Saturday 27 November 2021

Isthmus Of Tehuantepec

November 22, 2021

The Isthmus of Tehuantepec represents the shortest distance between the Pacific and Atlantic in Mexico. Located in Veracruz and Oaxaca states, the width of the isthmus is only 200 km from ocean to ocean. While mountains are prominent geographical features in much of Mexico, they form a gap at the isthmus, breaking down into a broad plateau that is only 224 m at its highest elevation. These two factors - the narrowing of the continent, and the lack of prominent mountains - led to the importance of the Isthmus of Tehuantepec as an overland transport route prior to the construction of the Panama Canal. 

Aspidoscelis deppii - Isthmus de Tehuantepec, Oaxaca, Mexico

Generally speaking, unique geographic features often lead to corresponding biogeographic curiosities. With regards to the Isthmus of Tehuantepec, several unique species and forms have evolved here over millenia. The broad valley is surrounded by three separate mountain ranges; montane species in these corresponding ranges are separated from each other, while the valley itself is isolated. Several unique bird species can be found only in the isthmus including the Cinnamon-tailed Sparrow and Rose-bellied Bunting. The latter is absolutely gorgeous, a species that I have wanted to see for years.

Laura and I drove towards the Isthmus of Tehuantepec on our way to Chiapas state in the east. We overnighted in the city of Juchitán de Zaragosa and prepared for an early start in the morning. 

Isthmus de Tehuantepec, Oaxaca, Mexico

We began our morning at Ojo de Agua Tolistoque. A beautiful spring of water flows out of the limestone rocks next to a picturesque cave. At least, it would have been picturesque if humans hadn't spray-painted graffiti and strewn garbage about the place. We humans are a lovely species. At least it was possible to photograph the scene from a particular angle to avoid the graffiti and garbage. 

Ojo de Agua Tolistoque - Isthmus de Tehuantepec, Oaxaca, Mexico

We birded along the entrance road. Despite our early arrival, birdsong was almost nonexistent. The time of year did not help, nor did the very strong winds that seem to be a common theme in this region. We quickly observed the first Turquoise-browed Hummingbirds of the day along with a small mixed flock of warblers and vireos. 

Turquoise-browed Hummingbird - Isthmus de Tehuantepec, Oaxaca, Mexico

And then, there it was! A female Rose-bellied Bunting shot across the road and perched in view for a few seconds. 

Rose-bellied Bunting - Isthmus de Tehuantepec, Oaxaca, Mexico

And then, the magic happened. Our first male Rose-bellied, followed by several others! We counted around 20 individuals in this flock. Sensing an opportunity, I slowly walked up to several individuals while they fed happily on seeds from a type of aster. They tolerated my approach.

Rose-bellied Bunting - Isthmus de Tehuantepec, Oaxaca, Mexico

Rose-bellied Bunting photoshoot - Isthmus de Tehuantepec, Oaxaca, Mexico

The colours on a male Rose-bellied Bunting are absolutely ridiculous. I kept shooting in the soft morning light and managed a series of photos that I was thrilled to capture. 

Rose-bellied Bunting - Isthmus de Tehuantepec, Oaxaca, Mexico

This next photo is the money shot, as far as I am concerned. What an incredible experience. 

Rose-bellied Bunting - Isthmus de Tehuantepec, Oaxaca, Mexico

Female buntings in the genus Passerina often get no love. She was quite pretty, though, with a gorgeous blue tail that sadly is not visible in this photo.  

Rose-bellied Bunting - Isthmus de Tehuantepec, Oaxaca, Mexico

We continued to bird down the track. I refocused my attention on the Cinnamon-tailed Sparrow. While this species lacks the incredible plumage of a male Rose-bellied Bunting, it is also restricted to the Isthmus of Tehuantepec and I was quite keen to see it here. Unfortunately, the sparrow stayed quiet and out of sight. A small consolation was our first Green-fronted Hummingbird that landed for around 10 seconds, never to be seen afterwards. We felt fortunate that it chose to perch near us, at least. 

Green-fronted Hummingbird - Isthmus de Tehuantepec, Oaxaca, Mexico

Several other birds made appearances. A Ferruginous Pygmy-Owl called from somewhere up the hillside, as did a Citreoline Trogon. We noted our first Golden-fronted Woodpeckers and Scissor-tailed Flycatchers for Mexico, while a Red-tailed Hawk and Cooper's Hawk provided nice views. We even found another flock of Rose-bellied Buntings!

