| Welcome to CHIL EagleCAM. We hope you enjoy your visit. You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are some features you can't use. If you join our community, you'll be able to access member-only sections, and use many member-only features such as customizing your profile, sending personal messages, and voting in polls. Registration is simple, fast, and completely free. Join our community! If you're already a member please log in to your account to access all of our features: |
| Discussion of other Raptor species; their anatomy, biology, ecology, etc. | |
|---|---|
| Tweet Topic Started: Sep 16 2007, 11:04 AM (18,124 Views) | |
| Raptorman | Nov 8 2007, 11:00 PM Post #271 |
|
Advanced Member
|
edit |
![]() |
|
| Raptorman | Nov 8 2007, 11:33 PM Post #272 |
|
Advanced Member
|
edit |
![]() |
|
| Raptorman | Nov 8 2007, 11:52 PM Post #273 |
|
Advanced Member
|
edit |
![]() |
|
| ostrich2 | Nov 9 2007, 08:28 AM Post #274 |
|
Advanced Member
|
Bill, I've been doing some more searching around on the rough-legged hawk to see if it could have been the bird I sighted outside my building. Several references mentioned that the RL will feed on birds, but didn't go into any specifics, so I hadn't been able to tell whether sparrows would be a reasonable prey for a RL. I did find this reference which does state that RL will prey on sparrows and other songbirds: RCA - Rough-legged Hawk
I know we had previously speculated that a Cooper's was a possibility - and this would suggest a RL would also be possible, especially given the markings I saw. However, given this is a relatively large buteo with long wings, I'm a bit confused as to how the RL would be able to chase and hunt passerines. Wouldn't you then expect the RL to have a flight pattern more like a RT, in which soaring is effective but very quick agility in flight necessary to chase small birds is not expected? I know the bird I saw certainly seemed quite agile - it immediately turned in a tight loop once it reached the building and flew immediately off in the opposite direction once the sparrows it was presumably chasing scattered into the bushes. |
![]() |
|
| Raptorman | Nov 9 2007, 09:19 AM Post #275 |
|
Advanced Member
|
edit |
![]() |
|
| Patti | Nov 9 2007, 11:10 AM Post #276 |
|
Advanced Member
|
Bill---yes, I went back and checked my Black kites and they are, of course, ALL Milvus migrans -- so, yes, I once again goofed! I'm having so much fun along the way that I can see where being wrong (a lot-- ) is a valuable part of the journey.I was thinking I found the Black-shouldered kite, yes! And...when I Googled and Goodsearched "Black-tailed" kite (was mixed up right from the start), I did see a lot of available Black-shouldered kite links. The owl/s started calling and phone rang, so I trailed off and also posted the wrong Black kite pix. My edition of Eagles, Hawks, & Falcons of the World. Brown & Amadon, 1989. ISBN 1-55521-472-X is in the mail right now, coming across country and I'm very excited. Parrot people often hear of hawks taking pet parrots. In my area, I guess that would mean the Cooper's hawk? I have seen a crow-like size hawk pinning its eyes on my African grey and it was AWFUL. My grey was inside my own home! I have a friend who saw her good-sized cockatoo plucked from her yard tree by a hawk & taken away. This was in Ojai...not far. It is fairly common; not a rare occurence. No doubt before the 1970's, one didn't often hear of hawks pulling down pet parrots. This goes along with what Bill has suggested in his last post. |
![]() |
|
| Raptorman | Nov 9 2007, 11:29 AM Post #277 |
|
Advanced Member
|
edit |
![]() |
|
| Patti | Nov 9 2007, 02:06 PM Post #278 |
|
Advanced Member
|
Bill, parrot people are learning this the hard way...but not me. I overly protect and have been known to chase hawks off the roof by banging my broom along the roof edge. :lol: This is a GOOD bird/animal I.D. website and am sorry I didn't include it in my list a few weeks ago. It's one I've used since becoming interested in bald eagles. It has super photos of the Red-shouldered hawk. This is the link to a nice photo with an AUDIO to the White-tail Kite/Black-shouldered Kite. See, I "get" it now. I would not have thought this was a hawk call, so worth the listen. http://www.enature.com/fieldguides/detail....e=&curPageNum=1
|
![]() |
|
| Raptorman | Nov 10 2007, 10:35 AM Post #279 |
|
Advanced Member
|
edit |
![]() |
|
| Patti | Nov 10 2007, 02:05 PM Post #280 |
|
Advanced Member
|
Bill, thank you for the barn owl photo and info! That is amazing about changing the shape of the facial disk. I did mess up the other night and not sure what I heard, but MANY a night I've heard what sounds like two owls calling back and forth. I assumed it was two owls, but boy, LIVE and LEARN...right! :lol: I'm really enjoying this thread. |
![]() |
|
| ostrich2 | Nov 11 2007, 11:57 AM Post #281 |
