Factors influencing family rupture and parent‐offspring conflict in the Black Kite Milvus migrans

Juvenile and adult behaviour was studied at eight nests of Black Kites Milvus migrans within the Donana Biological Reserve, Spain. Parental investment in vigilance and defence of offspring progressively decreased during the post-fledging dependence period. The number of feeds was also slightly reduced towards the end of the period. However, this does not seem to be the main factor which leads to juvenile independence. The fact that the family rupture is sudden and that the post-fledging dependence period tends to shorten as the season progresses suggests that juvenile and adult migratory urgency may be as important a factor as reduced parental investment in breaking the family ties.

[1]  N. Davies.  PARENTAL MEANNESS AND OFFSPRING INDEPENDENCE: AN EXPERIMENT WITH HAND‐REARED GREAT TITS PARUS MAJOR , 2008 .

[2]  L. Brown.  OBSERVATIONS ON SOME KENYA EAGLES , 2008 .

[3]  J. Alonso,et al.  Parental care and the transition to independence of Spanish Imperial Eagles Aquila heliaca in Doñana National Park, southwest Spain , 2008 .

[4]  P. J. Edwards.  Brood division and transition to independence in Blackbirds Turdus merula , 2008 .

[5]  R. Green.  BREEDING BEHAVIOUR OF OSPREYS PANDION HALIAETUS IN SCOTLAND , 2008 .

[6]  R. Meinertzhagen.  THE EDUCATION OF YOUNG OSPREYS , 2008 .

[7]  J. Bustamante,et al.  Post-fledging dependence period and maturation of flight skills in the Black Kite Milvus migrans , 1989 .

[8]  J. Moreno.  Parental care of fledged young, division of labor, and the development of foraging techniques in the Northern wheatear (Oenanthe oenanthe L.) , 1984 .

[9]  P. Woodward.  Behavioral Ecology of Fledgling Brown-Headed Cowbirds and Their Hosts , 1983 .

[10]  P. M. Rogers,et al.  Research advance in potassium cycling in agroecosystems , 1980 .

[11]  R. Trivers.  Parent-Offspring Conflict , 1974 .

[12]  V. Gargett.  OBSERVATIONS AT A BLACK EAGLE NEST IN THE MATOPOS, RHODESIA , 1972 .

[13]  H. B. Tordoff.  An Automatic Live-Trap for Raptorial Birds , 1954 .

[14]  D. Gilmer,et al.  Post fledging behavior of ferruginous hawks in North Dakota , 1986 .

[15]  B. Bruun.  «Urgency» in the migration of European raptors with special emphasis on the middle east , 1986 .

[16]  K. Steenhof,et al.  Evaluation of Patagial Markers for Raptors and Ravens , 1983 .

[17]  N. Davies.  Parental Care and the Transition To Independent Feeding in the Young Spotted Flycatcher (Muscicapa Striata) , 1976 .