Thursday, February 27, 2014

Season Highlights

Although it certainly doesn't feel like it, a full month has gone by since the NPARS team returned to North America from its latest excursion to the American tropics.  For seven weeks, our team of volunteer researchers lived and worked on the Nicoya Peninsula of northwestern Costa Rica collecting important data on neotropical birds.  To officially close the research season, I'd like to look back at some of the highlights of the trip, including some of my favorite photos of and encounters with birds and other wildlife.

American Crocodile (Crocodylus acutus) near our banding site at Refugio Curu
Scarlet Macaw
This Crab-eating Raccoon (Procycon cancrivorus) paid the
banding station at Refugio Curu a visit just after Christmas
Occasionally we would have slow days at the banding station, which would give us opportunities to divert our attention to things other than birds.  No matter how much time we devote to looking, the tropical forests of Central America never fail to offer something exciting and new - especially when we turn our attention to the small and easily-overlooked.

Nogodinid Planthopper Nymph
Occasionally we encountered the remarkable-looking planthoppers of the family Nogodinidae.  Nymphs of these planthoppers grow long, waxy filaments that resemble optical fiber from the tips of their abdomens.  This feature has earned such nymphs the informal nickname "fluffy bums".  The exact function of these wax-like filaments remains unknown, although they may provide a defense somewhat like the detachable tails of lizards and geckos; an attacking predator may end up with a mouthful of wax rather than the insect itself.  If disturbed, these planthoppers will catapult themselves into the air with an audible 'POP'.

Dead Leaf Katydid (Mimetica sp.)
Bark Mantis (Liturgusa sp.)
Caterpillar 'feet' (Automeris sp.)
A lot of people have been asking me how we get the shots with white backgrounds; the method used involves photographing subjects on a sheet of translucent white plastic, which is illuminated from above and below using remote-controlled flashes.  The goal is to have an evenly-lit subject on a perfectly white background, free of shadows.  I'm an amateur when it comes to this mode of photography, and experienced photographers can have much more elaborate (and innovative) studios.  Twan Leenders, president of the Roger Tory Peterson Institute, constructed a field studio from the back of his rental car while he was visiting the banding stations, and used it to photograph banded birds prior to their release.

Twan Leenders photographing birds in a field studio
Prothonotary Warbler - Photograph © Twan Leenders; used with permission
The team completed its third unofficial Christmas Bird Count on January 11th.  Since there is no official Audubon Count Circle in this region of Costa Rica, we decided to make this year's bird count purely a numbers game with the object of seeing as many species as possible.  This sort of birding has little scientific value, but it's a great way for the team to take a break from research, practice their identification skills, and have a great deal of fun.  After a session of serious strategizing at the Finca the night before, we had laid out an agenda for the following day to cover as many habitats as possible and maximize our species potential.

Chestnut-sided Warbler
Snowy Egret at the ferry in Paquera
We birded for nearly twelve hours, and had visited sites along the entire eastern coast of the Peninsula.  By the end of the day we had a total of 128 species, just seven species behind last year's high count of 135.  Just like last year, the final species of the day was a Pacific Screech-Owl singing in the yard at Finca Pura Vida just after dark.
Pacific Screech Owl, # 128 on our Christmas Bird Count
Most reptiles and amphibians are active at night, making this the best time to find them.  We spent several late nights cruising the roads after dark, which is a good way to cover a lot of ground and spot critters more easily against the asphalt.

On a particularly slow evening, when we were about to turn the car around and call it a night, "WHAP!" - something large, about the size of a baseball, fell 40 feet from the trees above the road and landed on the car.  When we stopped to look, attached to the passenger-side mirror was Costa Rica's largest tree frog, the Veined Tree Frog (Trachycephalus venulosos).  This species can, when disturbed, secrete copious amounts of a sticky, irritating milky liquid (hence its Spanish common name Rana Lechera, or Milk Frog).  Incredibly, the frog remained healthy and intact after its encounter with our car.

Veined Tree Frog (Trachycephalus venulosus)
During a two-day visit to the Karen Mogensen Reserve in the mountains of the Nicoya Peninsula, we found, among other things, a gorgeous Tropical Kingsnake (Lampropeltus triangulum); these snakes are spectacular mimics of the venomous Coral Snake (genus Micrurus).  Although kingsnakes are completely harmless, their strong resemblance to the "real thing" causes most would-be predators to opt out.  Even though we have both Kings and Corals here on the Nicoya Peninsula, this was our first encounter with L. triangulum since we began the project.
Tropical Kingsnake (Lampropeltus triangulum), a convincing Coral Snake mimic
The author with a Coral Snake in 2012; photograph © Jared Flesher
Hummingbirds aren't the only creatures that enjoy our nectar feeders at Finca Pura Vida; after dark, nectar-feeding bats come in droves to sip sugar water.  One night when we had the mist-nets open at the feeders to capture and photograph bats, we had an incidental capture of an insectivorous (insect-eating) species we'd never seen before, the Black-winged Little Yellow Bat (Rhogeessa tumida).  "Little" seems to be an understatement, as this bat was minuscule, about the size of a hummingbird.

Black-winged Little Yellow Bat (Rhogeessa tumida)
We also found that it was carrying a tiny hitchhiker called a Flat Fly, a type of parasitic fly that we find often on birds in North America.  As their name suggests, Flat Flies (Family Hippoboscidae) are dorsally compressed, allowing them to navigate the spaces between feathers or fur with unsettling speed, thereby avoiding the beaks, claws, or teeth of their hosts while they groom themselves.  Most species are host-specific, meaning they may only be found on one, or at most few, host species.

Flat Fly (Hippoboscidae) found on the
tail membrane of Rhogeessa tumida
Even after some editing, I have nearly 10,000 photos from the trip.  For my parting shot, I discreetly took this photo of NPARS's co-director Sean Graesser and banding technician Benny Jacobs-Schwartz photographing birds near Monteverde.  It's hard to convey these seven weeks of experience in one blog post, and harder still to articulate just how special this area of the world is; but if I had to try using a single photo, it would be this one: