Excerpts from Jim Conrad's
from the June 9, 2007 Newsletter issued from Sierra Gorda Biosphere Reserve, QUERÉTARO, MÉXICO
Pauraques (pow-RAH-kehs) are big, tropical, Whip-poor- will-like birds. Whip-poor-wills are often known as nightjars, and belong to the same family as high-flying nighthawks. Officially at the Reserve we have three members of the Whip-poor-will/ Nighthawk Family: The Mexican Whip-poor-will, which may be a subspecies of the Northern Whip-poor-will; the Lesser Nighthawk, and; the Pauraque. You can hear a Pauraque calling exactly as I heard them by clicking on the speaker icon at http://identify.whatbird.com/obj/858/overview/Common_Pauraque.aspx.
For years I couldn't reach the 100%-certainty threshold that I was actually seeing Pauraques. The problem was that the plumages of all nightjars are variations on the brown, mottled theme. Moreover, they all sit motionless and beautifully camouflaged on the forest floor until you almost walk upon them, and then they fly away with such unnerving fleetness that you just never get an adequate view. Did the bird's neck show a "slight cinnamon hindcollar" like the Mexican Whip- poor-will, or were the primary feathers "barred rufous basally," as with the Lesser Nighthawk?
Happily, the various nightjar species can be told by their songs, and nowadays anyone who can plug keywords into a search engine can locate audio files displaying what the various species sound like. The Pauraque has the burry p'weeEER call heard at the above link. The Mexican Whip-poor-will's call is also burry but it's phrased like pwurr-p'wiirr, plus that species stays in the pine and pine-oak highlands and we're in this hot, muggy valley. The third member of the family we have, the Lesser Nighthawk, produces a low, toad-like trill, urrrrr.
So, audio files have convinced me with 100% certainty that the birds I get fleeting glimpses of when I tramp the scrub at dawn and dusk really are Pauraques. And once again the Internet proves its value to the field naturalist.
You can see some nice shots of Pauraques at http://www.greglasley.net/pauraque.html.