Saturday, December 20, 2008

I can die happy now

In the months leading up to my Venezuela trip, I spent a lot of time on google researching the llanos and its wildlife. This lead me to discover the photo album of Matt, a field grunt on the Forpus project the year before me. Particularly I was stoked to see this photo. What an awesome place Masaguaral must be, with anacondas and crocs killing each other all over the place! I was giddy with excitement.

Fast forward to mid-October. I was half-way through my stay at Masaguaral, and I had largely exhausted herp diversity. As far as snakes go, I had seen only a handful, representing only three species. Anacondas were nowhere to be found, despite abundant habitat and frequent searches of places staked out by the llaneros for me. They even showed me the anaconda door in the croc pens (a hole in the barbed-wire fence) and where the 'conda frequently enters to bask. No luck, despite checking every time I passed the place. I was getting worried.

Then one evening before dinner, Elysa comes in after talking to the ranch manager. You want to see an Anaconda? she says. Well... YEAH!!! I say. So I grab my camera and headlamp and rush out the door. The results...

A huge anaconda (Eunectes murinus) with a Spectacled Caiman (Caiman crocodilus) in its death grip! Awesome!!! The whole time we watched it there was almost no movement at all. At least, until I leaned a bit too close and she stuck up her head to take a look. Not wanting to mess, I backed down.

There wasn't any struggle from the caiman, because he was already very dead. Just look at the angle the head makes with the long axis of the body, or the look on his face:

More 'conda pictures for your enjoyment:

We watched these beasts for a while before we got bored with the lack of movement. I came back later in the night just to see the progress, and nothing had changed. The ranch manager (thank god he tipped us off!) said the last time a kill like this happened, the anaconda was present for two days before getting the caiman swallowed and moving on. So, I went to bed, but not before capturing my favorite shot:

In the morning, 'conda and caiman were gone, with only displaced vegetation on the pond's edge to mark the scene of the struggle. She's somewhere out there, digesting, and I couldn't be happier.

Sunday, December 7, 2008

Nature Fight!

The life of a Green-rumped Parrotlet (Forpus passerinus) is not an easy one. Adults face a constant risk of death by tooth and talon, and their nests are easy targets for all manner of raiding predators. The long-running Forpus project has generated empirical knowledge about mortality rates, predation risks, competition, and the life-history strategies parrotlets have adapted to survive them. I’ve broken the struggles of the parrotlet into three rounds:

Round 1: Finch vs Parrot! (Interspecific competition)

Many other species attempt to make use of the parrotlet nestboxes for themselves, providing competition for a limited resource – nesting sites. Several different types of ants frequently colonize the woodchips in the bottom of the nest box. Various small mammals including rats and mice build grass nests in the boxes. Wasps and bees use the PVC boxes as anchor points to build colonies (we abandon any hope of checking those boxes until they clear out on their own!). Several bird species also think the parrotlet nest boxes make good homes – Myiarchus flycatchers, the Straight-billed Woodcreeper (Xiphorhynhus picus), and the Saffron Finch (Sicalis flaveola) being the most common. We try to empty out the nest material of these species before they get an egg laid (we are here to study parrotlets, not finches!), but sometimes they beat us. This Saffron Finch nest was particularly crafty and had us stymied for a while, so we let them breed. This pair, instead of lining the bottom of the chamber with plant fibers, somehow built a platform and a nest suspended right up by the entrance of the box.

The woodcreepers have also snuck a few nests in this year. They line the boxes with woodchips, making for a very distinctive nest.

In September I saw some parrotlets decide they liked a box occupied by woodcreepers. A woodcreeper was brooding three chicks unseen inside the box while her partner was off foraging. The parrotlet pair, in typical prospecting behavior, approached the box, chattering. They sat on the top, looking down at the hole, then moved down on the perch and looked nervously inside. At this the woodcreeper came up and sat in the hole, with a chick’s fecal sac in her beak. The parrotlets retreated to the top of the box and the fence, chattering. It was something of a standoff for several minutes – the woodcreeper in the box, not leaving because of the parrotlet overhead, and the other woodcreeper on a nearby tree trunk, calling, bill full of invertebrate prey. Eventually the parrotlets gave in and flew off, allowing the woodcreepers to reunite and feed their nest.

