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Data from: Body size evolution on islands: are adult size variations in tiger snakes a non-adaptive consequence of selection on birth size?

Aubret, Fabien
Published Feb 01, 2012 on Dryad. https://doi.org/10.5061/dryad.14cr5345

Cite this dataset

Aubret, Fabien (2012). Data from: Body size evolution on islands: are adult size variations in tiger snakes a non-adaptive consequence of selection on birth size? [Dataset]. Dryad. https://doi.org/10.5061/dryad.14cr5345

Abstract

Mean adult size has been used as the traditional measure of body size to explain trends of insular gigantism and dwarfism in a wide array of taxa. However, patterns of variation in body size at birth have received surprisingly little attention, leaving open the possibility that adult body-size differences are nonadaptive consequences of selection acting on neonate body size. Here I used an empirical and correlative approach to test this hypothesis in a mosaic of 12 island and mainland snake populations in Australia. Data collected on 597 adult and 1,084 neonate tiger snakes showed that (1) both adult and neonate mean body sizes varied strongly across populations; (2) prey diversity and size convincingly explained birth-size variations: birth size—notably, gape size—correlated with prey size; (3) neonate snout-vent length was significantly correlated with neonate gape size; and (4) neonate snout-vent length was significantly correlated with adult snout-vent length. Postnatal growth rates recorded under common-garden conditions differed across populations and were correlated with mean prey size. These data collectively suggest that (1) prey size is the main driver for the evolution of body size at birth in gape-limited predators, (2) adult size variations may reflect selective forces acting on earlier life stages, and (3) adult size variations may also reflect resource availability during ontogeny (notably, prey diversity).

Usage notes

Aubret 53172

Excel file contains 4 sheets. First sheet titled Adult Tiger snakes contains field data collected on Adult Tiger snakes (sex, body mass and snout-vent length). Sheet titled Mothers litters and neonates contains laboratory and museum data about reproductive output in female tiger snakes for several populations. For each female is given birth date, mean litter body mass (calculated average body mass for all neonates in a given litter), mean litter svl (calculated average snout vent length for all neonates in a given litter), and mean litter jaw (calculated average jaw length for all neonates in a given litter). Sheet titled Prey contains data collected in Museum collection for prey available at each study site. Latin names are given with body mass and maximum circumference of each prey item. Sheet titled Growth experiment contains experimental data on growth rate and food consumption in neonate Tiger snakes from several populations. Headings indicate for each mother its population of origin, neonate identification number, birth date and morphometrics at birth. Body mass and snout vent length are recorded every two months until the end of the experiment. Column titled Total growth in body mass indicates the difference in body mass between the start and the end of the experiment. The two last columns are Total food (total amount of food consumed by each neonate over the course of the experiment) and Length of experiment (total duration of the experiment). Conversion rates were calculated (column titled Increase in body mass per g of food) and daily growth rates in body mass (increase in body mass in mg per day). Similar calculation were made for snout vent length (increase in svl per g of food; increase in svl in mm per day).

Location

Western Australia
Tasmania
South Australia