Environmental Education, Science and Research, Volunteers and Visitors

A Night with Bats

Bats. These nocturnal creatures tend to get a bad rap. Associated for centuries with mythical creatures of the night, and used as Halloween decorations to add eeriness to a haunted house, the real life mammal often gets overlooked. OC aims to change that by collaborating with experts and educating the public on the crucial role bats play in restoration.

Recently, Osa Conservation was honored with a visit from 2 remarkable scientists in the bat world: Cullen Geiselman, bat biologist and board member of Bat Conservation International & Gloriana Chaverri, a University of Costa Rica professor and respected bat biologist who conducts ongoing research at OC’s properties.

Chaverri and Geiselman visited Osa Conservation to brainstorm with OC on how we can help make people aware of how crucial this magnificent animal is to the Osa and the myriad ecosystems they inhabit.

Along with OC Science & Education Director, Jim Palmer, they explored Chaverri’s research sites and visited Osa Conservation’s newest property, Osa Verde. Osa Verde will, among other things, be the site of experimental restoration plots where researchers and students will study the process of forest succession in the Osa to help improve reforestation efforts. (For more information, please visit http://osaconservation.org/visit-the-osa/volunteer/tropical-reforestation/). This site will be important for bat research and conservation efforts as we study their impact on regeneration through seed dispersal and monitor their presence in strategically placed bat boxes.

One night of the visit, under the cover of the dense canopy and the starry Costa Rican sky, these expert bat wranglers set up mist nets to capture and study bats. Volunteers and visitors watched in awe as they collected data on the bats and released them.

It was a fun, successful visit. OC staff and station visitors learned a lot from hearing about the work of Geiselman and Chaverri and taking part in an evening of mist netting. We all gained a great appreciation for these cute mammals and OC looks forward to sharing this information and spreading the message! Bats rock!

Fast Facts About Bats!

  • Bats eat bugs! In the U.S. bats are estimated to be worth more than $3.7 billion a year in reduced crop damage and pesticide use.
  • Bats are important pollinators! Some of the commercial products that bats help provide include: bananas, peaches, cloves, carob, and agave.
  • Bats play a key role in reforestation! Fruit-eating bats help repopulate tropical forests by dispersing the seeds of fruiting trees over wide areas. Bats are important seed dispersers for avocados, dates, figs, and cashews – to name a few.

Source: Bat Conservation International

Science and Research, Volunteers and Visitors

Golfo Dulce Poison Dart Frogs

Submitted by Steven Waldron; Seattle, WA

Twenty years ago, I backpacked and hiked along the wild beaches and coastal rainforests of the Osa peninsula and became acquainted with some of the fantastic wildlife that the region is well-known for. Near the Sirena station at Corcovado National Park, I became intimate with the loud squawks of Scarlet Macaws sailing overhead, the crash of surprised tapirs bolting through the forest, and the pre-dawn chorus of Howler monkeys. One of the sensory aspects I appreciate most about exploring this region is the rich array of sounds that greets the rainforest naturalist. The forests of the Osa are alive with every kind of exotic screech, hoot, cry, whistle and howl. However, there was one voice that alluded me during that first trip many years ago; that of a little poison dart frog unique to the region, Phyllobates vittatus, the Golfo Dulce poison dart frog. Though the call of Phyllobates vittatus was certainly in the mix of the rainforest cacophony that greeted me back then, I just didn’t know how to identify it and discover its secrets within the complex mystery of the jungle matrix. On a recent trip to the Cabo Matapalo region, I was focused on encountering this beautiful red/black/green jewel of a frog and to document some of its natural history and beauty in photos.

From my research, I knew that Phyllobates vittatus is endemic to southwestern Costa Rica and found from Domincal in the north to (likely) the Boruca peninsula in the south. Due to its limited distribution, P. vittatus is listed by the IUCN as an endangered species. P. vittatus is known to inhabit primary forest microhabitats near streams; it’s diurnal and dwells in the leaf litter of the forest understory. Phyllobates vittatus is one of the true poison dart frogs with another sister species found in the Caribbean slope of Costa Rica and Panama (Phyllobates lugubris) and three other known relative species in the Chocó rainforest of Colombia (Phyllobates aurotaenia, Phyllobates bicolor and Phyllobates terribilis). The evolutionary links to the Chocó appear to be a common theme in Osa natural history.

19881843978_7859cdbac4_oDuring our first day in the Matapalo forest, my wife and I went for a late afternoon walk along a perennial creek with a rocky stream bed covered in fallen leaves. It seemed like the ideal habitat for Phyllobates vitiates, and it was! My wife found our first Phyllobates vittatus hanging out in a sheltered spot below a fallen log. Interestingly, I found this very frog in the same spot during my informal surveys over the course of the next week. P. vittatus appears to be fairly territorial in its habits. As the night was approaching quickly, my wife and I decided to resume our Phyllobates search for the following morning. A few hours after the next dawn, we were rewarded with the discovery of several vocalizing males singing from the creek banks. Luckily, I was able to photograph the frogs in their microhabitat and witnessed several courting male/female pairs.

