Saturday, February 21, 2009

Mexico - a HAPPY birthday

So, from those dizzy heights we return to the coast. This is more of a day-in-the-life type blog. It was one of the last days of the AOU conference and we were all a little dizzy from hearing hundreds of presentations. It was also my birthday and we were in Veracruz… surely that required celebration! So we trundled down to the bus station pre-dawn and got on the first bus to a small town near the coast from where we got a cheap taxi with a very friendly taxi driver to take us down to the beach – Playa Juan Angel (Jimmy Angel Beach) to be precise. Our target bird was Collared Plover, a tiny little plover that I had never managed to connect with elsewhere in Mexico, despite the fact that they are distributed along both coasts. We had to take our shoes off to get to cross the channeled stream to get to what looked to be the best section of beach and as we walked along we quickly saw plovers… but those were Snowy Plovers (or Kentish Plovers if you prefer). Fortunately 30 minutes or so later I spotted 3 Collared Plovers and the birthday lifer celebrations began. Later we found another adult with a juvenile (on the side of the beach where we didn’t need to get our feet wet) and here is a photo of that adult Collared Plover. The way the foot is tensed you can see the semipalmation well.



There were other shorebirds on the beach too like this beautiful Long-billed Curlew. I just love the barred pattern in their upperpart feathers.



And there were other waterbirds too of the long-legged wader type like this white-morph Reddish Egret


And this juvenile Snowy Egret. Compare the proportions of both egrets and you’ll notice their different giss/gizz (general impression, shape and size).


On the beach there were a large bunch of terns including this juvenile Black Skimmer (Royal Tern behind). With the lower mandible longer than the upper mandible, skimmers may look odd – but they have a neat fishing trick of course!


Sandwich Terns were also common


And we tried very hard to turn this tern into a Roseate Tern (it has some puzzling features, e.g. the combination of full black cap with long, thin, all-black bill suggests Roseate Tern but the primaries appear too dark for Roseate and it seems that the white inner webs characteristic of that species are missing. Also, the tail appears too short for Roseate)… but we eventually decided it must be an unusual (maybe transitional plumaged?) Common Tern after all. Comments anyone?


Away from the beach there were other beautiful birds to look at like this male Vermillion Flycatcher.


And perched Black Vulture.


After an hour or two at the beach we walked back to the road and flagged down a bus to Cardel. In October, this is a phenomenal spot for raptor watching and the conditions seemed perfect. Yes, we were in for a treat. To understand why southern Mexico is so good to watching migrating raptors you have to realize three key facts: 1) raptors don’t like to flap much and conserve their energy by soaring on thermal currents, 2) the thermal currents raptors need only occur over land, and 3) North America is shaped like a big triangle standing on its apex so if you need to travel to South America over the land no matter where you start your journey, east middle or west, you will get funneled down through some key bottle necks, the Isthmus of Tehuantepec and further south along in Panama’s narrow corridor of land. As it turns out, Veracruz City and Cardel are just north of the Isthmus of Tehuantepec and boy do they see some raptor traffic in the fall.

So there we were on top of the tallest building in Cardel (a hotel). As the day warmed up and the thermal started to climb, we saw distant “funnel clouds” spiraling upward over the hills on the horizon. Of course, these weren’t funnel clouds but rather streams of raptors circling in the thermals. When they got high enough they broke from their thermal and started streaming in a “river of raptors” looking for the next thermal. These "rivers" would come right over our heads and sometimes there were so many raptors in one river that it would take them over half an hour to pass us. On the roof the raptor counters were clicking away while on the terrace one story below the rest of us sat astounded at the spectacle. A sky full of raptors!

In the morning the dominant species in the flocks was Broad-winged Hawk. In fact well over 100,000 Broad-winged Hawks passed us by – here is just a few of them (the larger black birds mixed in are vultures)!


