The aim of the current research was to evaluate the tick Ornithodoros amblus Chamberlin in Mazorca Island, Lima, Peru and its relationship with the presence of seabirds, intensity of guano and wind. The tick samplings were performed between 28 and 29 February of 1998. On each point of sampling was placed during three minutes a black coarse cotton cloth of 0,35 m 2. O. amblus showed a spatial clumped distribution. Abundance of ticks was not related with the presence of colonies of birds. Only larvae of O. amblus were in relationship with colonies of seabirds. The preference of different growth states of O. amblus follow the next sequence: Guanay Cormorant > Peruvian Pelican > Camanay Booby. Different growth states did not found relation with intensities of guano. A preference of tick population of O. amblus was observed in relation with strong intensities of winds. The effects of Niño 1997-1998 related to this tick specie is discussed.