Dawn M. Smith's Blog
Posted by Dawn M. Smith
Amphibians have long been known to camouflage themselves by changing color. But some tree frogs in Costa Rica may also have been using the technique to kill off the chytrid fungus that is devastating amphibians around the world. Comparing these frogs with others who lack this particular pigment may tell scientists whether reduced light levels are involved in the increase in disease.
The scientists are using a new type of scanning mechanism called Optical Coherence Tomography (OCT) to study the changes in the skin of the frogs. Using OCT they don’t have to touch the frogs to get their information, meaning the amphibians are less stressed and the scientists will not unwittingly transmit the chytrid disease by handling the frogs.
The ability to withstand strong sunlight appears to be linked to the presence of a skin pigment known as pterorhodin. The frogs that have pterorhodin also appear to be able to change skin texture to a metallic sheen, which may allow them to withstand higher temperatures, such as those they would be exposed to when basking in the treetops of the rainforest.
Those temperatures may be just what is needed to kill off the chytrid fungus that is affecting frogs populations all over the world. But if, as the scientists suspect, increased cloud cover over the rainforest is reducing the frogs’s exposure to the temperature (or possibly the type of UV light) needed to destroy the fungus, it would help explain why the disease is on the rise.
And give us all one more reason to be concerned about the myriad effects climate change may be having.
Posted by Dawn M. Smith
Translocation is the capture, movement and release of wildlife from one location to another.
Reintroduction, a specific type of translocation, is the movement of animals back into an area they once inhabited.
Reintroduction can be used:
- To create separate populations of endangered species, improving the species’ chance for survival
- To repatriate species which have been confiscated from illegal trade
- To repopulate areas where heavy poaching has removed many, or even all, of the important species originally found there.
Reintroduction of endangered species tends to be controversial because the results have been mixed. A 1989 US Fish and Wildlife Service (FWS) report states that:
“The least successful translocations involved short-term releases of small numbers of captive-reared threatened or endangered species on the periphery or outside of historical ranges, in areas of low quality habitat quality where physically similar competitors are present.”
There are at least 5 variables (number of animals, captive rearing, historic presence, habitat quality and competition) listed here that could have an effect on the success of the translocation. Do each of the variable affect success equally or are some more critical than others? To me it seems illogical to move endangered animals into marginal habitat. Removal of just that one variable might create significantly different results.
Another type of translocation involves moving species to mitigate human-animal conflict issues. This is probably the most controversial as it does often result in merely relocating the problem. Careful selection of translocation sites may prevent further conflict.
While some types of translocation have earned a permanent place in wildlife conservation, in general, movement of animals needs to be carefully considered to ensure that the best interests of the individual animals and the species are being protected.
Posted by Dawn M. Smith
It is a shame that the record numbers of manatees lost in 2006 were the main impetus for the decision by the Florida Fish and Wildlife Conservation Commission to delay downlisting the species from Endangered to Threatened. But the manatee situation helped focus public interest on the underlying problem, a flawed system for evaluating whether a species was endangered or not.
As an example, the Florida panther (Puma concolor coryi), would also be eligible for downlisting under the present criteria used by the Florida FWCC. This panther is considered one of the most endangered subspecies on earth with less than 100 adults in only one known breeding population.
But the public spoke, nearly 28,000 messages were sent to the governor’s office, asking him to keep the pressure on the commission. For those who made the effort, a very special thanks from the manatee and all the other Florida wildlife that will be helped by this change in attitude.
As 2007 comes to a close it is good to focus on some positive wildlife conservation news. I hope I can share more good news in 2008.
Posted by Dawn M. Smith
On both coasts of the United States, sea turtles are receiving some much-needed attention. When an area is designated as critical habitat for an endangered species, increased protections are put in place. This is the goal of two petitions presently before US government agencies charged with safeguarding sea turtles in US waters.
Fisheries interaction is the most important threat sea turtles face. Designation of critical habitat would reduce incidence of fisheries entanglement for sea turtles in both the Atlantic and Pacific.
In the Pacific, a petition to designate critical habitat for leatherback sea turtles would prevent fishermen from gaining access to feeding areas used by the leatherbacks. The areas would still be open for fishing when the sea turtles are not present.
In the Atlantic, efforts are underway to protect both feeding and nesting areas used by the North Atlantic population of loggerhead sea turtles. Two important feeding areas and 4 nesting areas would benefit from decreased fishing. The nesting areas would be protected against other types of human interference, including light pollution which disorients females returning to lay their eggs and hatchlings making their way to sea for the first time.
Lets hope that the US Fish and Wildlife Service and the National Marine Fisheries Service make the right decision this time. Our oceans are much the richer for the presence of these ancient sea creatures.
Posted by Dawn M. Smith
The slow moving, coastal dwelling manatee has come up against the powerful boating and development lobbies, both in Florida and nationally. On December 5th, 2007 the Florida Fish and Wildlife Conservation Commission (FWCC) meets to vote on downlisting the Florida manatee from Endangered to Threatened.
Whether the Commission will spend the time at the December meeting in review of their questionable listing categories or go ahead and downlist the Florida manatee remains to be seen. What happens will tell a great deal about Florida’s commitment to protecting wildlife.
Meanwhile there is pressure at the federal level to for the US Fish and Wildlife Service (FWS) to downlist the Florida manatee as well, despite the fact that there were record numbers of deaths of this endangered species in 2006.
Let the FWS and the FWCC know that you want the Florida manatee properly protected. Your message will be most effective if you add a personal note or, better yet, if you take the information and use it to create your own message.
