is on your left, about three kilometers down from the highway. There's a small sign at the top of the driveway that says, "Senderos Restaurant El Asca" -- if I recall correctly. At any rate, you can't miss the place because there's a new and rather impressive home being built just across the road from the entrance.

Recent Rare Raptor Sightings

A number of rare raptors have been seen in the past few months. Here are the reports that have reached me:

On several occasions in early August, César Sánchez saw and heard Ornate Hawk-Eagles (Spizaetus ornatus) at the Quebrada Gonzalez sector of Braulio Carrillo NP. Actually, this species has been rather frequently reported from this site in the last few years, but it's good to know that they're still around after the shooting of an Ornate Hawk-Eagle in the area a year ago.

Also at Quebrada Gonzalez, but along the Río Sucio where it can be seen from the El Ceibo Trail, my son Leonardo twice observed a Solitary Eagle (Harpyhaliaetus solitarius) while birding there on 03 September.

Just down the road at the Rain Forest Aerial Tram, a Crested Eagle (Morphnus guianensis) was seen perched quite near the gondolas, between towers nine and ten. This sighting took place on 14 August, around 11:30.

A day later, on 15 August, Freddy Madrigal was birding at La Selva and happened upon a Black-and-white Hawk-Eagle (Spizastur melanoleucus) that was perched "about 40m overhead at 1850m on the Sendero Tres Ríos."

And on 10 October, during a brief early afternoon foray into the San Ramón Forest Reserve with Paul Murgatroyd, I spotted a male Tiny Hawk (Accipiter superciliosus) perched atop a bare tree near the abandoned guard house. [By the way, the Southern Lapwing (Vanellus chilensis) is still at the Los Lagos pond across the road from the entrance to reserve.]

And this just in, on 20 October, Julio Sánchez spotted an adult Solitary Eagle at Carbón Dos, just inland from Cahuita.

Sex and Violence at Two Well-Known Birding Lodges

Ruddy and Short-billed Pigeons (Columba subvinacea and C. nigrirostris, respectively) are quite similar in appearance, so much so that only the latter is illustrated in the Costa Rican field guide. Noheless, the Ruddy is, well, ruddier. Their songs are also of a similar quality, but the phrasing is different, with the Ruddy singing, "cu, cu-CU, cu," while the Short-billed sings, "cu, CU, cu-cu," if you will. Usually, there isn't much problem deciding which species you're seeing (or more likely hearing) since they separate out by altitude, with Short-billed in the lowlands and Ruddy in the highlands. However, Ruddy Pigeons sometimes occur at elevations as low as 900m on the Caribbean side of the country, becoming temporarily sympatric with Short-billed Pigeons.

It was just such an occurance that Jay VanderGaast and his March Field Guides trip experienced on the morning of 21 March 2003 while birding at Rancho Naturalista. Jay reported that, "We were hearing one of each species calling from the same area of Rancho Naturalista's forest, and I began playing the two calls as I explained the differences. The Ruddy Pigeon flew in right away, then flew to another perch back in the direction from where the two birds had been calling. There it was joined by a second bird, which looked to me like it might be a Short-billed. They went through a little posturing and interacting, then they mated. Afterwards, they sat near each other and began calling back and forth, not the primary song, but the 'growling' call typical of these birds. I noticed that there was some difference between the calls, one being a little higher-pitched, longer, etc. The [female] was clearly different, much duller in coloration without the Ruddy's reddish tones. I don't think the difference can be attributed solely to sexual differences between male and female Ruddy, therefore I am reasonably sure that what we saw was a mating between a male Ruddy and a female Short-billed. The picture I've sent shows the post-coital birds, and the plumage differences are quite apparent."

  * * * * * * * * * * *

These are strange, violent times in which we live. I personally cannot help but feel that in no small part our species' aggressive acts are often attributable to the reinforcement of violence through the media. However, despite our veneer of "civilized" behavior, there is undoubtedly a deep-rooted biological basis that spurs many of our aggressive impulses.

