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        Discussion Area 討論區 >> Photo Gallery 相片分享 I >>  White-fronted Goose
        
(Message started by: HKBWS Office on Nov 10^th, 2004, 5:39pm)

Title: White-fronted Goose
Post by HKBWS Office on Nov 10^th, 2004, 5:39pm

A juvenile White-fronted Goose was found at Lok Ma Chau on 8 November 2004. Please find below photo of the bird. The area is a Frontier Closed Area, it is also the KCRC private land. Access to the area is restricted.

Share with you this interesting information:
Date: 9 November 2004
Time: 7:30am
Equipment: Nikon Coolpix 4500 + Swarovski ATS 65HD

http://www.hkbws.org.hk/fileServer/Projectofficer/temp/DSCN8331.jpg

http://www.hkbws.org.hk/fileServer/Projectofficer/temp/DSCN8343.jpg

http://www.hkbws.org.hk/fileServer/Projectofficer/temp/DSCN8349.jpg

Title: Re: White-fronted Goose
Post by KK Hui on Nov 10^th, 2004, 7:18pm

Thanks for sharing these shots! ::)

Why are we seeing mostly juveniles when it come to rare visitors?

KK Hui ARPS
www.geocities.com/kkhui_001

Title: Re: White-fronted Goose
Post by pippenho on Nov 10^th, 2004, 7:49pm

on 11/10/04 at 19:18:06, KK Hui wrote:

Thanks for sharing these shots!  ::)

Why are we seeing mostly juveniles when it come to rare visitors?

KK Hui ARPS
www.geocities.com/kkhui_001

小朋友貪玩易走失 ???

Title: Re: White-fronted Goose
Post by Betty on Nov 10^th, 2004, 9:05pm

See if quotation from the book "Birds & Weather- A Birdwatcher's Guide" by Stephen Moss can give us some hints.

" Migrants appear to use a variety of cues and mechanisms to find their way successfully. Some of these are inherited, others learned from experience. One inherited mechanism-vector navigation- is the main method used by juvenile and first-winter birds undertaking their first outward migration.

Vector navigation is similar to the 'point -and-compass' method used by early sailors. In practice, vector navigation is crude and not very effective- even the lightest of crosswinds would, if not corrected, send the bird many kilometres off course.

Over-reliance on the simpler method of vector navigation probably explains why such a high proportion of wind-drifted autumn vagrants are juveniles of first-winter birds, on their first outward journey. "

This also explains why they are rare visitors. They are off-course, this may not be their route. Adults have many other skills to compensate.

The above book has detail explanation, plus historical events & data to tell the whole story of migration. Very interesting. I borrowed it from public library.

Title: Re: White-fronted Goose
Post by Anguslau on Nov 11^th, 2004, 11:22am

Thanks very much for the info, Betty. ;)
If I have the choice, I like the juveniles more than the adults. They all have beautiful fresh plumage! ;D
Hope they like it here and will come back next year. But our awful polution really doesn't help... :( :-[ :-/

Title: Re: White-fronted Goose
Post by KK Hui on Nov 11^th, 2004, 7:31pm

Thanks for the interesting info, Betty!

Just hope these youngsters will manage their way home when the time comes using this simple "vector navigation" method ... ;D And I thought bird migration never takes place with just one single bird when on the move anyway?! ???

KK Hui ARPS
www.geocities.com/kkhui_001

Title: Re: White-fronted Goose
Post by madsen122020 on Nov 11^th, 2004, 8:40pm

???What is the chinese name of White-fronted Goose ???

Title: Re: White-fronted Goose
Post by Betty on Nov 11^th, 2004, 9:12pm

I also have the same question :
Most birds migrate in flocks but how come we only see one or two birds of a certain species.
Could it be these youngsters not so strong & skillful in long distance flight that they are BLOWN off course ? ???

or they are a bit lag behind so cannot catch the flock ? ???

or we can apply Pippenho's theory ;D since different birds have their own character.

Title: Re: White-fronted Goose
Post by Betty on Nov 11^th, 2004, 9:20pm

on 11/11/04 at 20:40:44, madsen122020 wrote:

???What is the chinese name of White-fronted Goose ???

白額雁