red@redpoll.neoucom.edu (Richard E. Depew) (12/09/90)
In article <1990Dec7.150814.12291@granite.cr.bull.com> horvath@granite.cr.bull.com (John Horvath) writes: >Speaking of generic terms for various raptors: >Someplace in Ohio (Hinkley?), they have some sort of media blitz >every spring about the return of buzzards to hinkley. It was difficult >to determine whether they meant turkey vultures or hawks in general. >Its an entertaining story, but I have always been curious about >which bird they were talking about. >Has anybody been there? Finally, someone is asking about MY neck o'the woods. :-) Yes, Hinkley Ohio (just south of Cleveland) is the place you are thinking of, and turkey vultures are the celebrated buzzards that return to Hinkley each spring, along with the TV remote crews. :-) No wimpy swallows, bugs, or subterranian rodent for Hinkley (1)... I wonder if we could get the buzzard accepted as the state bird? We do accept a lot of out-of-state garbage. :-) Speaking of buzzards, my boss had a couple of them perched on his fence this spring (about the same time they returned to Hinkley), and reported that they were staring at his neighbor's garden. Then he remembered that his neighbor had hit a deer with his car the previous fall, killing it, and had buried it in his garden. He surmised that the vultures had been attracted by an odor from the buried deer. Either that, or the buzzards had bugged the deer before they left for Florida the year before. :-) Wonderful birds, these buzzards! (1) For our overseas readership, "swallows" refers to the LITTLE birds that supposedly return to Capistrano, California on the same date each year, "bugs" refers to the over-wintering swallowtail butterflys of someplace in California (Ocean Grove?) and "rodent" refers to the "Groundhog Day" groundhog (Pete?) of Punxsutawney, Pennsylvania. Any excuse for a party! :-) Dick Depew -- Richard E. Depew red@redpoll.neoucom.edu Village of Munroe Falls, OH. uunet!aablue!redpoll!red
mad@descartes.math.purdue.edu (Michael A. Dritschel) (12/10/90)
In article 3295, Richard Depew writes, >Speaking of buzzards, my boss had a couple of them perched on his >fence this spring (about the same time they returned to Hinkley), and >reported that they were staring at his neighbor's garden. Then he >remembered that his neighbor had hit a deer with his car the previous >fall, killing it, and had buried it in his garden. He surmised that >the vultures had been attracted by an odor from the buried deer. >Either that, or the buzzards had bugged the deer before they left for >Florida the year before. :-) Unfortunately I do not remember the source for this, but someone has studied what cues turkey vultures use in locating their next meal. A ripe dear carcass was placed under a tarp so that it could be smelled but not seen, and even though turkey vultures were common in the area, they did not respond to this. However, as soon as the carcass was uncovered, it was immediately found by the vultures. So I doubt the turkey vultures were responding to the remains of a buried deer. Perhaps there was something else in your boss' neighbor's yard. Another possibility is that they were just sunning themselves. On numerous occasions I have seen a group of vultures perched in a tree in the early morning with their wings spread cormarant style, presumably warming themselves. An impressive sight. Michael Dritschel mad@math.purdue.edu
tirone@acsu.buffalo.edu (stephen t tirone) (12/10/90)
>Unfortunately I do not remember the source for this, but someone has >studied what cues turkey vultures use in locating their next meal. A >ripe dear carcass was placed under a tarp so that it could be smelled >but not seen, and even though turkey vultures were common in the area, >they did not respond to this. However, as soon as the carcass was >uncovered, it was immediately found by the vultures. So I doubt the John James Audubon was the 'someone', as I understand. He also painted a deer carcass on a tarp (no carcass underneath) and attracted vultures. I too am foggy on my source (some bibliographic writeup), but I am pretty sure in any case that it has been determined that vultures find their food by sight. Steve Tirone tirone@acsu.buffalo.edu
bob@delphi.uchicago.edu (Robert S. Lewis, Jr.) (12/11/90)
In article <2510@mentor.cc.purdue.edu> mad@descartes.math.purdue.edu (Michael A. Dritschel) writes: >On >numerous occasions I have seen a group of vultures perched in a tree >in the early morning with their wings spread cormarant style, >presumably warming themselves. An impressive sight. I've heard they do this to kill bacteria (the UV rays kill bacteria, I guess)--does anyone know if this is true? Cormorants dry themselves in the sun--their plumage is not as oily as the plumage of other seabirds, and so water penetrates to their skin.
