How Many Shrews Can a Rainbow Trout Eat?
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shrew fish final
Today, we meet a rainbow trout with an unbelievable appetite. Mark Lisac is a fish biologist at the Togiak Refuge, and just a few weeks ago he and group of his colleagues were catching rainbow trout for a tracking project. But, one unusually large fish they caught was bleeding, and wasn’t going to survive. So…
“So, the guys who caught it decided to dissect it. Its belly was pretty full, so they wanted to see what it had been eating. No one ever thought they would pull 19 shrews out of it, ” said Lisac. You read that correctly. 19 almost fully preserved shrews. Lisac was shocked.
“I can’t say for certain that I’ve ever seen a well preserved shrew in a stomach analysis,” Lisac said. Let alone 19 of them. Granted, Lisac says they don’t usually dissect fish at the refuge, although he’s seen plenty of trout cut open in his 29 years as a biologist. He says it’s not uncommon for trout to eat small mammals, but a number this large is stunning. He has a theory on how it happened.
“It’s possible that this fish just happened to be in a good channel and there was a flood event or something and then all of the shrews that got washed into the river weren’t actually swimming. They were probably drowned, and this fish just happened to be in the right spot at the right time,” says Lisac. He says that’s because shrews aren’t strong swimmers, unlike voles who can swim across an entire lake. He says some fishermen are aware of this, and use it to their advantage.
“It’s pretty common for fly fisherman to use a vole pattern or a shrew pattern. It’s just a big wad of deer hair tied on a hook, and then it’s trimmed to look like a mouse or a vole. And if the fish are there, they usually find it pretty irresistible,” Lisac said.
Togiak Refuge posted a picture of the trout and its shrew feast on Facebook. It immediately went viral – over 70,000 views at the time of our interview. And right before I spoke to Lisac, he had just gotten out of a phone interview with the BBC.
It sounds like the celebrity trout’s 19-shrew meal might be a record. Lisac says the most he’s ever heard of is seven, and that was inside of a grayling. “It may be surprising at how many fish actually do specialize in that, or it could have just been a freak event,” Lisac said.
And now that this shrew obsession some fish share is more common knowledge, Lisac wonders how many people will still want to catch them. He says a friend of his might have a solution. “He said he’s not going to tell his wife about it. He’s afraid if he tells her she won’t eat grayling anymore,” Lisac said.
And, in case you’re wondering, Lisac says the chances you find a shrew inside of a Salmon are next to impossible.