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

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

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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!