Life History, Abundance, Activity, and Special Behaviors
This species is a common and nocturnal treefrog. Breeding occurs in the dry season, when the streams are shallow and clear. Males may call sporadically during the non-breeding season. Often, they will call in succession from a segment of the streambed on rocks or gravel bars (Savage 2002). Their calls are characterized by pulsing, high-pitched notes, which rise in volume at the end. They may be in single or double pairs, and are often called in rapid succession for approximately 5-10 seconds, then followed by silence for a long period of time (Guyer and Donnelly 2005). Females are stimulated by heavy rains to gather in large groups to breed. This may occur a few times at each site during the breeding seasons, depending on the number of rainy days. It is not known whether females lay more than one clutch per breeding season. Amplexus occurs near the shore or in the water. Oviposited eggs adhere to each other in masses of 20 to 50 eggs. The benthic larvae live in shallow, clear water where they use their large oral discs to clamp onto rocks to maintain stability (Savage 2002).
Malone (2004) observed that S. sordida constructs three different types of basins for egg deposition, in addition to laying eggs directly into streams or on substrate over streams. Eggs were either buried beneath substrate, deposited in an open basin with water, or deposited in an open basin with eggs attached to rocks or substrate at the bottom. While amplectant pairs dug to lay eggs beneath substrate, single males continuously attacked them to dislodge the male. Of the five pairs, one male was successfully dislodged. During digging, some females will use a dig/turn method where they will dig a depression, turn 45 to 90 degrees, then continued digging. This created an open basin with edges "delineated by small ramparts." These different methods in egg deposition may be attempts at avoiding cannibalism of the eggs by conspecific tadpoles. At the beginning of the breeding season, tadpoles are scarce and thus females will lay eggs directly in the stream. However, towards the middle and end of the breeding season, eggs were deposited in basins, apparently due to higher tadpole densities in streams (Malone 2004).
- Duellman, W. E. (2001). The Hylid Frogs of Middle America. Society for the Study of Amphibians and Reptiles, Ithaca, New York.
- Guyer, C., and Donnelly, M. A. (2005). Amphibians and Reptiles of La Selva, Costa Rica and the Caribbean Slope: A Comprehensive Guide. University of California Press, Berkeley.
- IUCN, Conservation International, and Nature Serve. 2006. Global Amphibian Assessment: Smilisca sordida. www.globalamphibians.org. Accessed on 21 November 2007.
- Leenders, T. (2001). A Guide to Amphibians And Reptiles of Costa Rica. Zona Tropical, Miami.
- Malone, J. H. (2004). ''Reproduction in three species of Smilisca from Costa Rica.'' Journal of Herpetology, 38(1), 27-35.
- McCranie, J. R., and Wilson, L. D. (2002). ''The Amphibians of Honduras.'' Contributions to Herpetology, Vol 19. K. Adler and T. D. Perry, eds., Society for the Study of Amphibians and Reptiles, Ithaca, New York.
- Savage, J. M. (2002). The Amphibians and Reptiles of Costa Rica. University of Chicago Press, Chicago and London.