Global Amphibian Decline
The past two decades, amphibians have had significant declines in their population worldwide. There is a great deal of evidence for such declines from North, Central and South America, Europe, Africa and Australia.
Global amphibian decline is attributed to the effects of habitat destruction; alteration, isolation pockets, climate change, chemical and other pollution, fungal, bacterial have contributed to declines that often have no obvious cause.
The vast majority of the more than 6,000 species of frogs in the world lay eggs in water, but many tropical frogs make it out of the water environment to lay eggs. This strategy protects amphibian eggs from predators, but in times of insufficient rain fall and drought this strategy can destroy whole reproduction cycles because of dehydration, in some cases of endangered species it can wipe them out entirely.
Researchers report that climate change may be altering the evolution of some amphibians, causing these animals to alter behaviors to adapt to low rainfall.
Research in biological hotspots such as Panama and Costa Rica show that over the past 4 decade rain fall has declined but maybe more importantly it is frequency and consistence of rain periods that have changed. In Costa Rica there are approximately 175 amphibious species
The embryos of some amphibian are extremely susceptible to rain frequency in some cases they die in just a few days if there is no rain. Rainfall also triggers reproduction cycles, so the lack of rain in the period immediately after the egg laying phase has dramatic effects on population.
With climate change, amphibians are considered one of the most threatened species with approximately half of the more than 6,000 known species in decline and one in three in danger of extinction.
Amphibians are very susceptible to environmental conditions and pollutants because of their sensitive skin requiring certain levels of moisture to survive and reproduce.
Fungal diseases such as Batrachochytrium dendrobatidis, sometimes called simply Bd, kills amphibians affecting their permeable skin, ultimately causing heart failure.
In Costa Rica and Panama the disease continues to advance, according to the Smithsonian Tropical Research Institute (http://www.stri.si.edu/espanol/index.php) that has the Amphibian Rescue and Conservation Project.
In Costa Rica this year there cause for alarm this year as El Niño has resulted in approximately 18% less rainfall nationally and as much 80% in some northern regions, some experts have stated the possibility of a “tropical drought” this coming summer season, which could have devastation effects of amphibious population and other species as well.
The Costa Rica News (TCRN)
San Jose Costa Rica