Sometimes the Broad-wings had more company. Spiraling with them here are Wood Stork, Black Vulture, Swainson’s Hawk and if you can pick out the Great Black Hawk in the mix you’re doing extremely well! (hint: look for a bird with a different giss underneath and to the right of the Swainson’s Hawk and Black Vulture flying close together.. but actually you’d need to see the larger file to ID this bird)


Later in the afternoon, the conditions meant that the raptors were moving a little inland rather than hugging the coast. We therefore left Cardel and went to a nearby site called Chichicaxtle, where there was an observation tower near a soccer field. Here we started to observe a changing in the guard with Swainson’s Hawks beginning to dominate, although there were still some Broad-wings mixed in. By the end of the day the official count was over a quarter of a million raptors (all species combined).


A final treat, on the edge of the soccer field, was an endemic hummingbird, the Mexican Sheartail. Most of this species’ range is in the Yucatan Peninsula but it seems there is a small disjunct population in Veracruz. What better way to finish a smashing birthday than with a lifer!


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Thursday, February 19, 2009

Mexico - pine-oak forest

Climbing up out of the cloud forest, the colder drier high elevations become dominated by conifers and more “temperate” tree species. You are now in the high-elevation pine-oak forests. The high elevation forests have something in common with temperate forests and in fact, some of the same birds make their home in both. For example, up above 2500m or so in Mexico you start seeing Hairy Woodpeckers, House Wrens and Red Crossbills – resident species that i can also see in my “backyard” here in Canada.

I thought I’d start this entry with an owl in the pine-oak forest, just because it is a fun birding story. Stygian Owls did not seem to be calling much when we were there. I had only heard two and both give a single hoot just before dawn then shut up. As many will testify, I am owl obsessed and was determined to see this species well. On our last day in range, I hiked up alone at 4am and heard a single hoot at 6am coming from across the large canyon (Barranca Rancho Liebre). Muttering "one last shot" under my breath, I hiked across to the area where i thought the hoot had come from. I then reached into my bag of tricks from my screech-owl research and went into roost-search mode – scouring the area as systematically as i could and probably missing good birds around me. Shortly after 8am i spotted a lump high in a pine tree that turned out to be the “devil” himself (I believe he was male based on that one call)! Yep, the Stygian is aptly named with that dark plumage, long "horns", and unusually deep orange eyes.


As the sun got brighter, a flock of Tufted Jays came in behind me and i got photos of them mobbing the Stygian Owl (though we had words about just who was supposed to be finding the owls for whom!). So here is one of those tufties! A truly beautiful jay in the rather diverse Cyanocorax genus (to which Green Jay and Brown Jay also belong) and yet another west Mexican endemic. Tufted Jays have a tiny global range in a strip about 300km long from Sinaloa to northern Nayarit with a narrow altitudinal range of just 1500 – 2100m. For that reason alone, it amazes me that they are not listed by Birdlife International as near-threatened but, despite being so range-restricted, they are locally very common.


The Eared Poorwill is a very seldom seen wet Mexican endemic and finding one on this trip was a major bonus... we had not heard any at all despite our efforts and then, on that fateful night, our owling adventures didn't start off very well... we got a wheel stuck on the side of the road and as I got out to investigate ended up falling about 20 feet off the side of the cliff and getting scratched on barbed wire (it could have been much worse though)... some ever-friendly, ever-helpful Mexicans went and got a cable and pulled us out with about 6 people piled in the back of their van to balance the weight... anyway, not to be deterred by a little blood sacrifice we owled on but it was totally dead - not so much as a peep. We decided to drive out, Kyle driving with me spotlighting as you have to go very slow on Mexican dirt roads anyway. We had nearly reached the pavement when i detected a speck of red eyeshine about 100 metres away on a hillside... it took a while to manoevre closer and for everyone to get good enough views to confirm the ID, but amazingly it was an EARED POORWILL and it sat remarkably still for us! Maybe an offering to the gods is necessary to see this species because in just about the only other trip report I found online where people saw this species, they got hopelessly lost on the same road we were on and ended up seeing the poorwill in a state of panic!


If you’ve been to Arizona, the Whiskered Screech-Owl will be more familiar. We had a few sightings including a pair just before dawn right over our makeshift campsite.


By virtue of their tiny size and cryptic plumage, pygmy-owls can be tough to spot. You may not notice the Mountain Pygmy-Owl in this photo at first. The Mountain pygmy-Owl is considered the same species as Northern Pygmy-Owl by the AOU (American Ornithologists Union) but there is mounting vocal and genetic evidence that these taxa should be split. The Mountain Pygmy-Owl also occurs in extreme southern Arizona and may be partially sympatric with Northern Pygmy-Owl in that area.


Next, another one of those “magical moment” birding stories... at midday i had settled in for a culturally-appropriate siesta at a lookout over the canyon only to be woken 30 minutes later by the distant calls of Thick-billed Parrots from across the abyss (of space, not consciousness, I hope). In a dazed state, I tried cueing up my tape to make sure I was correct, and indeed the recording sounded exactly like the rhythm in my mind. Strangely enough though, something responded to the tape that was clearly much deeper and gruffer than Thick-billed Parrot. Stumbling across a few boulders to a break in the trees where I could see over the canyon, I arrived just in time to see a STUNNING pair of Military Macaws flying up towards me from the canyon below! If that wasn't enough to wake the dead, they flew past me at eye level and circled back once and then looped back again (i.e. 3 eye-level passes) before disappearing into the mist that had been slowly climbing the valley walls below them. Their magnificent green then faded to white with the echoes of their quaking voices reverberating in my bones. If you've never seen a macaw fly around your head before, all i can say is it is a little bit like being engulfed by a rainbow! I still wonder if they were real flesh and blood or figments of the mist! Now of course, I was a little bit dazed by all this and I didn't react in time to adjust the setting of my camera to compensate for the movement and mist so these shots are nothing in comparison to the experience... but enjoy!


After the yellow-bellied trogons in the previous post, here is a red-bellied one – the beautiful Mountain Trogon. Check out that dramatic tail pattern!


The two woodcreepers with the northernmost distribution are the Ivory-billed Woodcreeper (that’s Ivory-billed Woodcreeper, not Ivory-billed Woodpecker) and the White-striped Woodcreeper shown here. This little guy is demonstrating how woodcreepers can do more than climb straight up trunks. They have no qualms about feeding upside down.


The beautiful Tufted Flycatcher (or Northern Tufted Flycatcher if you prefer) is a delightful little bird. The one was darting out to catch bugs on the wing and then returning to the same perch. This species’ range extends to within <200km>

The beautiful long needles of the pines create a whispy air to the forests up here. They also rustle gently to add to the surreal effect. You might get a sense of this in this composite photos of a Hermit Warbler on the left and Grace’s Warbler on the right. You may also have noticed these long needles in the previous photos of White-striped Woodcreeper and Stygian Owl (and burnt ones in the photo of Mountain Pygmy Owl).


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Sunday, February 15, 2009

Mexico - moist forest

In central Mexico, at the right elevation on the continental divide, one enters into lush bands of cloud forest, where the moisture provided by the fog creates a rich diversity of vegetation and animal life. If you have climbed up from the dry lowland areas to the west, this feels like another world altogether. This forest only starts at a certain elevation but if you keep climbing, the higher elevations pose many challenges and the cloud forest trees start to drop out whilst hardy conifers become increasingly dominant (in the same way as if you travel north in the temperate zones). This is the reason for the word “band” of cloud forest, i.e. an altitudinal band.

The south of Mexico also has lowland rainforest. In fact, the northernmost extension of lowland Neotropical rainforest is in Veracruz and before fragmentation of this forest occurred it was the northernmost realm of area-sensitive species like the Scarlet Macaw. This post is a combination of some of these moister forest types to contrast them with the dry forest type of the previous post.

