Wandering Cave Crickets

Cave crickets in Texas venture up to twice as far from their homes than previously thought, a new study reports.

The finding may mean that protective buffer zones around the caves need to be extended to protect the crickets (Ceuthophilus secretus) and endangered invertebrate species that live in the caves.

The U.S. Fish and Wildlife Service use data from such fieldwork when drawing up buffer zones around caves. Buffer zones in turn are used to determine where treatments against red fire ants, an invasive species that compete with the crickets, are applied.

Crickets are a crucial link in the food chain of cave invertebrates, some of them endangered. Various spiders, pseudoscorpians and beetles depend on the nutrients that crickets bring in from their night foraging for their survival.

Previous measurement studies involving the use of bait stations reported that most crickets stayed within 50 meters (64 feet) of their caves. But bait stations could lead to biased measurements since the crickets would be drawn towards the free food, the researchers said.

Instead, the researchers collected the crickets as they emerged from their caves at night and marked them with fluorescent paint. On subsequent nights, the researchers would then go out looking for crickets using portable blacklights and document where they found the crickets.

The researchers believe their method of measuring cricket foraging behavior is more natural. Their findings suggest that most crickets travel up to 80 meters (262 feet) from the cave entrances, and some even venture as far out as 105 meters (344 feet).

The researchers also suggest creating buffer zones around the base of the cave and not just the entrance, since the crickets may be leaving through hidden openings apart from the main entrance.

The finding was reported in a September issue of the journal American Midland Naturalist.

--Ker Than

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Credit:  Jean K. Krejca, Zara Environmental LLC