Birds

Featured Bird: Crested Guan

Crested Guan by Kory Kramer

Lately we have been seeing Crested Guans (Penelope purpurascens) along the road up in the trees heading up to Friends of the Osa’s Osa Biodiversity Center at Cerro Osa.  I first noticed a family of 4 Guan individuals in one of our forest restoration plots a few weeks back as I was conducting bird counts.  The adult female of the group became fairly agitated as I walked right underneath her on my way to my next monitoring point.  I assumed she either had a nest or was with her young of the year.  Though my nest searching instincts tend to be very strong I left her alone as I continued on with my bird count.  They can be quite loud when they feel threatened and I was unable to hear any other birds in the forest with her so upset. Since then we have seen several Crested Guans (or Penelope, as they are fondly referred to as here in Costa Rica for its genus), along the road and so I thought this would be a good time to introduce them here on the pages of our blog and talk a bit about why it is so special to have them here.  Oh, and they are also called Pava which means turkey in Spanish.

The Crested Guan is quite large, about turkey size, weighing in at about 1.7 kg.  Because of their large body size and evidently tasty meat they have been hunted along with other species in the Cracidea family such as Curassows, Guans and Chachalacas all throughout their range.  Larger bodied birds tend to have low abundance, and that along with a small clutch size of 2 to 3 eggs, a slow reproduction period (incubation alone may take as long as 34 days), and hunting pressure makes this species rare in unprotected forests and more vulnerable to changes in the landscape.

Why are these species so important you might ask?  These species are essential to the biodiversity of the tropical rainforest because they are mainly frugivores (fruit eaters) and play an important roll in fruit seed dispersal which helps with seed germination and forest regeneration.  When we lose large seed dispersers like Crested Guan we lose the mechanism by which larger seeds are moved and placed elsewhere for them to germinate and take root.

This is why it is so special to see them around here as much as we do.  Cerro Osa is a 600 ha parcel acquired by Friends of the Osa in 2008 and is an important area for species protection and conservation.  Now with the decrease in hunting pressure and our forest restoration projects underway, we hope to be seeing a lot more Crested Guans, Great Curassows and Gray-headed Chachalacas here at the Osa Biodiversity Center.

The Crested Guan was photographed here at the Osa Biodiversity Center at Cerro Osa by Kory our managing director here at Friends of the Osa.

Birds

Featured Bird: Band-tailed Barbthroat

Band-tailed Barbthroat by Gianfranco Gomez

The Band-tailed Barbthroat (Threnetes ruckeri) is a medium sized hermit in the hummingbird family.  They are a common resident of wet lowland forest on the Caribbean and Pacific slopes and range from Guatemala on down to Western Venezuela and Ecuador.  They are often found along edges and the understory of old second growth feeding on mainly Heliconia, Calathea and banana flowers with their specially shaped decurved bill.  This and other hermit species can be found here at Friends of the Osa’s Osa Biodiversity Center

So what’s the difference between a Hermit and a Hummingbird?  Hermits are hummingbirds but they do have some characteristic differences between them.  Hermit feathers are typically brown, rufous, green, and gray in color and do not have the iridescent plumage that hummingbirds do.  There is often little difference in appearance between the sexes normally seen in most hummingbirds.  The Band-tailed Barbthroat is known for its round tail which is banded in black and white with two green center tail feathers which extend farther out looking as if they were dipped in white paint.

Interestingly, this hermit forms breeding leks.  Males gather in courtship groups also known as leks which is the traditional display ground where females come to choose their mate.  They are less aggressively territorial than hummingbirds which tend to defend particular flowers as their territories, hence the brighter iridescent feathers against their chosen flowers.  Nests are small cups attached to the underside of Heliconia or banana leaves up to 4 meters high; using the leaf as a bit of cover allowing for much needed respite during heavy rains.

We would like to thank Gianfranco Gomez from the Drake Bay Rainforest Chalet and Photographs by Bob Levy for their stunning photographs and allowing us to showcase them.  You can find them just up the coast from us in Drake Bay, Costa Rica.

Birds

Featured Bird: Buff-throated Foliage Gleaner

Buff-throated Foliage Gleaner by Gianfranco Gomez

The Buff-throated Foliage Gleaner (Automolus ochrolaemus) is part of the ovenbird family, an extremely diverse group of birds in form and habits.  Besides, foliage gleaners, there are treerunners, leaftossers, castlebuilders and treehunters.  The ovenbird name comes from nests of many species that resemble “baking ovens” placed on the ground.  Most species in the ovenbird family build some sort of covered nest or place it in a covered structure.  The Buff-throated Foliage Gleaner builds its nest at the end of a burrow as long as 30” deep along the side of an embankment beside a trail or stream and nest from February to May.  They forage for insects, spiders, small frogs and lizards from within curled up dead leaves or leaf litter in tree thickets in mature or secondary wet forest.  They spend a lot of their time hanging upside down or creeping along branches and often travel alone or in pairs sometimes in mixed species flocks.  They are commonly found in lowland forests of both the Caribbean and Pacific slopes and are common here on the Osa Peninsula at the Osa Biodiversity Center.  They range from South Mexico all the way down to the Amazon in Brazil.  Most notably they puff out their throats when they get excited!

We would like to thank Gianfranco Gomez from the Drake Bay Rainforest Chalet for their stunning photographs and allowing us to showcase them.  You can find them just up the coast from us in Drake Bay, Costa Rica.