Let’s start on the ground! On the slopes of the two Volcanes de Colima with their evocative names, Volcan de Nieve and Volcan de Fuego, lies some of the lushest forest I have seen in western Mexico. This is probably the best place in the world to see the secretive Long-tailed Wood-Partridge, endemic to 4 mountainous areas of central Mexico, including the high elevations around Mexico City. This was our best sighting of this beautiful bird as it walked out across the jeep track in front of us.


Also on the ground is the much smaller Singing Quail of humid evergreen and semi-deciduous forests. This bird was photographed in the eastern part of the range. Singing Quail have superb camouflage – their brown and white plumage matching dappled light on leaf litter – making finding and photographing them a challenge.


Much easier to see than the two previous species is the Plain Chachalaca. This calling bird reveals the red gular patch that would otherwise be hidden. Chachalacas are cracids of course and more arboreal than New World Quails.


The Common Pauraque will be a familiar species to many. In parts of Mexico they are VERY common and on some night we found many sitting on the roads.


The Squirrel Cuckoo seems to be a favourite of many, with their beautiful long “full” tails. This is one of the most widespread Neotropical Cuckoos and occurs in a variety of habitat types from scrub to moist forest on both the Pacific and Caribbean slopes.


There is something special about the colour of trogons. Whether red or yellow bellied, their soft plumage seems to emphasise their rich colour. Of course, the most colourful part is the belly, but their greenish blue backs are also magnificent. Note the highlights in this Black-headed Trogon.


And here a Violaceous Trogon strikes a pose that shows their colour to good effect.


Speaking of colour… what can i say about the Keel-billed Toucan except - WOW what a creature!! There is hardly a more quintessential symbol of the Neotropical forests than the toucans! Veracruz is as far north as this family gets. Look how that huge bill can be used to delicately pluck even tiny fruit. The bill looks heavy but it actually quite light.


Also the northernmost representative of a uniquely Neotropical family, the Red-capped Manakin light up the forest with their superbly contrasting colours. The stocky little manakins pack quite a punch, delighting observers with not just their colour but also they peculiar dancing displays when on leks.


The becards are a peculiar group that no-one seems to agree on – at least when it comes to their taxonomy (other than the fact that they are Neotropical suboscine passerines). This is a male Rose-throated Becard showing off the feature that gives them their name. Also note the flycatcher-like bill shape – they are related to tyrant flycatchers at least to some extent (Sibley and Monroe actually put them in the same family though others disagree).


The woodcreepers are another Neotropical family that reach their northern limit in Mexico. No woodcreeper has yet been recorded north of the U.S border, although this may happen in future. This photo shows a Streak-headed Woodcreeper climbing along under a thick tree limb. As you may have guessed they gleam and probe for insects with those long decurved bills. Woodcreepers are NOT related to treecreepers (the family to which the American Treecreeper, better known as the Brown Creeper, belongs) but, since both spend their time climbing up tree trunks, they have converged in some features such as cryptic brown or reddish brown plumages, pointed rectrices to aid climbing and (usually) slightly decurved bills suited to probing.


Also clad in browns and white are the wrens. Unlike woodcreepers though, wrens are true songbirds (oscine versus suboscine passerines). Whereas the woodcreepers are a South American radiation that drifted north (probably during the Great American Exchange when North and South America came into contact about 3.5 million years ago), the wrens are a North American family that radiated southward to conquer South America. These handsome Band-backed Wrens were often high in the canopy and hard to photo but they came out onto this snag after a torrential downpour offering me a great photo op.

The “silkies” are also known as silky-flycatchers but they are not flycatchers at all. They are a small family of their own (Ptilogonatidae), most closely related to waxwings. The Phainopepla is also a member of this family. They share some features in common with waxwings such as their soft plumage texture, crests, small bills, plumage patterns dominated by grey or black with splashes of colour and flocking behaviour. Like waxwings they eat fruit and insects but probably more insects than waxwings do. Here is a Grey Silky in a feeding tree (the short shaggy crest doesn’t show well from this angle).


