Section V: the Question: What Do They Eat?

1. Aims This section sets out to answer the second aim of this study, namely:-ii) To determine qualitatively and quantitatively the food eaten by that population,. The information presented in this section (unless otherwise stated) has been obtained from the Study Block (see Section II) by the methods described below. The previous section, which considered the population aspects, formed an essential background to this and the following section. A list of food items alone is an insufficient answer to the question heading this section. It is necessary to know the relative importance in terms of quantity eaten, how this varies seasonally, and when the critical periods occur. A series of subaims can be framed:-a) What food items does a squirrel eat during an annual cycle in the selected area of habitat, and what is its feeding behaviour? b) How much food does the squirrel eat? c) What proportion of the general activity pattern consists of feeding activity? Other important questions are involved when evaluating the food of the squirrel. Food consumed should be considered in relation to food available. Availability is a difficult parameter to measure, because the squirrel may not take freely all items apparently available; it may be selecting within a particular type of food item in terms of size and/or quality. This aspect has been explored where possible in the present study. 2. Methods Variation in food intake and feeding activity can be considered in a number of ways. In this Section variation between individual squirrels, other than broad aZ.ult:juvenile differences, has not been considered, but rather variation between days, between seasons and between years for the population considered as a whole. A. gualitative methods FIELD OBSERVA!LIONS: The availability of potential foods, and squirrel feeding signs, were recorded on specially designed punch cards, together with date and location. The information could be rapidly sorted to give a seasonal calendar of foods available and eaten at Edensmuir; the results suggested which were the most important food items (primary foods), and which were used only in s;rall amounts or for restricted periods (secondary foods) under normal circumstances. Time gaps in the supply of primary foods, when secondary foods were of necessity more heavily utilised, were defined as potential critical periods. For such gaps to be really criticalit would be necessary to show that the secondary food sources were inadequate, or in temporary short supply. STOMACH CONTENTS: Identification of food …