Science and Research, Sea Turtles / 13.11.2012

By Katie Mascovich [caption id="attachment_4646" align="alignleft" width="300"] The green sea turtle's wounds are healing naturally[/caption] No two night patrols on the Osa are the same, but they usually have the same rhythm. Every now and then, however, something unexpected happens that makes the whole night worthwhile. On November 3, I had one of these experiences. But to fully understand it, I have to tell you about the patrol I had on October 21. That night I was patrolling Pejeperro Beach with Emily, another Research Field Assistant. It was one of those long nights where we knew we would not be back to the station and in our beds until dawn.
Science and Research / 26.10.2012

While the Osa Peninsula, rich with biodiversity and sheer beauty, is a wonderful place to kick back and relax, there are numerous opportunities for visitors to catch a glimpse of some of the world's most fascinating reptiles. Some of which, like the Terciopelo, can be especially hard (and dangerous) to spot. The Terciopelo is a beautiful dark grey, brown or olive green snake, with a dorsal pattern of triangular designs on both sides of its body, resembling a letter 'X' visible from above. It’s a large snake that can grow up to 250 cm (over eight feet!) in length, although the average adult is between 140 and 180 cm (4.6 to 5.9 ft) long. The females are much longer than the males. It principally eats small mammals and birds. The species is viviparous, which means that the embryos grow inside of the mother and are born fully formed. Furthermore, the snake is very fruitful; it can give birth to up to 90 offspring. This high fertility explains in part why the Terciopelo is one of the most abundant snakes in Costa Rica.
Marine Conservation, Science and Research / 12.10.2012

[caption id="attachment_4566" align="alignleft" width="300"] Mogos Islands mark the highest waters of Golfo Dulce.[/caption] By Brooke Bessesen While Jorge and I both loved working on the water, the results of our research brought the greatest rewards. Golfo Dulce is a true bio-gem—one of Costa Rica’s preeminent riches. Several hundred Green sea turtles, critically endangered Hawksbill sea turtles, Olive Ridley sea turtles and (reportedly) Pacific Leatherback sea turtles, rest, feed, mate and nest in the gulf. A rare xanthic colony of pelagic sea snakes resides around the inner basin. Both Northern and Southern Hemisphere Humpback whales enter the inlet to give birth and possibly provide sanctuary for young calves. Whale sharks aggregate in Golfo Dulce. Resident dolphins and other toothed cetaceans breed and raise offspring. Scalloped hammerhead sharks are born there and needlefish spawn. What a remarkably vibrant bionetwork!
Science and Research / 14.09.2012

[caption id="attachment_4406" align="alignleft" width="241"] The view from Cerro Osa[/caption] We at Osa Conservation would like to extend a warm welcome and congratulations to Samantha Weintraub, Kevin Smith and Juan Manuel Ley, this year’s Greg Gund Memorial Fellowship recipients. Osa Conservation’s Greg Gund Memorial Fellowships provide funding for Costa Rican and international researchers to conduct science-based research in the Osa Peninsula. These fellowships are provided through the generous support of the Gund family. Kevin will be studying amphibian populations, communities and habitat in the southern part of the peninsula and will be developing materials for participatory amphibian monitoring projects on our properties in Osa. These will be a great tool to support of citizen science at our stations!
Marine Conservation, Science and Research / 30.08.2012

By Brooke Bessesen [caption id="attachment_4304" align="alignleft" width="300"] The name "Brown pelican" belies the attractive hues of a mature bird.[/caption] I’m sure it comes as no surprise that during our 400+ hours of observation in Golfo Dulce, Jorge and I witnessed an astonishing array of marine life. Indeed, we were astounded by the intense biodiversity revealed to us during our research. In addition to the animals I’ve already blogged about in this series, many more are worth mentioning. Some were officially documented, others were not, but all helped define our emerging portrait of Golfo Dulce. Brown pelicans (Pelecanus occidentalis) are commonly seen in Golfo Dulce and we located a year-round communal roosting area along the banks of Piedras Blancas National Park in the upper half of Golfo Dulce. We saw many other marine birds, too, including Brown boobies, magnificent frigates, osprey, several species of gulls, terns, swallows, herons, ibis and dozens more wading and estuary birds.
Marine Conservation, Science and Research / 19.06.2012

[caption id="attachment_3816" align="alignleft" width="315" caption="A video still of a Pseudorca, or false killer whale, in Golfo Dulce"][/caption] Brooke Bessesen conducted Marine research at the Osa in 2010 and 2011 as a recipient of the Greg Gund Memorial Fellowship. Check out her Golfo Dulce report on our website. Jorge and I were always thrilled to see dolphins, as they are icons of the sea. Luckily, sightings were relatively common (only sea turtles were seen more frequently) and these graceful cetaceans graced our bow almost every day we were on the water....

