[mou] Sax Zim observations (long)
markfalcon@comcast.net
markfalcon@comcast.net
Mon, 22 Nov 2004 05:30:40 +0000
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Videographing birds is rewarding in many ways. I am clearly terrible in terms of the quality of my video – not publishable at all, yet it brings unforeseen benefits, adding to my enjoyment of birding. Saturday was no exception. On 11/20/04, All Nelson and I birded the Sax-Zim Bog in St Louis County. Here are some of my observations.
A Northern Hawk Owl sat perched 40 feet away on a telephone line, surveying a grassy swale/drainage ditch running parallel to the road. Al was trying his hand at taping and filled the frame with the bird when it swooped out of his view. I saw it veer left, stoop right and landed on the ground 40 feet in front of us, mantling its wings and gaping at us. It flew back to the perch with a vole in its right foot, the back legs swinging free, the bird clasping the front shoulders of the vole. The NOHA fully encircled the mouse circumference with its talons; there was no sign of life. It held it in its left foot and tore at it with its beak, jerking its head to bolt the portions it was tearing off. Small tufts of fur wafted downwind. The bird had its back to me, so I could not see the exact operation but it proceeded to feed in this manner for 15 seconds (on video, you can play it back and time it). It was similar to feeding behavior I had seen from Cooper’s Hawks in my yard. It
took the rest of the vole in one gulp and sat placidly, head tilted back.
This bird prior to feeding had peered down on its surroundings, body and neck elongated, intently moving its head in quick movements for more than 180 degrees of rotation, aiming its facial disks slightly downward. After it fed, it seemed more compact, its beak pointed parallel to the ground, its body and head squat in appearance. It seems to me that as we become more acquainted with these birds we can learn their body posture and its meaning, much as we do with pets. Something to look for next time.
Of the 10 NOHA we saw this day, 5 were at close range, less than 60 feet direct line of sight. A NOHA just east of the intersection of 133 & 7 was noticeably smaller in size; I presume it to be a male. I read females normally disperse while males stay on territory, so it makes sense more of the birds would be the larger females. If we know the diameter of a telephone pole top we may be able to accurately estimate a bird’s size when they are perched nearby. Something to look for next time.
In years of low rodent populations up north, it has been estimated that up to 90 % of the birds irrupting southward are immature. Is there any way with live owls to determine adult or immature status? Primary growth, color of beaks or feet? I have video of a NOHA in flight and we may be able to age it, but I do not know how to do so. Please send me info if you have it. Where is Frank Nicolleti when you need him?
I missed filming two NOHA in flight. I read that their flight is accipiter-like; I do not share that opinion. I saw a NOHA fly ¼ mile between Black Spruce tops, swooping low to ground, covering ground at great speed, I thought it was in pursuit of prey until it swooped up to a new vantage point, very Shrike-like. I observed this same pattern 10 years ago in Blaine with the bird on 99th Avenue. Another bird flew ¼ mile from one pole to another. Its level flight reminded me of a gyrfalcon. I have friends that are falconers and have seen them in action at close range. The power of the stroke and the sturdy tapered wings are consistent with this image. The airspeed of the NOHA did not seem close to what a Gyr can do, but it was direct and quick, covering the distance in a very short time. Its overly long tail adds to the impression. Another NOHA flew in a hover for about 15 seconds, with brisk wing beats reminiscent of a Kestrel as opposed to the light airy flutter of a Ro
ugh-legged Hawk. So I vote for describing its flight as Falcon-like, even if we have to include all American Falcons to complete the analogy. I believe a NOHA might catch any bird it needs to; I would like to see it. I read an article stating the NOHA feeds primarily on birds in winter, I can see how this could be true, but the NOHA I saw were aiming their ears in areas where voles would be running. Are they hunting visually, by ear, or both? Something to look for next time.