Generally, this kind of interspecific competition for nest sites doesn’t lead to violence. How about something with a bit more blood?

Round 2: Snake vs Bird! (Predation)

The most obvious mortality risk to a parrotlet of any age is predation. Parrotlet nestlings and eggs fall victim to snakes (including the boids Boa constrictor, Epicrates cenchria, Corallus ruschenbergii, and the colubrid Spilotes pullatus), mammals (including the lowly Rat (Rattus rattus) and the mouse opossum (Marmosa robinsoni)), and even nasty carnivorous ants (any entomologists want to join the project?).

On average, a little less than 40% of the parrotlet nests monitored by the project failed without fledging young. Of these, the proportion of failures due to predation varies year to year, but somewhere between 10 and 30% of the nest failures are due to predation, which is concentrated mostly when the parrotlets have nestlings and are frequently away collecting food. The impact of snake predation on the Forpus project can be significant when nests under observation get hit, so we catch and relocate any potential snake predator we can. This means I get to play with more snakes! The most common snake I found in the parrotlet boxes is Leptodeira annulata, all of which have been too small to pose much of a threat to the parrotlet nests except maybe to the eggs. I’ve even found them residing in the bottom of a box underneath an active nest.

The next most common snake I found is the tree boa, Corallus ruschenbergerii. I recovered three of these lovely guys from boxes (none with active nests) and relocated them to distant forest patches.

The third snake I caught in the act. While approaching an active nest, I noticed both adults sitting on the surrounding fenceposts, quiet. Thinking this was odd, I stopped and realized there was a snake crawling up the fencepost and across the top of the nestbox. It was a gorgeous adult Chironius carinatus. I chased it off the box, but it kept the fence between us and escaped up a tree. Later I cornered it in the tree and got some pictures of it, before it again saw fit to flee.

We know less about adult parrotlet survival, since it is impossible to separate emigration from the study area from death, but we can make some estimates. Sandercock et al. (2000) estimated an average local survival rate on the parrotlets at Masaguaral of 0.56, meaning a little more than half of the adult population persists locally each year. As you might guess from these data, Green-rumped Parrotlets are not very long-lived, with the oldest individuals monitored by the project reaching an old age of around ten years.

Adult parrotlets have plenty to fear from the predators that also attack their nests, but they also face aerial predators outside of the box. Aplomado Falcons (Falco femoralis), Savannah Hawks (Buteogallus meridionalis), and Roadside Hawks (Buteo magnirostris) are known to attack adults or recently fledged parrotlets. I myself witnessed an unsuccessful Aplomado Falcon attack on a parrotlet, and I’ve seen plenty of strafing runs from the resident pair.

Round 3: Parrot vs Parrot! (Intraspecific competition)

Even if a parrotlet succeeds in claiming a nestbox for its own, even if it avoids the attention of any predators as they raise their young, they may still fall to their most vicious foe: another parrotlet’s beak. Competition for nesting sites is fierce, and these tiny, compact little birds are actually quite vicious to one another, putting those powerful parrot jaws to good use (as my band-aid covered fingers can attest). Prospecting pairs looking for a suitable nestbox will destroy any unattended nests they happen across, breaking and burying the eggs. An experiment (Beissinger et al 1998) placed extra boxes containing eggs along the fences to monitor the rate of nest destruction. 40% of these unguarded nests were destroyed by prospected birds within 72 hours, a third of those were destroyed on the same day the nest was placed in the field.

Beissinger et al. believe this rate of destruction is one of the factors influencing parrotlet breeding biology. Parrotlets begin incubation on laying the first egg, and space their eggs out every 1-3 days. With large clutch sizes (7-10 eggs), this creates a huge asynchrony in hatching. The first egg hatches not that long after the last egg is laid. It is believed that limited nesting opportunities (rotten stumps) drives this fierce competition for nests and frequent nest destruction, which in turn drives females to incubate earlier, because Beissinger’s studies have also shown that a female’s presence significantly reduces the rate of nest destruction.