Next, I’ve combined two unrelated “sparrows” in one photo: the Collared Towhee (genus Pipilo) and the Green-striped Brushfinch (genus Atlapetes). The idea behind putting these photos together is to show how unrelated birds sometimes look very similar. In addition to sharing structural features driven by ecological conditions and ecological niches like the woodcreepers and the treecreepers, species can also “converge” in plumage patterns. Sometimes a particular pattern just works well in a particular environment. I guess for ground-dwelling sparrows in western and central Mexico at reasonably high elevations (>1500m) where these species are found, something about that environment makes the combination of dark forecrown, supercilium, black face-mask, white throat and black breast band work to sends a clear signal… to your kind and others too apparently!


Why not finish with a tanager – the beautiful Yellow-winged Tanager, even though that yellow spot is not always so visible.


You can view some of these photos in larger size on my web page: artusophotos.com

Saturday, February 14, 2009

Mexico - thorn forest, dry forest

Many people think of the tropics as always hot and wet; however, there are many areas of the tropics that show strong seasonal variability between dry and wet seasons. This variability is caused by monsoons or other climactic conditions. Plants in such variable climates have adaptations to cope with the annual cycle of change, e.g. many lose their leaves in the dry season. Thorns are another brilliant adaptation that not only reduce herbivory but also deflect sunlight, keeping the plant cool. You’ll find some large thorns on the trees and shrubs of Mexico’s dry thorn forests and some large areas where thorn forests dominate the landscape, especially south of the true deserts around 20°N - 30°N. Most of the world’s deserts in fact occur 20° – 30° from the equator due the air currents that cause warm tropical air to descend. The exceptions like the Great Basin in the U.S.A and the Gobi in Asia are the product of large rain shadows, i.e. the Sierra Nevada and the Himalayas suck out the moisture coming from the coast leaving the leeside dry. Anyway, i digress… the thorn forest, like other tropical dry forests are influenced by the dry air around them and the long dry season and can seem brown and harsh… until you look a little closer! Tropical dry forests and a very threatened ecosystem throughout the world, because the sparse vegetation in the dry season leaves them vulnerable to clearing and other forms of human incursion… but at least the thorn forests have a little self-defence (yes, they hurt!)

With a tiny global range confined to Western Mexico’s thorn forests and surrounding arid landscape, the Balsas Screech-Owl is the perfect place to start this entry. This is a large screech-owl and their bouncing ball song sounds A LOT like the closely-related Western Screech-Owl. Nonetheless, to me though they look quite different to a Western Screech-Owl, being larger in size with a long tail and gorgeous brown eyes. This was one of only a few owl species of owl calling regularly in September (we heard 16 in 3 hours!!). This may have had to due with the heat but I suspect it's more likely an artifact of tropical breeding phenology.


Since we started with an owl why not run with that theme. This next character, the Mottled Owl, is found in a variety of forest types from northern Mexico all the way down to northern Argentina from the lowlands up as high as 2500m asl. Their large repertoire of explosive hoots are commonly heard, even around human habitation, making then arguably one of the most characteristic Neotropical owls. This photo was taken in dry forest – can you see the acacia leaves? Mottled owls are among the smallest owls in the genus Strix (round-headed woodland owls), little more than half the size of a Barred Owl for example.


Sticking with the owl theme, here is a lamentably poor shot of a Ridgway’s Pygmy-Owl in thorn forest (a taxon i believe should be split from the Ferruginous Pygmy-Owl – see my “Colombia – brown and rufous” post from January to compare)


The similar Colima Pygmy-Owl also occurs in thorn forest, although the bird in this photo is a little higher up in semi-deciduous forest. You’d be hard pressed to identify the 6 species of Pygmy-Owl found in Mexico unless you listened to their call first. Fortunately they call a lot and many of them are diurnal or crepuscular, so you can find them (the ones that are nocturnal like Central American Pygmy-Owl are super tough to see). At 14cm, the Colima Pygmy-Owl is very small (Ridway’s averages about 17.5cm but is quite variable), has a longer tail than Ridgway’s (which you can just see here) and has a spotted not streaked crown, which you can’t see so well here because the bird’s head is angled up while calling (note the throat feathers puffed out).


