Butterflies in a mountain area in the northern Iberian peninsula were studied to see how their distribution and abundance are affected. The researchers found that the altitude where butterflies are found is related to how many different species are there. The higher up you go, the more species you'll find. The size of the butterflies and how far they are from the edge of their range also play a role in where they are found. However, the number of butterflies in an area is more influenced by the type of plants they eat as larvae, rather than their size or altitude. This suggests that where butterflies live is mostly determined by the climate they can tolerate, while how many there are in a specific area depends on the available resources.