Red-tailed Hawk - Isthmus de Tehuantepec, Oaxaca, Mexico

We had only been here for 90 minutes but I made the decision to bail and drive to a different spot. The Cinnamon-tailed Sparrows had not cooperated, and the cool hours of the morning would only last so long. This other spot, sometimes referred to as Jabba's Canyon, also seemed like a good bet to find the Lesser Ground-Cuckoo (another potential lifer for both of us). 

Sphenarium histrio - Isthmus de Tehuantepec, Oaxaca, Mexico

My anxiety about missing the Cinnamon-tailed Sparrow was quickly put to rest. A pair of them happened to be some of the first birds we observed after getting out of the car!

Cinnamon-tailed Sparrows - Isthmus de Tehuantepec, Oaxaca, Mexico

The birds were incredibly confiding, providing "walk-away views", as they say. 

Cinnamon-tailed Sparrow - Isthmus de Tehuantepec, Oaxaca, Mexico

Cinnamon-tailed Sparrows - Isthmus de Tehuantepec, Oaxaca, Mexico

Cinnamon-tailed Sparrows - Isthmus de Tehuantepec, Oaxaca, Mexico

Cinnamon-tailed Sparrow - Isthmus de Tehuantepec, Oaxaca, Mexico

Jabba's Canyon happened to be a very productive location, even though the sun was beating down by this point in the morning. 

White-lored Gnatcatcher - Isthmus de Tehuantepec, Oaxaca, Mexico

Laura spotted a snake just off the trail - a Pacific Patchnose Snake. I managed a few poor photos before it slipped away. In the heat of the late morning, this one was certainly far too fast to be catchable!

Pacific Patchnose Snake (Salvadora lemniscata) - Isthmus de Tehuantepec, Oaxaca, Mexico

We heard the first Lesser Ground-Cuckoo from behind the small research building (it was locked up with no one around during our visit). We followed a path around behind the building into the dry scrub at the base of the hills. 

Isthmus de Tehuantepec, Oaxaca, Mexico

This was the domain of the Lesser Ground-Cuckoo. While we never managed the fully unobscured photos I had hoped for, we still enjoyed excellent views of two birds. A second pair was vocalizing nearby. 

Lesser Ground-Cuckoo - Isthmus de Tehuantepec, Oaxaca, Mexico

The Lesser Ground-Cuckoo isn't a "real" ground-cuckoo, as in, one of the five rare and elusive Neomorphus species found in the Neotropics. But it is a unique bird, the only member of the genus Morococcyx. The day could not get any better!

Lesser Ground-Cuckoo - Isthmus de Tehuantepec, Oaxaca, Mexico

Just for good measure, a few Rose-bellied Buntings were around including several sharp males. Even after the morning's experience, I could not resist snapping a few more photos. Who knows how long it will be until I see another bird of this beauty?

Rose-bellied Bunting - Isthmus de Tehuantepec, Oaxaca, Mexico

Rose-bellied Bunting - Isthmus de Tehuantepec, Oaxaca, Mexico

The wind in the isthmus is something to behold. From what I gather, it is nearly always windy here - not a surprise given the region's geography. This has become the number one area in Mexico for renewable energy projects. Turbines spin as far as the eye can see. Even for someone who spends a lot of time in southwestern Ontario, where turbines are more numerous than trees (I'm sadly not exaggerating by much), the sheer number of them in the isthmus was mind-boggling. 

Turbines - Isthmus de Tehuantepec, Oaxaca, Mexico

With all of our targets in the bag, Laura and I backtracked the half an hour to our hotel to pack our bags and continue east. So far in Mexico, we have used an abundance of caution to reduce the potential of break-ins to our vehicle. A friend of ours had his truck broken into at Ojo de Agua Tolistoque several weeks earlier and we did not want to take any risks. While this meant that we had to waste an extra hour driving, it gave us the peace of mind that none of our valuables were unattended in the vehicle while we explored. As it turned out we only saw one other vehicle during the entire morning, making it a moot point. But, better safe than sorry! Knock-on-wood, but we have never had any item stolen during all of our travels, and we would like to keep it that way. 

Rose-bellied Bunting - Isthmus de Tehuantepec, Oaxaca, Mexico

We drove for several hours eastward, leaving the isthmus and its wind behind, and entered Chiapas state.  We checked into our hotel in Tonalá and began a search for the Giant Wren. Stay tuned...

