Have you noticed a flock ton of birds? Here's why

After weeks of waiting eagerly to dust off the binoculars, New Mexico birdwatchers are getting their fix as flocks of late-arriving migrant avians pour into the state.

The spring migration for birds — of all shapes and colors — typically begins in April and ends in late June, though the bulk of bird movement is in May.

On April 21, 2.6 million birds crossed New Mexico on the way to their new homes — a small number compared to weeks later, on May 2, when over 5 million birds traveled through the state in one night, according to BirdCast, a bird migration dashboard from the Cornell Lab that tracks birds in flight. Experts say bird migration times have fluctuated in recent years due to a variety of things, including climate change and resource availability.

“When you look at it from individual species, it’s a real mix, and that’s kind of typical for the way things go,” said Andrew Farnsworth, visiting scientist at the Center for Avian Population Studies at the Cornell Lab of Ornithology. “Part of the reason that’s the case is because these birds are coming from different places, so there are different delays that befall them. There are different levels of preparedness for the birds to migrate.”

The United States typically sees over 3 billion birds migrating during the spring, some of those species soaring over New Mexico include yellow warblers, black-headed grosbeaks and hummingbirds, to name a few. The birds that choose to fly over New Mexico’s largest metro area — Albuquerque and surrounding areas — will face challenges that other feathered friends soaring over more remote areas may avoid.

“From the human perspective, it allows people to see concentrations of birds, which hopefully, in the end, is a good thing for birds, because … it sort of engages people,” Farnsworth said. “... But on the opposite side, cities are super dangerous spots for birds. You think about the built environment and there are two major threats specifically associated with city structures: a lot of glass, reflective and transparent surfaces, and light pollution.”

In the last 50 years, the bird population worldwide has decreased by over a billion, according to Brian Anderson, a member of the Central New Mexico Bird Alliance.

Because of this, the Central New Mexico Bird Alliance has championed the “Lights Out” initiative, which urges people to turn off unnecessary lights, close blinds or curtains and avoid using lights pointing toward the sky to prevent confusion for the avians, who believe reflective surfaces may be large bodies of water, causing harm and even death in some cases.

Climate change is also a factor since bird migrations are based on the seasonality of the planet, Farnsworth said. He added that drier conditions can make it more difficult for birds to travel due to limited resources, such as the lack of water.

“Climate change has some dramatic impacts, both in terms of it speeding up and slowing down movements,” he said. “It kind of depends on the species and where they start. There’s lots of variation.”

As spring transitions to summer, bird watchers and advocates alike will have their eyes on the night sky to watch thousands of birds make their way through New Mexico to their next home.

“Birding is very therapeutic,” Anderson said. “Sit back and get acquainted with the birds in your yard. It can be very relaxing, educational and fun.”