We drove out of the Blue Spruce loop to find a Ruffed Grouse standing along the edge of the road upright, seeming not to even look at us. I have seen many Grouse and they are wary birds, usually flushing or walking chicken-like out of view into the brush. This plump Rufous-phased adult stood absolutely upright, as though stuffed, motionless, so we stopped the car 15 feet away to observe it. I got out my video camera, rolled down the window and was surprised to be able to film the bird for 30 seconds – still not a movement, not even a head twitch. I presume my great skill as a wildlife photographer was finally paying off, stalking one of the world’s wariest bird with an Oldsmobile with 130k miles on it. I thought this would be a great chance for us to get a shot of the bird flushing, so I asked Al to get out so it would flush. Al clambered out of the car - the bird didn’t flinch, still not acknowledging us. Al took steps toward the bird and the bird flushed right at us! 2
feet to the left of Al and right over the car 1 foot from my outstretched camera! I considered it to be a cinematic triumph, so I set my camera down and went out to scan with binos for other birds. Al and I walked 5 feet from the car. A Great Grey Owl flew from 15 feet away, huge as it veered into the woods, its wingspan at a right angle to the ground, 5 feet tall to the tip of the left wing. We never found it again, but we realized what was going on. This Grouse had been caught in the open and seen the Owl. It was frozen for defense, like a rabbit when a Hawk flies over, but its camouflage isn’t much good on an open road, hence we spotted it. Better off lucky than good for us once again. Great Grey Owls either don’t eat Grouse (I hear they have small feet and weak beaks) or this one didn’t see it. I haven’t witnessed a Great Grey attempt quick flight before, very impressive, eerie, ghost-like. I got a great shot of a flushing grouse flying within 1 foot of me! The shot o
f a Great Grey taking the largest prey ever recorded will have to wait till next time. Yesh, right, something to look for next time.
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<P class=MsoNormal style="MARGIN: 0in 0in 0pt; TEXT-INDENT: 0.5in">Videographing birds is rewarding in many ways.<SPAN style="mso-spacerun: yes"> </SPAN>I am clearly terrible in terms of the quality of my video – not publishable at all, yet it brings unforeseen benefits, adding to my enjoyment of birding. Saturday was no exception. On <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" /><st1:date Month="11" Day="20" Year="2004">11/20/04</st1:date>, All Nelson and I birded the Sax-Zim Bog in <st1:place><st1:PlaceName>St Louis</st1:PlaceName> <st1:PlaceType>County</st1:PlaceType></st1:place>. Here are some of my observations.</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt; TEXT-INDENT: 0.5in">A Northern Hawk Owl sat perched 40 feet away on a telephone line, surveying a grassy swale/drainage ditch running parallel to the road.<SPAN style="mso-spacerun: yes"> </SPAN>Al was trying his hand at taping and filled the frame with the bird when it swooped out of his view. I saw it veer left, stoop right and landed on the ground 40 feet in front of us, mantling its wings and gaping at us.<SPAN style="mso-spacerun: yes"> </SPAN>It flew back to the perch with a vole in its right foot, the back legs swinging free, the bird clasping the front shoulders of the vole. The NOHA fully encircled the mouse circumference with its talons; there was no sign of life. It held it in its left foot and tore at it with its beak, jerking its head to bolt the portions it was tearing off.<SPAN style="mso-spacerun: yes"> </SPAN>Small tufts of fur wafted downwind.<SPAN style="mso-spacerun: yes"> </SPAN>The bi
rd had its back to me, so I could not see the exact operation but it proceeded to feed in this manner for 15 seconds (on video, you can play it back and time it). It was similar to feeding behavior I had seen from Cooper’s Hawks in my yard. It took the rest of the vole in one gulp and sat placidly, head tilted back.<SPAN style="mso-spacerun: yes"> </SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt; TEXT-INDENT: 0.5in">This bird prior to feeding had peered down on its surroundings, body and neck elongated, intently moving its head in quick movements for more than 180 degrees of rotation, aiming its facial disks slightly downward. After it fed, it seemed more compact, its beak pointed parallel to the ground, its body and head squat in appearance. It seems to me that as we become more acquainted with these birds we can learn their body posture and its meaning, much as we do with pets.<SPAN style="mso-spacerun: yes"> </SPAN>Something to look for next time.</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt; TEXT-INDENT: 0.5in">Of the 10 NOHA we saw this day, 5 were at close range, less than 60 feet direct line of sight. A NOHA just east of the intersection of 133 & 7 was noticeably smaller in size; I presume it to be a male.