Frogs and salamanders like glow sticks say Penn State researchers
While glow sticks have illuminated many parties, concerts and celebrations for years, they now have a new application: biological research, according to a recent report released by Penn State.
With amphibian populations declining around the world and funds to find the causes scarce, a team of Penn State researchers demonstrated that glow sticks — cheap, self-contained, short-term light-sources — attract adult salamanders and frogs to traps set in vernal pools where they come to reproduce in the spring, according to Penn State.
“This work is important because research funding is often limited, especially when we're talking about amphibians and reptiles compared to mammals or other charismatic species,” said David Miller, assistant professor of wildlife population ecology, Penn State's College of Agricultural Sciences, in Penn State's report.
As part of a long-term national study, Miller's lab has been monitoring amphibian populations at sites around the state.
One of the researchers using the glow sticks is David Munoz, doctoral degree candidate in ecology, who helped create the Salamander Population Adaptation Research Collaboration Network.
It was his idea to “bait” traps with glow sticks at one site, State Game Land 176 in Centre County, where there is a dense network of vernal pools where Miller's lab has been monitoring amphibian populations for years.
Over the course of nine trapping nights, researchers captured 4,935 amphibians.
Glow sticks increased the average number of captures of spotted salamanders by more than three times, Jefferson salamanders by nearly four times, wood frogs by almost three times and Eastern newts by as much as six times, compared to control traps.
Why are glow sticks effective lures for capturing amphibians? Penn State researchers are not sure. It is likely a straightforward visual cue, but it could be more than that, according to Munoz.
It is generally accepted that amphibians do not eat while they are breeding but it is possible that the light actually attracts different organisms that the amphibians may eat — perhaps the amphibians are gravitating toward those species, he explained.
The research using the glow sticks was published in Herpetological Review and focused on adult amphibians, according to the lead researcher Michael Antonishak, an Penn State undergraduate majoring in wildlife and fisheries science when the study was done.
“We specifically focus on the adult stage of amphibians because life history suggests adults play the most critical role in population persistence,” he said in Penn State's report. “Capturing adults also make techniques such as mark-recapture feasible, providing estimates of abundance and survival to improve conservation decisions.”