It is rare to observe intraspecific acts of mortal aggression in non-human species, but the following report sent to me by Alfredo Scott illustrates that they do occur:

"One morning at Savegre Mountain Lodge, I witnessed an aggressive behavior that I had never seen before in a Rufous-collared Sparrow (Zonotrichia capensis). An adult bird repeatedly flew down from his perch on a fence post and vigorously pecked at something. Looking through binoculars, I saw that it was attacking a juvenile of the same species. The adult pecked intensely at the young bird for a few minutes, then returned to its perch to rest before renewing the attack. The juvenile died as a result of the aggression."

Do similar acts take place in nature far more often than we might suspect?

Christmas Bird Counts Coming Up Soon

Here are the dates and contact information for the various CBC activities that will be taking place in Costa Rica. The venerable Grecia count will be celebrating its 20th anniversary (Rafa will be out of the country until early December, so only an e-mail address is given below) and the La Selva count will mark its 19th version. On the other end of the spectrum, the Aerial Tram and La Merced counts will both be hoping to repeat the success of their inaugural year, and on the Osa Peninsula a brand new count circle will be initiated. All interested birders are welcome to participate. Hope to see you out there!

Cartago: 14/12/03 César Sánchez <harpyhaliaetus@yahoo.com> 551-2509

Grecia: 14/12/03 Rafael Campos <ticornis@earthlink.>

Monteverde: 20/12/03 Wagner López <rbolanos@cct.or.cr> 645-5122

Aerial Tram: 22/12/03 Daniel Torres <danieltorrescr@yahoo.com> 364-1841

Osa Peninsula: 27/12/03 Neyer Campos <neyer@costarricense.cr> 377-5707

La Selva: 28/12/03 Joel Alvarado <joel@sloth.ots.ac.cr> 766-6565 ext. 107

La Merced: 03/01/04 Noel Ureña <selvamar@racsa.co.cr> 771-4582

Mystery Bird Photo Quiz

What a follow-up to the record number of correct IDs from the April mystery photo! The July quiz photo produced a record number of wrong responses! The irony is that in the April photo, you couldn't see the bird's bill, whereas that anatomical part was the pertinent thing in last edition's quiz. In bird identification we're always told to look at the bill, because that will provide valuable information as to which family the bird belongs. However, misidentifications of the most recent mystery species included: (4) Scarlet-rumped Tanager (Ramphocelus passerinii) -- actually, two of those people were more specific and proclaimed Cherrie's Tanager (Ramphocelus costaricensis), (3) juvenile Scarlet-rumped Cacique (Cacicus uropygialis), (2) juvenile Yellow-billed Cacique (Amblycercus holosericeus), (2) Melodious Blackbird (Dives dives), (1) juvenile Chestnut-headed Oropendola (Psarocolius wagleri), and (1) Brown Jay (Cyanocorax morio), for a total of seven species in three distinct families! Given a second opportunity, several of those participants were able to provide the correct answer, but I'm not certain that they would want their names spread all over the Inter in the runner-up category.

Therefore, a most deserved applause goes out to Jan Axel Cubilla, David Garrigues (yes, he's my son, but he made the ID with no assistance, and hey, he even submitted his answer via e-mail!), William Granados and Lori Conrad, who correctly identified the bird as a young Giant Cowbird (Molothrus oryzivorus)!

The photo was taken from the balcony at Rancho Naturalista on 18 June 2003, but unfortunately I missed my chance at the classic confirmation photo by just a few days. According to the local guide at the time, Tom Rodriguez, the bird was still being fed by its Montezuma Oropendola (Psarocolius montezuma) foster parent just several days prior to our visit. At least in this alternate image you can see the suggestion of a neck ruff, indicating that this is indeed a juvenile male Giant Cowbird.

The experience of seeing this bird, even though it did not associate with any other birds while we watched it, brought to mind the following report I received from a colleague several months ago. (I won't reveal any names since it is not the aim of this newsletter to ridicule, but rather to promote learning through sharing of information.)

"At Selva Verde Lodge, we observed a group of Montezuma Oropendolas foraging in the forest. The interesting thing was that a Yellow-billed Cacique appeared to have been adopted by the group, at least that's how it seemed to us. Every time the group moved, the cacique followed, staying near one particular oropendola. It maintained constant proximity to this oropendola, as if the two were mother and child, and the oropendola permitted this closeness without any apparent bother. Each time the oropendola perched on a branch, the cacique perched beside it, bodies touching.

