Certainly – I am very glad that this study and the pictures were useful for your class. I hope the students enjoyed learning a bit about polar bears. Sorry I missed you guys as well.

I am in Denver this evening, and will be flying all day tomorrow to arrive in Barrow in the evening. Have a good start to autumn!

John

Love and miss you! Niki

Thanks for reading the dispatch. We gather lots of data at each capture. Much of our sampling is based on previous work on black bears and brown bears, but which has not yet been applied to polar bears. First, we use tape measures to collect physical measurements such as length, chest girth, neck girth, and skull measurements. We weigh the bear, and collect a fur sample. Using a syringe we collect a blood sample, similar to how a sample is collected from a person during a visit to a doctor. Some of these measurements are described here (http://icestories.exploratorium.edu/dispatches/on-the-edge-of-the-arctic-national-wildlife-refuge/).

We employ a technique called Bioelectrical Impedance Analysis (BIA) to measure body fat content, described here (http://icestories.exploratorium.edu/dispatches/how-fat-is-a-polar-bear/). Similar to deluxe bathroom scales this technique measures the bear’s resistance to a harmless electrical current, then converts the resistance to percent body fat.

We collect a breath sample by having the bear breathe through a mask into a bag, described here (http://icestories.exploratorium.edu/dispatches/getting-by-without-food/). We analyze the breath to establish whether the bear is eating or burning internal stores for energy, and whether the main food source consists of protein, fat, or carbohydrates.

Using a sterile approach (sterile tools and gloves) we collect a small sample of fat and muscle from the bear’s leg. These samples are analyzed to find out if the bear is eating or fasting, the condition of its fat stores, and whether the bear has reduced its activity to reduce its energetic needs. We also implant a tiny data logger beneath the skin to record body temperature. It has been hypothesized that polar bears reduce their body temperature and metabolic rate in summer to reduce their energetic needs, but such measurements have not been recorded.

Finally, some bears are fitted with a radio collar. If we recapture the animal we remove the collar; if we don’t recapture the animal, the collar has an automatic release device programmed to cause the collar to fall off after a certain time period.

Thanks,
John