caa a22 4500 463175700 CHVBK 20180406164825.0 cr unu---uuuuu 170326e20071201xx s 000 0 eng 10.1007/s10336-007-0158-9 doi (NATIONALLICENCE)springer-10.1007/s10336-007-0158-9 Coppack Timothy Institute of Avian Research "Vogelwarte Helgoland”, An der Vogelwarte 21, 26386, Wilhelmshaven, Germany aut Experimental determination of the photoperiodic basis for geographic variation in avian seasonality [Elektronische Daten] [Timothy Coppack] Geographic variation in the timing of breeding, moult and migration of birds reflects adjustment of their annual cycles to regional differences in environmental conditions. Understanding to what degree this variation results from phenotypic plasticity or from genetic adaptation is important both as a goal of primary research and especially because we need to understand the potential for species to adapt to global environmental change. The annual change in day-length remains invariant, year after year, and birds depend primarily on this environmental information to match breeding and migration schedules with the changing seasons. Here, I review what is known about the role of photoperiodic responses in shaping geographic variation in avian life cycles, focussing on intraspecific comparative studies in passerine birds. Experiments with hand-raised individuals from different populations kept under identical conditions (common-garden experiments) suggest that differences in the timing of events are not photoperiodically determined when trait differences persist. A single common-garden experiment has no neutral testing ground, however. Thus, if birds breeding at different latitudes have evolved (or retained) non-parallel reaction norms, a single test environment is not sufficient to quantify genetic and environmental influences. While reciprocal transplantation may control for this problem, such an extended experimental design has only rarely been considered. More recently, population-specific reaction norms have been studied by assigning full siblings to various photoperiodic regimes. Through this approach, the extent of genotype-by-environment interaction can be estimated, which is essential information when interpreting trait differences among populations under natural conditions and predicting how species or populations will respond to photoperiodic conditions outside present-day geographical ranges. Dt. Ornithologen-Gesellschaft e.V., 2007 Circannual rhythms nationallicence Life-cycle nationallicence Migration nationallicence Phenotypic plasticity nationallicence Reaction norm nationallicence Journal of Ornithology Springer-Verlag 148(2007-12-01), 459-467 0021-8375 148<459 2007 148 10336 https://doi.org/10.1007/s10336-007-0158-9 text/html Onlinezugriff via DOI 1 review-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10336-007-0158-9 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Coppack Timothy Institute of Avian Research "Vogelwarte Helgoland”, An der Vogelwarte 21, 26386, Wilhelmshaven, Germany aut NATIONALLICENCE 773 0- Journal of Ornithology Springer-Verlag 148(2007-12-01), 459-467 0021-8375 148<459 2007 148 10336 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer