I might have a new favorite bird...
Oct. 26th, 2009 11:51 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
eregyrnSo, the exciting thing I promised on Friday (for certain values of "exciting") was that on Friday evening, I attended a saw-whet owl banding demonstration at Drumlin Farm Audubon Sanctuary. I really didn't quite know what to expect from this, but it sounded kind of interesting. I ended up at the "family night" session, so it was me, some parents with kids, and the Young Birders group.
Well, let me tell you, it was totally cool.
I should say at the outset that these aren't the best-quality pics in the world, because mostly I was refraining from using my flash so as not to disturb the birds, and the ambient lighting was all compact-fluorescents (bah). And, I selected some shots that were fuzzy but that were interesting nonetheless. Still, I think the cuteness shines through.
So first, they brought out some demonstration owls that are resident at Drumlin Farm (which does not rehabilitate wildlife, but which does house some wild animals that for one reason or another can't be released).
First up: the Eastern Screech Owl (rufous phase):
I had no idea that screech-owls were so cute! I feel, in fact, that most pictures I have seen of them don't do them justice. This little fellow (boy or girl -- they don't know; you'd basically have to do DNA testing to find out) is, if I recall correctly, blind in one eye, and that's why he can't be released. As the handler pointed out, it takes a lot of training just to get to the point where a formerly wild owl like this will sit calmly in a bright room full of people.
Next up, a resident Great Horned Owl. I forget what problem this one had, though I recall the handler explaining that they'd gotten him/her quite young, and for some reason, the owl has never learned to hoot, or something. It's this gigantic bird, but it makes little tiny baby trills all the time.
Then we all trooped out into the dark woods to go to the nets.
The banding project has been going since the mid-90s, it sounds like, and there are more than 50 banding station nationwide. Only a very small percentage of the owls caught in any one season are banded, but when they ARE recaught, it helps to provide data about owl migration, as well as being an overall survey of owl populations. (See Project Owlnet site.)
It didn't sound like there's much of a concentrated effort to band other types of owl. The head owl bander told us that they do sometimes get screech owls in the nets, but I forgot to ask whether they opportunistically band those when they do, or not. What they do is, they put up these very long lengths of net out in the woods, and then they play a recorded version of the call of the bird they want to attract; in this case, the toot-toot-toot of the male saw-whet owl. Then you go out and walk the nets and look to see if anything's entangled in them. (It's hard to describe, but the nets are kind of... pouched, so that birds can fly in but then not get out.)
If there is, you detangle (which involves figuring out how they went IN so you can reverse it), and put the bird in a little bag. I suppose that in most cases you do the recording stuff out in the field, but we took the birds back to the cabin to process. The processing was done by the head bander, who handled the birds, and some volunteers. You have to train with someone who's a master bander for a number of years before you work up to being able to handle the birds yourself, so we didn't get to handle any, we just watched.
They process by weighing the birds, taking a certain wing measurement, checking for feather age (which helps to give at least a rough idea of the bird's age, because they molt on a certain schedule; this also involves shining a blacklight on the wings, and the utterly cool thing is that in the dark, the newer feathers are pink and the older feathers are blue), and checking for body fat (which helps to determine the health of the bird).
Sexing a bird that doesn't have any plumage difference between males and females is apparently extremely difficult, without DNA testing. I've mentioned this in relation to the redtail hawks. Males are smaller than females, but you kind of need to have them side by side for comparison; a single individual tells you nothing. And of course there are ranges amongst individuals. And, I think that when you start getting into birds as small as the saw-whet, there probably is not a lot of visual difference in size.
We were told that a number of years ago, someone did a formal study in which they trapped over 2000 saw-whet owls, took blood samples and DNA tested them to determine the sex, and then took measurements, and graphed them. So all of the banders have this graph to use, which plots the weight and wrist-to-tip wing measurement for the size ranges of males and females (with a section in the middle for "unknown", where a bird is juuuuust too big to be a male for sure, and juuuuuust too small to be a female for sure). The bander told us that the majority of owls they get are females, probably because they are playing the male call. (The females don't really have a call.)
So! Actually, while we were looking at the screech-owl and the great horned owl, the volunteers went out and walked the nets to find out if it was even worth going out. (Success varies, of course. Some nights you get few or none, I guess. The bander told us that 2007 was a banner year in which they processed 280+ owls at Drumlin, 62 in one night.) It was! So we went out and watched the process of detangling two saw-whets, which we took back to the cabin.
I was really unprepared for the UTTER ADORABLENESS of the saw-whets, let me tell you. (See above.) It's one thing to read that the owl is 7" long, but a completely different thing to see one.
(The saw-whet is not the smallest owl. The Elf Owl and the Pygmy Owl are both smaller. Saw-whets prey primarily on small rodents -- deer mice, shrews, voles -- and occasionally on smaller songbirds, frogs, and insects.)
After weighing and checking the wing measurement, I think this was the pre-blacklight checking the wing feathers for age:
(The owls molt fully every 3 years. So if all the feathers are new, it's probably a first-molt, 1-year-old owl. Older owls will show feathers of a variety of ages.)
All of these shots show the head bander holding the owls around the legs (and in some cases, around the neck as well).
Getting the band put on, a two-person job:
Doing that owl "I will turn my head almost completely around to keep an eye on things" trick:
Hanging out:
The bander told us that there's a pretty wide variation amongst individual owls, in terms of their disposition. Some of them are fairly phlegmatic about the whole thing, and seem almost curious about people. (You can tell, she said, by how long they hang out after the processing is done. Owls are then sort of perched on someone's arm, and allowed to fly away in their own time. She said that there have been some that have really stuck around for a long time, including one that she had to move up to her shoulder so she could get on with work, and that must have stayed with her, watching her process other owls, for a good 20 minutes or more.) Then there are owls that really want no parts of the whole thing, and let you know.
All three of the owls we had that evening were feisty owls. They didn't make any noise, except for clacking their beaks at us. It's kind of hard to take them seriously, although it should be noted that their little claws are very needly, and they can certainly get you with them. The bander had some puncture marks after this:
She was trying to show us what the owl's feet looked like, but the owl wasn't really cooperating, keeping its feet clenched up into little fists:
Still, head-stroking is calming:
And that was it! One female, and two unknowns for the night (one unknown was just a gram and a couple of milimeters from being a male; the other was just a scootch under being a female).
Unfortunately, Friday night was pretty rainy; maybe that had something to do with getting so few owls, maybe they just weren't flying? If so, smart. By the end of the evening, with worse rain forecast, the volunteers went out to roll up the nets for the night. (Had it been a clear night, they would have kept checking for quite a while.)
It was pretty awesome, and has really gotten me to thinking about whether it's something I'd like to try to learn to do. (The time committment -- which is mostly in Oct-Nov, I think -- makes me hesitate a little; but I'm thinking about it.) They were awfully compelling, and the study itself is kind of interesting.
Well, let me tell you, it was totally cool.
I should say at the outset that these aren't the best-quality pics in the world, because mostly I was refraining from using my flash so as not to disturb the birds, and the ambient lighting was all compact-fluorescents (bah). And, I selected some shots that were fuzzy but that were interesting nonetheless. Still, I think the cuteness shines through.
So first, they brought out some demonstration owls that are resident at Drumlin Farm (which does not rehabilitate wildlife, but which does house some wild animals that for one reason or another can't be released).
First up: the Eastern Screech Owl (rufous phase):
I had no idea that screech-owls were so cute! I feel, in fact, that most pictures I have seen of them don't do them justice. This little fellow (boy or girl -- they don't know; you'd basically have to do DNA testing to find out) is, if I recall correctly, blind in one eye, and that's why he can't be released. As the handler pointed out, it takes a lot of training just to get to the point where a formerly wild owl like this will sit calmly in a bright room full of people.
Next up, a resident Great Horned Owl. I forget what problem this one had, though I recall the handler explaining that they'd gotten him/her quite young, and for some reason, the owl has never learned to hoot, or something. It's this gigantic bird, but it makes little tiny baby trills all the time.
Then we all trooped out into the dark woods to go to the nets.
The banding project has been going since the mid-90s, it sounds like, and there are more than 50 banding station nationwide. Only a very small percentage of the owls caught in any one season are banded, but when they ARE recaught, it helps to provide data about owl migration, as well as being an overall survey of owl populations. (See Project Owlnet site.)
It didn't sound like there's much of a concentrated effort to band other types of owl. The head owl bander told us that they do sometimes get screech owls in the nets, but I forgot to ask whether they opportunistically band those when they do, or not. What they do is, they put up these very long lengths of net out in the woods, and then they play a recorded version of the call of the bird they want to attract; in this case, the toot-toot-toot of the male saw-whet owl. Then you go out and walk the nets and look to see if anything's entangled in them. (It's hard to describe, but the nets are kind of... pouched, so that birds can fly in but then not get out.)
If there is, you detangle (which involves figuring out how they went IN so you can reverse it), and put the bird in a little bag. I suppose that in most cases you do the recording stuff out in the field, but we took the birds back to the cabin to process. The processing was done by the head bander, who handled the birds, and some volunteers. You have to train with someone who's a master bander for a number of years before you work up to being able to handle the birds yourself, so we didn't get to handle any, we just watched.
They process by weighing the birds, taking a certain wing measurement, checking for feather age (which helps to give at least a rough idea of the bird's age, because they molt on a certain schedule; this also involves shining a blacklight on the wings, and the utterly cool thing is that in the dark, the newer feathers are pink and the older feathers are blue), and checking for body fat (which helps to determine the health of the bird).
Sexing a bird that doesn't have any plumage difference between males and females is apparently extremely difficult, without DNA testing. I've mentioned this in relation to the redtail hawks. Males are smaller than females, but you kind of need to have them side by side for comparison; a single individual tells you nothing. And of course there are ranges amongst individuals. And, I think that when you start getting into birds as small as the saw-whet, there probably is not a lot of visual difference in size.
We were told that a number of years ago, someone did a formal study in which they trapped over 2000 saw-whet owls, took blood samples and DNA tested them to determine the sex, and then took measurements, and graphed them. So all of the banders have this graph to use, which plots the weight and wrist-to-tip wing measurement for the size ranges of males and females (with a section in the middle for "unknown", where a bird is juuuuust too big to be a male for sure, and juuuuuust too small to be a female for sure). The bander told us that the majority of owls they get are females, probably because they are playing the male call. (The females don't really have a call.)
So! Actually, while we were looking at the screech-owl and the great horned owl, the volunteers went out and walked the nets to find out if it was even worth going out. (Success varies, of course. Some nights you get few or none, I guess. The bander told us that 2007 was a banner year in which they processed 280+ owls at Drumlin, 62 in one night.) It was! So we went out and watched the process of detangling two saw-whets, which we took back to the cabin.
I was really unprepared for the UTTER ADORABLENESS of the saw-whets, let me tell you. (See above.) It's one thing to read that the owl is 7" long, but a completely different thing to see one.
(The saw-whet is not the smallest owl. The Elf Owl and the Pygmy Owl are both smaller. Saw-whets prey primarily on small rodents -- deer mice, shrews, voles -- and occasionally on smaller songbirds, frogs, and insects.)
After weighing and checking the wing measurement, I think this was the pre-blacklight checking the wing feathers for age:
(The owls molt fully every 3 years. So if all the feathers are new, it's probably a first-molt, 1-year-old owl. Older owls will show feathers of a variety of ages.)
All of these shots show the head bander holding the owls around the legs (and in some cases, around the neck as well).
Getting the band put on, a two-person job:
Doing that owl "I will turn my head almost completely around to keep an eye on things" trick:
Hanging out:
The bander told us that there's a pretty wide variation amongst individual owls, in terms of their disposition. Some of them are fairly phlegmatic about the whole thing, and seem almost curious about people. (You can tell, she said, by how long they hang out after the processing is done. Owls are then sort of perched on someone's arm, and allowed to fly away in their own time. She said that there have been some that have really stuck around for a long time, including one that she had to move up to her shoulder so she could get on with work, and that must have stayed with her, watching her process other owls, for a good 20 minutes or more.) Then there are owls that really want no parts of the whole thing, and let you know.
All three of the owls we had that evening were feisty owls. They didn't make any noise, except for clacking their beaks at us. It's kind of hard to take them seriously, although it should be noted that their little claws are very needly, and they can certainly get you with them. The bander had some puncture marks after this:
She was trying to show us what the owl's feet looked like, but the owl wasn't really cooperating, keeping its feet clenched up into little fists:
Still, head-stroking is calming:
And that was it! One female, and two unknowns for the night (one unknown was just a gram and a couple of milimeters from being a male; the other was just a scootch under being a female).
Unfortunately, Friday night was pretty rainy; maybe that had something to do with getting so few owls, maybe they just weren't flying? If so, smart. By the end of the evening, with worse rain forecast, the volunteers went out to roll up the nets for the night. (Had it been a clear night, they would have kept checking for quite a while.)
It was pretty awesome, and has really gotten me to thinking about whether it's something I'd like to try to learn to do. (The time committment -- which is mostly in Oct-Nov, I think -- makes me hesitate a little; but I'm thinking about it.) They were awfully compelling, and the study itself is kind of interesting.