Thursday 25 November 2021

Dry Forest Birding In Parque Nacional Huatulco

Parque Nacional Huatulco protects roughly 12,000 hectares of dry coastal forest/desert scrub, mangroves, and coral reefs along the south coast of Mexico. It is famous among muggles due to its beautiful and secluded beaches, but among birders, the park is well known for a number of localized species. None of these birds are restricted in range to the immediate surroundings of PN Huatulco. But some are only found along the coastal strip in southern Mexico, while others range a little further afield along the coast, west to Sinaloa State. 

My target list was relatively short and sweet, having already snagged Citreoline Trogon at Parque Botánico Hagia Sofia, and Yellow-winged Cacique in the town of La Crucecita (where we were staying). Remaining targets included Turquoise-crowned Hummingbird, Lilac-crowned Parrot, Colima Pygmy-Owl, Flammulated Flycatcher, Red-breasted Chat and Orange-breasted Bunting. I also "needed" Lesser Ground-Cuckoo, Northern Potoo and Olive Sparrow; widespread species that I just haven't encountered before. Among the above, the Orange-breasted Bunting and Red-breasted Chat were highly coveted species for Laura and I due to their beauty. The Colima Pygmy Owl was also high on our Most Wanted list, because, well, it is an owl. And finally, we hoped to find some Russet-crowned Motmots, a species that Laura had never seen before. She is a big fan of motmots (who among us is not?). 

Citreoline Trogon - Parque Nacional Huatulco, Oaxaca, Mexico


November 20, 2021

I hope Laura had enjoyed her sleep-in the previous day, because today we were back to work. The only saving grace was that sunrise occurs around 6:30 AM here due to our latitude. Even so, I did not want to miss the best birding hours of the morning and so we parked our vehicle at the chosen birding spot around 6:00 AM. 

Our destination was the end of a paved access road along the east side of PN Huatulco (location is at 15.7319036, -96.1597252). Right away our first birds of the day made their presence known by voice: Collared Forest-Falcon, West Mexican Chachalaca, Nutting's Flycatcher, Rufous-naped Wren. 

Rufous-naped Wren - Parque Nacional Huatulco, Oaxaca, Mexico

The first two target species to make their way onto my eBird checklist were both heard-only, unfortunately. The first was a Colima Pygmy-Owl, while just a little further down the road I locked onto a Flammulated Flycatcher. Despite them being relatively close to the road, I was unable to obtain a visual on either. We pressed on, walking eastwards along the quiet road. Even on a weekend, at an early hour we had the place to ourselves. 

Entrance road to Parque Nacional Huatulco, Oaxaca, Mexico

Laura came through with a motmot, just off of the road: a Russet-crowned!  

Russet-crowned Motmot - Parque Nacional Huatulco, Oaxaca, Mexico

I kept an ear open for flyover parrots, hoping for a Lilac-crowned. Due to collection for the pet trade coupled with habitat loss, the Lilac-crowned Parrot is classified as Endangered. This is a species for which eBird has obscured the records, to make it more difficult for the poachers. Therefore, I was going in blind with this species (just like the old days!). All of the parrots that flew overhead were of the more expected species, White-fronted. I had to really overexpose the images to confirm an identification, otherwise they all looked like black-headed black parrots. 

White-fronted Parrot - Parque Nacional Huatulco, Oaxaca, Mexico

The sun slowly crested over the hills behind us and the bird activity increased. Things were a bit frantic as we went from one species to the next. Several Turquoise-crowned Hummingbirds buzzed us. The looks were poor but their calls were distinctive. Finally, a female obliged by perching in a roadside shrub. 

Turquoise-crowned Hummingbird - Parque Nacional Huatulco, Oaxaca, Mexico

Frenzied bird activity by a fruiting tree stopped us in our tracks for fifteen minutes. Citreoline Trogons, White-throated Magpie-Jays, Rufous-backed Robins, Altamira and Streak-backed Orioles, Yellow-winged Caciques and a Masked Tityra all took part and provided incredible views. 

White-throated Magpie-Jay - Parque Nacional Huatulco, Oaxaca, Mexico


Yellow-winged Cacique - Parque Nacional Huatulco, Oaxaca, Mexico

Rufous-backed Robin - Parque Nacional Huatulco, Oaxaca, Mexico

Masked Tityra - Parque Nacional Huatulco, Oaxaca, Mexico

By this time, the coolness had long-since abandoned the air and so we did our best to stick to the shadows. Some chip notes in the undergrowth alerted us to a pair of Olive Sparrows. They nearly succeeded in evading my camera lens. All I managed were a few blurry photos that barely count as record shots. 

