Radio telemetry and nest searching

The VHF (very high frequency) radio collars that we fitted on the necks of the hens when we were night-trapping  produce a radio signal. Each radio collar emits a signal at a specific frequency. By using an antenna, radio receiver we can listen to the beeps, determine the direction and find hens. Sage-grouse hens start nesting towards the end of April to all the way up to June. We will be spending the rest of the project locating these nests, monitoring their progress and then tracking the hatched broods in the late summer.

Telemetry requires lots of hiking and patience: frequencies on old collars often need to be dialed down, sometimes signals bounce between canyons and valleys or disappear altogether. I drive around and hike up tall mountains and walk for miles to best hear these frequencies. By following the direction of the signal (which can be more than 10 km away) and dialing down the gain I can track these birds down. These birds tend to nest under low sage brush and, after a couple million years of evolution, are so well-camouflaged that they are almost impossible to see. I cannot tell you how many times I have been deceived by a suspicious looking tree trunk, rocks, leaf litter, moss or a dark patch under a sage brush.When I am closing in on a hen, I will start to circle around the location and get a visual on her. Even with a human being walking around her, a good mother hen will stick on her nest, but there are times when an especially skittish female will fly away. My objective is to get a visual confirmation of the bird and not flushing her off her nest. Typically, sage-grouse hens do not nest under pinyon pine or juniper but the last three birds that I have found all have their nests under short trees. This is highly unusual and there is a elevated risk of nest depredation.

It is really exhausting work but the rush that I get when I am closing in on a nesting hen and looking for her under the brush with my binoculars cannot be duplicated. I am a sage-grouse junkie and the only cure is finding more nests.

Can you find the nesting hen?

Which corner is the hen in?

Because of her location out in the open, this hen was obviously not nesting.