|
Advanced Member
|
Well, today was unfortunately a very disappointing day at Hawk Hill - not a single raptor was sighted while I was there I think the conditions were pretty poor for seeing migrating raptors today - there was virtually no wind and things were pretty overcast as well, which probably does not make for good thermals. When the wind finally did pick up a bit it was coming from the south from the lake, which is the opposite of the migration direction. I did have a chance to drop by briefly yesterday and there was better luck - nothing spectacular, but there was a smattering of red-tails as well as a few Cooper's hawks. Once again they were mainly soaring very high, and I did attempt to take some pictures, but nothing turned out. Aside from their being very high and small, the other big difficulty I found was that even with maximum zoom, it was very difficult to make out your target in the digital's LCD viewfinder against a bright blue sky (or even clouds). I may fool around with the settings a bit to see if there is a way to alleviate that. I did take a couple of pictures of the view from the hill: This is the view looking directly east from the hill. No spectacular scenery to be seen like San Francisco Bay I'm afraid. But most of the migrating raptors are seen coming from this direction (sometimes they are very distant and you can see them in the gaps between the trees). ![]() This is the view looking north - you can also see them in this direction generally as they come across from an easterly direction. Sometimes they will pass by north of the hill, other times you can see them pass over south closer to the lake. ![]() I did also come across this video posted on YouTube, which was taken in High Park of a red-tailed hawk consuming a squirrel. If you're not squeamish I found it quite interesting the way the hawk had the squirrel draped over the tree branch and then pinned it, so that it could then tear at it. I wonder if that's a common thing for them to do. Red-tailed Hawk In High Park |
![]() |
|
| Raptorman | Nov 11 2007, 12:51 PM Post #282 |
|
Advanced Member
|
edit |
![]() |
|
| ostrich2 | Nov 11 2007, 03:16 PM Post #283 |
|
Advanced Member
|
Although I found some of the accompanying music a rather odd combination this is an interesting video :D. "Fly Like An Eagle" at the end was kind of funny - although I gather the flight of an accipiter like a goshawk would not necessarily be wholly unlike that of an eagle, I imagine goshawks still fly like goshawks, not eagles At one point the goshawk is shown with someone holding a pole with a bright red stick on the end of it and it is being moved and twirled in front of the bird - is there a purpose to that? The pinning of prey to eat certainly makes sense - what surprised me a bit was that the hawk seemed to so easily be able to get the whole squirrel up there and still keep it in place when only the head and shoulders of the squirrel seemed to be over the branch. I certainly wouldn't be surprised if a squirrel weighs more than a RT, and with most of its body hanging in midair, I was trying to figure out how the hawk was holding it in place
|
![]() |
|
| ostrich2 | Nov 11 2007, 07:51 PM Post #284 |
|
Advanced Member
|
I wholeheartedly agree that identification is not just a matter of plugging the information into a canned formula and coming up with your answer - and I think that is a big part of being a more skilled observer - having enough experience to be able to interpret when a bird doesn't quite fit into the "book" definition. I also think what is important (and only experience and practice can give this) is to get to the point where you can immediately focus in on the specific parts of a bird that are distinctive and will help id the bird, without having to think about it consciously or consult a field guide first. For example, the next time I see a bird that fits the general profile of a red-tail, I will know to look for patagial wing markings which will help confirm a RT. Just to be clear so nobody gets confused, there were two different observations which I was mentioning the possibility of the rough-legged hawk - the first was the bird that I saw in a tree on the property at work. Bill had suggested the RL as a possibility based on my description of the bird, and that certainly seems like a reasonable possibility. The second bird was the other raptor I saw chasing birds outside my building at home, and I hadn't thought of the RL previously, but when I looked up the RL I saw there were some similarities to that bird as well. So when trying to judge these types of observations, one rarely explicitly does so, but really what you're doing (or should be doing) is judging the chances of one exception scenario relative to another. For example, for the bird I saw at home, the fact that the possible RL was chasing small birds could have been a