If you live in the Rio Grande Valley, you have probably heard heard the strange croaks of the sandhill crane or the honk of the Ross’s goose overhead when out for a walk along the river.
That’s because, in the fall and winter, tens of thousands of large migratory geese, cranes, and other water fowl nesting in Alaska, Canada, and the northern United States fly south to roost and forage for food.
“It just gets cold up there,” said Tucker Davidson, who primarily works with Audubon Southwest on expanding riparian restoration projects with the aim of improving water availability for birds. “They need soft soil that they can probe their bills into to find invertebrates that aren’t totally frozen over.”
Davidson said that migratory birds look for a combination of wetlands or flooded fields with nearby sources of food to tide them over until they ultimately head back north to nest in the spring.
As it happens, Albuquerque lies in the middle of one of the four major migratory bird corridors in the United States. Beginning in North Dakota, the so-called central flyway pushes birds from north to south – utilizing portions of the Rio Grande as a sky highway that naturally funnels birds down to New Mexico.
It’s pathways like these that are much more preferable than the seemingly indistinguishable prairies and grasslands in other parts of the country. By using the Rio Grande, birds can use unique visual clues like the mountains and the river’s winding ribbons as a guide. There are also other benefits that attract birds.
“Everything needs water on their way south,” Davidson said. “Some of these trips are really, really long. Especially for large migratory birds, they are cuing in on the wetlands along the river.”
Currently, New Mexico is experiencing its driest 20-year period in the last 1200 years, often referred to as a “megadrought” by scientists.
Drought has consequential effects that directly impact birds by causing bouts of dehydration or hypothermia, and reducing the availability of insects, vegetation, and fruits that birds rely on for nutrients.
And conditions for the future are not looking any better. Climate modeling estimates that New Mexico will have significantly less snowfall and, therefore, runoff to fill the Rio Grande – one of the main travel corridors for these birds.
Snowpack is a crucial piece of the climate puzzle for understanding how much water will be in the state’s rivers and streams. For example, models run by KUNM show a decline of 67% to 80% in the average amount of water in New Mexico’s January snowpack, depending on future emissions scenarios.
In addition, state of New Mexico reports estimate that flows into the Rio Grande above Elephant Butte Reservoir will decrease by up to 25% in the next 50 years as annual average temperatures increase from anywhere between 3 to 7 degrees. Other models estimate that the climate could warm even more.
While it is true that the state has made significant strides to reduce its water use since historic peaks in municipal/agricultural use in the 1980s and 90s, a disproportionate amount of the state’s water is used for agriculture.
A recent report estimates that New Mexico uses an eye-popping 80% of its fresh water for agricultural uses – including for dairies, alfalfa, pecans, and chile farming. Within those irrigated acres, most are irrigated with sprinkler systems or flooding.
The widespread technique of flooding fields for crops is a big reason why birds continue to visit New Mexico, even during times of extreme drought.
“Attracting the cranes and geese really is a manufactured thing at this point,” Davidson said. “We have to flood up fields, and if we don't provide corn or supplemental food, then they would probably start to find other places to overwinter.”
But in an increasingly arid Southwest, water policy experts are wary of using scarce water resources to flood fields in the face of a drier future. Instead, they’re endorsing more climate-friendly solutions like drip-irrigation to balance the West’s increasing water appetite and the needs of wildlife.
Without water in the Bosque ecosystem, scientific evidence suggests birds might decide to reroute their migratory path elsewhere in the decades to come, maybe avoiding New Mexico entirely.
