The food of 177 mallard dnas platyrhynchoa platyrliyncha L. collected from coastal ancl estuarine areas during t.he shooting seasons of 1957-60 is clescribetl. This sanrplo is subdivided into 1 15 birch obtained froin various localities scatteretl around the coast, antl sixty-two birds collected from one locality, the Greenhorough and Milfordhope Islands in the River Medway, Kent.
From observations and viscera. analyses it was apparent that the coastal marshes aro used as roosting and to a lesser extent, as feeding grouncln. Much of the food of the hirtls shot over coastal marshas had been obtained from nesrhy hrackish-watnr was, antl at tho beginning of the season from inland stubble-fields.
Plant seeds formed the main bulk of the food antl occurred more frequently than any other item.
Mallard feeding in saltmarshes were found to be taking mainly the seeds of Salicornin spp., Atriples spp., antl Suneda rncrritima. The most frequently taken animal materials were the mollusc Snhannecr uvne antl tlie crustaceans Cnrcircts innrnrt, Crnngov wrlgaris and Corophium spp.
In brackish-water areas, xnallarct were fonnr to the feeding mainly on the seeds of Scirpw maritimw, S . tahernaemonnni, Poanrogeon, lectinahis, Riippin spp. and Cerabphylluni subniersum. Tho nio11usr Hdrohia jenkin.oi and the crustacean Palaemonetes vnriana were the niost frequently nrrurring animal foods. At the heginning of the shooting season anti mainly in Septenihei, barley (Hordeurn spp.) was eaten ancl often in conxiderahle quantities.
It was fonnd that the sixty-two hirds collertetl from the m e loralitp of the Metlway islands had been feeding on similar speries to tllose hirds rollerted fivnn a numher of different localities.
The differences in diet from year to year and as the season progressed a described A general survey of the literaturr is given and the impnrtance of Scirpus maritimus emphasized.
It. is suggested that mallartl feeding ill thr intertitlal muds are taking hivalves (e.g. Macoma balthica and Scrohiculnrin plana) and Crustarea (e.g. Corophiwrn dctfaov). Phew are a number of saltniaii plant species (e . g. Sprrrtinn toulnaradii agg., Hrrineionr prtulacoidrs) which are not eatan to any great extent, even though tliey may be rommoii constitucmts of the marsh. There in probably littie liinitation in rhoire of food itenis (lue to hardness, though there may be Home limitation by the size and berausr of the rnethod of feeding, by the mobility of the food speries.
The pomihle management, of saltmarsh and twarkish-water areas to inrretwe the food supply is discussed.