A Motivating Herd of Squirrel Frogs

I’ve really neglected this blog the last few months… There’s really no excuse for the lack of posts; I’ve just been tied-up with work, extra work (thanks for nothing BP) and personal commitments. In an effort to get things rolling again, I thought that posting a couple of snapshots would be a good idea. Small steps…

Despite a recent malaise brought about by incidents in the Gulf of Mexico, I was briefly inspired this weekend when I discovered a couple hundred juvenile frogs in my backyard. Yeah, a COUPLE HUNDRED!

Though, I’m not exactly certain where the deed went down (no ponds or puddles around), my best guess is that about 45-days ago (tadpole-to-froglet growth time) a couple (perhaps a few) of the squirrel frogs that reside in the rafters of my porch got “frisky” (i.e. mated). The result: hundreds of these guys in my yard:

Squirrel frogs (Hyla squirella) are common throughout the Southeastern United States. They’re terrestrial tree frogs that breed and undergo early development in water (puddles, ponds, ditches, etc…). Once sufficiently mature to undertake travel, they move to forested areas (or the exteriors of human dwellings) to live as adults. Eventually, the upland dwelling adult frogs return to water to reproduce and the cycle starts anew.

As another quick natural history note, Hyla squirella are at least bimodel when it comes to sexual selection. Like many frog species, the females home-in on distant males by converging on the sound of the male’s song; but, in addition to sound, female squirrel frogs also select mates based on appearance.

Squirrel frog in rafters of porch

Males with low-frequency and energetic calls are preferred by the females, but the females also consider the size of the yellow stripe that runs down the male’s side. The male’s yellow stripe may give some indication as to his overall health.

Dead Zones, Conservation and Commercial Fishing

I’ve just read in the local news that Kevin Craig from the Florida State University’s Coastal and Marine Laboratory will be heading-up a collaborative four-year project funded by NOAA's Northern Gulf of Mexico Ecosystem and Hypoxia Assessment Program. The project’s goal is to assess the impact of the Gulf of Mexico’s ‘dead zone’ on marine ecosystems with a particular focus on shrimp and the shrimping industry.

It has long been known that agricultural run-off carrying excesses of fertilizer from the ‘bread basket’ of the United States are finding their way into the tributaries of the Mississippi River, and in turn, into the Gulf of Mexico. Once in the Gulf they consequently spawn explosions of algae growth resulting in hypoxic conditions and the conception of massive Dead Zones. Surges in the growth of algae and other noxious plants as a product of fertilizer facilitated Nitrogen and Phosphorous loading is called eutrophication. Eutrophication leads to de-oxygenated environments, and the resultant death of those organisms that require oxygen - of which there are many. The loss of oxygen-dependent organisms leaves vacant important positions in long established food-webs, potentially leading to the total breakdown of ecosystem function. To make matters worse, far from being stationary the dead zones move or “creep” from their epicenters corrupting ecosystems both far and wide. For Florida, the Gulf of Mexico Dead Zone may contribute to “Red Tide” and the death of everything from phytoplankton to manatees in the State’s coastal waters.

Kevin Craig is certainly the person for the job; back in 2005 he wrapped-up a research project that examined the effects of hypoxia on the abundance and distribution of Farfantepenaeus aztecus - the Gulf of Mexico’s ‘brown shrimp’. In that study, Craig, Larry Crowder, and Tyrrell Henwood used shrimp trawl surveys to compare the distributions of shrimp between hypoxic and non-hypoxic areas. What the team found was that the spatial distribution of shrimp in hypoxic regions was substantially different that those associated with non-hypoxic areas. The researchers also concluded that the effects of hypoxia contributed to as much as a 25% loss in F. aztecus’s available habitat.

The new NOAA funded project will undoubtedly have implications for both the science of ecology and in that of conservation. Shrimping is a major industry in the United States, and as such the participating fishermen and other commercial industries hold considerable economic and political clout. I'm eerily reminded of the warnings from biologists that were left unheeded and initially overthrown by rule-makers during the collapse of the Northern Cod Fishery…


Craig, J., Crowder, L., & Henwood, T. (2005). Spatial distribution of brown shrimp (Farfantepenaeus aztecus) on the northwestern Gulf of Mexico shelf: effects of abundance and hypoxia Canadian Journal of Fisheries and Aquatic Sciences, 62 (6), 1295-1308 DOI: 10.1139/f05-036