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

VERSATILITY OF CURLEWS FEEDING ON NEREIS
VERSATILITY OF MALE CURLEWS NUMENIUS ARQUATA
PREYING UPON NEREIS DIVERSICOLOR: DEPLOYING
CONTRASTING CAPTURE MODES DEPENDENT
ON PREY AVAILABILITY
Curlews Numenius arquaia use 2 methods to capture Ragworms Nereis diversicolor. they search for
worms at the surface, which are taken with a single peck (called N k) and/or they search for visual cues,
such as burrow entrances, and probe deep to extract the worm from the burrow (called Npmbc). It is argued
that male Curlews select predominantly active worms, which are either grazing at the surface
(N k) or are filter feeding within their burrows (Nprilbc and sometimes N k). Profitability (mg s" 1 handling
i increases with worm length and is greater for N k. because of its shorter handling time, than for
Nprobc. Worms of both prey types < c. 6 cm are ignored, since profitability is below the intake rate
(mg s" 1 feeding). During low water there is a shift from Nprobc to Np