Naturalist Newsletter of January 21, 2008
issued from Yerba Buena Clinic just outside
Pueblo Nuevo Solistahuacan, Chiapas, MÉXICO
about 1740 meters in elevation, ± LAT. 17° 11' 27"N, LONG. -92° 53' 35"W
By "goatsuckers" I mean the bird family containing the nocturnal and twilight-appearing (crepuscular) species known as nighthawks, nightjars and whip-poor-wills. The technical family name of the birds, Caprimulgidae, translates to "goatsucker," reflecting the ancient European belief that these weird-looking birds sucked milk from pasturing goats at night.
I got to thinking about Chiapas's goatsuckers Saturday morning when for the first time I stepped from my dwelling a little before dawn and distinctly heard a sound familiar from summer nights back in Kentucky -- the heartfelt call of the Northern Whip-poor-will, Caprimulgus vociferus.
I was a little surprised to hear the bird here because Howell writes that it's "Unlikely to be heard in region, except perhaps in spring migration when may give a slightly burry whir-pr-iweeu... " I suspect that Saturday morning's calling was triggered by it being unusually warm that day, as well as by our lengthening days trigging spring's hormones. Northern Whip-poor-wills are commonly heard throughout much of eastern North America on balmy summer nights. The species overwinters in the US Deep South, through much of eastern Mexico, all the way to Panama.
At http://www.backyardnature.net/chiapas/birds-ch.htm I list seven species of the Goatsucker Family to be looked for in Chiapas above 1500 meters. They are:
# MEXICAN WHIP-POOR-WILL, permanent resident
# CHUCK-WILL'S WIDOW, winter visitor
# BUFF-COLLARED NIGHTJAR, permanent resident to 1800m?
# NORTHERN WHIP-POOR-WILL, winter visitor
# LESSER NIGHTHAWK, permanent & winter visitor
# COMMON NIGHTHAWK, migrant & summer visitor
# PAURAQUE, permanent resident to 1800m
Some authorities lump the Mexican Whip-poor-will with the Northern Whip-poor-will.
It's interesting that the Common Nighthawk is a summer resident here, same as in North America. Of 456 species on my upland-Chiapas list, well over a hundred are winter visitors while only nine are summer visitors. Common Nighthawks overwinter in South America.