Contribución al conocimiento del gorrión común, Passer domesticus, en el naranjal de Sagunto (Valencia)

Abstract

The House Sparrow in an orange grove of Sagunto (Valencia, Spain) builds its nest in orange trees. Average sizecof eggs: F = 21,71 x 15,21 mm. Max.: 24,2 x 15,3 and 20,7 x 16,8 mm. Min.: 19,3 x 14,0 and 19.0 x 14,2 mm. Average weigt of eggs: = 2,64 gr. Clutch size varies from 1 to 7 eggs (X = 4,4). Incubation period varies from 13 to 19 days (F = 15,3). Fledging period varies from 13 to 16 days (F = 14,8). The development in weight of nestling is quite obvious until the 10-1 1 th day of age. The nestling development of wing length is constant until fledging success. The average number of nestling fledged per successful nest was 1.7 chickens. These data shows no significant differences with other authors. Conclusion: Passer domesticus has not suffered a sub-speciation but it possesses a pluricapacity for breeding only expressed obove the threshold of competition.