Even worse than destruction of eggs is what happens when nestlings are targeted. Sometimes prospecting birds can actually stage a takeover of a box, killing of the nest and driving away the parents. Infanticide also happens when a member of a pair is killed or otherwise goes missing, and the remaining parent cannot defend the nest. Somehow the other parrotlets in the neighborhood quickly discover these undefended nests, and flocks of lone males and prospecting pairs can bring a whirlwind of chaos down on them. Sometimes the lone bird persists in defending the box and raising the young, or selects a new partner and starts over. The bloodiest result, as I observed at B106, is when the parent is driven off and the whole nest killed. Infanticide is a really nasty business, as the following pictures of a massacre at Box 106 show. All of the nestlings were killed by bites on the head and cleaving off the beak, the mark of infanticide in parrotlets.

Well, I think that is a good note to end this post on. I hope you enjoyed a glimpse of the dark side of parrotlet study.


Beissinger SR, Tygielski S, Elderd B (1998) Social constraints on the onset of incubation in a neotropical parrot: a nestbox addition experiment. Animal Behavior 55:21-32

Sandercock BK, Beissinger SR, Stoleson SH, Melland RR, Hughes CR (2000) Survival rates of a neotropical parrot: implications for latitudinal comparisons of avian demography. Ecology 81(5):1351-1370

Stoleson SH, Beissinger SR (2001) Does risk of nest failure or adult predation influence hatching patterns of the green-rumped parrotlet? Condor 103:85-97

Waltman JR, Beissinger SR (1992) Breeding behavior of the green-rumped parrotlet. Wilson Bulletin 104(1):65-84

Saturday, December 6, 2008

I'm Back!

I've been back in the states for a week now. I immediately dived back into work in the lab, while my evenings have been spent organizing photos, editing videos, checking taxonomy... so, posts are coming soon! Stay tuned.

As a side note, does anyone know why my photobucket images have suddenly become enormous?

Thursday, November 20, 2008

Random, Fun Kenya Pics

*Note: Text and all photos in all Kenya posts are by Shawn Billerman unless otherwise noted.

This post has absolutely no story to it, just a bunch of random pictures that I wanted to share that didn't really fit in with any of my other posts... (if any of these pictures have appeared in other posts, its just because I forgot I've used them)


A tray full of Vitelline Masked Weavers (Ploceus velatus) and Yellow-spotted Petronia (Petronia pyrgita) coming to fruit at our camp; Fork-tailed Drongo (Dicrurus adsimilis) in camp; Egyptian Goose (Alopochen aegyptiacus) (all 3 of these photos by Jess Marion)

White-throated Bee-eater (Merops albicolis) part of a flock of 3 or 4 birds that moved through camp one day; Another view of camp; View of the Research Center (note elephant poo scattered all over the ground); Namaqua Doves (Oena capensis) part of a group of 7 or 8 individuals that were occasionaly seen at the center

Finally, Jess (click here for her blog), who so graciously provided me with many of the bird photographs I used (and all the good bird photos I used)... Thanks Jess!

If I can get more bird pictures in the coming weeks and months, I will post them. Otherwise, here is a link to our class website.

Sunday, November 16, 2008

The Final Kenya Blog

*Note: Text and all photos in all Kenya posts are by Shawn Billerman unless otherwise noted.

So, with Nick still away, and me finally having a break from classes, I thought I would finish up some of my Kenya blogging. Hope you have enjoyed these guest posts!

