June: Springtime at Deer Flat National Wildlife Refuge. Team members of the US Fish and Wildlife Service are taking me out onto the lake to check out the colonies of Western Grebe; it's mating season. Lake Lowell's smartweed is beginning to spread — a good sign.
Eddie Owens, Deer Flat National Wildlife Refuge Manager, explains, "The smartweed was planted in the '40s and '50s by refuge staff. This was intentional; staff planted it as habitat for fish and wildlife. We have historical records of large colonies on the southeast side of the lake."
Western Grebes are water birds — taking off and landing exclusively in the water makes studying difficult.
"We know these birds breed here. When they leave here, we don't know exactly where these birds are going," Owens says.
Migratory birds' travel is often tracked by solar GPS units on their feet, but that doesn’t work with grebes. They spend so much time with their feet in the water that their GPS units don’t get enough sun to stay charged.
Water levels have been rising throughout the spring. Water flows from the New York Canal began to fill Lake Lowell in March. The lake is used as storage for irrigation water, serving over 200,000 acres of farmland throughout Canyon County. In April, the lake will be ready for recreationists.
The morning on the lake is a quiet one — the Grebes hidden in the smartweed as mating season begins. Their courtship—a dance that sees them skipping along the water.
September: Four months after observing the Grebes' mating rituals, it’s time for the Fish and Wildlife Service to survey the smartweed to see how the Grebes are faring.
Christina Contreras, Urban Wildlife Biologist, says, "I'm looking for grebes either nesting on the smartweed or just swimming through it. So any sort of data that will indicate nesting success and also just general population success."
The team's first surveys of the season counted 209 birds.
"And as of last week, we now have a population count of 585, and 70 of those were juveniles and chicks, which indicates good nesting success," Contreras reports.
Deer Flat National Wildlife Refuge has been seeing a decline in the Grebe population — an added mystery to their migration patterns.
Owens states, "Because the grebes are understudied and we don't fully understand what's causing the population decline here at Deer Flat, we're taking every precaution."
"The primary precaution: no-wake zones. We use these no-wake zones to identify where they nest, set up a buffer zone for them, have a closed area, and just to be extra cautious," he adds.
The lake's purpose for irrigation causes water levels to fluctuate more than in a natural lake. As the season progresses, some nests get left high and dry.
"We know there's a decline just in general," Owens says. "There’s enough citizen science out there to show the trends over time and indicate the decline."
