Water causes ripple in Fermilab bird sightings
Great blue heron
Image courtesy of Eric Vaandering
Fermilab has always been a haven for our feathered friends, but this year bird expert and AD physicist Peter Kasper said we're seeing fewer birds than in the past two years.
But the decline in bird sightings has more to do with the end of a drought-fed spike than a drop in Fermilab's avian appeal. A 2005 drought brought a general influx of birds in 2005 and 2006, including herons, egrets and cormorants. The drought also attracted a rare influx of shorebird species. The increased rain this year destroyed the muddy shores they used for breeding, removing Fermilab's appeal.
"During the past two years, Fermilab was a bird-watcher's paradise," said Kasper, who runs the Birds of Fermilab Web site.
The 2005 drought caused water levels to drop at DUSAF and A.E. Sea ponds near the Village on the laboratory's east side. At the same time, the laboratory started pumping water out of DUSAF Pond to replenish the cooling system that was hit hard by the heat wave.
"DUSAF Pond was pretty much totally dry," said Rod Walton, Fermilab's resident ecologist.
Kasper said that the low water levels and the developing mud flats -- exposed muddy deposits along the pond shores -- were coinciding factors that made Fermilab look like a bird resort. Wading and seabirds, attracted by the easy fish access, flocked to the ponds. Varying species of shorebirds, very long-distance migratory birds that travel from the southern portion of the Southern Hemisphere to the Artic tundra, stopped at Fermilab's new mudflats.
The drought eased in 2006, but the ecological impacts from 2005 brought a different crop of birds. New plants had taken root in the mud. That trapped more silt, raising the pond floor and creating a more-bird friendly environment when the water returned. Wet-area plants, including reeds, sprang up along the shore, and in some cases, in the middle of the lakes themselves. These plants provide ideal breeding conditions and a thriving aquatic food source.
The rain has returned, and the number and types of birds spotted has reverted to its normal state, which includes a slow area-wide increase in fishing birds, such as herons, egrets and cormorants.
Change brings biodiversity, said Kasper, meaning that Fermilab's areas will attract different species at different times, a great thing for birdwatchers. Although water levels have risen somewhat, the drought's lasting impacts on vegetation could be an attraction for birds in the future.
View a list of bird species seen at Fermilab this year.
-- Tona Kunz and Rhianna Wisniewski
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