Day 15-16 – July 9-10 2008

I realize that I am jumping ahead multiple days at a time, but, to be honest, not much happened in those other days. I added few new birds in those days, and we pretty much just worked on our final projects and papers. One new bird that I added that requires a bit of recognition though, is the African Green Pigeon. This was a bird that I very much wanted to see, but didn’t think I would. But, one morning, I woke up, and wandered around my tent before breakfast, and noticed a dark lump of a bird in a snag just across the river. I saw it, and thought it looked pigeon like, but hadn’t recalled seeing Speckled Pigeons around camp at all. Since I was looking east, the bird was very silhouetted, so I walked down-river a bit, and looked back, and, lo-and-behold, it was GREEN! As I was watching it, it flew upriver a bit, out of sight. I went back to my tent, and looked up, and there were 2 Green Pigeons right across from my tent. As the sun came up over the hill, I got much better looks at them, and I just sat, staring at these birds for a good 20 minutes. As I was watching, it suddenly got very foggy, and cloudy. With the sun covered, I was able to get more detail on the birds. I finally made my way to the mess tent, elated with my sighting.
African Green Pigeon (Treron calva) (photo by Jess Marion)

Anyway, back to Day 15… this was our last full day in Kenya, our last day at Mpala, and thankfully, we had no work left to do! This was a day for a game drive and some clean-up. We went to the hippo pools again (well, I went again, the class went for the first time), and got to see most of the hippos lounging on the far shore of the pool, some grazing on the bank. Others still were in the water, but most were out on the bank. Surprisingly, I added 4 new species to my trip list that day, including Common Sandpiper (my first, and only Scolopacid for the trip), Red-chested Cuckoo, African Hawk-eagle, and a group of 4 Pink-backed Pelicans that circled overhead. Also around were a group of Green Wood-hoopoes, a flock of 15+ Red-billed Oxpeckers (some foraging on the hippos), and the Malachite Kingfisher I had seen on my birthday. There was also a Hamerkop roosting on the far shore, which was actually one of the few I saw not flying (most mornings I would see a pair flying upriver by camp).

Hippos and hippo watching; Habitat at the hippo pools; Malachite Kingfisher (Alcedo cristata) (really, its there); Hamerkop (Scopus umbretta) (photo by Jess Marion)

From the hippo pools, the plan was to do the typical airstrip loop, but those plans fell through when Dustin’s brakes stopped working. We all then piled into Irby’s van (all 12 of us, plus Harry, Ben, Jamie, and Colistus), and headed back to camp, while Dustin went to the center to get the brakes fixed. We spent the rest of the day packing, cleaning, and just getting ready to leave the next day. After dinner came our last bit of fun. We made smores, and Harry and Irby both sang to us, Harry with his “Be my little Warthog,” and Irby with his rendition of “My Humps,” by the Black-eyed Peas (altered, of course, to the more appropriate, “My Camel Humps”). I was pretty tired that night, since I was still getting over being sick the day before, so I went to bed after the main festivities, missing the planned pranks later in the evening.

Augur Buzzard (Buteo augur) (photo by Jess Marion)

The next day, we left the camp, and Mpala, by 8 in the morning. The ride back to Nairobi was pretty depressing. We made a brief stop on the Equator for some more shopping. Luckily, Dustin had given us a lesson in bargaining, so I did quite a bit better for myself.

Further south along the road, back into the greener forests in the hills, Irby stopped by this marshy pond on the side of the road for me, where I saw dozens of Common Moorhen, a few Grey Heron, Sacred and Hadada Ibis, more Yellow-billed Ducks, 5+ Black Crake, and three new species, Red-knobbed Coot, African Jacana, and White-faced Whistling-duck.

While Irby was traversing the busy streets of Nairobi, trying to get us all to the airport safely, I added my last bird of the trip to the list. Sadly, this was not even a life bird, or even an exciting bird in any respect; last bird to be added to the trip list from my spectacular trip to Kenya was nothing more than Columba livia, the Rock Pigeon. I tried desperately to see something else that would be new… anything, a swallow, a sparrow, anything, but, alas, my last bird was the Pigeon. Back at the airport, we said our goodbyes to the two Kenyan students who joined us, and to Dustin, Irby, and Jamie. Once we were through security at the airport, we had 7 hours to kill, so we did what any sensible tourist would do, and we shopped! We also ate, and sat around, and had a fun time recounting our many adventures. By 11:30 PM Kenya time, I was on a plane, leaving Kenya. But, I had an incredible time, and it was certainly a life changing experience.

