If you think some of those salamanders that you've seen crossing area roadways recently are much larger than normal, you are right. For reasons unknown, this has been a banner year for producing huge salamanders. So much so that the known record length could soon be shattered.
"These are gigantic," said Christopher Beachy, a Minot State University biology professor who closely studies salamanders. "We're working the problem now."
The problem is, why is the Minot region suddenly producing huge salamanders that are nearly double their usual length? The record length for a North Dakota salamander, according to Beachy, is 13 1/2 inches. The record still stands, but Beachy has already seen hundreds of salamanders this year at least a foot in length. It may only be a matter of time before someone comes across a salamander that will shatter the record.
These salamanders were collected northwest of Minot by Steve Whitesell. They are much larger than those normally seen in North Dakota, but typical of the phenomenal growth of salamanders in the region recently. Christopher Beachy, Minot State University biology department, is leading an effort to discover why the salamanders have reached such large sizes.
North Dakota salamanders typically leave ponds and sloughs in late April or early May during the breeding season. It is then that motorists often see the slow moving creatures crossing roads and highways, sometimes in large numbers. This year though the spring movement was barely noticeable. Instead, the salamanders began their visible movements in late July and, to some extent, are continuing to move today.
"The timings are weird," said Beachy. "These big salamanders apparently received some cue when to metamorphosize."
Salamanders date back millions of years, to the age of the dinosaurs. They are incredibly unique due to their ability to breathe underwater as young "mud puppies" and then undergo a metamorphosis that allows them to move onto land, the habitat usually preferred by adult salamanders. In one of nature's most unusual changes, salamanders metamorphose into a terrestrial animal, losing their gills and developing lungs. However, says Beachy, it appears that salamander movement to land was delayed this year.
"Apparently, under certain conditions, they can become a breeding animal without ever leaving the water," said Beachy. "If they don't have a reason to leave the water they can grow to great sizes."
They certainly have. Many of the salamanders seen crossing roadways recently more closely resemble small alligators that the normal 6 to 8 inch salamander. Their immense size, in salamander terms, may be evidence that pond living has been very good recently. That could be due to an excess of moisture that had built up in the area prior to the flood of 2011. Many area water bodies remain at or very near their highest recorded levels. Higher water generally leads to more food in a lake or slough.
"As big as they are they are full of the tiniest little things," said Beachy. "Things like midge larvae and water fleas. They can be loaded with them. They act like whales, filter feeding. We are discovering things we never knew before."
One of the discoveries occurred in North Dakota when one of Beachy's students, Alex Radi, discovered salamander activity under the ice. Radi was able to video the salamanders swimming and feeding during a time period of which little was known about salamander behavior.
"No one knew this before," said Beachy. "The pond under the ice was loaded with salamanders. I think they are feeding and growing in the middle of winter. I've been working with salamanders for 25 years and the more I learn, the less I know."
Beachy recently returned from a conference on reptiles in Vancouver, B.C. During a presentation he showed several videos of salamanders which were collected during the winter months.
"I didn't expect it, but the video just blew away everybody at the conference," said Beachy. "In wetlands with no fish, salamanders are effectively the alligators in the wetlands. The big ones are just unstoppable."
It may be that life in overflowing wetlands full of food was just to good for salamanders to lose their gills and crawl onto land. The recharged wetlands may be responsible for allowing salamanders to gorge themselves, producing some of the largest salamanders ever seen in North Dakota.
"These animals, the gigantic ones, could be anywhere from 1 to 5 years old," said Beachy. "Their growth is really remarkable, more so in North Dakota than elsewhere."
North Dakota's salamanders have long been known as Tiger salamanders, even though many of them lacked the telltale striping that gave tigers their name. Researchers now generally agree that North Dakota is home to two distinct species of salamanders - the Eastern tiger and the Western salamander.
"No one denies it anymore," said Beachy. "Once upon a time they were tigers all across North America. It's clear now that what we have is a different species. Now everyone calls what we have here the Western tiger salamander. In North Dakota you can see almost anything for color. Occasionally we see yellow and green salamanders, but usually they are plain olive with black spots."
Beachy is always eager to learn more about salamanders and he seeks as much input from the public as possible. He encourages anyone with information or photographs of salamanders to contact him at MSU either by e-mail at email@example.com or by calling the MSU biology department at 858-3164.
Information on salamanders in North Dakota, including video of salamanders swimming under the ice, can be found at (amphibiangrowthproject.org).