Dr. Jill Russell, associate professor of biology, spends summers in Alaska doing research on Boreal Owls. We've profiled Jill before and some of her sweet little friends. Jill and her husband, a professor at Miami University, regularly enlist the help of students with the research.
How have you expanded on your Boreal Owl research?
This year we have installed about 20 cameras inside Boreal Owl nest boxes that are located in the White Mountains within a 200 mile radius of Fairbanks. These cameras will provide us with, for the first time, real time images of what happens inside a nest box. We are monitoring the footage from the cameras to count how many times the adults provision the boxes with food for the chicks. At the same time, we are conducting live animal trapping in the regions around the boxes to correlate Red-Backed Vole populations (the favored food of Boreal Owls), with the number of voles we see on the cameras being brought to the boxes. We also weigh and measure each chick every 3 days, and collect tissue samples so that we can run their DNA and determine if the chicks are male or female. Andy Rasmussen in Biology and his students run the DNA for us.
How is the research coming?
It has been a very busy, exciting and exhausting summer for us here in the interior. This is the view from one of the nest box sites in the White Mountains.
The focus of this Summer’s research was to look at the effect forest fires have on Boreal Owl chick survival.
In order to answer this question, we monitored Boreal Owls in two different areas: an area that has not been burned, and then compare it with an area that has recently been burned. With 27 occupied nest boxes (and around 200 chicks) on two different Alaskan Highways, we put about 7,500 miles on our field truck, and clocked about 720 hours in the field. (That’s about sixty 12-hour days in a row – including weekends). Boreal Owl chick fledged on July 1st, and we were able to take our first day off (since May 1st) on July 2nd.
In order to determine the density of prey items for the owls, we conducted two small mammal trappings.
One trapping in the spring, as soon as the snow melted, and then another trapping after the young rodents were born and leaving the nests.
The occupancy of the traps will give us an idea of Red-backed Vole populations so we can correlate food availability with Boreal Owl chick survival. This trap had a Red-backed Vole inside it.
The mammals are marked (in case we recapture them) and set free. This next photo was taken as the vole jumped off of the weigh plate and scampered up my arm and hid in my hair!
What have the cameras inside the nest boxes been able to show?
Cameras inside the nest boxes have revealed interesting behaviors such as the first ever recorded siblicide event of Boreal Owls. Data indicates that when the chicks are not fed for over 24 hours, they will eat the youngest or weakest chick in the box. We have also learned that the adult male is the primary food provisioner of the box.
The adult female spends all of her time in the box protecting and feeding chunks of food to the chicks. Camera footage indicates that when she does leave the nestbox, it is only for a matter of minutes, and occasionally she will return with a fresh food item for the chicks.
Prey items brought into the boxes include: Red-backed Voles, Masked Shrew, Red Squirrel and a juvenile Snowshoe Hare. We also found evidence of some birds being brought to the nestbox as food, which included: Dark-eyed Junco, Swainson’s Thrush, Varied Thrush, Boreal Chickadees and Yellow-rumped Warblers.
How is the DNA sampling working—how do you get the information to Dr. Andy Rasmussen here at the Mount?
We are using DNA to determine the sex of each chick in the nest boxes. This year we removed a few body feathers from each chick. These feathers are kept frozen until they are mailed to Dr. Rasmussen at the Mount. DNA can be extracted from the epithelial cells at the base of the feathers, and can be used to determine the sex of each chick. We can then correlate the morphometric data we collect (wing length, bill length, skull width, hand length, and weight) with the sex of the chicks.
This will give us a rubric that we can use to determine the sex of the chicks in the future – without having to taking DNA samples.
How is this research helping the boreal owl population?
The study this year will provide vital information on the effect of forest fires on Boreal Owl populations. This information is important, because as the climate in the boreal forest changes, there has been an increase in forest fire frequency and intensity. Most forest fires in the boreal forest are started by lightning strikes during thunderstorms, and because this is an arctic desert, the ground and understory is very dry and ignites quite easily. It is common to have forest fires that engulf thousands of acres of boreal forest each year. Currently, there are about 305 active forest fires in Alaska and 140 of those are in the Interior where our research sites are located. In fact, the Aggie fire burned one of our small mammal trapping sites!