Behavioral Genetics and Animal Science - Genetics and the Behavior of Domestic Animals - page 18

laboratory rats both dig elaborate burrows. Learning has some effect on the
efficiency of burrowing, but the configuration of the burrows was the same
for both the wild and domestic rats. Albino laboratory rats dug excellent
burrows the first time they were exposed to an outdoor pen. Nest building in
sows is another example of the interaction between instinct and learning.
When a sow is having her first litter, she has an uncontrollable urge to build
a nest. Nest building is hard-wired and hormonally driven. Widowski and
Curtis (1989) showed that injections of prostaglandin F 2 a induce nest build-
ing in sows. However, sows learn from experience how to build a better nest
with each successful litter.
Other behaviors are almost entirely learned. Seagulls are known to drop
shellfish on rocks to break them open, while others drop them on the road and
let cars break them open ( Grandin, 1995 ). Many animals ranging from apes to
birds use tools to obtain food. New Calendonian crows use complicated tools
to obtain food and can solve problems other birds cannot ( Weir and Kacelnik
2006 ). Griffin (1994) and Dawkins (1993) provide many examples of complex
learned behaviors and flexible problem solving in animals.
Innate behaviors used for finding food, such as grazing, scavenging,
or hunting, are more dependent on learning than behaviors used to consume
food. Sexual behavior, nesting, eating, and prey-killing behaviors tend to be
governed more by instinct ( Gould, 1977 ). The greater dependence on learn-
ing to find food makes animals in the wild more flexible and able to adapt
to a variety of environments. Behaviors used to kill or consume food can
be the same in any environment. Mayr (1974) called these different behav-
ioral systems “open” or “closed” to the effects of experience. A lion hunt-
ing her prey is an example of an open system. The hunting female lion
recognizes her prey from a distance and carefully stalks her approach.
Herrick (1910) wrote, “the details of the hunt vary every time she hunts.
Therefore, no combination of simple reflex arcs laid down in the nervous sys-
tem will be adequate to meet the infinite variations of the requirements for
obtaining food.”
Interactions Between Instinctual Hardwired Behavior
and Experience
Some of the interactions between genetics and experience have very complex
effects on behavior. In birds, the chaffinch learns to sing its species-specific
song even when reared in a sound-proof box where it is unable to hear other
birds ( Nottebohm, 1970, 1979 ). However, when chaffinches are allowed to
hear other birds sing, they develop a more complex song. The basic pattern
of canary song emerges even in the absence of conspecific (flock-mate) audi-
tory models ( Metfessel, 1935; Poulsen, 1959 ). Young canaries imitate the
song of adult canaries they can hear, and when reared in groups they develop
song patterns that they all share ( Nottebohm, 1977 ). Many birds, such as the