Antbirds, Antwrens, Antthrushes, Antpittas, and Antshrikes, oh my!

An army ant solider. (Eciton) You can see the reduced eyes quite well in this picture, army ants are effectively blind: they must smell and feel for prey.

As a kid, for whatever reason, nothing said the unexplored  jungle like army ants. I didn’t know all that much about them, just that they were these carnivorous ants that ravaged the forest floor. They were like quicksand, giant anacondas, piranha, or predatory cats; a near mythical denizen of the jungle that any would-be explorers would have to be mindful of, and avoid. (Think Indiana Jones and the Kingdom of the Crystal Skull)

Army ant Workers (Eciton) moving in a line. Their high organization makes these ants really interesting to watch.

The term army ant actually applies to many different genera of ants and  more than 200 species. They are linked by convergently evolving the trait of “raiding”, that is that they move in large numbers along the forest floor hunting for food. The most archetypal army ants is Eciton. Contrary to the visions of giant flesh-eating ants dancing around in my head as a kid, they are actually quite small when compared to something like the bullet ant, which also commanded legendary status in my mind as a child. (though saying that, army ant soldiers are as big as the largest temperate carpenter ants I have seen) Eciton are extremely polymorphic; there are  tiny workers only a fraction of the size attained by soldiers. Unlike a typical ant, they don’t make a nest in the ground; they clump together forming a nest out of workers, complete with passages and chambers, all  to protect the queen and the brood, in a structure known as a bivouac. They do this because when rearing brood they require a huge amount of food and have to move daily. Once the larvae pupate, they can settle down and stay in the same patch for a couple weeks. They also don’t breed like normal ants. To reproduce the colony breaks up with new queens taking a full complement of workers and soldiers with them when they leave, in a process called fission.

An army ant solider guarding a trail of workers.

While any person wondering the neotropics has little to fear from these ants, (I myself got stung by a couple and was surprised to find it fairly weak) arthropods in the leaf litter and understory shrubs do. They flee before the front, hoping to outpace the fast moving swarm. This is the really interesting part; army ants are such a force in neotropical forests that many other species from a wide range of taxonomic groups have become associated with these ants, taking advantage of these fleeing arthropods. Parasitoid wasps fly just ahead of the swarm, hovering like military helicopters, laying eggs is the very visible insects rushing away. Flies fill the air waiting to lay there eggs in anything substantial they do not eat, like vertebrates they kill by chance. Along with these arthropods, larger animals also take advantage of these ants.

Zeledon's Antbird (Hafferia zeledoni) at an ant swarm. This antbird can be found at mixed flocks, as well as by ants.

Many birds have learned that these ants stir up insects, and so follow these raids. These birds are kleptoparasites, stealing food that the ants would otherwise get. In my own experience various woodcreepers hang on tree trunks above the ants, puffbirds wait on the branches above, and gray-headed tanagers hang in the understory. Several groups of birds though are named for their association with ant swarm; antbirds often hop between pieces of wood, lianas, and shrubs while antthrush strut around like they own the place.

Two different antthrushes: the Black-headed Antthrush (Formicarius nigricapillus) and the Black-faced Antthrush (Formicarius analis). These birds move like little forest rails, and sort or strut around ant swarms

Birds with an ant prefix include: antbirds, antthrushes, ant-tanagers, and antpittas. Antbirds (family thamnophilidae) are further divided up into antbirds, antshrikes, antvireos, and antwrens. What can be a little confusing is a lot of the birds in these groups are not associated with ants at all, preferring to hunt for food without the aid of ants. Some of these birds join into mixed-flocks with other birds and they all forage together, while others hunt alone or in pairs.

Two birds named for ants that are not common at ant swarms: The Black-cheeked Ant-tanager (Habia atrimaxillaris)and the Barred antshrike (Thamnophilus doliatus). The Barred Antshrike sometimes will join ant swarms, while the ant-tanager, which is endemic to the Osa Peninsula, is not well understood.

    Costa Rica is home to a variety of both army ants and ant associated birds. One antbird though stands above the rest in terms of its beauty and difficulty to see, the Ocellated Antbird (Phaenostictus mcleannani). It is considered an obligate ant follower, rarely straying from the swarm. This is unlike many other antbirds like Zeledon’s Antbird (Hafferia zeledoni) which though often found attending raids, can also be found foraging with mixed flocks or by itself. Of Costa Rica’s some 900 bird species, the Ocellated stood out as one of the species I most wanted to see. My journey took me from Monteverde, over the continental divide, and down to San Gerardo Station in the Children’s Eternal Rainforest. It is at mid-elevation overlooking the highly photogenic Arenal Volcano, and stands out as one of the most beautiful places I have ever been.

Arenal from San Gerardo Biological Station. This was one of the most beutiful views I have had the pleasure of witnessing.

