caa a22 4500 46578271X CHVBK 20180323111959.0 cr unu---uuuuu 170327e19901001xx s 000 0 eng 10.1007/BF00164901 doi (NATIONALLICENCE)springer-10.1007/BF00164901 Temporal increase in nest defence intensity of the willow tit ( Parus montanus ): parental investment or methodological artifact? [Elektronische Daten] [Seppo Rytkönen, Kari Koivula, Markku Orell] Summary: Nest defence responses of experimentally naive and revisited willow tits (Parus montanus) towards a predator model were studied near Oulu, northern Finland, in 1988-1989. Intensity was measured with three variables in 228 trials at 90 nests. Two hypotheses explaining the temporal changes in the nest defence behavior were examined. In naive birds the nest defence intensity was positively correlated with the brood age, supporting the "parental investment” hypothesis. The number of previous trials did not cause additional variation in nest defence behavior in comparison between naive and revisited birds. Similarly, experiences in a previous breeding attempt did not affect the nest defence behavior during the course of the subsequent brood. Thus, the temporal increase in multiply visited nests was not due to the birds becoming familiar with the nest threat, i.e., no support was found for the so-called positive reinforcement hypothesis. We think that methodological problems in avian nest defence studies can hide the adaptive significance of the behavior, not explain it. Springer-Verlag, 1990 Rytkönen Seppo Department of Zoology, University of Oulu, Linnanmaa A, SF-90570, Oulu, Finland aut Koivula Kari Department of Zoology, University of Oulu, Linnanmaa A, SF-90570, Oulu, Finland aut Orell Markku Department of Zoology, University of Oulu, Linnanmaa A, SF-90570, Oulu, Finland aut Behavioral Ecology and Sociobiology Springer-Verlag 27/4(1990-10-01), 283-286 0340-5443 27:4<283 1990 27 265 https://doi.org/10.1007/BF00164901 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00164901 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Rytkönen Seppo Department of Zoology, University of Oulu, Linnanmaa A, SF-90570, Oulu, Finland aut NATIONALLICENCE 700 1- Koivula Kari Department of Zoology, University of Oulu, Linnanmaa A, SF-90570, Oulu, Finland aut NATIONALLICENCE 700 1- Orell Markku Department of Zoology, University of Oulu, Linnanmaa A, SF-90570, Oulu, Finland aut NATIONALLICENCE 773 0- Behavioral Ecology and Sociobiology Springer-Verlag 27/4(1990-10-01), 283-286 0340-5443 27:4<283 1990 27 265 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer