Rare, tagged weta eaten by eel.
15/05/2009 17:09:06
Giant weta, showing transmitter. Photo © Karori Sanctuary Trust.
Conservation staff at a ZEALANDIA were in for a surprise when they tried to track down a tagged giant weta. May 2009. As part of a recent species release, staff at the world-first wildlife sanctuary in Wellington, New Zealand, had fitted 10 giant weta (a large and extremely rare insect) with radio transmitter units to monitor their survival and movements after release.
"We were having trouble locating one of the tagged female weta which had been seen several times sleeping near the stream." said conservation manager Raewyn Empson.
Making a special effort to locate the transmitter before the battery failed, one of the team followed the signal to the source. He was surprised to find the signal emanating from the middle of the stream, not least because weta can't swim. As the signal moved closer to shore, the culprit revealed itself - a very large eel!
Long-finned eel. Photo © Karori Sanctuary Trust.
New Zealand has two species of freshwater eel, and both are found in the Sanctuary. They are aggressive carnivores, hunting fish, crayfish and even ducklings.
"We have observed eels stalking swimming ducklings and assume that they are responsible for the regular disappearance of many ducklings, but this is certainly the first record we have of a giant weta being eaten" said Empson.
$350 transmitter
"Apparently eels don't feed much over winter - it's just a pity that the weta chose to spend her time near the stream at a time a hungry eel was nearby. To be honest, we're hoping the eels don't develop a taste for them! Not only are giant weta are highly endangered but, at $350 a pop, the transmitters make this a very expensive snack!"
Like the clock swallowed by the crocodile in Peter Pan, the batteries in the transmitter have since failed so we don't know where the eel is. Or what she'll be dining on next!
Additional information on the long-finned eelThe long-finned eel is one of the largest freshwater eels in the world. It is found only in New Zealand
They live mainly in rivers and inland lakes but can be found in almost all types of waters, usually well inland from the coast. They are legendary climbers and have made their way well inland in most river systems. Young eels (known as elvers) will climb waterfalls and even dams. It is not unheard of for an eel to climb a waterfall of up to 20 metres. The eel's life-cycle is an extraordinary natural phenomenon. After up to 80 years living in the streams and lakes of New Zealand, they find their way back to the exact area of the Pacific Ocean where they hatched, where they breed for the first time, and then die. Instinctively, the new elvers will migrate back to New Zealand to repeat a cycle that has been going on uninterrupted for 65 million years!
| During the day, eels are secretive, hiding under logs and boulders or under riverbanks. Occasionally, they may be seen out hunting for food but most of their hunting takes place at night. Eels hunt by smell rather than sight. Long-finned eels have a well-developed sense of smell. They have tube nostrils that protrude from the front of their head, above their upper lip. They also have a very large mouth with rows of small, sharp, white teeth. The top teeth form an arrow shape on the roof of the eel's mouth.
Habitat loss (hydro development, culverts, dams, drainage and irrigation schemes and river diversions) has affected eel numbers and impeded their migration. Eel habitat is also impacted by pollution. Sewage and effluent from meat works and pulp and paper plants
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In the UK the headline reads "Rare tagged eel eaten by Weta"
Posted by: John Laughlin | 31 Jan 2012 11:57:02