e343gv@tamuts.tamu.edu (Gary Varner) (12/11/90)
>>On numerous occasions I have seen a group of vultures perched in a tree >>in the early morning with their wings spread cormarant style, >>presumably warming themselves. An impressive sight. > >I've heard they do this to kill bacteria (the UV rays kill bacteria, I >guess)--does anyone know if this is true? I've never heard the bacteria story before, but at the raptor center I volunteered at we were taught that they sun themselves in order to get vitamin D. The sunning stimulates an oil gland at the base of the tail, exposure to the sun produces vitamin D in the oil (much as exposure of our skin to the sun produces vitamin D from pro-vitamin D), and the vulture ingests the vitamin D when it subsequently preens itself. Vultures are quiet in the morning because they need thermal updrafts for their foraging flights. They are large, heavy birds (four or four and a half pounds, as I recall -- your arm would really get tired holding one) and they search for carrion by flying with relatively few wing flaps, which is only possible later in the day when the same sun-driven convection which gives us afternoon cumulus clouds (and, eventually, thunderheads) is operative. Notice that they often gain a lot of altitude by flying in fairly tight circles. What they are doing is catching a cell of hot, and therefore rising air, and sticking with it until they get up high. At which point, like a glider pilot, they can set off for a distant spot in a long shallow glide. I've always wondered how different a nation we might have become if the turkey vulture -- a shy, quiet scavenger -- had been our national bird, rather than the bald eagle -- a noisy, aggressive raptor (*) . . . +---------------------------------------------------------------------+ | Gary Varner "It's too late to die young." | | Department of Philosophy -- Gregg Brown | | Texas A&M University | | College Station, TX e343gv@tamuts.tamu.edu | +---------------------------------------------------------------------+ (*) Before this remark touches off another semantic frenzy like my earlier unguarded remark about "hawks" vs. "accipiters and falcons" (I meant the buteos, by the way, I was speaking carelessly), let me emphasize that the vultures and condors _are_ raptors. "Raptor" is actually a functional rather than a phylogenetic category. The owls on the one hand and the hawk and falcon families (which includes everything from eagles and buteos to kites and kestrels, _as_well_as_ vultures_and_condors_) are now thought to be examples of convergent evolution: both categories of birds developed keen eyesight, strong feet with sharp talons, and sharp, hooked beaks, because they lead similar lifestyles (catching and killing fast moving prey). The vultures still have keen eyesight and sharp, hooked beaks for tearing flesh, but they have lost the strong feet the other raptors need for catching and killing their prey. Since vultures eat carrion, they don't need strong feet, and since they spend a lot of time on the ground (unlike other raptors, who prefer to carry their prey into a tree or onto a ledge to eat it, if possible), the strong grasping feet of (say) a great horned owl would actually be maladaptive.
andrewt@cs.su.oz (Andrew Taylor) (12/11/90)
In article <2510@mentor.cc.purdue.edu> mad@descartes.math.purdue.edu (Michael A. Dritschel) writes: > Unfortunately I do not remember the source for this, but someone has > studied what cues turkey vultures use in locating their next meal. A > ripe dear carcass was placed under a tarp so that it could be smelled > but not seen, and even though turkey vultures were common in the area, > they did not respond to this. However, as soon as the carcass was > uncovered, it was immediately found by the vultures. So I doubt the > turkey vultures were responding to the remains of a buried deer. No unlike most (all?) other vultures and condors turkey vultures are capable of locating carrion entirely by smell. So it is quite possible they were attracted by the buried deer. Stager K. E. 1967 Avian Olefaction, American Zoologist 7:415-419
andrewt@cs.su.oz (Andrew Taylor) (12/11/90)
In article <10775@helios.TAMU.EDU> e343gv@tamuts.tamu.edu (Gary Varner) writes: > I've always wondered how different a nation we might have become if the > turkey vulture -- a shy, quiet scavenger -- had been our national bird, > rather than the bald eagle -- a noisy, aggressive raptor Isn't the Bald Eagle reputation and hence its choice as US national bird based (anthromorphically) on its appearance? I thought, like many eagles, it is by preference a timid scavenger, taking live prey only when carrion is unavailable. Does the Bald Eagles range touch Asia? In other words are there Soviet Bald Eagles? Andrew
bob@delphi.uchicago.edu (Robert S. Lewis, Jr.) (12/13/90)
In article <10775@helios.TAMU.EDU> e343gv@tamuts.tamu.edu (Gary Varner) writes: >let me >emphasize that the vultures and condors _are_ raptors. "Raptor" is >actually a functional rather than a phylogenetic category. The owls >on the one hand and the hawk and falcon families (which includes >everything from eagles and buteos to kites and kestrels, _as_well_as_ >vultures_and_condors_) are now thought to be examples of convergent >evolution: Just as a sidelight: I've heard that some ornithologists now consider the New World Vultures to be related more closely to storks than to the other falconiform species.
grp@Unify.com (Greg Pasquariello) (12/13/90)
In article <1599@cluster.cs.su.oz.au>, andrewt@cs.su.oz (Andrew Taylor) writes: > In article <10775@helios.TAMU.EDU> e343gv@tamuts.tamu.edu (Gary Varner) writes: > > I've always wondered how different a nation we might have become if the > > turkey vulture -- a shy, quiet scavenger -- had been our national bird, > > rather than the bald eagle -- a noisy, aggressive raptor > > Isn't the Bald Eagle reputation and hence its choice as US national bird > based (anthromorphically) on its appearance? I thought, like many eagles, > it is by preference a timid scavenger, taking live prey only when carrion is > unavailable. Bald Eagles often take carrion, mostly dead fish and the like. They will also take live fish and some small mammals. They often harass other species, most often Ospreys and Gulls, in order to pirate their catch as well. I believe it was the first and last traits that caused Ben Franklin to declare it unfit for the national symbol. > > Does the Bald Eagles range touch Asia? In other words are there > Soviet Bald Eagles? The bald eagle has indeed been recorded in Siberia. Rather ironic. > > Andrew -- --- Greg Pasquariello Unify Corporation grp@Unify.Com
stewartw@cognos.UUCP (Stewart Winter) (12/13/90)
In article <10775@helios.TAMU.EDU> e343gv@tamuts.tamu.edu (Gary Varner) writes: >themselves in order to get vitamin D. The sunning stimulates an oil >gland at the base of the tail, exposure to the sun produces vitamin >D in the oil (much as exposure of our skin to the sun produces vitamin >D from pro-vitamin D), and the vulture ingests the vitamin D when it >subsequently preens itself. I believe that the sun converts the vitamin D into vitamin D3 which is what birds require. Stewart -- Stewart Winter Cognos Incorporated S-mail: P.O. Box 9707 VOICE: (613) 738-1338 x3830 FAX: (613) 738-0002 3755 Riverside Drive UUCP: uunet!cognos!stewartw Ottawa, Ontario The bird of the day is .... Meyer's Parrot CANADA K1G 3Z4