... prisoner (oystercatchers again) by Bruno Ens and Marcel Kersten, Winter hazards for waders: c... more ... prisoner (oystercatchers again) by Bruno Ens and Marcel Kersten, Winter hazards for waders: cold snaps and mortality peaks (more oystercatchers) by Jan Hulscher, From individual to population and back again (barnacles and oyster-catchers) by Jaap van der Meer, and Do ...
IIn vertebrates, darker individuals are often found to be more active and willing to take risks (... more IIn vertebrates, darker individuals are often found to be more active and willing to take risks (representing characteristics of a ‘proactive’ coping style), whereas lighter individuals are instead more cautious and less active (representing characteristics of a ‘reactive’ coping style). It is thus generally expected that melanin-based colouration and proactivity form a suite of positively integrated traits at the among-individual level. Here we use a multi-generational pedigree of free-living great tits (Parus major) to partition variation in, and the correlation between, melanin-based breast stripe (‘tie’) size and exploration behaviour (a proxy for coping style) into its among- and within-individual components. We show that both traits harbour heritable variation. Against predictions, tie size and speed of exploration were negatively correlated at the among-individual level due to the combined influences of permanent environmental and additive genetic effects. By contrast, the two traits were weakly positively correlated within individuals (i.e., individuals increasing in tie size after moult tended to become more explorative). The patterns of among-individual covariance were not caused by correlational selection as we found additive and opposite selection pressures acting on the two traits. These findings imply that testing hypotheses regarding the existence of a ‘syndrome’ at the among-individual level strictly requires variance partitioning to avoid inappropriate interpretations as the negative ‘unpartitioned’ phenotypic correlation between exploration and tie size resulted from counteracting effects of within- and among-individual correlations. Identifying sources and levels of (co)variation in phenotypic traits is thus critical to our understanding of biological patterns and evolutionary processes
The datafile is an excel file containing 5 sheets with the data used for the article. Please read... more The datafile is an excel file containing 5 sheets with the data used for the article. Please read the accompanying text file 'README.txt' for more information on the datasets and the meaning of the columns
111 The fields of chronobiology and physiological ecology lost a prominent member when Serge Daan... more 111 The fields of chronobiology and physiological ecology lost a prominent member when Serge Daan, Emeritus Professor at the University of Groningen, passed away on 9 February 2018. Serge was a clever and critical researcher who inspired and trained many of us. He made seminal discoveries in hibernation research, ecological energetics, behavioral biology, sleep research, and sex-ratio adaptation. Serge was born in 1940, in the historic windmill “De Plasmolen” in Mook, Limburg, the Netherlands. In 1944, during the Second World War liberation, the Daan family fled from the Plasmolen only hours before it was shelled by American troops. After the war, the family moved to the estate “Het Schol” near Deventer, where Serge grew up with seven brothers and sisters. The family had a great interest in biology, and together the children built an impressive collection of skulls for their museum. Many visitors may remember part of this collection displayed in the hall of Serge’s house “Villa Later” in Paterswolde. Serge studied biology at the University of Amsterdam and obtained his master’s degree in 1966. During his studies he worked with evolutionary biologist Dick Hillenius at the Zoological Museum Amsterdam, which was at the time a meeting place of biologists, artists, writers, and poets. Serge expanded the museum collections by catching amphibians in southern Limburg, using his Harley Davidson as a field vehicle. In Greece he collected reptiles, and to his surprise a newly discovered Agama lizard subspecies was named after him: Agama stellio daani (Beutler and Frør, 1980). Unwilling to spend the rest of his life in dusty museums, Serge returned his PhD grant to the Dutch Science Foundation and instead obtained stipends to investigate hibernation with Prof. dr. Punt in 1968 (Daan, 1973a; PhD cum laude, University of Amsterdam). This venture took Serge back to southern Limburg, where he discovered that hibernating bats would save energy by moving to colder parts of the cave (Daan, 1973b). To test whether this behavior was a temperature response, he carried large blocks of ice into the cave to attract hibernating bats. The result of this experiment was that Serge caught pneumonia, but it also represents a landmark: Serge had changed from a descriptive taxonomist to an experimental biologist. Activity patterns during hibernation were further studied in garden dormice in the laboratory. Serge described that euthermic arousals clearly followed a circadian pattern, interrupted by multiday torpor (Daan, 1973c). These patterns were the first free-running circadian data collected by Serge. They sparked his interest in biological rhythms, further boosted by Mike Menaker’s early publication on circadian rhythms in hibernating bats (Menaker, 1959). It was many years later, in 2009, when Serge, as faculty Dean, was able to show his gratitude and admiration to Mike Menaker by awarding him an honorary professorship at the University of Groningen: “For a generation of researchers into the biological clock, including those in Groningen, Michael Menaker is the giant on whose shoulders they stand.” Serge wanted to learn more about the emerging field of circadian rhythms by visiting Jürgen Aschoff. In one day they wrote a successful Humboldt postdoctoral fellowship application allowing Serge to work with Aschoff at the famous Max Planck Institute 768594JBRXXX10.1177/0748730418768594Journal Of Biological Rhythms research-article2018
... prisoner (oystercatchers again) by Bruno Ens and Marcel Kersten, Winter hazards for waders: c... more ... prisoner (oystercatchers again) by Bruno Ens and Marcel Kersten, Winter hazards for waders: cold snaps and mortality peaks (more oystercatchers) by Jan Hulscher, From individual to population and back again (barnacles and oyster-catchers) by Jaap van der Meer, and Do ...