Despite their toxic nature and bold coloration, P. vittatus is a fairly shy frog that is more often heard than seen. Once you learn the song of this frog, you realize that they are locally abundant in the Osa forests. However, the calling males will usually quickly fall silent and retreat into rock crevices or leaf litter when they feel threatened or discovered. Without this interruption, the typical reproduction process would proceed as follow:

The male P. vittatus serenades the female as she looks on. If all goes well, and both parties are mutually interested, the pair will retire to a sheltered spot in the fallen leaves where they will lay 7 to 21 eggs. The eggs will hatch in a couple of weeks; during that time period the male will periodically return to the developing embryos and moisten them with water shed from a specialized patch of vascularized tissue on his posterior. When the tadpoles hatch, they will then be visited by their father, climb onto his back and he will hop off into the forest to find a small pool of water for them to complete their development into little frogs some forty-five days later.

As our days of birding, botanizing and frogging unfolded during our relaxing week in Cabo Matapalo, the song of Phyllobates vittatus was a constant companion as it greeted us cheerfully from nearly every creek, spring and stream bed along the forest trails we visited. I came to look forward to hearing it as much as I enjoyed the raucous call of the macaws, the screech of the parakeets, the complaints of monkeys and the crashing of waves along the wild beaches. I realized that Phyllobates vittatus presence in these forests is a small but critical voice in the rich tapestry of biodiversity that gives southwestern Costa Rica its unique and charming character.

Environmental Education, Science and Research, Volunteers and Visitors

Bats Abound!

The Magnificent Gleaning Phyllostomines of the Osa

Submitted by : Doris Audet and Elène Haave Audet, University of Alberta, Canada

Slide1 (1)

Among the rich bat fauna to call Osa Conservation home, a select group speaks to the pristine nature of its old-growth forest: the gleaning phyllostomines.  These large-eared members of the highly diverse leaf-nosed bat family favour habitats of high ecological integrity that include mature forests and undisturbed riparian corridors.

They kindly allowed us to take before going on with their lives.

They kindly allowed us to take their photos before going on with their lives.

Phyllostomines are typically found in low abundance throughout their ranges, however since we started surveying the bat fauna around the Piro Biological Station in 2012, eight of the 33 bat species that we identified belong to this special group. This represents about half of the phyllostomines species expected to inhabit the lowlands of the Osa Peninsula.

 

 

Phyllostomines are primarily insectivorous, and their unusual manoeuvrability allows them to forage within the forest understory, either gleaning their prey from the vegetation or catching them in flight. Some of the larger species, such as the frog-eating bat (Trachops cirrhosus), also include vertebrates in their diet.  Their large, sensitive ears allow them to eavesdrop upon the mating calls of frogs and insects. The similar sized white-throated round-eared bat (Lophostoma silvicolum) has the peculiar habit of roosting in live termite nests, making it one of the rare bat species known to dig out its own shelters.

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Striped-headed round-eared bat

 

The striped-headed round-eared bat (Tonatia saurophila) (shown right), like many other phyllostomine species, occurs in low abundance and is relatively rare throughout its range.  Consequently, we have much to learn about their lives in the wild.

 

 

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Common big-eared bat

The smallest of them all (shown left), at around 5 g, is the common big-eared bat (Micronycteris microtis). As its name suggests, it is among the more frequently encountered bats of this group;  nevertheless, it is unlikely to appear in highly disturbed habitats. Common big-eared bats are known to include fruit in their diet, as is probably the case for many other more secretive phyllostomines.

 

The star of our bat encounters at Osa, the woolly false vampire (Chrotopterus auritus) (shown below), is the second largest bat species in the New World, with a wingspan of over half a meter.  Ten times the weight of the common big-eared bat, it is one of the top nocturnal predators.

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Woolly false vampire bat

 

The presence of diverse phyllostomines in Osa’s old growth areas is good news for the outcome of forest restoration, as they will provide the source populations necessary to re-colonize restored areas as they become suitable. On each of our visits to the Osa, at least one additional phyllostomine species revealed its presence, and we are eager to continue discovering what bats call this forest home!

Marine Conservation, Science and Research

Osa Conservation Supports Research in Golfo Dulce: Drawing Conclusions

Mogos Islands mark the highest waters of Golfo Dulce.

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!

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Marine Conservation, Science and Research

Osa Conservation Supports Research in Golfo Dulce: More Species, More Understanding

By Brooke Bessesen

The name “Brown pelican” belies the attractive hues of a mature bird.

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.

