The clock struck 7 a.m. Before a backdrop of amber sunrise, thousands of goose silhouettes speckled the sky. The uproar of a many thousand goose choir, which echoed from the darkness before first light, now had visual presence for couple dozen birders watching the sky from the bank of Freezout Lake Friday morning.
Annually, near the end of March, the lake plays host for up to 300,000 “white geese” -- Ross’ Geese and Snow Geese -- as they migrate north from California to their nesting grounds in the Arctic.
“We have actually been seeing the numbers of white geese hovering between 10,000 and 15,000 for the last week,” said Montana Fish, Wildlife and Parks wildlife biologist Brent Lonner.
The population spiked to 50,000 on the Thursday, which signaled biologists to think the peak of the migration is occurring through the next couple of days. On Friday, geese numbers were around 20,000 and swans around 150.
For most of the geese, the central Montana wetland is the “first main stop to rest and feed after leaving their winter grounds of California,” said Lonner.
“I expect a week from now we will start to see a decrease in the numbers of white geese migrating through,” said Lonner.
The migration usually peaks between the 26th and 28th of March every year, but it is most likely occurring a few days earlier this year.
According to Lonner, a major weather system in the northwest can slow down the migration, but it is predominantly driven by the length of days. As the days get longer, the birds a begin to initiate the migration based on the “photo-period” of the day.
Acquiring a precise count on the birds is more difficult as flock numbers get greater. Biologists count the birds in units of hundreds, then multiply same size units until they have a good guess on the whole flock size.
“With the migration a little earlier this year, this weekend will be a good time to see it,” Lonner said.