Biology Reference
In-Depth Information
CHAPTER 1
Natural Selection,
Ecology and
Behaviour
Photo © Craig Packer
Watching and wondering
Imagine you are watching a bird searching in the grass for food (Fig. 1.1). At first your
curiosity may be satisfied simply by knowing what species it is, in this case a starling
Sturnus vulgaris . You then watch more closely; the starling walks along and pauses
every now and then to probe into the ground. Sometimes it finds a prey item, such as a
beetle larva, and eventually, when it has collected several prey items, it flies back to the
nest to feed its hungry brood.
For students of behavioural ecology, a whole host of questions comes to mind as this
behaviour is observed. The first set of questions concerns how the bird feeds. Why has it
chosen this particular place to forage? Why is it alone rather than in a flock? Does it
collect every item of food it encounters or is it selective for prey type or size? What
influences its decision to stop collecting and fly back to feed its chicks?
Another set of questions emerges when we follow the starling back to its nest. Why
has it chosen this site? Why this number of chicks in the nest? How do the two adults
decide on how much food each should bring? Are these two adults the mother and
father of all the chicks? Why are the chicks begging so noisily and jostling to be fed?
Surely this would attract predators to the nest. If we could follow our starlings over a
longer period, we may then begin to ask about what determines how much effort the
adults put into reproduction versus their own maintenance, about the factors
influencing the timing of their seasonal activities, their choice of mate, the dispersal of
their offspring and so on.
Behavioural ecology provides a framework for answering these kinds of questions.
In  this chapter we will show how it combines thinking about behaviour, ecology
(the  'stage' on which individuals play their behavioural strategies) and evolution
Asking questions
Search WWH ::




Custom Search