Just Duke - Mostly Tech Ponderings

Several years ago, I caught a story on cable news pretty much quoting a BBC News report about a phenomenon that was happening in Germany. Witnesses were reporting that thousand's of Frogs from a certain pond were swelling up and literally exploding with their entrails spreading as far as three feet! What made this even more interesting was that most of the time, this seemed to happen between 2:00 and 3:00 AM. At the time, there were a few theories, but no concrete evidence to explain specifically why this was happening.

This morning, for some reason, I remembered that story. I wondered if this mystery ever got solved. So I opened up Google, and started the quest. Most of the material that I found seemed to be dated around an April 2005 timeline. Wikipedia offered some possible theories.

Toads

According to worldwide media reports in April 2005, toads in the Altona district of Hamburg were observed by nature protection officials to swell up with gases and explode, propelling their innards for distances of up to one metre. These incidents prompted local residents to refer to the area's lake—home to the toads—as "Tümpel des Todes" (Pool of Death). The incidents were reported as occurring with greatest frequency between 2 and 3 a.m. Werner Smolnik, environmental movement worker, stated on April 26, 2005, at least 1,000 toads had died in this manner over a series of a few days.

According to a witness, "toads swell up to three-and-a-half times their normal size before blowing up", and were noted to live a short time after exploding.

Theories

Berlin veterinarian Franz Mutschmann collected corpses and performed necropsies. He theorised that the phenomenon was linked to a recent influx of predatory crows to the area. He stated that the cause was a mixture of crow attacks and the natural puff up defense of the toads. Crows attacked the toads to pick through the skin between the amphibian's chest and abdominal cavity, picking out the liver, which appears to be a delicacy for crows in the area. In a defensive move, the toads begin to blow themselves up, which in turn, due to the hole in the toad's body and the missing liver, led to a rupture of blood vessels and lungs, and to the spreading of intestines. The apparent epidemic nature of the phenomenon was also explained by Mutschmann: "Crows are intelligent animals. They learn very quickly how to eat the toads' livers.

Other theories included a viral or fungal infection, possibly one also affecting foreign horses involved in racing at a nearby track. However, laboratory tests were unable to detect an infectious agent.

My personal problem with the Crow Theory is that if crows are eating the livers, are they eating up to one thousand frog livers in this area in a day? And why do the frogs who are now missing livers all seem to wait until 2:00-3:00 AM to explode?

Panda's Thumb blog did a piece on this, surmizing that this was probably something sensationalized by the media.  This article, as well as some of the comments are very entertaining. 

Mythbusters forum asked it's viewers if this would be worth doing on their TV show. This piece does a good job of summarizing exploding frogs in popular culture.

But here is the bottom line: It seems that this mystery never did get totally solved! It seems there really was something going on here for a few weeks, but whatever that was, it seems to have ended.

Your speculation is totally welcome in the comments below.