3/22/2011 5:45:53 PM
Triplets in Churchill
The sun is now setting on my last night in Churchill, Manitoba, and I'm overwhelmed by how amazing my last couple weeks have been. I've been in Churchill with Dr. Nick Lunn to research the Western Hudson Bay polar bear population, in particular mother polar bears emerging from their dens with cubs.
We're interested in the condition of the mothers at this time of year, and we want to tag the cubs in order to follow their progress over the coming years. The opportunity to study the condition of mothers and cubs in spring is rare and very special; I feel extremely fortunate to have had this opportunity.
This was my first trip out onto the sea ice and it was absolutely spectacular. The terrain is so varied, with stretches of flat, pure white ice intermingled with explosions of huge bright blue crystals in fantastic configurations. It is amazing how frozen water can be so beautiful! At one point, while working right on the floe edge right next to Hudson Bay, a curious seal swam nearby to check out what was going on. I would have loved to know what it was thinking!
It was very cold out on the sea ice but working on polar bear moms and cubs is well worth some frozen fingers. We take measurements from the cubs such as length and weight, then give them ear tags and a tattoo with individual ID numbers. This way if we ever capture him or her again then we can look up the ID number to get an idea of his or her age and capture history. We also check mom for ear tags and tattoos to see if she has ever been captured before. If she has been, then we have our "Polar Bear Bible" with us. In this one huge book, we have all the information for the thousands of polar bears captured over the last several decades. In it we can look mom up by her unique ID number and see her whole capture history, including how old she is, when we first caught her, if she's ever had cubs before, etc. It is amazing all the information that scientists have been able to get over the last few decades!
Overall we captured 14 family groups in six days, for a total of 40 bears. There were a few moms with a single cub, many with twins, and one mom even had triplets! It was great to see a mother supporting three cubs, though it was easy to tell who the runt of the litter was. The heaviest cub we weighed over the last couple weeks was 36 lbs. and the smallest came in at 14 lbs., so there was quite a difference among the family groups. Most moms were thin (they haven't eaten for months at this point!) but seemed to be in good enough shape to be able to make it out onto the sea ice and find food fairly soon. I hope the sea ice lasts long enough so that the polar bears can eat enough to sustain them over the coming summer months.
Being able to see the cubs up close and handle them was an unforgettable experience. Saying goodbye to the families was always bittersweet. I never wanted to leave them, but at the same time I want them to get out to the sea ice as soon as possible so that the moms can eat and the cubs can grow into healthy adults. Maybe I'll meet their cubs one day!
Photos ©Alysa McCall.