Post by L Roebuck on Jun 13, 2006 8:33:44 GMT -5
Longtime volunteer project at Caverns provides information on cave swallows
By Stella Davis
Current-Argus Staff Writer
CARLSBAD --Nobody knows for certain how many cave swallows share the home of the Mexican free-tail bats at Carlsbad Caverns, but for the past 26 years, volunteers have come back year after year to learn more about them.
Since 1980, Steve West, a science teacher at Carlsbad High School and an avid birder and researcher, has been part of a cave swallow banding project that he helped initiate to determine their migratory range and lifespan.
Also a member of the Chihuahuan Desert Conservation Alliance, West said that members of his organization and volunteers from 38 states and 15 countries have over the years banded an estimated 17,000 cave swallows starting each spring and ending in the fall when the birds leave the cave for the winter and head to Mexico.
"We needed to know their winter range and where they spend half a year when they are not living in the entrance to the caverns," West said, explaining the project's mission. "But we have collected a lot of other data about them in the past 26 years.
West said the cave swallows at Carlsbad Caverns National Park were discovered inside the big entrance to the caverns in 1966.
"There were three nesting pairs found there in 1966. There was a population explosion in the 1970s, but by the early 1980s, the population had maxed out," he said.
West said although the banding project has been ongoing since 1980, determining the number of cave swallows is difficult at best. However, he said if he had to guess, he would estimate about 1,600 cave swallows make their home at Carlsbad Caverns during the summer months.
"The number that return in the early spring varies from year-to-year, so there could a little more or slightly less," he said.
West said that banding the birds is not an easy task. First they have to be captured in a net, then a little aluminum band is placed around the bird's leg containing pertinent data relating to the capture and banding that includes the date and where they were banded.
"Although we have not had many birds returned documenting where they were found, we have had a few that had died and were returned to us because the of bands. When that happens, it gives us good data of their range and when they were banded by us."
"The oldest bird that we recaptured in the cave that I know of was last year. It was about 12 years old," West said. "It had a band on that shows it was banded in the cave in 1993. Normally, these birds don't live that long. Generally, about 65 percent die off in the first year. If they pass the two-year mark, generally they can live about eight years. In England, they recaptured a banded cave swallow 17 years after it had been banded. That was amazing."
West said that in order to be allowed to conduct the banding and do the research, his organization has to get federal and state approval, as well as permission from Carlsbad Caverns to be in the cave.
"We provide the research data to the U.S, Fish and Wildlife Service and the park," West said. "I also make the data available to students and anyone else that is conducting cave swallow research. My philosophy is that what good is the scientific data if it is not shared? I have had students that have used the data we have collected for their science projects."
West said he became interested in cave swallows shortly after he left military service in the 1970s.
"My mother and brother were living in Alpine, Texas, at the time. When I got out of the army that's where I went," he recalled. "They had a small group of people there that were members of the Texas Bird Banding Association, which is no longer in existence. I joined the group and someone said that we needed a project, and the suggestion was made to band cave swallows. There was a place in Alpine that had a small colony of cave swallows, and I banded my first cave swallow in 1978."
In 1980, West moved to Carlsbad and said that he believed cave swallow banding at Carlsbad Caverns would be a logical thing to do. At that time, little was known about the cave swallows living there, he said.
After receiving permission from park officials, West and a small band of volunteers rolled up their sleeves and began the project, not knowing at the time that 20 years later they would still be doing it.
"I don't know of any banding project that has been going on for so long," he said. "I appreciate the support of the park in allowing this project to continue."
West said banding generally takes place in the evenings after visitors have left, and before the bats leave for a night of feeding.
Like the cave swallows, the bats summer in the cave and head south for the winter.
He noted that the bats roost further into the cave than the swallows, which unlike the bats, are daytime flyers and feed primarily on insects.
"The bats and the cave swallows co-exist. The birds fly out in the morning when the bats come in after being out all night," he said.
West said that through his research it has been determined the cave swallows winter in Puerto Vallarta and Acapulco, Mexico, and El Salvador.
"A few of them will winter in Texas," he added. "Before we started the research, nobody knew for sure how far these birds flew for the winter."
West said that since he first started his research, he has seen a shift in the migratory pattern of the cave swallows summering at Carlsbad Caverns.
"They are coming back earlier and leaving later," he said." Since the birds are living in the cave at night, they are expending less energy. They are protected in the cave. I think another reason the birds are leaving later is because of the global warming effect. The birds used to come back around early March. Now, we are seeing them return in January."
West said that although the cave swallows appear healthy on the outside, it is not uncommon for some to die young from internal parasites.
"I have conducted autopsies on dead cave swallows and have found round worms. That may be twice a long as the bird. It's not something that impacts humans, but it does kill the bird," he explained.
West said that currently volunteers are spending one to three evenings per week in the cave banding birds. However, he said extra volunteers are also needed and welcome.
Anyone interested in spending an hour or two inside the entrance of the cave helping with banding or tasks associated with the project can contact West at 302-6187.