The heat of the morning sent numerous lizards out of the woodwork. Dry forests like these are perfect for these scamperers, and every step off into the forest sends numerous individuals scurrying. I often wonder what the density of lizards per hectare is in places like this! Surely, this number contains at least four, perhaps even five digits at PN Huatulco. 

Mexican Racerunner (Aspidoscelis guttatus) - Parque Nacional Huatulco, Oaxaca, Mexico

We turned around after reaching the first roundabout and retraced our steps along the road. Our peripheral vision picked up a bunting-sized flash of electric blue cross the road. Could it be?

Orange-breasted Bunting - Parque Nacional Huatulco, Oaxaca, Mexico

A male Orange-breasted Bunting! The colours were almost unbelievable, but there it was, right in front of us. I never managed the five-star photos I craved, though the views were incredible. 

Orange-breasted Bunting - Parque Nacional Huatulco, Oaxaca, Mexico

After a few minutes it popped out of the shadows onto a sunlit branch. Then, just like that, it flashed back across the road and disappeared into a shady thicket. We were stoked! This species is supposed to be relatively common in this park, and we would go on to see several others, but the first was unforgettable.

Orange-breasted Bunting - Parque Nacional Huatulco, Oaxaca, Mexico

Not five minutes later, another target appeared. While not the hoped for male, the female Red-breasted Chat is not bad looking at all. She also sat out in the open for us, flashing her tail. 

Red-breasted Chat - Parque Nacional Huatulco, Oaxaca, Mexico

Red-breasted Chat - Parque Nacional Huatulco, Oaxaca, Mexico

The day was really cooking now and bird activity was slowing. I paused near the vehicle to crack off a couple photos of a female Pale-billed Woodpecker that was working some dead snags, while we also stopped so Laura could see her first ever Bell's Vireo. 

Pale-billed Woodpecker - Parque Nacional Huatulco, Oaxaca, Mexico

Several other lizards were waiting for us by the vehicle. 

Western Spiny-tailed Iguana (Ctenosaura pectinata) - Parque Nacional Huatulco, Oaxaca, Mexico

Longtail Spiny Lizard (Sceloporus siniferus) - Parque Nacional Huatulco, Oaxaca, Mexico

Laura and I continued down a sandy track into the national park, trying (and failing) to find an access trail to a large wetland located somewhere to the south. 

Parque Nacional Huatulco, Oaxaca, Mexico

We explored the dry forest for an hour or so longer. We finally managed to see some Happy Wrens, a bird which we had heard on numerous occasions earlier in the trip. Unfortunately, I wasn't so...um....happy with how my photos turned out. 

Happy Wren - Parque Nacional Huatulco, Oaxaca, Mexico

Laura and I returned to the vehicle shortly after 10 AM. If I was on a short birding trip I would have pushed to stay out for several more hours - birds can be found during the heat of the day, it just gets trickier. But since we are hoping to travel for quite a while, I am ok with taking it easy and picking our moments to go all out. It is a marathon, not a sprint. 

Cinnamon Hummingbird - Parque Nacional Huatulco, Oaxaca, Mexico

We chilled for the hottest part of the day and returned to the same spot shortly after 4 PM. We planned to hike through the dry forest to a secluded beach, swim and watch the sunset, and then walk back in the dark, trying for owls, potoos, snakes, and whatever else. 

Short-tailed Hawk - Parque Nacional Huatulco, Oaxaca, Mexico

The afternoon birding was much slower than the morning's visit, but we added a few things, including the Short-tailed Hawk pictured above and some Orange-fronted Parakeets pictured below.

Orange-fronted Parakeet - Parque Nacional Huatulco, Oaxaca, Mexico

We noted a new lizard as well, the Tropical Tree Lizard (Urosaurus bicarinatus). 

Tropical Tree Lizard (Urosaurus bicarinatus) - Parque Nacional Huatulco, Oaxaca, Mexico

The beach was absolutely stunning. Located in a cove, white-sand stretched out in front of us for quite a distance. A cactus-studded island was situated not far offshore. I optimistically kept an eye out for distant seabirds; pelicans and frigatebirds were all I could find, as expected. But the view was magical and, best of all, we only had to share the beach with five other individuals. 

Bahia de Cacaluta - Parque Nacional Huatulco, Oaxaca, Mexico

As the sun set we watched several unidentified rays leaping high into the air, possibly in an attempt to rid themselves of parasites clinging to their bodies. 

