Exploding toad

An exploding toad occurs when a crow, hunting for toad liver, attacks a toad which then puffs up as a natural defense. The phenomenon was first noticed in April 2005 in districts of Hamburg, Germany, and near a lake at Låsby, Denmark, dubbed "The Pond of Death." No other animals in the area were exploding.

What differentiates the exploding toads in these incidents from most other exploding animals is that they explode while alive. Exploding whales, for example, are a result of the buildup of gases during the process of decomposition.

Description

According to worldwide media reports in late April 2005, numerous 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 meter. 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".

Explanations

Berlin veterinarian Franz Mutschmann collected corpses and performed autopsies. From his work, it was determined that the phenomenon was linked to a recent influx of predatory crows to the area. 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."

Previous explanations 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. Danish biologists suggested pesticides as an explanation. Yet another explanation was that increased ultraviolet radiation caused by ozone depletion was to blame.

See also

• Decline in frog populations
• Spontaneous human combustion