Hypothermia, starvation claim one-third of purple martin hatch
It was a dismal year for purple martins. Starvation and hypothermia claimed the lives of one-third of Minnesota's largest colony, located in Hubbard County.
"There were a lot of people who lost everything," said Don Wilkins, whose Long Lake beachfront houses the colony. "It just was bad news."
Wilkins said two cold snaps and rain are to blame. Although his colony escaped the first wave, the second was catastrophic for his 100+ homes, most of them occupied.
"I probably lost 200 young birds. The hatch was around 600," he said. "It was not good."
Wilkins said because martins primarily eat insects, which don't breed in colder weather, food supplies were scarce.
"It depends on when the cold weather hits," he said. "Up until they get feathers they can't keep themselves warm so the female has to sit on them. But on the other hand she should be out there getting food for them too."
He said some young birds died of the cold. Others died of starvation waiting for a parent to get back to the nest with food.
"When you have cold weather there aren't many insects out there flying and it takes longer for them to get food so they're (the babies) uncovered longer," he said.
"The loss that we had this year was primarily starvation because they were fully feathered birds, looked like they were almost ready to fly," he said. "Those birds can regulate their temperature and they have a good layer of insulation so I think it was more a loss of food than cold weather."
But Wilkins said the chicks are particularly vulnerable at the "quill stage" when they are just beginning to grow feathers and their quills are protruding through their skin.
"The feather is folded up inside it (the quill)," he said. "But also there's a lot of blood vessels in there at that stage when they're still growing the feathers so the little quills are sitting there acting like radiators, yet the birds have gotten into a size where if the females sits on all of them she can't cover them all anyway."
Cold weather then claims them. he added.
"It's a stage where they're very vulnerable to chill," he said. "This is true of other nesting birds, too. But the martins get hit hard because of the way they get their food.
Wilkins will put the colony out again next year and hope for better weather.
"This was not the worst year I've had, incidentally," he said. "Back in 1992 I had 92 nesting pairs and I lost all but three boxes. It was almost a total wipeout that year."
Wilkins is trying to re-establish martins along the Fish Hook River and gradually back into Park Rapids. If homeowners along the river are interested, he will furnish and establish a home for them and help them monitor it.
Wilkins can be reached at 732-3456. If lakeshore property owners are interested in establishing a colony, Wilkins will assist them attracting the birds if they purchase the home.