Bahia de Cacaluta - Parque Nacional Huatulco, Oaxaca, Mexico

We trawled for owls and potoos on the way back but it was not to be, the exception being a single pygmy owl that teased us with its vocalizations. We saw a dark shadow whiz past; the owl resumed calling from much further away. 

Laura spotted a group of West Mexican Chachalacas, hilariously roosting together on a branch. 

West Mexican Chachalacas - Parque Nacional Huatulco, Oaxaca, Mexico

The rest of our night hike was relatively uneventful with no herps or other birds to speak of. We even spotlighted for potoos on the drive back into town, to no avail. Can't get them all...

Out AirBnB hosts recommended a local taquería to us, located just down the road. We were pretty glad they suggested this spot! All of the food pictured below cost around 10 Canadian dollars. It included four types of grilled meat as well as grilled onions, cactus and jalapeño peppers, fresh limes,  various salsas, a stack of 22 tortillas, and drinks. We had leftovers for lunch the next day as well. Pretty incredible!


November 21, 2021

We awoke at the same early hour. Due to increased efficiency with our morning routine we arrived at our birding site, a quiet forest trail, while it was still quite dark out. I made the judgement call to return to the road from yesterday until we had better visibility. The more open roadway would at least give us some light to work with. I hoped that maybe I would get lucky with a flyover Lilac-crowned Parrot as well. 

West Mexican Chachalaca - Parque Nacional Huatulco, Oaxaca, Mexico

We noted mostly the same birds from yesterday's visits including the Colima Pygmy-Owl and Flammulated Flycatcher. Once again, we struck out on obtaining a visual of either! And the only parrots that flew over were the White-fronted again. It was worth a shot at least.

Brown-crested Flycatcher - Parque Nacional Huatulco, Oaxaca, Mexico

After an hour or so we returned to our original site. Called Sendero Cruz del Monte, this quiet track is located a bit more inland and also heads west into PN Huatulco. 

Sendero Cruz del Monte - Parque Nacional Huatulco, Oaxaca, Mexico

While we had found a female Red-breasted Chat yesterday, we still hoped to see one of the males. And we were in luck. We passed the territories of at least three individuals, one who posed nicely for photos.

Red-breasted Chat - Parque Nacional Huatulco, Oaxaca, Mexico

Olive Sparrows seem to be common along this path as well, and their chips and twitters were frequently heard from the undergrowth. Finally, one popped out in the open for a while, proving excellent views of its...oliveness. 

Olive Sparrow - Parque Nacional Huatulco, Oaxaca, Mexico

Olive Sparrow - Parque Nacional Huatulco, Oaxaca, Mexico

I have mentioned on this blog before how Laura has a fantastic eye for spotting birds at rest, especially cryptic ones that are easy to pass by. I confess that I am not very good at this, I need to see the movement most of the time. Once again, Laura came through. This time, it was a Colima Pygmy-Owl! 

Colima Pygmy-Owl - Parque Nacional Huatulco, Oaxaca, Mexico

We were thrilled. The bird was off the trail and obscured by branches but somehow Laura picked up on the subtle shape of the roosting owl. I'm going to keep her around, I think! 

Two species of pygmy-owls inhabit this region. The widespread Ferruginous Pygmy-Owl is found in towns, parks, and other open areas while the Colima Owl is tied to dry scrub forest. They sound very similar, though with slight differences, and the best way to identify them is visually. Among other features, the Colima Pygmy-Owl has white dots on the crown, while the Ferruginous Pygmy-Owl has streaks there. 

Colima Pygmy-Owl - Parque Nacional Huatulco, Oaxaca, Mexico

We concluded our walk without any more avian surprises. I held out hope for a last minute flyover Lilac-crowned Parrot to no avail. I guess I will have to wait for a west Mexico trip to finally see that species. 

The walk back to the car was hot and the bird life had slowed. We entertained ourselves by looking for insects and lizards. 

Calephelis sp. - Parque Nacional Huatulco, Oaxaca, Mexico

Longtail Spiny Lizard (Sceloporus siniferus) - Parque Nacional Huatulco, Oaxaca, Mexico

Pink-spotted Cattleheart (Parides photinus) - Parque Nacional Huatulco, Oaxaca, Mexico

And with that, our time in Parque Nacional Huatulco had come to a close. We pointed our vehicle east, heading for the Isthmus of Tehuantepec, where a rare and incredibly beautiful bunting awaited us. The Isthmus will be the subject of my next post.