For those who are interested, my final tally for the trip was 218 species of bird (of which 214 were new), in 72 families (of which 33 were new). Mammal-wise, my final tally for the trip was approx. 42, with highlights being Aardvark, Leopard, and a pack of 17 African Wild Dogs, along with seeing the classic African megafauna.

Sunset over Mpala

Thanks for reading about my adventures in Kenya! There will be more mini-posts about Kenya in the near future!

Wednesday, October 15, 2008

Not dead yet

If you´ve been wondering what I´ve been up to for the past few weeks, check out my guest post up at 10,000 Birds -

Forpus passerinus and the Ornithologists of Masaguaral

Wednesday, September 24, 2008

I Have Landed

Monday, 1 September 2008

The main terminal of the Miami International Airport has a cold, hard floor not at all comfortable for sleeping. At 4:30am, there is a gradual increase in foot traffic as people rouse themselves from slumber on chairs, against pillars and walls, and shuffle to the opening security checkpoints. I join them, trying to shake off the chills and aches from trying to sleep for two and a half hours in a corner of the well air-conditioned terminal.

Several hours earlier, I arrived in Miami from Syracuse (via Chicago) with Karl, bound for Caracas. We had settled in at the right concourse for our flight the next morning, when I realized I didn’t have any cash on hand. Wanting to withdraw from an ATM before I left the states, I wandered around the many concourses blindly looking for an ATM. I couldn’t find one, so I left the security section and perused the main terminal. I quickly found one there, disturbing the people sleeping nearby with the electronic beeps. It was then I turned around to discover the security checkpoints were closed for the night, necessitating my sleeping on the floor (instead the chairs in the concourse). I called Karl, still inside the concourse, and said goodnight.

That little mishap aside, our hopping series of flights was uneventful. The televisions were showing nothing but coverage from Hurricane Gustav making landfall in Louisiana. Tropical Storm Hanna was churning in the Bahamas, so I felt like we were barely squeeking through Florida between the two storms. They ended up causing no delays, and we took off as scheduled for Caracas, Venezuela at 7:20am.

The combination of cloud cover and me catching up on sleep prevented any sight seeing on the Caribbean overflight (I really wanted to at least see Hispaniola, whose endemic birds were the subject of my thesis). I awoke just in time for the descent into the Caracas airport, which is actually ~40 km north of Caracas on the Caribbean coast. We turned and flew in parallel to the coastal city of Maiquetia, consisting mostly of a narrow strip of flat land wedged between the sea and the steeply rising coastal mountains between there and Caracas. The landing strip looked like it was one series of dunes away from the sea.

Arriving in the airport around 10am, I went right to work. First birds of the trip were a couple blackbirds flying by outside, but I identified the Rock Pigeons (Columba livia) inside the terminal first. Is there no birding trip in the world without Rock Pigeon? I later identified the blackbirds as the omnipresent Carib Grackle (Quisculus lugubris), the first lifer of the trip.

The airline had misplaced one of our duffel bags, an important one with all sorts of adaptors and wires for electronics for the project, and decided it was probably on the next flight from Miami, 3 hours later. We decided it would likely be stolen if we had it shipped out to the ranch, so we decided to stay in the area until it arrived. We left the terminal and met up with Virginia, a Venezuelan ornithologist who also studies parrots who would be taking us out to the ranch and visiting for a few days.

Virginia took us down the coast to a nice restaurant, for lunch as well as to escape the hot, crowded airport and enjoy the sea breeze. Sitting right on the waterfront munching calamari, I started racking up my list. Carib Grackles were all over, foraging, calling, and standing around panting in the mid-day heat. Brown Pelicans (Pelecanus occidentalis) flew by up and down the coast, and at one point a Brown Booby (Sula leucogaster) coasted by close enough to identify without binoculars – lifer number 2!

