by Kelly Madden
A bat net is very large and cumbersome. It has long poles, ten feet tall or so, to which thin netting is attached. The netting and poles are set in a somewhat square or modified L shape, across and parallel to streams or creeks. It is difficult to see the net and bats will fly right on in. This is how bats are caught for examination, recording and release. I may sound like an expert now, but last Tuesday was my first time in the woods in the dark for a Land Trust outing and definitely my first experience with bats.
We arrived about 6:15 pm on July 3rd to get set up for the Owl and Bat night at the Metolius Preserve. It was a chilly evening down in the woods, complete with the promise of the full moon. The air had the charge of excitement, being the eve before a major holiday. There were no mosquitoes and the air was clear. It was a perfect early summer evening. A dedicated group of Land Trust volunteers and members sat in the woods as day turned into night. We were there to watch and listen and learn: Tom Rodhouse, our leader, is an ecologist with the National Park Service, who was our bat expert; Jim Anderson, a local naturalist, was our owl expert and Sue Anderson, Jim’s wife, was our butterfly expert and a fabulous photographer!
The evening began with Jim talking about owls. Jim spoke about the great greys, the screech owl, the northern pygmy owl, boreal owls, barred owls, northern spotted owls, flammulated owls, and the saw-whet owl. We even had the marvelous pleasure of hearing Jim and Tom making some convincing owl calls. Periodically while Jim spoke, an errant bird or bat would swoop low and activate the bat detector, and then Tom and his daughters would head to the nets and use big very bright lights to see if we caught a bat.
I really enjoyed learning about the owls and hearing some calls. It is very important to note however, that making bird calls in the woods during nesting season is NOT a very good thing to do. Its one thing to hear the calls in an educational setting, but it’s another thing all together to go into the woods just to call owls so the birder can see them. This can disrupt the feeding cycle and rhythm of the parent birds and wreak havoc on the owlets.
We learned many interesting facts about owls: Great grey owlets grow very quickly. Northern pygmy owls are small and can look like a robin perched on a tree, but if you look closely, there is no tail. Owls swallow things whole. Their internal body temperature is higher than ours at about 105 degrees. The flammulated owl spends its winters in Panama. And to quote the wonderfully kind and lovable Jim Anderson; “Owls are so neat.” I also learned that pine squirrels will destroy nesting boxes and gobble them up! The only bummer was that we didn’t hear one hoot or see one owl. I think we were too loud and the weather was too chilly to make for easy hunting.
After Jim finished, it was still light, but at 9:20 pm as the dark crept upon us, things started to change. As coats and jackets and hats were affixed, Tom began telling us all about the bats. And as Jim finished up, Tom remarked that: “Bats are misunderstood and remarkable creatures.”
Bats don’t like the cold. They prefer to hunt when it is warmer, easier to move and the warmth means insects will be flying about. Because bats fly so swiftly and energetically and because they use eco-location, they expend huge amounts of energy. These two activities take a lot of their brain space, so they need to somehow maintain and manage their energy budget, and if it is cold and there are not a lot of insects, then bats won’t feed to save energy. When the weather is poor they won’t fly and in winter they hibernate. Is this why they live so long? Bats can live up to 34 years and they weigh so little…5 or 6 grams.
There are 15 species of bats in Oregon. They are all insectivores. Tom projected that there could easily be 12-13 types in the Metoliuos Preserve. Bats are very sensitive little mammals. They won’t fly in your hair, they are not blind, and they are not mice. They are also good measures of the biological and ecological health of an area. That is why the white nose syndrome, a powerful fungus that has already killed maybe 5-6 million bats in the US since 2006, is an important issue. Currently, in Oregon there are NO infected bats, but the syndrome, which is deadly because it disrupts their hibernation patterns, started out back East, coming from Europe and is slowly making its way across the US.
At 9:35 pm it happened! A small bat swooped over the detector, and flew into the net. Isabel and Tom and Violet carefully extracted the bat from the net while we waited in our chairs. Sue Anderson gave us the bat protocol and everyone was still and respectful during the capture. The bat was brought to the field table. Tom was following his own protocol, which is a result of the Regional Bat Grid assessment for Oregon, Washington and Idaho, begun in 2002.
We caught a California myotis bat. It was very small. Tom examined it for signs of fungus and ill health; he measured it, weighed it, and recorded the results. The bat weighed 4½ grams. He spread its wings and showed us this small mammal. It was a very healthy male bat that was chocolate brown. I even got to touch the tiny body! Finally after about ten minutes of examination and recording, Violet told her father: “Daddy, we should let it go!” and in the beam of a bright light, the stunned and perfect little guy, flew out into the meadow, I am sure he was feeling lucky.
That too was our cue to end the evening. We drifted out of the woods, our headlamps and flashlights flying the light over the ground and into the sky. I could hear the laughter of children. We helped find lost things in the dark, a cup, a flashlight, a little bag. We dismantled the huge net, folded up the table, closed our chairs and gathered the blankets and headed back to our cars. It was an excellent night for a bat and owl adventure.