When is a house a home? If you’re a spider, it doesn’t need to be a mansion. It can be as simple as a clump of leaves caught in a tree above a stream.
Biologists call these leaf-litter domiciles “hovels.” Basically they’re clots of stems, twigs, and leaves snagged in tree branches during floods. In a 1998 study on West Clear Creek, researchers from Northern Arizona University found that 92 percent of hovels held at least one spider. Larger ones housed as many as twenty-five spiders representing ten taxonomic families.
NAU graduate students Kayla Lauger, Ryan Lumen, and Heather Gillette, in professor Tom Whitham’s field ecology course, recently revisited the study. They went back to West Clear Creek and added Red Tank Draw, a nearby drier site.
They took random samples of hovels at each location. Back in the lab, they examined the spiders living inside. They found considerably fewer spiders overall, and fewer kinds of spiders, compared to the results eighteen years earlier.
Spiders are top-of-the-line predators in ecosystems, and are also important prey for birds. Because of these dual roles, any actions that affect them deserve attention – protecting riparian habitat, managing for occasional floods, and studying spider response to climate change.
Humble they may be, but without hovels many spiders could become homeless – a fate that could ripple through an entire ecosystem.