partial inconsistency. Unfortunately without knowing the species well (and most sources don't go into this kind of detail) it's hard to judge - if the chances that a RL would be chasing small birds were 1 in a 1000, for example, you'd have to strongly consider that it's another species. On the other hand, if chasing birds by a RL is unusual, but it's only 1 in 10, then if there are other strong diagnostic indications of a RL that may still be the best guess. Identification may in many cases be only the best estimate possible in many cases anyway because you may not get a good enough view of the bird to be 100% sure. Certainly in the case of the bird I saw outside my building for example, I only got a brief view of it under circumstances when I wasn't expecting or prepared to see anything, so I can't even be sure of how much of my recollection is accurate or complete. On the topic of bird watching and bird lists, I have to wonder a bit whether keeping a "life list" is a good idea in terms of making accurate observations, particularly if people have a big emotional investment in their "lists" - this can result in serious observational biases in what people "see", especially when they strongly expect and/or wish to see something. A few weeks ago I went to this fascinating talk at the astronomical society: UFOs - Belief In Search Of Data Dr. Alcock presented many fascinating examples of how our perceptions and even our memories of what we observe can be fooled or just be plain wrong. Although the talk was about UFOs, the same things apply to many of our everyday observations/experiences. One story he told was actually about a group of birdwatchers at Point Pelee, and one member of the group pointed at something very distant on the horizon which they thought was some rare bird that would be a very special "life list" bird. As soon as this happened, more and more members of the group spotted this bird, and everyone in the group became more and more excited at the prospect of adding this bird to their lists. This excitement grew as the bird drew closer, until finally when it got close enough it revealed itself to be...a Cessna. To give you an idea of how easily people's observations and recollections of what they observed can be changed or warped completely unconsciously, Dr. Alcock described some experiments where people were shown video of a traffic accident and then given a questionaire about what they saw. Then a few days later they were again given questions about what they observed. The interesting part is that subject's responses could be influenced by what they were asked. For example, some people would be asked, "When the blue car bumped into the red car, did you see any broken glass on the ground?", whereas others would be asked "When the blue car smashed into the red car, did you see any broken glass on the ground?". Many people who were asked the latter question reported that they recalled broken glass, even though there was no broken glass in the video nor did many report seeing glass in their initial report. The brain is definitely not just a passive "recorder" of what is observed by the eyes and ears - it is actively interpreting what comes in and tries to fit it into a coherent overall picture based on what it "knows" is true - and this can alter perceptions completely unconsciously. Something to keep in the back of one's mind the next time they are out trying to identify some distant bird and someone says "that's a red-tailed hawk" ![]() Although of course having lots of experience is a good and valuable thing, I sometimes think that there can be occasional advantages in being a naive observer too, in that you don't have any preconceived expectations. For example, when I was at Hawk Hill last week, I spotted the only large kettle of hawks that we saw. The reason I spotted it is because these birds appeared from the west, and I was the only person who was bothering to look in that direction. The regular observers always expect the birds to be travelling from east to west and north to south, and so are almost always looking to the east and north. Someone wondered out loud when I pointed these birds out how I had happened to spot them there, and it really was because I didn't know enough to know that there "shouldn't" be any birds in that direction
|
![]() |
|
| Raptorman | Nov 11 2007, 10:08 PM Post #285 |
|
Advanced Member
|
edit |
![]() |
|
| Go to Next Page | |
| « Previous Topic · What are your questions? · Next Topic » |






) is a valuable part of the journey.
I think the conditions were pretty poor for seeing migrating raptors today - there was virtually no wind and things were pretty overcast as well, which probably does not make for good thermals. When the wind finally did pick up a bit it was coming from the south from the lake, which is the opposite of the migration direction. 


11:00 AM Jul 11