Re: [SBB] Western Tanager & Spotted Sandpipers

[Les Chibana <[[email protected]]>]

And I recall reading a monograph (sorry, I don't have a citation) in  
which the research determined that female Spotted Sandpipers could  
delay fertilization of their eggs after mating. I think the research  
even went as far as to say that the female may even be able to select  
which male's sperm she would allow to fertilize her eggs. That would be  
quite a trick... so to speak.

I think I've heard that elephant seals can delay fertilization, too.

Les
---
Les Chibana
BirdNUTZ(tm) - Ornigasmic Birding
Palo Alto Baylands Birding Classes
em <[[email protected]]>
web <http://www.birdnutz.com>
ph 650-949-4335
fx 650-949-4137
snailmail: SR2 Box 335, La Honda CA 94020

On Apr 27, 2005, at 6:59 PM, Alvaro Jaramillo wrote:

> Birders
>
>   Spotted Sandpipers have very different breeding behaviour than most  
> birds,
> and they are much more like Phalaropes than anything else most birders  
> are
> familiar with. Spotted Sandpipers are sex role reversed, so the  
> females are
> larger and "compete" with each other for access to breeding males. The  
> males
> do all of the parental care, and females are known to have more than  
> one
> male mate (polyandry). Therefore once a female mates and lays a clutch  
> she
> moves on to another male, if available, and repeats the process. Thus,  
> how
> you define a pair is actually very complicated.
>
> Note that sex role reversed is the standard term in behavioural  
> ecology to
> refer to situations where males are the limiting sex in calculations of
> reproductive success, a scenario that selects for inter-female  
> competition
> and usually larger size and ornamentation. It implies that this  
> situation is
> somehow incorrect (reversed) but really this just refers to the  
> reality of
> this breeding system being rarer than the one we are used to. Sex-role
> reversal is moderately common in various shorebirds and other birds,  
> and it
> is also known in many amphibians and fish - mammals have about the most
> conservative family values in the animal world, kind of boring in the  
> wide
> spectrum of behaviour.
>
> Cheers
>
> Al
>
> Alvaro Jaramillo
> [[email protected]]
> Half Moon Bay, CA
>
> Field Guides - Birding Tours Worldwide
> http://www.fieldguides.com/home.htm
>
>
> > -----Original Message-----
> > From: south-bay-birds-bounces+chucao=[[email protected]]
> > [mailto:south-bay-birds-bounces+chucao=[[email protected]]]  
> > On
> > Behalf Of Bill Bousman
> > Sent: Wednesday, April 27, 2005 5:22 PM
> > To: [[email protected]]; South-Bay-Birds
> > Subject: Re: [SBB] Western Tanager & Spotted Sandpipers
> >
> > Dear Randy and everyone,
> >
> > At 12:24 PM 4/27/05, [[email protected]] wrote:
> > > Hi Everyone,
> > >
> > > Another recent sighting has given rise to a question.  Yesterday,
> > Tuesday,
> > > I was birding along San Fransquito Creek at the end of Geng Rd in  
> > > Palo
> > > Alto.  I saw two Spotted Sandpipers foraging together.  Usually seen  
> > > as
> > > single individuals in the Bay Area, I was wondering if there have  
> > > ever
> > > been any evidence of breeding in or around the South Bay?  I think of
> > them
> > > breeding being more in the Sierras.
> >
> > They nested along the Russian River at the end of the 19th century,  
> > but
> > nesting further south appears more recent, at least if you look only  
> > at
> > first nesting records.  In Santa Clara County our first record was in  
> > 1989
> > and we found them nesting in scattered locations in four blocks  
> > during the
> > atlas period of 1987 to 1993.  All nest locations have been in low-
> > gradient
> > streams on the valley floor.  Last year they nested at Almaden Lake.
> >
> > We have irregularly had birds along the Bay edge in summer and we have
> > discussed the possibility of breeding in some area with gravel,  
> > somewhat
> > like the low-gradient stream beds they use now.  But our conclusion is
> > that
> > these are nonbreeding birds.
> >
> >
> > > The next question would be, do they pair up prior to moving to  
> > > breeding
> > areas?
> >
> > Good question.  Another question is how does one define a pair.   
> > Breeding
> > pairs in the county have been very active with lots of calling to each
> > other and flight displays, jumping in the air, etc.  Really quite
> > spectacular.  Two birds without courtship behavior may be just two
> > migrants
> > or nonbreeders.
> >
> > Bill Bousman
> > Santa Clara County records compiler
> >
> > _______________________________________________
> > Do not post admin requests to the list. They will be ignored.
> > south-bay-birds mailing list      ([[email protected]])
> > Help/Unsubscribe/Update your Subscription:
> > http://www.plaidworks.com/mailman/options/south-bay-
> > birds/chucao%40coastside.net
> >
> > This email sent to [[email protected]]
> >
> > --
> > No virus found in this incoming message.
> > Checked by AVG Anti-Virus.
> > Version: 7.0.308 / Virus Database: 266.10.4 - Release Date: 4/27/2005
>
> --  
> No virus found in this outgoing message.
> Checked by AVG Anti-Virus.
> Version: 7.0.308 / Virus Database: 266.10.4 - Release Date: 4/27/2005
>
>
> _______________________________________________
> Do not post admin requests to the list. They will be ignored.
> south-bay-birds mailing list      ([[email protected]])
> Help/Unsubscribe/Update your Subscription:
> http://www.plaidworks.com/mailman/options/south-bay-birds/ 
> les%40birdnutz.com
>
> This email sent to [[email protected]]
_______________________________________________
Do not post admin requests to the list. They will be ignored.
south-bay-birds mailing list      ([[email protected]])
Help/Unsubscribe/Update your Subscription:
http://www.plaidworks.com/mailman/options/south-bay-birds/list_fred_archives%40plaidworks.org

This email sent to [[email protected]]