El relevo rnicrosucesional entre los Scarabaeoidea coprófagos (Col.)

Resum

The microsuccessional sequence among dung beetles Scarabaeoidea (Col.)
The successive appearance of fauna associated with the dispersion of an ephemeral food source, such as the droppings of large herbivorous mamrnals, is known as microsuccession or heterotrophic succession. The microsuccessive occurrence and permanence of dung-beetles (Scarabaeoidea) is studied under four different climatic conditions in the Central Massif of Gredos (Ibenc Central System). The timing of successional mean occurrence and permanence for different species of dung-beetles depends, among other factors, on environmental temperature and species abundance. An increase in environmental temperature reduces the average occurrence and permanence times for any given species, while there seems to be a higher probability that individuals from more numerous populations will manage to colonize a given dung-pat. This faunistic group does not seem to select from among available dung pats according to quality cntena. It is supposed that any niche displacement in the microsuccessional dimension would require the modification of feeding habits due to the inestability and rapid alteration of tbe excrement food source. This study provides empirical evidence and the basis for theoretical arguments against the existence of competitive exclusion and niche displacement in this dimension among coprophagous Scarabaeoidea.