Subject: [Tweeters] Re: Birds recognizing individual humans
Date: Aug 7 23:19:16 2007
From: Bob and Barb Boekelheide - bboek at olympus.net


Tweeters,

Concerning birds recognizing individual humans, see an interesting
article by Larry Spear about gulls recognizing specific humans on the
Farallon Islands, found on the web in the 1988 archives of Natural
History Magazine, entitled -The Halloween Mask Episode-. Just do a
search for Halloween Mask Episode Spear, or go to the Natural History
Magazine website and click on Archives then Picks from the Past, or
if it works the website is:

http://www.naturalhistorymag.com/master.html?http://
www.naturalhistorymag.com/editors_pick/1988_06_pick.html

Somewhat like John Marzloff's work, Larry used a halloween mask to
conceal his true identity when banding adult gulls, after they
recognized Larry as a horrible predator that grabbed gulls around the
island when banding. He found that gulls clearly had the ability to
recognize individual researchers (aka potential predators), and, not
surprisingly, that human faces were the principal feature they used
to recognize us.

An excerpt from Larry's article: These results seemed amazing at
first, but why shouldn?t Western Gulls use the same methods we do to
recognize individuals? Biologist Niko Tinbergen has noted that, like
humans, gulls have an excellent ability to distinguish among forms.
Both species? sensory mechanisms are primarily audio-visual and are
similarly keen. Taking this a step further, these powers of
recognition work to the advantage of gulls living in a large colony.
For example, we know from Tinbergen?s work that nesting gulls can
recognize their mates in flight at a distance of one hundred feet,
and that they also recognize neighbors by sight. Well-developed
recognition between mates is important because the pair must prevent
other gulls from landing in their territories and stealing eggs or
young. Recognition of neighbors is also important because some
members of the colony specialize in pirating food or plundering
nests. We don?t know what cues are used, but as Tinbergen suggested,
facial features may well be important?especially since the shape of a
gull?s head is determined largely by bony structures that vary
considerably, whereas body areas are more densely feathered and, at
least to the human eye, are less individualized.

So they know us by our faces, and we're not the only ones doing the
watching!

Bob Boekelheide
Sequim



On Aug 7, 2007, at 12:00 PM, tweeters-
request at mailman1.u.washington.edu wrote:

> From: vogelfreund at comcast.net
> Date: August 6, 2007 8:34:15 PM PDT
> To: Tweeters at u.washington.edu
> Subject: Re: [Tweeters] Local newscast on UW crow research
>
>
> I've long had the impression that local crows knew me by sight,
> when I cut through the parking lots between my apartment and the
> local shopping center (lots of small trees); from the way I'm
> singled out for scolding or discussion when walking by. Also, I'm
> pretty sure a robin knows me quite well, durinng spring nesting
> season. Maybe that's from when I had a baby robin, a few years
> ago, huddling beneath the tree outside my bedroom window.
>
> Phil Hotlen
> Bellingham, WA
> -------------- Original message ----------------------
> From: Andrea Wuenschel <chyroptera at yahoo.com>
>> For the last few days, NorthWest Cable News (NWCN) has
>> been running a 3 minute piece on crow research by UW
>> Professor John Marzloff and students. It seems to be
>> showing repeatedly at 19 minutes past the hour (at
>> least in the afternoons). The article and video are
>> also at:
>>
>> "UW research shows crows may hold a grudge"
>> http://www.nwcn.com/sharedcontent/northwest/environment/stories/
>> NW_073007WAB_cro
>> w_research_uw_TP.c7589917.html
>>
>> It's a pretty amusing piece.
>>
>> Andrea Wuenschel
>> North Seattle
>>




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