there is a relationship between eating habits and sleeping habits.
Birds that eat together often sleep
together has many benefits for birds.
There are many reasons for birds
to sleep together, even if we cannot see these reasons easily.
stay warm and save food in the winter if they sleep together.
In the wintertime, when it is cold
and there are not many plants growing, it is even more important for birds
to stay warm and try to save the food that they have stored for the
that do not sleep with other birds will find other ways to stay warm.
One way to stay warm and save food
is to find a place to sleep that is protected from the cold weather.
four examples of how birds can keep warm.
For example, birds that have to
sleep alone will try to find some plants that are growing close together
and sleep "inside" these plants. Another type of bird, the
horned lark, will dig a hole in the ground to stay warm. Another bird, the
ptarmigan, will dig a hole in the snow to stay warm. However, even though
these birds can stay warm by doing these things, other birds are able to
stay even warmer by staying together in groups. Several types of
birds do this. For example, wrens, swifts, brown creepers, bluebirds, and
anis are types of birds that stay together at night in order to stay warm.
contact helps birds stay warm.
One reason that birds are able to
stay warmer when they stay together is that when their skin touches, less
heat is lost to the colder air around them.
some facts about staying warm with skin contact.
For example, research has shown
that one type of bird, the kinglet, can reduce heat loss by 25% if two of
them are together, and they can reduce heat loss by 33% if three of them
together has more benefits--birds can share information.
There is another benefit to
staying together--if all the birds stay together, they can give one
another more information.
example, birds look for food every day.
For example, groups of birds leave
their nests during the day to look for food.
birds are not lucky and do not find food.
When these birds come back at
night, some of them have found food to eat, but others have not.
day, after looking for food, the birds tend to follow the
"lucky" birds (the ones that found food).
Scientists have seen that, on the
next day, when the birds have to leave again to find food, the birds that
did not find enough food on the previous day tend to follow the birds that
did find food on the previous day.
see more evidence of the relationship between eating and staying together
in two other types of birds that are similar.
There are two other types of birds
that are related, the common kestrel and the lesser kestrel. These two
types of birds are related, but they have different nesting habits and
different eating habits.
of bird hunts animals, the other type of bird looks for insects.
One of these birds, the common
kestrel, tends to hunt vertebrate animals (animals that have spines) in a
small area that they are familiar with. The lesser kestrel, on the other
hand, hunts for insects over a wide area.
type of bird hunts alone and sleeps alone; the second type hunts together
and sleeps together.
The first bird (the one that likes
to hunt animals), the common kestrel, sleeps alone and hunts alone. In
contrast, the lesser kestrel sleeps and hunts together with other birds.
Some people think that the lesser kestrel hunts with other birds so that
it can learn from the other birds where the insects are.
sleeping together helps protect the birds.
The last reason that birds stay together is that some birds that are
not sleeping can send a signal to the other birds if they are attacked.
in some ways, sleeping together can be more dangerous.
However, even though staying together gives the birds this extra
benefit, there are some disadvantages to staying together. For example, if
a predator (hunter) sees so many birds together in one place, it will be
more likely to attack them. Furthermore, birds that stay together on the
ground are more easily attacked than are birds that sleep in trees.
birds in trees can be attacked.
However, even birds that sleep in trees can be attacked by other
birds at the edges of the group can be attacked more easily.
Finally, the birds that are at the edges of the group (not at the
center) are more vulnerable to attack than are the birds at the center
since they are the first ones that predators will find.