caa a22 4500 465782043 CHVBK 20180323111958.0 cr unu---uuuuu 170327e19900301xx s 000 0 eng 10.1007/BF00172089 doi (NATIONALLICENCE)springer-10.1007/BF00172089 Wiklund Christer Department of Zoology, University of Gothenburg, 250 59, S-40031, Gothenburg, Sweden aut Offspring protection by merlin Falco columbarius females; the importance of brood size and expected offspring survival for defense of young [Elektronische Daten] [Christer Wiklund] Summary: Nest predation was simulated by presenting a stuffed raven close to nests of merlins. This was done to examine the influence of brood size related factors on female defence intensity. The original clutch size did not affect nest defense after hatching, but brood size was important. It determined the attack frequency and, for each brood size level, the proportion of attacking females. When brood sizes were manipulated, the defense intensity increased and decreased, respectively, in relation to the size of the brood. In addition, broods with high future survival (first broods) were defended more vigorously than broods with low future survival (replacement broods). Hence, expected benefits in terms of fledgling production and chick survival seem to be important determinants of female investment in offspring protection. The lower predation rate among females responding with overt aggression to the raven compared to that of less aggressive females suggests that defence of young is beneficial. Springer-Verlag, 1990 Behavioral Ecology and Sociobiology Springer-Verlag 26/3(1990-03-01), 217-223 0340-5443 26:3<217 1990 26 265 https://doi.org/10.1007/BF00172089 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00172089 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Wiklund Christer Department of Zoology, University of Gothenburg, 250 59, S-40031, Gothenburg, Sweden aut NATIONALLICENCE 773 0- Behavioral Ecology and Sociobiology Springer-Verlag 26/3(1990-03-01), 217-223 0340-5443 26:3<217 1990 26 265 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer