The relationship between the size of a bird and its perching behavior
The hypothesis holds true: the crow puts a greater distance between itself and another crow when it perches on a wire. The sparrow puts a smaller distance between itself and another sparrow when perching on a wire.
Birds that sit on a power cables or telephone lines usually sit at equally spaced distances between one another. It is almost as if the birds have a way of measuring the distance between their perching neighbor. This gap is commonly referred to as the "individual distance" and it is a characteristic displayed by a few species of birds. It arises due to the territorial nature of the bird species.
Conduct the experiment under different weather conditions (a sunny, cloudy, windy or rainy days).
Identify a different species of bird for the experiment (eg. pigeons). How does their behavior compare with that of the birds in this experiment?
What determines individual distance? - http://birdcentral.net/distance.htm
Sparrow - http://en.wikipedia.org/wiki/Sparrow
Crow - http://en.wikipedia.org/wiki/Crow
Passerine - http://en.wikipedia.org/wiki/Passerine