    I had been brought to Costa Rica on a study abroad program through the

Council on International Educational Exchange (CIEE) on a tropical biology and conservation program over the summer. This program, which began in the early 90s, has been exposing students to the tropics and allowing them to do independent research. I feel privileged to be able to be part of this. We were doing a four day field trip to the Station, to marvel at the Atlantic Slope, which was going to be the only time we ventured over to this side. This would be my shot, during free time, to try and find this king of the antbirds.

Bicolored antbird (Gymnopithys bicolor) in the Osa Pennisula. This little bird was at every ant swarm I have come across.

  My approach was to find the ants. If the Ocellated is an obligate follower, then if I find the right swarm, then I find the bird. It took me until the 2nd day to find the ants. They were moving into a pile of logs and other debris, forming their nightly bivouac. If they were camping out for the night, then that probably meant they were raising larvae, and so more attractive to antbirds. While I watched them move in, carrying their brood and some meat, (One large worker was dragging the head of a centipede that I certainly wouldn’t want to tangle with) a few birds hung around. My guess is they where some smaller antbirds, but I really didn’t get a good look at them. I did some macrophotography with the ants. I have been rapidly improving with my skills at macrophotography over the last year, and have already taken even better pictures of Zion Snails than those on the post from Spring 2018.

The next morning I headed to the swarm after breakfast. I arrived to see the raid in progress. Several lines of ants crossed the trail from the wood pile and into a patch of heliconia. In the thicket, I could hear an antthrush, and what could have been the Occelated. I wanted a visual though, since the Bicolored antbird sounds very similar. I began looking for either a way to look into the patch from the trail or a relatively open patch of forest to get up to the swarm. I quickly realized that there was no easy access into the patch. I thought about diving right into the heliconia recklessly, but I began thinking about all the potential venomous snakes and spiders that might be on the foliage. I then reasoned that the army ants would have chased off or killed anything I didn’t want to be bitten by, so I decided to follow there raid off trail. I entered into the heliconia, and began following alongside their line, I can understand why people use machetes. I followed them out into a more open area, where the center of the swarm was located. Everything was covered in ants, from the leaf litter, fallen branches and even the heliconia. The air was thick with mosquitos and flies. (my elbows are covered in mosquito bites as I write this) I quickly spotted a Zeledon’s antbird in the clearing. Ants began to get into my boots and up my pants, and I got stung. (but now I can say I have had army ants in my pants)

The Ocellated Antbird. (Phaenostictus mcleannani) This was the best of the 3 pictures I got of the largest and most beutiful antbird in Costa Rica.

    Then I saw it, an antbird with dark scalloping. It perched low on a branch in thick foliage. Like I had heard, it stayed right in the center of the swarm. Like many understory birds I found the Ocellated Antbird quite difficult to photograph. In the understory it is dark, and this particular bird also stayed in fairly thick foliage. I also spied a Bicolored antbird in the swarm, and many Zeledon’s antbirds. One was quite young, still having a gape. (a feature of young birds) The swarm began to move on, and the ocellated moved out of the clearing. The ants were heading down a slope that I certainly didn’t want to try to go down. I also had to get back to the station, so I began to work my way out of the thicket and back to the trail.

Sources

Franks, Nigel R.; Hölldobler, Bert (1987). "Sexual competition during colony reproduction in army ants". Biological Journal of the Linnean Society. 30 (3): 229–43. doi:10.1111/j.1095-8312.1987.tb00298.x.

Garrigues, Richard and Dean, Robert (2014) “The Birds of Costa Rica second edition” Zona Tropical Publication ISBN 978-0-9816028-8-2

Trouble With Trogons

The Elegant Trogon (Trogon elegans) is on of the most colorful birds in the United States.

Few Birds in North America capture a birders imagination like the Elegant Trogon. Trogons are a birds found throughout the world's tropics. However, A few species can be found in more temperate habitats. The Elegant Trogon is the most Northerly living of trogons. Found mostly in the mountains of Mexico, it's range just barely extends into the United States in a few places. Their presence is a major draw to places like Madera Canyon; just check out the Santa Rita Lodge gift shop: Trogon pins, Native American Pottery depicting trogons, Trogon socks, etcetera. I caught Trogon fever, and took my high school graduation trip to southern Arizona. Not only that, I decided I wanted to finally get into SLRs to get a gorgeous picture of this exotic bird.

On the day I was here Madera Canyon felt like a "Lost World" with the peaks enveloped in clouds.