<SPAN style="mso-spacerun: yes"> </SPAN>I read females normally disperse while males stay on territory, so it makes sense more of the birds would be the larger females. If we know the diameter of a telephone pole top we may be able to accurately estimate a bird’s size when they are perched nearby. Something to look for next time. </P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt; TEXT-INDENT: 0.5in">In years of low rodent populations up north, it has been estimated that up to 90 % of the birds irrupting southward are immature. Is there any way with live owls to determine adult or immature status?<SPAN style="mso-spacerun: yes"> </SPAN>Primary growth, color of beaks or feet?<SPAN style="mso-spacerun: yes"> </SPAN>I have video of a NOHA in flight and we may be able to age it, but I do not know how to do so. Please send me info if you have it. Where is Frank Nicolleti when you need him?</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt; TEXT-INDENT: 0.5in">I missed filming two NOHA in flight. I read that their flight is accipiter-like; I do not share that opinion.<SPAN style="mso-spacerun: yes"> </SPAN>I saw a NOHA fly ¼ mile between Black Spruce tops, swooping low to ground, covering ground at great speed, I thought it was in pursuit<SPAN style="mso-spacerun: yes"> </SPAN>of prey until it swooped up to a new vantage point, <SPAN style="mso-spacerun: yes"> </SPAN>very Shrike-like.<SPAN style="mso-spacerun: yes"> </SPAN>I observed this same pattern 10 years ago in <st1:City><st1:place>Blaine</st1:place></st1:City> with the bird on <st1:Street><st1:address>99<SUP>th</SUP> Avenue</st1:address></st1:Street>. Another bird flew ¼ mile from one pole to another.<SPAN style="mso-spacerun: yes"> </SPAN>Its level flight reminded me of a gyrfalcon.<SPAN style="mso-spacerun: yes"> </SPAN>I have friends that are falconers and have seen them
in action at close range. The power of the stroke and the sturdy tapered wings are consistent with this image. The airspeed of the NOHA did not seem close to what a Gyr can do, but it was direct and quick, covering the distance in a very short time. Its overly long tail adds to the impression.<SPAN style="mso-spacerun: yes"> </SPAN>Another NOHA flew in a hover for about 15 seconds, with brisk wing beats reminiscent of a Kestrel as opposed to the light airy flutter of a Rough-legged Hawk. So I vote for describing its flight as Falcon-like, even if we have to include all American Falcons to complete the analogy. I believe a NOHA might catch any bird it needs to; I would like to see it.<SPAN style="mso-spacerun: yes"> </SPAN>I read an article stating the NOHA feeds primarily on birds in winter, I can see how this could be true, but the NOHA I saw were aiming their ears in areas where voles would be running.<SPAN style="mso-spacerun: yes"> </SPAN>Are they hunti
ng visually, by ear, or both? Something to look for next time.</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt; TEXT-INDENT: 0.5in">We drove out of the Blue Spruce loop to find a Ruffed Grouse standing along the edge of the road upright, seeming not to even look at us.<SPAN style="mso-spacerun: yes"> </SPAN>I have seen many Grouse and they are wary birds, usually flushing or walking chicken-like out of view into the brush.<SPAN style="mso-spacerun: yes"> </SPAN>This plump Rufous-phased adult stood absolutely upright, as though stuffed, motionless, so we stopped the car 15 feet away to observe it.<SPAN style="mso-spacerun: yes"> </SPAN>I got out my video camera, rolled down the window and was surprised to be able to film the bird for 30 seconds – still not a movement, not even a head twitch. I presume my great skill as a wildlife photographer was finally paying off, stalking one of the world’s wariest bird with an Oldsmobile with 130k miles on it. I thought this would be a great chance for us to get a shot of the bird flus
hing, so I asked Al to get out so it would flush. Al clambered out of the car - the bird didn’t flinch, still not acknowledging us.<SPAN style="mso-spacerun: yes"> </SPAN>Al took steps toward the bird and the bird flushed right at us! 2 feet to the left of Al and right over the car 1 foot from my outstretched camera!<SPAN style="mso-spacerun: yes"> </SPAN>I considered it to be a cinematic triumph, so I set my camera down and went out to scan with binos for other birds. Al and I walked 5 feet from the car. A Great Grey Owl flew from 15 feet away, huge as it veered into the woods, its wingspan at a right angle to the ground, 5 feet tall to the tip of the left wing. <SPAN style="mso-spacerun: yes"> </SPAN>We never found it again, but we realized what was going on. This Grouse had been caught in the open and seen the Owl. It was frozen for defense, like a rabbit when a Hawk flies over, but its camouflage isn’t much good on an open road, hence we spotted it.
Better off lucky than good for us once again. Great Grey Owls either don’t eat Grouse (I hear they have small feet and weak beaks) or this one didn’t see it. I haven’t witnessed a Great Grey attempt quick flight before, very impressive, eerie, ghost-like. <SPAN style="mso-spacerun: yes"> </SPAN>I got a great shot of a flushing grouse flying within 1 foot of me! The shot of a Great Grey taking the largest prey ever recorded will have to wait till next time. Yesh, right, something to look for next time.</P></DIV></body></html>
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