FORAGE QUALITY IN BROOD REARING AREAS OF THE LESSER SNOW GOOSE AND THE GROWTH OF CAPTIVE GOSLINGS

1. Experimental feeding trials using captive goslings of lesser snow g eese were carried out on the breeding grounds at La Perouse Bay, Manit oba, in order to determine the birds' ability to utilize different for age types. 2. The birds were allowed to graze salt-marsh swards of eit her Puccinellia phryganodes or Carer subspathacea, and inland swards o f Festuca rubra and Carex x flavicans. Duck chow and freshly chopped l eaves of Carer aquatilis were provided in further trials. The experime nts were fully replicated and birds feel for 6 hours. 3. Besides net c hanges in weight of birds, the following were measured: acid-detergent fibre, silica, nitrogen, and phosphorus and ash contents of forage ti ssues and faeces. Amounts of serveral inorganic cations and anions in these materials were also determined. 4. In general, the birds gained or maintained weight on the salt-marsh forages which had higher nutrie nt contents, and lower fibre and silica contents than the alternative species. The birds either maintained or lost weight when feeding eithe r on inland swards or on Carer aquatilis. 5. These results support the field evidence that the decline in gosling weight over the last decad e reported at La Perouse Bay is the result of a lack of preferred salt -marsh forage and the use of alternative species by the birds.