IIn vertebrates, darker individuals are often found to be more active and willing to take risks (... more IIn vertebrates, darker individuals are often found to be more active and willing to take risks (representing characteristics of a ‘proactive’ coping style), whereas lighter individuals are instead more cautious and less active (representing characteristics of a ‘reactive’ coping style). It is thus generally expected that melanin-based colouration and proactivity form a suite of positively integrated traits at the among-individual level. Here we use a multi-generational pedigree of free-living great tits (Parus major) to partition variation in, and the correlation between, melanin-based breast stripe (‘tie’) size and exploration behaviour (a proxy for coping style) into its among- and within-individual components. We show that both traits harbour heritable variation. Against predictions, tie size and speed of exploration were negatively correlated at the among-individual level due to the combined influences of permanent environmental and additive genetic effects. By contrast, the two traits were weakly positively correlated within individuals (i.e., individuals increasing in tie size after moult tended to become more explorative). The patterns of among-individual covariance were not caused by correlational selection as we found additive and opposite selection pressures acting on the two traits. These findings imply that testing hypotheses regarding the existence of a ‘syndrome’ at the among-individual level strictly requires variance partitioning to avoid inappropriate interpretations as the negative ‘unpartitioned’ phenotypic correlation between exploration and tie size resulted from counteracting effects of within- and among-individual correlations. Identifying sources and levels of (co)variation in phenotypic traits is thus critical to our understanding of biological patterns and evolutionary processes
The datafile is an excel file containing 5 sheets with the data used for the article. Please read... more The datafile is an excel file containing 5 sheets with the data used for the article. Please read the accompanying text file 'README.txt' for more information on the datasets and the meaning of the columns
111 The fields of chronobiology and physiological ecology lost a prominent member when Serge Daan... more 111 The fields of chronobiology and physiological ecology lost a prominent member when Serge Daan, Emeritus Professor at the University of Groningen, passed away on 9 February 2018. Serge was a clever and critical researcher who inspired and trained many of us. He made seminal discoveries in hibernation research, ecological energetics, behavioral biology, sleep research, and sex-ratio adaptation. Serge was born in 1940, in the historic windmill “De Plasmolen” in Mook, Limburg, the Netherlands. In 1944, during the Second World War liberation, the Daan family fled from the Plasmolen only hours before it was shelled by American troops. After the war, the family moved to the estate “Het Schol” near Deventer, where Serge grew up with seven brothers and sisters. The family had a great interest in biology, and together the children built an impressive collection of skulls for their museum. Many visitors may remember part of this collection displayed in the hall of Serge’s house “Villa Later” in Paterswolde. Serge studied biology at the University of Amsterdam and obtained his master’s degree in 1966. During his studies he worked with evolutionary biologist Dick Hillenius at the Zoological Museum Amsterdam, which was at the time a meeting place of biologists, artists, writers, and poets. Serge expanded the museum collections by catching amphibians in southern Limburg, using his Harley Davidson as a field vehicle. In Greece he collected reptiles, and to his surprise a newly discovered Agama lizard subspecies was named after him: Agama stellio daani (Beutler and Frør, 1980). Unwilling to spend the rest of his life in dusty museums, Serge returned his PhD grant to the Dutch Science Foundation and instead obtained stipends to investigate hibernation with Prof. dr. Punt in 1968 (Daan, 1973a; PhD cum laude, University of Amsterdam). This venture took Serge back to southern Limburg, where he discovered that hibernating bats would save energy by moving to colder parts of the cave (Daan, 1973b). To test whether this behavior was a temperature response, he carried large blocks of ice into the cave to attract hibernating bats. The result of this experiment was that Serge caught pneumonia, but it also represents a landmark: Serge had changed from a descriptive taxonomist to an experimental biologist. Activity patterns during hibernation were further studied in garden dormice in the laboratory. Serge described that euthermic arousals clearly followed a circadian pattern, interrupted by multiday torpor (Daan, 1973c). These patterns were the first free-running circadian data collected by Serge. They sparked his interest in biological rhythms, further boosted by Mike Menaker’s early publication on circadian rhythms in hibernating bats (Menaker, 1959). It was many years later, in 2009, when Serge, as faculty Dean, was able to show his gratitude and admiration to Mike Menaker by awarding him an honorary professorship at the University of Groningen: “For a generation of researchers into the biological clock, including those in Groningen, Michael Menaker is the giant on whose shoulders they stand.” Serge wanted to learn more about the emerging field of circadian rhythms by visiting Jürgen Aschoff. In one day they wrote a successful Humboldt postdoctoral fellowship application allowing Serge to work with Aschoff at the famous Max Planck Institute 768594JBRXXX10.1177/0748730418768594Journal Of Biological Rhythms research-article2018
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