Birding has become a popular way to get outside and connect to nature. But newcomers to the hobby might have a skewed baseline of what to consider normal as climate change disrupts the typical progression of seasons. So, what are some of the patterns that longtime birders are noticing in the Las Vegas Valley?
Nature is dynamic, not a still life. As climate change and other pressures, such as urban development, affect our world, it’s difficult to attribute one reason to changes in bird abundance and behavior. One example is migration.
Typically, in the springtime, hormonal cues triggered by increasing day length spark the urge for many birds to migrate north, beginning with the males racing to secure the best breeding territory. “It doesn’t take much to disrupt the vital flyway that birds have to go through twice a year,” says Tim Almond, a local who’s been birding here since 2000. “And we’re seeing earlier migrations.”
Warmer temperatures cause plants to bloom and insects to emerge sooner, so some migrants are arriving and breeding earlier in the calendar year. Whether they reap the rewards of coming early or suffer from a sudden cold snap is part of migration risk and will affect which genes are passed onto the next generation.
This year, birds such as American avocets, a type of shorebird vulnerable to wetland disturbance and drought, arrived as early as mid-February to the Henderson Bird Viewing Preserve, among other Southern Nevada destinations. Historically, they’d arrive in late March or April.
“And it just doesn’t seem to get that cold anymore,” Almond adds. “You see over winter a drop in waterfowl numbers; they’re not being pushed south.”
The warmer temperatures also affect the birding experience itself. Dave Anderson, a bird guide and vice president of the Red Rock Audubon Society, has been birding in Las Vegas since the late 1980s. “Because of the heat,” he says, “I’m birding earlier. The birds are not singing as long and are not active as long. I’m focusing on ... the water because the birds don’t have as (many) water resources, so I’m going to those places to see birds.”
Anderson has also noticed earlier breeding behavior in species such as resident LeConte’s thrashers, which typically sing and hold territories in April from low-elevation Joshua tree woodlands. Development and prolonged drought have affected this bird, along with other species.
As for urban areas, Anderson says, “You don’t really see the same changes,” because most urban birds are more adaptable and will use introduced plant species from our landscaping for foraging and nest building.
Of course, there are exceptions. Specialists such as Lucy’s warblers, which typically nest in mesquite tree cavities along Las Vegas Wash, and burrowing owls, which nest in abandoned burrows excavated by tortoises and small mammals, are experiencing declines because they have no alternatives for breeding in highly urbanized areas.
But while some species are becoming less common, new rarities made appearances in December. Species that normally migrate along the Mississippi Flyway — such as the Cape May warbler, Tennessee warbler, and Northern parula — made appearances at Clark County Wetlands Park, an urban park with cottonwood and willow habitat. Anderson speculates this may be triggered by warmer temperatures shifting the migratory routes of these birds.
“For bird watchers, it’s interesting, because something is messing up (their migration path), and birds are showing up that aren’t usually here,” he says.
These observations are more than anecdotal. Anderson and Almond, like many birders, use an online citizen science platform called eBird, run by the Cornell Lab of Ornithology, to keep checklists of the birds they see in the field.
While the effects of climate change on birds are complex, birders are one group who help contribute to understanding the bigger picture. And as birds change in response to warmer temperatures, prolonged drought, and the pressures of urbanization, birders will be watching.
