The choice of the word "niche" as used in ecology is unfortunate, having the primary meaning of place. As ecologists use it, though, it means the ecological role of an organism or the set of conditions suitable for the organism.
We generally don't expect to find two animals with the same ecological niche in the same place—one of them is almost certainly somewhat better fit than the other and eventually forces out the second by out-competing it. Often, though, related forms can divide up a niche through one being slightly better fit for one part and the other for a different part.
An example of this is seen in the two Chihuahuan Desert foxes. The Kit
Fox's home is in the desert bolsons where its sensitive hearing, small size, and
digging ability allow it to thrive. Its relative, the Gray Fox, excels in the rocky
desert ranges where its agility gives it the advantage in the rough terrain.
Differences in physical prowess, along with choices of diet and topography, allow the
two to share the landscape.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.