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What is motivation, and what motivates chickens?
Well, recently we talked about learning.
And this is a really good point in the course,
to tell you about motivation.
Motivation is defined as the strength of the tendency to perform
a given behavior or the urge to perform a particular behavior,
taking into account both internal and external factors.
So for example, my motivation to drink a glass
of water will be relatively high if it's a hot,
dry, windy day and I've been
outside in this weather for a couple of hours with nothing to drink.
But my motivation will be much lower to drink the water if the weather is cool and wet,
or if I've just drunk some water.
My motivation to drink is influenced by external factors like the weather but also,
internal factors such as how much fluid I've consumed recently.
Animals like chickens are thought to have
behavioral needs which they are motivated to perform.
If they're unable to perform these motivated behaviors, then they may suffer.
Motivation that is internally motivated in other words,
arising from changes within the animal itself,
are more difficult for us animal keepers to control and probably,
they have more serious implications for
animal welfare if the animal cannot perform an internally motivated behavior.
Whereas behaviors that are externally motivated in other words,
arising from changes within the animal's environment are easier to control.
So for example, the motivation for hen to find a secluded site,
build a nest and lay eggs is under internal control.
It's the ovulation of the follicle that results in
a cascade of hormones that drive these behaviors.
It's not the sight of a nest or the sight of
another hen sitting on eggs that motivates the behavior.
But not all behaviors that can be motivated,
need to be motivated to ensure a chicken has good welfare.
So for example, a bird will give an alarm call when threatened by
a predator so this is something that's externally motivated,
but it will probably never suffer if it never has to perform that alarm call.
It is thus not a behavioral need to perform alarm calls although it is indeed, natural.
So what might happen if chickens cannot perform motivated behaviors?
They're likely to show signs of deprivation,
which can manifest itself in several ways.
Some of the key signs of deprivation of motivated behavior include, frustration.
Frustration may manifest itself as redirected behavior where
the animal attempts to fulfill its motivated time budget with something similar.
So if breeding meat chickens are food-deprived for example,
in order to keep them at a healthy weight,
they will often compensate for the inability to eat lots of food which they're
motivated to do by foraging or by over-drinking instead.
Frustrated animals may also show displacement behavior.
This is seemingly irrelevant behavior that is taking out of context of the situation.
So if I show a mealworm to one of my hungry hens,
but I cover the dish up with see-through perspex plastic,
then she won't be able to reach it,
and she'll probably do something very odd such as preen, stereotypic behavior.
Stereotypic behaviors are repetitive sequences
of the behavior that the animal cannot complete.
So for example, many carnivores that are held in
captivity such as big cats and polar bears,
will show pacing behavior in anticipation of
feeding in a repeated sequence over and over again,
because they do not have the space or the stimulation to express hunting behavior.
Sham or vacuum behavior.
This is the expression of
a behavioral repertoire in the absence of the suitable stimulus.
So for example, hens that are kept in wire cages cannot show
dust-bathing behavior but they pretend to do it on the wire floor instead,
even though the suitable stimulus which would be dirt or
some other loose substrate is not present.
Also the behavior isn't successful per se.
So the hen dust-bathing on wire does not succeed in
removing stale preen oil which is what dust-bathing is for.
Dr Victoria SandilandsSenior scientist
