Bordering On Extremes
Along our southern border, birds not seen elsewhere in the United States cope in a region that is growing drier
Dove song may be a beautiful sound, but last spring so many white- winged doves had staked out territory in San Antonio, Texas, that people began to complain. During mating season, the birds' nearly ceaseless renderings of hhhooo-hoooo-hoo-hooo dominated entire neighborhoods.
The complaints were new to the area, and so was the noise. Until about 30 years ago, white-winged doves were almost never seen in the United States outside the remote thorn forests of far-south Texas or the Sonoran Desert of Arizona. For years after that, only a few wanderers were spotted further north. But in the middle 1980s, white-winged doves moved in great numbers into cities and towns as far north as San Antonio, Austin and Albuquerque.
"A lot of people think there's been a population explosion among white- winged doves, but I'm suggesting that this is a redistribution based on loss of habitat," says Jeff Haskins, chief of the U.S. Fish and Wildlife Service's migratory bird office for the Southwest.
White-winged doves are not alone. The fish- and insect-eating great kiskadee, the tiny Inca dove and even the shy, turkeylike plain chachalaca have all taken up residence in towns. And other birds-- including the green jay, red-crowned parrot and green parakeet--also have moved northward in recent years. Scientists don't know exactly why the birds are on the move, but they think that drier conditions, as well as an unprecedented loss of habitat, may be driving the birds out of their former territory along the U.S.-Mexico border and points south.
In the harsh climate of the border region--from the Texas Gulf Coast, through the mountains, deserts and plains of New Mexico and Arizona-- birds have developed strategies over the millennia allowing them to withstand heat and to draw moisture from available sources. Now dropping water tables, drying rivers, dying streamside forests and disappearing brushland are testing the limits of those abilities.
National Wildlife, June-July, 1999
Dove song may be a beautiful sound, but last spring so many white- winged doves had staked out territory in San Antonio, Texas, that people began to complain. During mating season, the birds' nearly ceaseless renderings of hhhooo-hoooo-hoo-hooo dominated entire neighborhoods.
The complaints were new to the area, and so was the noise. Until about 30 years ago, white-winged doves were almost never seen in the United States outside the remote thorn forests of far-south Texas or the Sonoran Desert of Arizona. For years after that, only a few wanderers were spotted further north. But in the middle 1980s, white-winged doves moved in great numbers into cities and towns as far north as San Antonio, Austin and Albuquerque.
"A lot of people think there's been a population explosion among white- winged doves, but I'm suggesting that this is a redistribution based on loss of habitat," says Jeff Haskins, chief of the U.S. Fish and Wildlife Service's migratory bird office for the Southwest.
White-winged doves are not alone. The fish- and insect-eating great kiskadee, the tiny Inca dove and even the shy, turkeylike plain chachalaca have all taken up residence in towns. And other birds-- including the green jay, red-crowned parrot and green parakeet--also have moved northward in recent years. Scientists don't know exactly why the birds are on the move, but they think that drier conditions, as well as an unprecedented loss of habitat, may be driving the birds out of their former territory along the U.S.-Mexico border and points south.
In the harsh climate of the border region--from the Texas Gulf Coast, through the mountains, deserts and plains of New Mexico and Arizona-- birds have developed strategies over the millennia allowing them to withstand heat and to draw moisture from available sources. Now dropping water tables, drying rivers, dying streamside forests and disappearing brushland are testing the limits of those abilities.
National Wildlife, June-July, 1999
