Last evening I took a short bike ride and noticed two WG&F biologists walking up the hill from the swampy area of the creek. They said they were setting up a bat net and invited me to watch them capture between 9 and 11:30.
By 9pm it was getting dark. I grabbed my headlamp and headed down the road. They were already beginning to catch bats in the nets.
The net set-up was in an ‘L’ shape, with fine nets about 10′ high. I spent the evening watching and helping a bit while they measured forearm lengths, ear lengths, weight, sex (I learned how to sex a bat!), determining juvenile or adult. They said it was one of the most productive evenings they’d had, with their count at 27 by the time I left at 11:30. Included in their equipment was a sonar detector, which allowed us to hear the bats at frequencies which aren’t auditory to the human ear.
Three kinds of bats were caught, and released: Brown, Hoary, and Silver-haired. WG&F is in their 2nd year of a four year study. The Brown is a Wyoming resident, but the Hoary and Silver-haired are migrants (What Wyomingites might call ‘snow birds’ in reference to people who live here but leave for the winter). I asked where they went and was told its not known.
It was such an awesome night, with the bats flying around, getting to see them up close (they are beautiful creatures), the Perseid meteor shower and clear skies, and finally around 11:30 an orange-yellow moon rising in the east. I couldn’t ask for more.
Here you can see the bat’s fingers, with the thumb at the very end. The thumb length was measured as well as the forearm.
Hoary bats are big bats and low fliers. They are moth specialists. They were fierce little guys when caught, with astounding faces. Their wings have hair on them.
Bats of different species emit sonar at different frequencies. The frequency has to do with what their specialty food is they are catching.
These silver-haired bats were fairly calm and gentle, and small.
Bats have a ‘hook’ around the outside of their ear. The mammalogist told me that its function is unknown.
Most of the bats we caught were males. Apparently that’s not unusual, with the females flying in a different location or tending the young.
Brown bats are generalists. A small percentage do carry rabies, while the Hoaries do not carry rabies.
If they set up another night in the same area, hardy any bats would come. The bats learn quickly how to avoid the nets. They are smart!
The Human Footprint 
Wow, lucky you–right place, right time, with camera = great story! Is there any problem with the “smuttynose” fungus in your area? It’s wiping out bat colonies in many parts of the US.
Echolocation is amazing. Some moths have figure out ways to “jam” the bats’ sonar.
LikeLike
The only odd thing we saw was mites in some of the brown bats ears. THe mites don’t seem to bother them though. Not sure what ‘smuttynose’ is but maybe it is what it sounds like.
Yep, I was soooo lucky!
LikeLike
Your pictures of “silver haired bats” are still pictures of Hoary Bats. I can tell by the size, color, and the fact you can still see the tan-fur lining on the inside of the wing. Silver haired bats are about half the size as Hoary Bats. I’ve rarely met a calm silver haired, but congrats if you have. Nice pictures. I am super glad you have such an interest in bats.
LikeLike
Thanks Merut for catching my mistake there. I’ve got the photos corrected now and you can see those are definitely smaller bats. I’ve never done this before, but those silver’s were calm that night as they just lay there and allowed themselves to be measured. They are low little fliers and the technicians sometimes had a hard time getting them off their arms for release and high enough to clear bushes. I loved getting the opportunity to see these bats so close and, even better, knowing they’re my neighbors and that we have a healthy population.
LikeLike
How cool! I would have loved to have been on this outing! We have a bat house in Michigan, but we only get a bat or two in it off and on, no bats seem to take up residence on a more permanent basis. I love it just as it is getting dark, and the bats come out, flying back and fourth over the lake and the shore line, sometime they come close over my head as the swoop back and forth.
LikeLike