The Bird That Acts Like A Bat

Explanation: How strange are these birds?

This week we are in a remote canyon in the mid-elevation subtropical forests of the Andes Mountains in western Ecuador.

I won't reveal this exact location, because these birds are rare and need protection.

But what birds they are!

These are Oilbirds -- the only species of their entire family.

Oilbirds are found only in South America (although a few sightings have come from Panama).

Although Oilbirds belong to the taxonomic order of nightjars -- Caprimulgiformes -- with which they share nocturnal habits ... they also take on some surprising bat-like behaviors.

Once collected for their oil, Oilbirds are essentially strictly noctural -- emerging from their caves and dank, shadowy grottos only at night, like bats.

And like bats, they congregate, often in numbers, during the day in their darkened roost sites. Or they may spend some daytimes hiding in dense, dark tree foliage -- again like many bats do.

Also like many fruit bats of these tropical forests, Oilbirds fly far to feed on fruits of palms and other tree species of the laurel family, plucking fruits while hovering. Oilbirds thus serve as important dispersal agents for fruit-bearing trees throughout the subtropical forest.

Perhaps most amazing is their bat-like use of echolocation. Oilbirds emit loud clicks on the wing by which they navigate and locate their food (in this case, fruits) in total darkness.

Just like bats.

Entrance to the Oilbird grotto in western Ecuador.

Perhaps because of low heat tolerance, Oilbirds prefer cool dark rockshelters and caves.

Information:
     Bosque, C., R. Ramirez, and D. Rodriguez. 1995. The diet of the oilbird in Venezuela. Ornitologia Neotropical 6:67-80.
    Holland, R.A., M. Wikelski, F. Kümmeth, and C. Bosque. 2009. The secret life of oilbirds: new insights into the movement ecology of a unique avian frugivore. PLoS One 4(12):e8264.
     Howe, H.F. 1984. Implications of seed dispersal by animals for tropical reserve management. Biological Conservation 30:261-281.
     Knudsen, K.M. 1979. The oilbird: hearing and echolocation. Science 204(4391):425-427.

EPOW - Ecology Picture of the Week