Catching a wild bird and strapping a band onto its foot may not seem that revealing if you aren’t in the bird world, but for biologists at Lassen Volcanic National Park the information they collect from this type of tracking tells them a lot about the park’s condition.
Each year Lassen Volcanic National Park holds public demonstrations on bird banding, which take place the third weekend in July. This year the demonstration was led by wildlife biologist Mike Magnuson who taught people everything from how to monitor birds to how to tell if they’re male or female.
"Birds are a good way to tell if your ecosystem is healthy. If you start seeing declines in those populations then something is usually going on." - Mike Magnuson, Wildlife Biologist at Lassen Volcanic National Park
He demonstrated the latter with a woodpecker, which he pulled out of a bag. Magnuson turned the bird upside down and blew on its feathers to expose its stomach – the spot on a bird where he can identify the bird’s sex.
“It has a brood patch for sure,” Magnuson said to the crowd.
A brood patch is a bare spot with loose feathers on the underbelly of a female bird and is where she incubates her eggs. If Magnuson were holding a male bird he would have found a colloquial protuberance.
“Which I like to call the little boy thing, and it’s usually engorged with semen, so you can flip it over and see that. So that’s usually how we sex a bird,” he said.
Next, Magnuson weighed the woodpecker. He put it head-first into a film canister and then set it on a scale. He then measured its wingspan. Finally Magnuson put a small band around the bird’s ankle, so that he’ll know this is a bird he’s already caught and counted. After the bird was banded, Magnuson let it go.
All of this handling may seem traumatizing for the birds, but Magnuson said the data being collected is extremely important for the park. The birds the park monitors are all migratory and travel down to South America during the winter. The data collected can show how well bird populations are faring.
“Birds are a good way to tell if your ecosystem is healthy,” Magnuson said. “If you start seeing declines in those populations then something is usually going on. We don’t know if it is up here or down in South America, but something is going on if birds start disappearing.”
"Only one percent of the surface area of the Sierras is meadow habitat, but within meadow habitats, you can find somewhere between 70 and 80 percent of all the biodiversity within the Sierra." - Wyatt Hersey, Field Biologist at Point Blue Conservation Science
Point Blue Conservation Science, partners with Lassen Volcanic National Park to analyze and record bird population data. Ryan Burnett, is their Sierra Nevada group director. He said current data shows a decline in migratory meadow bird populations across the Sierra Nevada. He’s not sure why this is happening, but one theory is habitat loss. Birds that spend part of their lives in the Sierra Nevada rely heavily off of meadows in order to fatten up on bugs before making the trip to South America.
Wyatt Hersey, is a seasonal field biologists with Point Blue Conservation Science and studies meadow habitat.
“Only one percent of the surface area of the Sierras is meadow habitat,” Hersey said. “But within meadow habitats, you can find somewhere between 70 and 80 percent of all the biodiversity within the Sierra.”
Hersey is helping with the day’s bird banding demonstration. He said that since meadows are rare in the Sierra Nevada to begin with, conserving the remaining area is crucial.
“Unfortunately a lot of the meadows in the Sierras are degraded and that’s part of the work that we’re doing is doing restoration and monitoring in the meadow habitats to try to get them back to fully functioning meadows,” he said.
Hersey hopes that by doing demonstrations people will have a better understanding about why the science to monitor birds – and birds themselves – are so important. He said there's a lot that’s unique about the birds in Lassen Volcanic National Park, including that many of the park’s birds live longer than usual.
“We have the oldest recorded MacGillivray that was at our Gurnsey Creek banding station and he was 18 years old,” Hersey said.
The average lifespan for the MacGillivray Warbler is five to six years. According to the data from the park’s bird banding station, lifespans for several other bird species are also higher in Lassen Volcanic National Park than the northwest regional average. Park biologists can’t say for certain why this is the case, but they say it does at least show that the park and its habitat are crucial for these species.
https://www.youtube.com/watch?v=Uxy5EMsRCro
