Birds

Featured Bird: White-crested Coquette

Male White-crested Coquette

Of all the hummingbird species, the coquette males that are most highly adorned with ornate feathers that are there to likely help in territorial defense and enhance species recognition.  The White-crested Coquette (Lophornis adorabilis) is the only coquette found here on the Osa Peninsula and is regionally endemic to south western Costa Rica and Western Panama.

The male of this species, which is also sometimes called Adorable Coquette, is known for its white crest and long green cheek tufts and may be arguably one of the most sought after birds to see when one visits this region.  They wander through forests high in the canopy and low along forest edges feeding on the nectar of flowering Inga, Vochysia, Stachytarpheta and Lonchocarpus plants and will also take small spiders and insects.  They hover with their tales cocked upward while feeding.

Male White-crested Coquette showing cheek tufts.

While courting a female the male will make short arcs side to side not much more than about a foot in either direction in front of the female.  He uses his colorful good looks to defend his flowers within his territory and the female takes on all nest duties with no help from the male.  The small lichen covered nest holding two minute white eggs is placed on the fork of a branch along the forest edge or a clearing and is not very well concealed.

They are said to be found from 300 meters up to 1220 meters but we have seen them here at the Piro Research Center which is near sea level as well as up along the Greg Gund Conservation Center’s northern border at Cerro Osa which sits at about 300 meters all within the last month.  At the moment they are engaged in reproductive behavior which takes place during the rainy season from December to February with courtship seen as early as October.   The male will lose his ornate regalia when the breeding season is over.

Sea Turtles, Volunteers and Visitors

Sea Turtle Conservation Program: October Update

We’ve completed another month of the sea turtle conservation program on the Osa Peninsula, Costa Rica and we’re getting close to the end of the nesting season. After 4 months of tireless work by our field coordinators, field assistants and volunteers, we have registered a total of 1233 sea turtle nests, between Piro and Carate (Fig. 1). As I mentioned earlier, for logistical reasons, we cannot gather daily information from all beaches and visits to Rio Oro beach have been very limited, so this number of sea turtle nests should be considered a minimum; i.e., the actual number of sea turtle nests on these beaches is higher than reported here.

Figure 1. Total nests registered, according to month, beach and species. CM: Chelonia mydas agassizii, DC: Demochelys coriacea, EL: Eretmochelys imbricata, LO: Lepidochelys olivacea

Of these 1233 recorded nests, we know that at least 242 (20%) were predated. Of predated nests, 43% were by humans, while the remaining 57% were predated by dogs, pigs, crabs and other animals. We can reasonably estimate that approximately 10,600 eggs have been illegally removed between Piro and Carate for human consumption (assuming that each nest had 100 eggs and they were all taken).

If we focus on the Olive Ridley sea turtles (Lepidochelys olivacea), the most common sea turtle species on the Osa Peninsula, not taking into account the Rio Oro data, as the data that we have doesn’t appear to be representative of the real situation, we can see that during the 2010 season, Carate beach is where we find the greatest amount of illegal harvesting of eggs (Fig 2). Throughout the season, more than 50% of reported predation is caused by humans, a situation that hasn’t occurred on Piro and Pejeperro beaches.

Figure 2. Percentage of Olive Ridley sea turtle nests predated by humans and other animals according to month and beach.

Remember that you can help us save sea turtles that visit the southern part of the Osa Peninsula in several ways: 1) tell others about our project and the importance of protecting sea turtles, 2) by volunteering with sea turtles or 3) by making a donation to support our sea turtle program or the other conservation work that Friends of the Osa does on the Osa Peninsula.

Miscellaneous, Science and Research

In Search of Amphibians on the Osa Peninsula

In 2008, in order to determine the distribution and abundance of leaf litter amphibian species, I began a monitoring program around the Piro Research Center along with Federico Bolaños and Gerardo Chaves, herpetologists from the University of Costa Rica. In 2010, with the support of the Mohamed bin Zayed Species Conservation Fund (MBZ), I expanded this project to Los Charcos and Petosa, a private property owned by Bert Kerstetter, an important supporter of Friends of the Osa.

The information generated by this project was included in the latest update workshop of the conservation status of amphibians in Costa Rica for the IUCN Red List, held in San Jose in July this year. The workshop was organized by the University of Costa Rica’s School of Biology and the Conservation Breeding Specialist Group (CBSG) of the Species Survival Commission of the IUCN. The workshop summary will soon be published by the organizers, and we’ll share that report through the blog.

Dermophis occidentalis

As part of this project, and with some good luck, we’ve observed many interesting species of amphibians.  One species in particular which has attracted the most attention is the caecilian seen in this photo.

Caecilians are a group of amphibians that has invaded the underground environment, so that their bodies are elongated, they have no limbs and their eyes are vestigial – all characteristics that allow them to squirm through their subterranean tunnels. Because of their penchant for the underground, these animals are rarely seen, and therefore, little is known about them.

According to the latest review of this group in the Osa Peninsula, there are three species of caecilians, one of these endemic (Oscaecilia osae), which has been reported only twice in Corcovado National Park.

The species that we have been observing, Dermophis occidentali, has been found at both the Piro Research Center, and the Greg Gund Conservation Center (GGCC).  The individual in the photo was found at the GGCC by Kory Kramer, in one of the buildings. This was in early July, when the onset of the rains saturates the ground forcing caecilians to surface.  If you’re lucky, you’ll see one. On this occasion, all Friends of the Osa staff were gathered for an activity so that everyone had the opportunity to observe this rare species.