While Karl and Virginia inquired about local hotels, in case our wayward duffel did not arrive as planned, I grabbed my binoculars and birded the trash-strewn abandoned lot next to the restaurant. In the trees across the street a Great Kiskadee (Pitangus sulphuratus) yelled its own name. Several bright yellow finchy birds flew around from the lot to the surrounding palms, singly sweet phrases. I tracked one down and found my first Saffron Finch (Sicalis flaveola). A Scaled Dove (Scardafella squammata) landed in the lot, providing my fourth lifer at lunch. I wanted to go grab my camera, but Virginia insisted I would be sick of these birds soon enough, why don’t I wait until a better landscape than a trashy lot? She was right, it turns out.

The lovely trash-strewn lot
Scaled Dove (Scardafella squammata)

A flock of shorebirds landed in the wetter portions of lot, prompting Virginia and I to investigate. 10 or so Wilson’s Plovers (Charadrius wilsonia) walked the dry portions of the lot on the way over. In the little muddy depressions walked a couple Greater Yellowlegs (Tringa melanoleuca), a Solitary Sandpiper (Tringa solitaria), a Least Sandpiper (Calidris minutilla), several Semipalmated Sandpipers (Calidris pusilla) and one peep that I identified in the field as a Baird’s Sandpiper (Calidris bairdi). I later learned from the Hilty guide that Baird’s has only a handful of unconfirmed records from the country, making me doubt my identification without a scope look and a photograph to check.

In the late afternoon thunderstorms clouded around the mountaintops looming overhead, dispersing the vulture flocks and coming down to drench us. Luckily by then we had retrieved our bag from the airport and were on our way. It was much to late in the day to drive all the way to the ranch, so we decided instead to crash at Virginia’s apartment in Caracas. I slept the whole ride, waking when we parked. Virginia’s apartment is on the sixth floor of a relatively short apartment building. Out her living room window I had a nice view of four 30-story apartment buildings but not much of the rest of the city. Blackouts had plagued us on the coast and here in Caracas, but power returned by the time Karl and Virginia returned from grocery shopping with dinner. A frog chorus of unidentified origin (they sounded a lot like the Spring Peepers from home) helped drown out the city noises while we slept.

The view from Virginia´s apartment

Dawn of the 2nd was much birdier than cities in the states. Many apartments, including Virginia’s, had gardens on their balconies or windowledges, attracting feeding Bananaquits (Coereba flaveola) and Blue-Gray Tanagers (Thraupis episcopus). Ruddy Ground-Doves (Columbina talpacoti) called from rooftops, and I spied a species of Myiarchus Flycatcher in a neighbor’s tree. Parrots shrieked from neighboring trees and swallows flew around overhead, but I did not manage to identify any before we hustled off southward to the llanos.

Still catching up on sleep, I dozed on most of the five hour drive. Black Vultures (Coragyps atratus) were a constant presence when I was awake. A stop for breakfast (arrepas, much like frybread from the reservation) produced more Carib Grackles and a few Tropical Kingbirds (Tyrannus melancholicus).

The foothills at the edge of the llanos

I missed most of our descent out of the coastal mountains, but managed to catch our movement through the capital of Guarico and the foothills of the llanos. Soon the lanscape flattened out into the scattered forest, ranchland, and flooded grasslands of the llanos. Karl was much more adept at drive-by bird spotting than I was in my drowsiness; I missed Oriole Blackbird (Gymnomystax mexicanus) and Gull-billed Tern (Sterna nilotica) which could’ve been lifers.

We made it to the front gate of Hato Masaguaral by midafternoon. On the kilometer-long dirt road winding through pasture and skirting a vegetation-choked wetland, I got my first glimpses of what would become commonplace: Pied Water-Tyrant (Fluvicola pica), Southern Lapwing (Vanellus chilensis), Cattle Tyrant (Machetornis rixosus), Fork-tailed Flycatcher (Tyrannus savanna). I got all of my gear thrown in my room, and after a hearty meal we all walked out to front pastures again to start getting acquainted with the place and with the Forpus project. I had arrived.