"Is this behavior normal in icterids??"

My reply was that no, I personally had never seen, nor heard of, such behavior between oropendolas and caciques. I now must admit, to my chagrin, that a red flag did not immediately hoist itself high in my brain cells alerting me that 1) what would a thicket-dwelling Yellow-billed Cacique be doing high on those branches with a flock of oropendolas? and 2) didn't the whole episode sound suspiciously like the interaction that might result from cowbird brood parasitism?

So, dear colleague, a bit late, but I think we've solved your puzzle.

Well, after all that, I think I'd better go easy on all of you with this edition's mystery photo quiz and eliminate those troublesome bills. If you saw this bird, would you know what you were looking at?

The answer will be announced in the January 2004 newsletter.

Bird Geography Quiz

With its introduction in the previous newsletter, the bird geography quiz turned out to be another real head-scratcher. I suppose that from the outset I really should apologize for having set such a difficult course for the maiden voyage of this new feature. There was no way one could have extrapolated from the information in the field guide the location where I saw Scaly-throated Foliage-gleaner (Anabacerthia variegaticeps), Slaty-capped Flycatcher (Leptopogon superciliaris), Red-crowned Ant-Tanager (Habia rubica), Elegant Euphonia (Euphonia elegantissima), and Sooty-faced Finch (Lysurus crassirostris) along the same trail within 200 meters of each other on 05 June 2003. (Unless, as Carson Wade suggested in attempting to solve the enigma, it just so happened that those 200 meters of trail were completely vertical!) However, encountering that unexpected species mix was precisely the catalyst for this new quiz, and highlighted the fact that our knowledge of species distribution in Costa Rica is still not complete.

Guesses included Monteverde (where all of these species can be found on the general area checklist, but not within any 200 meters of trail that I know of, since the ant-tanager is a Pacific slope species and the flycatcher is a Caribbean slope species -- in that part of CR) and La Virgen del Socorro (where the ant-tanager would be well out of range). However, true honorable mention must be given to Carson Wade for having tried so hard and amusingly; to Michael Biro, who without ever having been there suggested: Valley of Rio Coto Brus at elevation of 4000ft.; and likewise to Sandy Smith, who has yet to set foot on Costa Rican soil but ventured: somewhere in the Dota Region (I'm not even sure where that is), wet forest, Pacific slope, Cordillera de Talamanca about 6000 feet.

Pretty close! The actual site was the Las Quebradas Biological Reserve just above San Isidro de El General, at an elevation of approximately 1200m (4000ft) -- and more or less equidistant between the Coto Brus Valley and the fabled Dota region. In fact, both Jim Zook and Noel Ureña did give the site, but the judges have disqualified them since I had mentioned my visit to Jim and because Noel was the one who told me about the spot and even accompanied Jan Foiles and I on the day of our visit!!

But seriously, if you are in the San Isidro area and have the time, this site is well worth birding. On our three-hour mid-morning walk we barely scratched the surface of the existing trail system, and from what I saw and Noel told me of his own experiences there, I can tell the bird list for the site will be extensive. To get there, take the PanAmerican Highway north out of San Isidro and just on the outskirts of town you will see a sign for Las Quebradas (turning right off the highway). As I recall, there were one or two forks in the road that weren't signed, but keep to the right at any such junction.

So, ready to try again? Just to remind you, the idea of this geography quiz is to see how many readers can guess the actual site -- or at least come close in terms of naming the region of Costa Rica -- where a given set of five bird species occurs together.

Where in Costa Rica could one find the following five species on any given day of the year?

Fiery-billed Araçari (Pteroglossus frantzii)

Blue-and-white Swallow (Pygochelidon cyanoleuca)

Olive Sparrow (Arremonops rufivirgatus)

Melodious Blackbird (Dives dives)

Montezuma Oropendola (Psarocolius montezuma)

I'll look forward to your answers!

Thanks to everyone who contributed news of rare sightings and good finds. I hope that you've enjoyed this newsletter and welcome any comments at gonebirding@lycos.com or if you're in Costa Rica, feel free to give me a ring at 293-2710.

Wishing you all great birding,

Richard Garrigues

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