Tuesday, January 22, 2013

Winter Greater Sage-Grouse

A couple of weeks ago I was in northeastern Montana for some meetings and I managed to carve off a few hours one morning for a quick trip out to an area where I knew Greater Sage-Grouse have wintered in the past. I also had a local resident tell me that she had observed a number of birds in the area recently so I was hopeful that I would run across a few birds.
The weather that morning was fairly nice but somewhat windy, which is pretty typical for that area this time of year. The worst part was that there was a pretty heavy overcast too, which didn't provide for the best light for photography.
I had to search quite a bit for any birds, but finally found a small group of about 5 birds just off the road, just as I was about to turn around and head back towards town. They got nervous when I stopped to watch them and they flew off a short ways to the south, making the rather miserable light conditions even worse as I would be looking directly into what light there was.
I moved off down the road a ways and pulled off to check to see if I had any phone messages and there they were. A large flock of about 80 birds just off the road, plucking sagebrush leaves from the exposed sage in the snow.

I am not surprised that I had a hard time finding these birds. They are very good at blending in to a snowy sage landscape.

 After a short while the bird relaxed and continued to forage in the sage next to the road I was on.

 Maybe next time I can find them with a bit more light to work with, but it certainly was a nice way to spend a morning.

Tuesday, January 15, 2013

Bighorn Sheep Follow Up

For those of you that might not have checked out the comments on my last post, I wanted highlight a comment from Jesse DeVoe on that post. Jesse is a graduate student at MSU as part of The Greater Yellowstone Area Mountain Ungulate Project. The ewe bighorn I had the photo of is one of the study animals in this project.

As Jesse explained, the two collars on the ewe serve different purposes and this is further explained in the following from the projects website
"The dual collaring strategy involves the deployment of both a GPS and VHF radio collar on a
single individual.  The advantage of GPS technology is that it provides fine-scale (precise)
spatial data at regular, relatively short, time intervals. Such data are optimal for addressing
questions of spatial ecology.  Spatial studies will provide insights into movement dynamics at the
scale of individuals important in defining discrete populations, identifying migration pathways
and corridors, and describing patterns of fidelity, dispersal, and metapopulation dynamics.  GPS technology is the most appropriate method for this effort as detailed spatial studies would requireintensive and extensive aerial surveys if VHF telemetry were used.  The unpredictability of flying weather and the inherent hazards of flying in mountainous terrain would limit both the
spatial and temporal resolution of the data and, thus, erode the potential ecological insights that
can be gained from such an effort.
The disadvantage, however, of GPS technology is that deployment on animals is limited to
approximately 1 to 2 years due to short battery life which limits their utility for collecting
demographic (survival, reproduction) data.  The VHF collars, on the other hand, have the
capacity for long term deployment (about 5-8 years) and are optimal for addressing questions of population dynamics. Understanding and estimating the basic vital rates of the populations, that is survival and reproduction of adults and survival and recruitment of young-of-the-year, is
important knowledge for managing and conserving populations. In ungulates, these
demographic processes are age-dependent and can vary from year-to-year depending on
variability in warm and cold season weather which, in turn, influences forage quantity, quality,
and availability. VHF telemetry is a simple, reliable, and economical tool for long term survival
and reproduction studies of individual animals. Thus, the combined instrumentation of GPS and
VHF collars on individuals will serve to integrate and maximize ecological insight in an efficient
 More information on the telemetry part of the study, including capture techniques, immobilization, and more specifics about the collars can be found here (PDF).

Judging from what I could find in this document, this individual is marked as either B or C based on the location of the white mark (duct tape) on the brown collar (you can see the stripe across the collar just behind this ewe's ear) and she is part of Upper Yellowstone study site (did I get this right Jesse and might you have any further info I could share on this particular ewe?).

Thursday, January 3, 2013

Montana Bighorn Sheep

Last weekend we took a trip to Yellowstone National Park. As we entered the park just south of Gardiner I told the boys to be on the lookout for Bighorn Sheep on the cliffs east of the highway. Crean soon spotted a ram high on top of the cliff and Benton spotted a few more on our way out of the park later that afternoon.

The following morning we found a ewe and her lamb from this spring feeding on some shrubs right along the highway. The best view we got though was on our way home just south of Gardiner along the north side of the highway. A small band of sheep were bedded down just off the highway and we got good looks at these animals.

One of the ewes had two radio collars on her neck. I am not sure why she was double collared or what study she was part of, but I will try to find out.

One of the rams took a particular interest in her.