The Great New Mexico Bird die-Off: One Year Later

Last year thousands of migratory birds died across the state in August and September for reasons that were at first unexplained. Now ornithologists know these deaths were caused by starvation and hypothermia. A historic cold snap had killed insects that the birds depended on as a food source. Birds possess a unique physiology that allows them to put on and burn off fat in real time, allowing for instant thermoregulation and immediate energy. Without a stable food source to depend upon, the migratory birds fled the cold elevations, but didn’t have enough body fat stored to survive the cold.

This year our state is suffering from drought and forest fires, which exacerbate the environmental stresses on migratory birds. Sporadic rains across the state are promising, as monsoons are conducive to insect growth, but migratory birds still have a hard journey ahead of them. Extreme weather is not rare in New Mexico, but occurrences of extreme weather have been steadily increasing over the past 20 years in response to large-scale human actions.
How You Can Help Migratory Birds

Ornithologists don’t have a nationwide tracking system for measuring bird populations and depend on input from amateur bird watchers all across the country for data. The North American Breeding Bird Survey (BBS) is the main source of data for ornithologists and is a partnership between scientists in Canada, the US, and Mexico. Participants of the survey must be experienced birdwatchers, able to identify birds from song and sight, and take a training program to learn the methodology.

If you’re no pro at birdwatching, don’t fret, as there are other ways to help birds and the ornithologists who study them. While putting out bird feeders is a great way to help nesting birds, most of the migratory birds that died were primarily or exclusively insectivores. Mealworms are a favorite treat of insectivores and bags of dried mealworms are easily available. You can allow a natural insect population to flourish by planting a diverse array of native plants and letting them grow. Focus on nectar-producing plants, like Hollyhock, as these are more attractive to insects. Even if you just have a grass lawn, letting it grow will allow insects to thrive. Avoiding the use of pesticides and insecticides on your plants will invite nature’s winged pest controllers to do their job. You can attract more birds by leaving micro-habitats undisturbed—a wood pile, fallen leaves and flowers, or mulch. When winter comes around and trees shed their leaves, let them fall in situ. The birds will thank you for it.

Lastly, the eBird app https://ebird.org/home is a great resource for people new to birding that shares location data with ornithologist labs. If you feel you don’t have the experience to participate in the BBS, tracking your sightings with eBird is a great way to get started. Include as many photos of your sightings as you can, as these help scientists verify the movements of birds.

Note on bird feeders: Currently there is a mysterious illness killing droves of songbirds in the mid-Atlantic area. The cause and nature of the disease are unknown, and residents are being encouraged to clean their feeders with a 10% bleach solution. While there are no cases this far west, it doesn’t hurt to be extra cautious.
Special thanks to Christopher Witt of UNM’s Witt Lab for providing information for this article.