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Sea Turtles

Turtle Patrol: Searching the Osa beaches for sea turtles

By Jamie Cone

Photo: Claudio Giovenzana

An anticipatory rumble of thunder sounds far away, off shore. It has an almost calming sound as we make our way through the dark squishy forest path, the sky patterned with silhouettes of tree leaves. The jungle is alive with night sounds, from the echoing song of the nightjar to the almost space-invader beep of frogs on Las Rocas trail. A silky white two-toed sloth is spotted, high up in a tree, taking the night off. I envy its slow slumber for just a moment before I remember that this trail is taking me down to the beach, down to witness a spectacular and sacred event, one that only a few people in the world have the chance to be a part of. Tonight, I am walking a stretch of beach along which nesting mother sea turtles will, with great care and diligence, lay their precious eggs in the sand.

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Marine Conservation, Science and Research

Osa Conservation Supports Research in Golfo Dulce: So Many Sea Turtles!

Side by side, you can begin to see the characteristics that visibly differentiate the three sea turtle species we documented inside Golfo Dulce.

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.

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Marine Conservation, Science and Research

Osa Conservation Supports Research in Golfo Dulce: Photo-identification of Bottlenose dolphins

Dolphin B43 shown alongside a rendered outline of its dorsal fin. We saw this individual five times.

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.

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Community Outreach, Environmental Education

2012 Osa Science Symposium

The 2012 Osa Science Symposium was attended by 14 presenters and many members of the environmental community

Osa Conservation recently hosted a science symposium at the Piro Research Center. The event brought together scientists and conservationists to share information and results from various research conducted throughout the Osa Peninsula.  The symposium was organized in partnership with representatives from ACOSA (Osa Conservation Area) and was attended by 14 presenters and many members of the environmental community.

The day began with welcoming remarks from Osa Conservation’s executive director, Manuel Ramírez and ACOSA research department head, Wendy Barrantes.  The gathering provided a space to discuss the current status of Osa’s diverse ecosystems and wildlife, as well as identify priority areas for further research. Participants identified the need for comprehensive studies of land use change in Osa, methodologies for estimating costs of environmental damage, calculations for carbon sequestration potential in primary and secondary forests, scientific techniques for recovering degraded forests and the development of a model to build incentives for reforestation in the peninsula.

The symposium strengthened communication and collaboration among scientists and environmentalists and also fomented the role of Osa Conservation as one of the main facilitators of research in the area. The event was a great success and we would like to thank the following presenters and all symposium attendees.  Thanks for making this year’s symposium a success!

Wendy Barrantes, ACOSA
Conserving the Osa, Overview and Future Directions

Karen Leavelle, Osa Conservation
Spatial Biology and Conservation of the Yellow-billed Cotinga

Guido Saboío, Osa Conservation
Sea Turtle Conservation Project, Piro-Carate Beaches

Reinaldo Aguilar, Los Charcos de Osa
Vascular Plants of the Osa

Pablo Riba, Proyecto Carey, Universidad de Costa Rica
Population Structure of Two Dioceus Hardwood Species in the Osa Peninsula

Edgar Malayassi, Instituto Tecnológico de Cartago
Carbon sequestration in secondary and primary forest, Osa Peninsula

Jesús Mora Molina, Guillermo Calvo Brenes, Instituto Tecnológico de Cartago
Evaluation and Classification of the Quality of Several Water Bodies in the Osa Peninsula

Aida Bustamante, Yaguará
Research and Conservation of big cats and their preys on the Osa Peninsula

Gloriana Chaverri, Boston University
The Use of Social Calls in the Search for Bat Refuges

Julieta Carranza , Walter Marín, Universidad de Costa Rica
Inventory and distribution of macro-fungi at La Leona, Corcovado National Park

Science and Research, Volunteers and Visitors

Visitors at the Osa Biodiversity Center in 2009

Three different student groups visited the OBC last year: The Herpetology classes of the University of Costa Rica and Universidad Nacional led by professors Federico Bolaños and Marco Barquero, plus the Natural History and Zoology classes of the Universidad Latina, led by professor Luis Sandoval.


visitors02The Guides and Scouts of Puerto Jiménez, joined by a troop from Pérez Zeledón, went to the OBC to put in practice their camping skills for the first time, in an improvised camp set up by the children.


A group of forestry engineers from the Cartago Technological Institute, in partnership with CATIE and the University of Connecticut, established a series of plots in the surroundings of the OBC to determine forest structure at different stages of succession and document carbon sequestration.


Adrián García, working with bioacoustics in amphibians, has visited the OBC several times to record the songs of various species. His research is part of a project funded by an Evergreen grant.


Stuart Jeckel, of the University of North Carolina, was in the OBC in search of the Túngara frog Engystomops pustulosus, as he is studying their breeding behavior at the neural level.


Guido Saborio keeps impressing volunteers at OBC. He received this message from one of them who spent three weeks at the center:

Dear Guido,
Thank you so much for everything. Our time at the OBC was an absolutely amazing experience; we learned so much and met so many new, interesting people. It also was very helpful to me in realizing what I want to study in college, because I remembered how much I like plants and how interesting botany is for me. Thanks so much for everything you taught us!

-Brook Theis


Karen Masters brought a student group to Cerro Osa for their Sustainability and the Environment course.  They inaugurated the new camping platforms and composting latrines.visitors03