So my first shot at the species was in Madera Canyon, the first really mountainous stop in southern Arizona on the trip. Checking Ebird, the location to be was the Carrie-nation trail, which heads up canyon from the end of the canyon road. Two Sulfur-bellied Flycatchers flew around just above the parking lot. Waking up I saw my first bridled titmouse and saw the beautiful Arizona Sister butterfly drinking from the creek bed. Then from the above came the call of the Trogon. It is an unmistakable sound, which sounds, no joke, exactly like a barking chihuahua. Following the racket up the trail. I finally deduced it was on the hill side, so to get my picture I rushed up the steep slope through the poison ivy. There I set eyes on the bird, but as I lifted my camera he flew off his perch and into the canopy. After picking my way down the hill I heard the bird further away. The next year when I came back, I was talking to a guy staffing the Santa Rita Lodge gift shop and told this story, I learned this particular bird has befuddled many a birder, leading them to the top of his territory, calling the whole way, only to fly silently back to the bottom and resume calling; while being easily observed by average hikers. We then had a quick conversation on why the bird behaved this way, was it messing with birders, or was some behavior of birders actually more disturbing than people wondering by having a conversation. I figured someone shushing sounds a little like a Jay.

Hoodoos in Chiricahua National Monument, Arizona. These rock formations look very different than those commonly seen in the Colorado plateau region to the north. I live the green on the dark rocks, gives it an "exotic" look

After my failed attempt to get my sought after picture in Madera, I headed east to the Chiricahua Mountains. This little mountain range has some truly spectacular hoodoos, and a great variety of Mexican Birds. Trogons appear to be pretty uncommon on the Western side of the range, in the national monument. However, on the eastern side, Ebird indicated that Cave Creek Canyon was where trogons could be seen. Driving over the top of the Chiricahua Mountains is a highly recommend place to go birding, on the way up I got the red-face warbler. The descent into Cave Creek was a bit rough and steep and wore the breaks off the car. The place to go is the South Fork of Cave Creek, an abandoned washed out road. On the journey up an A-10 Thunderbolt flew through the canyon at low altitude. Eventually though I turned around to head off to the Cave creek lodge, which has feeders that bring in many species. Talking to them they said the Trogon had been sited in the South fork that day so I went back. Around a pair of cabins (which I joked would be a great place to own, and have Trogon nest boxes) the barking began and a male Trogon flew down to road at me. I finally got my Trogon shots I had wanted, but they were far from perfect.

An Elegant Trogon Perched above me in the South Fork of Cave Creek Canyon

The next year I enrolled in a Desert Ecology class through University, and headed back down for spring break. We got to stay in the Santa Rita Experimental range in Florida Canyon, right next to Madera. Better yet, a Trogon was seen regularly only a few hundred feet from where I was sleeping. I went out every day when I had free time. Yet the Trogon never showed up. Finally, one night I was waiting with one of the TAs in the parking lot where the bird had been seen; we were with a group of birders also looking for it. We ended up discussing the really rare animal of the Santa Ritas, a jaguar which had been detected by camera traps, and was the only Jaguar known to currently be wild in the United Sates. After they left as the sky darkened, the trogon burst across the parking lot calling loudly, disappearing just as quickly into the gloom.

Several Goldfinches Perched on Ocotillo Plants. The Ocotillo may be may favorite plant in the Sonoran Desert.

It was finally down to the last day of the class, we would be headed up north the next mourning. During the heat of the day I got the ABA rarity, the Black Capped Gnatcatcher, which were down the road in a very rocky wash. As evening approached and a large group of people from the class gathered to get the bird, I finally broke down and tried a recording. Recordings are definitely the “Jedi mind tricks” of birding, although maybe not outright bad, they are ethically muddy for sure. In Madera they are highly discouraged, as they have been known to habituate birds and probably fakes out birders. Ultimately, in my humble and inexperienced opinion should only be used to locate a bird you are having a lot of trouble with, like a Trogon you have been looking for a week. As soon as a particular recording rang out (which I will not share) the bird appeared. I got the camera up and started exposing images. After taking some incredible looking shots I did a quick check. To my horror the photographs were black and white. Somehow the dial has switched to creative. I quickly got it back to regular and took more shots. But the light was fading and High ISO led to some of the images being a little noisy. I took one flash shot, which ended up quite nice, although I felt it was a bit disturbing the bird, although it didn't seem to pass it or birds I have used it on since. In the end I spent a good long while with the Trogon, photography it as it worked it's way from Perch to Perch until it finally flew into the thicket surrounding the creek.

The most colorful bird in North America, in beautiful black and white. It is an amazing shot of a trogon, but sadly is in Black and White.

The black and white Trogon picture became a bit of a joke, and over time I have come to appreciate my folly. However, I would like to go back and do another photoshoot with this frustrating but exceptional bird.

Trogon Photograph taken with my onboard Flash. It turned turned out quite nice.

Trogon Tips

-listen for and know the trogons call, All of my sightings involved locating the bird by it's call. They disappear very easily if you don't have eyes on them.

-I would discourage using recordings, for three of the 4 times I have seen the bird l, I have not needed them, they are fairly vocal especially when most people are birding in the area so recordings are not necessary.

-When Trogons Perch they stay for about 30 seconds moving their head around, then fly off. This gives you the opportunity to get several shots with the head at different angles.

A nice picture taken strait on with the bird. This was among the last images before it took off into the gloom of dusk