title: Factors Affecting Growth of Tengmalm's Owl (Aegolius funereus) Nestlings: Prey Abundance, Sex and Hatching Order.
abstract: In altricial birds, energy supply during growth is a major predictor of the physical condition and survival prospects of fledglings. A number of experimental studies have shown that nestling body mass and wing length can vary with particular extrinsic factors, but between-year observational data on this topic are scarce. Based on a seven-year observational study in a central European Tengmalm's owl population we examine the effect of year, brood size, hatching order, and sex on nestling body mass and wing length, as well as the effect of prey abundance on parameters of growth curve. We found that nestling body mass varied among years, and parameters of growth curve, i.e. growth rate and inflection point in particular, increased with increasing abundance of the owl's main prey (Apodemus mice, Microtus voles), and pooled prey abundance (Apodemus mice, Microtus voles, and Sorex shrews). Furthermore, nestling body mass varied with hatching order and between sexes being larger for females and for the first-hatched brood mates. Brood size had no effect on nestling body mass. Simultaneously, we found no effect of year, brood size, hatching order, or sex on the wing length of nestlings. Our findings suggest that in this temperate owl population, nestling body mass is more sensitive to prey abundance than is wing length. The latter is probably more limited by the physiology of the species.
authors.affiliation: Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic.
authors.forename: Markéta
authors.initials: M
authors.lastname: Zárybnická
authors.affiliation: Department of Zoology, Faculty of Science, University of South Bohemia in České Budějovice, České Budějovice, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Riegert
authors.affiliation: Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic.
authors.forename: Lucie
authors.initials: L
authors.lastname: Brejšková
authors.affiliation: Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Šindelář
authors.affiliation: Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic.
authors.forename: Marek
authors.initials: M
authors.lastname: Kouba
authors.affiliation: Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Hanel
authors.affiliation: Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic.
authors.forename: Alena
authors.initials: A
authors.lastname: Popelková
authors.affiliation: Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic.
authors.forename: Petra
authors.initials: P
authors.lastname: Menclová
authors.affiliation: Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic.
authors.forename: Václav
authors.initials: V
authors.lastname: Tomášek
authors.affiliation: Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic.
authors.forename: Karel
authors.initials: K
authors.lastname: Šťastný
mesh_terms: D000818:Animals; D003411:Arvicolinae / Q000502:physiology; D001686:Biological Phenomena / Q000502:physiology; D005260:Female; D008297:Male; D051379:Mice; D009425:Nesting Behavior / Q000502:physiology*; D010829:Physiological Phenomena / Q000502:physiology; D012098:Reproduction / Q000502:physiology; D012725:Sexual Behavior / Q000502:physiology; D020305:Strigiformes / Q000254:growth & development* / Q000502:physiology*; D014921:Wings, Animal / Q000473:pathology