Marine Conservation, Science and Research / 06.04.2012

[caption id="attachment_2471" align="alignleft" width="300" caption="Side by side, you can begin to see the characteristics that visibly differentiate the three sea turtle species we documented inside Golfo Dulce."][/caption] When we began our research, nobody expected us to find very many sea turtles inside Golfo Dulce — most sea turtle activity was thought to occur on the Pacific side of the Osa Peninsula. It turned out that chelonids were the most frequently seen family of animals, accounting for 38 percent of our total sightings. Discovering such significant numbers of sea turtles was one of our most important findings. Sadly, fishermen with many years of experience in Golfo Dulce say the sea turtles there have declined at least 30 percent in recent years. Jorge and I documented three species: Pacific Black sea turtles, still commonly referred to as “Greens” (Chelonia mydas agassizii), Olive Ridley sea turtles (Lepidochelys olivacea) and Hawksbill sea turtles (Eretmochelys imbricata). Locals also reported seeing near-extinct Pacific Leatherback sea turtles (Dermochelys coriacea) inside Golfo Dulce. That’s four endangered species of sea turtles utilizing the embayment. Amazing! Our biseasonal data show Golfo Dulce to be a year-round feeding and breeding area for endangered Green sea turtles. We logged over a hundred sightings of them between both surveys. This species, by far the most common, was usually observed in the upper regions of the gulf resting at the sea surface. But we also documented Green sea turtles mating in all four quadrants of the inlet, so their use of the fiord waters appears widespread.
Marine Conservation, Science and Research / 23.03.2012

[caption id="attachment_2461" align="alignleft" width="300" caption="Dolphin B43 shown alongside a rendered outline of its dorsal fin. We saw this individual five times."][/caption] An unexpected but delightful result of our survey work in Golfo Dulce was the identification of about 80 individual Bottlenose dolphins (Turciops truncatus), some of which can be seen in the Appendix of my 2010 report. How does one go about identifying dolphins? Well, pioneering biologists studying various species discovered ingenious ways to distinguish individuals. Jaguars have unique spots. Gorillas have unique nose prints. Dolphins have unique dorsal fins. By examining the shape, natural markings, scars and trailing edge, a dorsal may appear as distinct as a fingerprint. Of course dolphins don’t sit quietly at the surface while you study the intricacies of their dorsal patterns, so ID work is best done through photos. Luckily, we managed to get photographs for almost 90 percent of our dolphin sightings.
Science and Research / 08.03.2012

By Claire Standley [caption id="attachment_3942" align="alignleft" width="300" caption="Our first sunset at the Greg Gund Conservation Center at Cerro Osa, January 2011 (© Claire Standley)"][/caption] Diseases aren’t supposed to be the first thing you think about when visiting a new place, especially one as beautiful as the Osa. However, when you’re a disease ecologist like my colleague Peter and me, it’s sometimes hard to keep parasites out of your head. Figuratively, that is! So, even before our first trip to Cerro Osa in January 2011, as part of a tropical ecology course with Princeton University, we had begun thinking of ways we could tie in the unique ecology of the Osa with our own research. Trawling through the wonderfully informative Osa Conservation website, we had eagerly devoured information on the landscape and ecosystem we would be exploring. We found out how Osa Conservation was working to create a biological corridor of rainforest habitat between Cabo Matapalo at one end of the peninsula and Corcovado National Park at the other. That intrigued us. Both of us also have conservation backgrounds, and so we were well aware of the positive benefits of connecting patches of habitat, such as giving predators larger areas to hunt in, and decreasing the chance of inbreeding, which can occur if animals are squished into too small an area. However, we also knew of some theoretical work that our boss, Professor Andy Dobson, had done looking at how corridors, by increasing connectivity between animal populations, might affect disease transmission. Could the Osa peninsula provide us with a natural laboratory for testing some of these ideas?
Marine Conservation, Science and Research / 02.03.2012

[caption id="attachment_2409" align="alignleft" width="300" caption="These three photos show a baby Humpback whale next to its resting mama – TOP: nursing; MIDDLE: breathing; and BOTTOM: spyhopping"][/caption] A variety of whale species may be found in the eastern Pacific Ocean off the coast of Costa Rica, including Byrde’s whale (Balaenoptera edeni), Fin whale (Balaenoptera physalus), Sperm whale (Physeter macrocephalus) and Killer whale (Orcinus orca). But the most commonly seen whale inside the Golfo Dulce is the Humpback whale (Megaptera novaeangliae), a species that annually migrates from colder feeding grounds near the...