Do Sea Snakes Anticipate Tropical Storms


Meeting Abstract

19.4  Monday, Jan. 4  Do Sea Snakes Anticipate Tropical Storms? LILLYWHITE, H.B.*; LIU, Y-L; TU, M-C; University of Florida, Gainesville; National Taiwan Normal University; National Taiwan Normal University hblill@ufl.edu

Laticauda spp. sea snakes inhabit coastal zones characterized by high energy due to tidal surge and wave action. The impact on sea snakes of the dynamic energy regimes associated with coastal environments can be especially intense during tropical storms, yet almost nothing is known concerning how sea snakes cope with rough seas. We are investigating the ecology of sea snakes at Lanyu Island, Taiwan, where we have sampled several coastal sites repetitively during 5 previous years. Three species of Laticauda are relatively abundant: L. colubrina, laticaudata, and semifasciata. The mean number of all sea snakes counted during prescribed 1h sampling periods at one focal site was 35 during 2005–2008. Recently, we were present on Lanyu during typhoon Morakot, which impacted the island directly from August 7–9, 2009. Winds gusted to near 150 km/h, and extremely rough seas pounded the shoreline and washed heavy rocks inland beyond the beach. We sampled the presence of sea snakes during the evenings of August 5 and 6 before the impact of the typhoon, and we continued observations following passage of the typhoon, Aug 12–17. We counted 7 snakes at one site on Aug 5, and we saw but a single snake during counts at 3 sites on Aug 6. Snakes returned quickly following passage of the typhoon (mean n=21 during Aug 12–17), and the numbers were similar to those we observed well before the storm (n=21, 24 on July 10, 20). A single dead snake was found at one of the sites. Observations suggest the possibility that sea snakes anticipate the approach of a tropical storm and probably find refuge in cavernous spaces beneath coastal rocks where they can surface to breathe air while being protected from wave action. It remains to be determined whether storm–related mortality significantly impacts the population.

the Society for
Integrative &
Comparative
Biology