The Free Amino Acids of the Commonest North Island Species of Metrosideros

Abstract

What makes a plant attractive as food to an animal? Animals, being heterotrophic, are dependent on plants for food. From this food they derive many if not all the major and minor elements needed for life, all the carbohydrates and amino acids, and all the vitamins. If an animal is able to live and reproduce on the vegetation of some particular area, this would seem to be an indication that the food supply is adequate in all requirements for metabolism. From using faecal pellet analysis to study the eating habits of the opossum in New Zealand, it is known that in a particular range area this animal eats certain plants only, and leaves others alone. Yet those not eaten are not rejected because they are known to be poisonous or toxic to animals generally. In one area under study by D.S.I.R. none of the plants rejected is known to be poisonous yet these are growing very close to plants which are frequently browsed. The following problem therefore presents itself: are certain plants more attractive (i.e. more palatable) to the opossum than others? If so, why are they more attractive? Do they contain certain classes of compounds which make them taste better?