Biology Reference
In-Depth Information
safety of a group or by hiding away alone? The best place to feed may have the highest
predation risk. How are these trade-offs solved by natural selection?
Thirdly, individuals are likely to have to compete with others for scarce resources. As
we shall discover, conflict occurs not only between rivals for mates or territories, but
also between members of a breeding pair and even between parents and their own
offspring. How are such conflicts resolved? Can the outcome sometimes be cooperation
rather than overt conflict?
Fourthly, individuals play their behaviour on an ecological stage. Different species live
in different habitats and exploit different resources. This, too, is expected to influence an
individual's best options. So we will also be exploring how ecological conditions
influence how individuals behave.
We will show how the same basic theories can be applied to a wide range of organisms,
from microbes to meerkats, and we will see the ingenuity required to design careful
experiments to test the theories, both in the field and the laboratory. Most of all, we hope
to show how ideas from behavioural ecology can help us to understand and appreciate
the marvels of the natural world.
Summary
Behavioural ecology aims to understand how behaviour evolves in relation to ecological
conditions, including both the physical environment and the social environment
(competitors, predators and parasites). It is important to distinguish proximate factors,
which explain how individuals come to behave in a particular way during their lifetime,
from ultimate factors, which concern adaptive advantage in evolution. Natural selection
works on genetic differences. Examples were discussed to illustrate how genetic
differences cause differences in phenotype and behaviour: foraging, learning and
courtship in
Drosophila
; foraging in honeybees; colour and mate/habitat choice in geese
and mice; and migration strategies in the blackcap, which provide an example of a
recent evolutionary change in behaviour.
Individuals are not generally expected to behave for the good of the group but rather
to maximize their own gene contribution to future generations. Field experiments reveal
that clutch size in great tits maximizes individual lifetime reproductive success. Life
history trade-offs include those between quantity and quality of offspring within a
brood, and between current and future reproduction.
Recent studies of how great tits have advanced their time of breeding in relation to
climate warming provide a good example of phenotypic plasticity (the ability of a single
genotype to produce different phenotypes in response to environmental conditions).
They also show that a full understanding of evolutionary responses requires studies of
proximate and ultimate factors to go hand in hand.
Further reading
The classic topics by Niko Tinbergen (1974) and Bert Hölldobler and Edward O. Wilson
(1994) convey the delight of watching and wondering in the field. The topics by Richard
Dawkins (1982, 1989) explain why evolution favours behaviour that benefits
