July 1 & 2 – Lemming Trapping

Joined: 23 Mar 2004 Posts: 74 Location: Barrow, AK

Kim and I got all of our work done on Tuesday and Wednesday so that we could help Mat Seidensticker with his lemming traps. Mat studies Snowy Owls with the Owl Research Institute in Charlo, MT. (http://www.owlinstitute.org/research.html) Mat sets out trap lines for 5 days each three times during each summer. There are 3 trap lines and each line has 10 locations where 10 traps (like large mouse traps) are set in the lemming runs within a 10 m radius of a marker stake.

So tell me, how many traps does Mat set out total?
How many individual traps does he check each summer total?
How much area of the tundra is he covering with his traps?
(Yes, there are prizes for correct emailed answers)

Each day that the traps are out, Mat checks all of the traps to see if any lemmings, or unfortunately an occasional sparrow, have been caught in the traps. If there are lemmings, he determines their species, brown or collared, their sex, masses them and then brings them in to be dissected. The dissection confirms the sex and allows the researchers to gain other data about the breeding of the lemmings.

Sexing a lemming

Massing a lemming

If there are birds, they are recorded, collected and donated as specimens for museums and such.

Currently, Mat is in the midst of study to see if different color traps will minimize the number of inadvertent bird kills. So at each tundra mound where he will lay traps he randomly picks the trap color by pulling an M&M from his pocket. The colors that they are testing are yellow, orange and brown. After he sets a particular color, he puts that M&M in his other pocket until all the colors are used.

Yellow Trap - http://archive.arcus.org/TREC/phpbb/album_pic.php?pic_id=1001
Orange Trap - http://archive.arcus.org/TREC/phpbb/album_pic.php?pic_id=1002
Brown Trap - http://archive.arcus.org/TREC/phpbb/album_pic.php?pic_id=1003

Click on the above links to see a picture of each trap color.

Which color do you hypothesize would inadvertently catch the most birds? I thought that brown would be the worst because the birds would not be able to see it and would accidentally step into the trap. I know that I had a hard time seeing the brown ones!

So far, with three years of data, though, Mat says that the yellow traps have caught about 75% of the inadvertent bird kills, while brown and orange account for about an equal amount of the remaining 25% or so. So rather than the birds wandering into the traps as they forage, it appears that the birds may be caught when they are possibly “investigating” the yellow traps. Only about 5% of the traps catch birds, so the number is small, but they would still like to minimize it further if possible.

Yesterday it was VERY cold. When we started out, it was windy and we were fogged in. It had gotten below freezing the night before, so icicles were blowing off of the power lines everywhere. We were so cold at first, but we bundled up in about 5 layers, hats and gloves and neck gaiters and once we started hiking, it wasn’t as bad.

We went to the first of the sites, which was back behind the NARL toward the southeast. We hiked about 3/4 of a mile to the beginning of the line and found the first stake. We fanned out to find all 10 traps. When we had found them all, we moved to the next stake. If we found a sprung trap, we looked to see if there were any feathers or fur, reset it, Mat made a note in his book and we moved on. We tried several methods of searching, but discovered that the best method was for everyone to make a line and move around the stake counting together, because sometimes you could only see the trap from certain angle.

Resetting a lemming trap

The second site was at Nunavak Bay, which is an inlet south of town along the coast. The inlet to the bay was running pretty good and it was deeper than our knee boots, so Mat had to ferry Kim and I over on piggyback.

Nunavak Inlet

Piggyback rides!

It was so cold yesterday, that we stopped at the grocery store in town, the Stuoqpaq. It is kind of like a Wal-Mart in that it has groceries and clothes and even four-wheelers! We got coffees and I bought a cool piece of etched baleen from a man named Earl Aiken. Then we continued to our third trap line location.

The last site was at the Mayoeak River, which is several miles past the BEO tower site. Over the course of the whole cold day, we only found 2 dead birds – both Savannah Sparrows – and no lemmings in the traps.

Today the temperature was colder, 31 F, but it was sunny and it seemed warmer. It actually did warm up during the day and we could wear fewer clothes. Of course, warmer and not windy weather in Barrow means mosquitoes galore on the tundra. Hmmm . . . I think I prefer cold and wind.

See that black blob that looks like an airplane? That's a mosquito chasing us on the four-wheeler!! Go faster, Mat!

We found our first lemming at the NARL site, a brown lemming male. He was very large – 77 g – and Mat said he was definitely a breeding male. This was a good sign because the low lemming population here in Barrow has meant that there are not very many Snowy Owls breeding here this year.

Brown lemming

At Nunavak Bay, we still had to be ferried across on piggyback. There we saw two male collared lemmings, which rather than being brown all over, have a blackish stripe down their back and a darker brown and rufous (reddish) sort of mane or collar. Both males were smaller, 36 g and 43 g, probably to young to be breeding, yet.

Collared lemming

While we were at Nunavak and fighting the mosquitoes, we also saw whales off the coast, probably grey whales. You could see the high water spouts as they blew water from their blow holes. We even could see their bodies and their black tail fins as they dove. There were at least 4-5 and they kept reappearing in the same general spot as we worked, so there must have been some good food there.

At our last site, we only caught one smaller collared male – 30 g.
Mat will check his traps again for the next two days and then check and collect them on Monday. In August, traps at the same trap lines will be set out again for 5 days.

You can learn more about Mat Seidensticker and his study of snowy owls in this USA Today article:
http://www.usatoday.com/weather/resources/coldscience/2002-08-27-arctic-owls_x.htm
There is also an article on Snowy Owls that came out in the December, 2002 National Geographic.
You can also look at the Owl Research Institute website:
http://www.owlinstitute.org/research.html

We are all looking forward to this weekend as there are quite a few celebrations and game competitions planned for the Fourth of July. Today there were kids games and races, a tug-o-war that pitted the Inupiaq women agains the Taniq (white) men and games of Eskimo baseball, which appears to be a combination of cricket and dodgeball.