Full Article and Photo's:
www.currentargus.com/apps/pbcs.dll/article?AID=/20060613/NEWS01/606130302/1001
By Stella Davis
Current-Argus Staff Writer
CARLSBAD --Nobody knows for certain how many cave swallows share the home of the Mexican free-tail bats at Carlsbad Caverns, but for the past 26 years, volunteers have come back year after year to learn more about them.
Since 1980, Steve West, a science teacher at Carlsbad High School and an avid birder and researcher, has been part of a cave swallow banding project that he helped initiate to determine their migratory range and lifespan.
Also a member of the Chihuahuan Desert Conservation Alliance, West said that members of his organization and volunteers from 38 states and 15 countries have over the years banded an estimated 17,000 cave swallows starting each spring and ending in the fall when the birds leave the cave for the winter and head to Mexico.
"We needed to know their winter range and where they spend half a year when they are not living in the entrance to the caverns," West said, explaining the project's mission. "But we have collected a lot of other data about them in the past 26 years.
West said the cave swallows at Carlsbad Caverns National Park were discovered inside the big entrance to the caverns in 1966.
"There were three nesting pairs found there in 1966. There was a population explosion in the 1970s, but by the early 1980s, the population had maxed out," he said.
West said although the banding project has been ongoing since 1980, determining the number of cave swallows is difficult at best. However, he said if he had to guess, he would estimate about 1,600 cave swallows make their home at Carlsbad Caverns during the summer months.
"The number that return in the early spring varies from year-to-year, so there could a little more or slightly less," he said.
West said that banding the birds is not an easy task. First they have to be captured in a net, then a little aluminum band is placed around the bird's leg containing pertinent data relating to the capture and banding that includes the date and where they were banded.
"Although we have not had many birds returned documenting where they were found, we have had a few that had died and were returned to us because the of bands. When that happens, it gives us good data of their range and when they were banded by us."
"The oldest bird that we recaptured in the cave that I know of was last year. It was about 12 years old," West said. "It had a band on that shows it was banded in the cave in 1993. Normally, these birds don't live that long. Generally, about 65 percent die off in the first year. If they pass the two-year mark, generally they can live about eight years. In England, they recaptured a banded cave swallow 17 years after it had been banded. That was amazing."
West said that in order to be allowed to conduct the banding and do the research, his organization has to get federal and state approval, as well as permission from Carlsbad Caverns to be in the cave.
"We provide the research data to the U.S, Fish and Wildlife Service and the park," West said. "I also make the data available to students and anyone else that is conducting cave swallow research. My philosophy is that what good is the scientific data if it is not shared? I have had students that have used the data we have collected for their science projects."
West said he became interested in cave swallows shortly after he left military service in the 1970s.
"My mother and brother were living in Alpine, Texas, at the time. When I got out of the army that's where I went," he recalled. "They had a small group of people there that were members of the Texas Bird Banding Association, which is no longer in existence. I joined the group and someone said that we needed a project, and the suggestion was made to band cave swallows. There was a place in Alpine that had a small colony of cave swallows, and I banded my first cave swallow in 1978."
In 1980, West moved to Carlsbad and said that he believed cave swallow banding at Carlsbad Caverns would be a logical thing to do. At that time, little was known about the cave swallows living there, he said.
After receiving permission from park officials, West and a small band of volunteers rolled up their sleeves and began the project, not knowing at the time that 20 years later they would still be doing it.
"I don't know of any banding project that has been going on for so long," he said. "I appreciate the support of the park in allowing this project to continue."
West said banding generally takes place in the evenings after visitors have left, and before the bats leave for a night of feeding.
Like the cave swallows, the bats summer in the cave and head south for the winter.
He noted that the bats roost further into the cave than the swallows, which unlike the bats, are daytime flyers and feed primarily on insects.
"The bats and the cave swallows co-exist. The birds fly out in the morning when the bats come in after being out all night," he said.
West said that through his research it has been determined the cave swallows winter in Puerto Vallarta and Acapulco, Mexico, and El Salvador.
"A few of them will winter in Texas," he added. "Before we started the research, nobody knew for sure how far these birds flew for the winter."
West said that since he first started his research, he has seen a shift in the migratory pattern of the cave swallows summering at Carlsbad Caverns.
"They are coming back earlier and leaving later," he said." Since the birds are living in the cave at night, they are expending less energy. They are protected in the cave. I think another reason the birds are leaving later is because of the global warming effect. The birds used to come back around early March. Now, we are seeing them return in January."
West said that although the cave swallows appear healthy on the outside, it is not uncommon for some to die young from internal parasites.
"I have conducted autopsies on dead cave swallows and have found round worms. That may be twice a long as the bird. It's not something that impacts humans, but it does kill the bird," he explained.
West said that currently volunteers are spending one to three evenings per week in the cave banding birds. However, he said extra volunteers are also needed and welcome.
Anyone interested in spending an hour or two inside the entrance of the cave helping with banding or tasks associated with the project can contact West at 302-6187.
Full Article and Photo's:
www.currentargus.com/apps/pbcs.dll/article?AID=/20060613/NEWS01/606130302/1001