Shifting gears, here are two super characteristic birds of the dry forests of western Mexico – the two magpie jays: the main photo is of Black-throated Magpie-Jays and the inserted bird on the bottom left is their sister species, the White-throated Magpie-Jay, for comparison. Famous for the LONG tails and crests, these jays are truly a rhapsody in blue and this photo does them no justice! The Black-throated Magpie-Jay is endemic to northwestern Mexico and graces the front cover of the Howell and Webb field guide. The White-throated Magpie-Jay has a more southerly distribution along the Pacific slope. Mostly allopatric, they do have a narrow range of overlap in Jalisco and Colima and they occasionally hybridise.


This photo is of a Lesser Roadrunner, the smaller, more southerly sister species of the Greater Roadrunner (the only two species in the genus Geococcyx). If you are familiar with the Greater Roadrunner, you notice the Lesser Roadrunner’s buffier underparts and shorter, thinner bill. The Lesser Roadrunner is also smaller but otherwise they are very similar. The Lesser Roadrunner is a Mexican near-endemic with a mostly west coast distribution, except for a disjunct population in the Yucatan peninsula. In this photo you can see the zygodactylous toes (two toes point backward) found in groups like cuckoos, woodpeckers, and owls (though in owls the fourth toe is reversible rather than being fixed in the backward position like the others).


The dry open forests are home to many woodpeckers. This composite shows two closely related species of Melanerpes woodpeckers, both of which are endemic to western Mexico. On the left, two male Golden-cheeked Woodpeckers interacting and on the right a male Grey-breasted Woodpecker perched on a cactus. Both of these species occur in dry forest types but the Grey-breasted has a more interior and very restricted distribution. You’ll notice the difference in crown coloration and facial markings.


The Lineated Woodpecker is not a bird I was expecting to find in thorn forest so I was surprised to see this female on a snag at the thorn forest ecotone. In addition to dry forests, this species is found in a wide variety of forest types including mangroves. This species is a congenitor of the larger Pileated Woodpecker.


Moving back to the passerines, here’s the beautiful Cassin’s Kingbird, sitting in the thorn forest canopy. This is arguably one of the most distinct of the yellow-bellied type Tyrannus kingbirds.


The beautiful Golden Vireo is a west Mexican endemic found mostly in drier forest types although here seen in semi-humid forest.


The Rufous-backed Thrush, a.k.a Rufous-backed Robin, is another west Mexican endemic although they do occasionally stray northward across the Mexican border into the ABA area. They are very common and use a variety of forest types including thorn forest. Like the American Robin, they are attracted to fruiting bushes and trees as shown here.


The Rusty Sparrow is one example of many sparrow species that utilize the dry forests and scrub


There are also Passerina buntings in this habitat type. The remarkably gaudy Painted Bunting on the right is a winter visitor to western Mexico but breeds in northeast Mexico. The Orange-breasted Bunting is, you guessed it, yet another west Mexican endemic. In case you are wondering by now, west Mexico’s dry forest habitats are surrounded by barriers: the continental divide to the east, the true desert to the north and dense rainforest to the south. These barriers are the biographical trigger for such extraordinary endemism, having separated the gene pools of many ancestral species to evolve in isolation on either side of their respective “fences”. This is also why some of the endemics, especially the ones with more specialized habitat requirements, are so range restricted. Of course, some other species have surmounted these barriers and have ranges that extend into northern South America, e.g. some coastal birds and waterbirds find suitable habitat and a ready means of dispersal along the coast.


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