Researcher gets hands-on with whoopers
March 23, 2014 at 10:04 p.m.
Updated March 23, 2014 at 10:24 p.m.
Felipe Chavez-Ramirez has scars on the back of his hands and forearms from catching whooping cranes. Part of a team of researchers from multiple organizations putting lightweight GPS devices on whoopers, he's the guy who first puts hands on the 5-foot-tall birds.
"The bird is standing up when I get there. When we're standing next to each other, we're looking into each other's eyes," the 5-foot-7 Chavez-Ramirez said. "It's very feisty. Its primary weapon is its legs."
The research team put tracking devices on 68 of the endangered birds of the Aransas-Wood Buffalo population during the span of four years. That was more than 20 percent of population, said Wade Harrell, whooping crane recovery coordinator for the U.S. Fish and Wildlife Service. The GPS units, which are attached to the bird's upper leg, send the location of the bird to a satellite four to five times a day, according to a U.S. Fish and Wildlife Service press release.
The team finished putting tracking devices on the birds this wintering season, and the study will continue through the life of the GPS units.
The birds' locations are downloaded from the satellite every two and a half days and are used to better understand the behavior of the birds, such as their migration routes, habitat use and nesting locations, according to the press release.
The most surprising information from the study so far is the number of the endangered birds that have been shot, said Chavez-Ramirez, director of conservation programs for Gulf Coast Bird Observatory. About a dozen whooping cranes have been shot in the past three years, but that number includes cranes from the captive bred population, he said.
"Some of the mortalities occurred in areas where hunting is prohibited," Chavez-Ramirez said.
He said the deaths may be linked to malicious intent or vandalism.
When the GPS unit indicates that a bird has been stationary for 24 hours, the bird is likely sick or dead, he said. Depending on when the bird is injured, researchers may not know about the incident for two and a half days because that's how often GPS information is downloaded from the satellite. When researchers identify a potentially dead bird, a game warden with the state where the bird is located is sent to investigate, he said.
Carcasses have been found with bullet wounds, he said, leading to an arrest in three or four cases.
Chavez-Ramirez was also surprised to find the number of mortalities that occur in Wood Buffalo, Canada, the breeding ground of the wild population.
"We thought most (mortalities) occurred in migration because they are moving a lot," Chavez-Ramirez said. "There's so much more information that is still unanalyzed."
The results of the ongoing study likely will lead to several publications in the next few years to include sources of mortality and wintering and migratory behaviors, he said. Being able to see the exact place where the birds move throughout the day is itself new and telling information.
"We've sort of always known what kind of roosting locations they like, but we had to guess," Harrell said. "Now, we can quantify exactly where the roost locations are and what they look like."
As the wild population grows in size, this information will help in conservation efforts.
"It's really an insight into behavior. What do they need to survive? What do they need to continue to grow?" Harrell said. "We know the population is growing. As they grow, they need more space."
The U.S Fish and Wildlife Service will use the information gathered in the study to work with other groups to conserve the habitats the birds need to breed, migrate and winter, Harrell said.
During the past four years, researchers have attached GPS units to chicks in Wood Buffalo National Park, where the birds nest, and adults in Aransas National Wildlife Refuge more than 2,000 miles away, where the birds winter. The team had 60 GPS radios. Some were recovered from mortalities, resulting in the team applying the device to 68 birds. There are 28 GPS units still active, Harrell said.
Most of his scars are from the whoopers' feet, Chavez-Ramirez said. The team caught each bird with a leg snare and in the course of 10 minutes put a GPS unit on its leg, took blood samples and weighed it.
"As soon as I control the legs and feet, somebody else puts a hood over the head. Somebody's at the back end of the bird trying to put a GPS on. And on the other side of the bird, we're collecting blood for analyses later on," Chavez-Ramirez said.
Once the hood comes off, Chavez-Ramirez gently tries to put the bird's legs on the ground, he said.
"I let it know it can stand. I try to let it go. Hopefully, they try to run away from us. Other times, they turn toward me and try to fight me," he said.
Chavez-Ramirez has been kicked, scratched and pecked, but his hands-on experience with the birds has given him a greater admiration for the endangered population.
"I've been studying them since the mid-90s. I'm very impressed with their tenacity - maybe even more so now that I've seen them up close," Chavez-Ramirez said. "They came back from a population of 15 birds in the whole world. They're fighters. Hopefully, we can help them out."