31.08.2013 Views

waders and their estuarine food supplies - Vlaams Instituut voor de ...

waders and their estuarine food supplies - Vlaams Instituut voor de ...

waders and their estuarine food supplies - Vlaams Instituut voor de ...

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

take rate. We might therefore expect that the maximum<br />

recor<strong>de</strong>d intake rate, <strong>and</strong> possibly also the average, to<br />

increase when Oystercatchers feed on the more profitable<br />

prey. As large prey are more profitable than<br />

small ones, we would expect an increase of intake rate<br />

wilh the average weighl of ihe prev taken. There was<br />

in<strong>de</strong>ed an effect of prey weight on intake rale, but intake<br />

rates were always relatively high when the birds<br />

PREY PROFITABILITY AND INTAKE RATE<br />

1000<br />

:® •<br />

500 •<br />

foraged less than I h after a long resting period. We focus<br />

here on intake as a function of prey weight <strong>and</strong> exclu<strong>de</strong><br />

the 11 studies in which feeding lime was less<br />

than I h. We analyse elsewhere the relation belween<br />

intake rate, feeding activity <strong>and</strong> duration of the feeding<br />

lime (Zwarts et al. 1996b).<br />

Most of the prey taken by Oystercatchers weighed<br />

between 30 <strong>and</strong> 1000 mg. Within this range, the aver-<br />

. • V"^<br />

\'*3>*.<br />

l*W*4.<br />

* • *i J 5F**<br />

in 1 • armoured<br />

• •» Ja?<br />

0) 100<br />

soil-bodied<br />

• ikjf* 9 y= 1.426x0 *18<br />

E »=l3.00ir3K' * p

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!