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Abstract. Animals can be important in modulating ecosystem-level nutrient cycling, although their importance varies greatly among species and ecosystems. Nutrient cycling rates of individual animals represent valuable data for testing the predictions of important frameworks such as the Metabolic Theory of Ecology (MTE) and ecological stoichiometry (ES). They also represent an important set of functional traits that may reflect both environmental and phylogenetic influences. Over the past two decades, studies of animal-mediated nutrient cycling have increased dramatically, especially in aquatic ecosystems. Here we present a global compilation of aquatic animal nutrient excretion rates. The dataset includes 10,534 observations from freshwater and marine animals of N and/or P excretion rates. These observations represent 491 species, including most aquatic phyla. Coverage varies greatly among phyla and other taxonomic levels. The dataset includes information on animal body size, ambient temperature, taxonomic affiliations, and animal body N:P. This data set was used to test predictions of MTE and ES, as described in Vanni and McIntyre (2016; Ecology

Abstract. Physiological measurements of both stress and sex hormones are often used to estimate the consequences of natural or human-induced change in ecological studies of various animals. Different methods of hormone measurement exist, potentially explaining variation in results across studies; methods should be cross-validated to ensure they correlate.We directly compared faecal and plasma hormone measurements for the first time in a wild free-living species, the Adelie penguin (Pygoscelis adeliae). Blood and faecal samples were simultaneously collected from individual penguins for comparison, and assayed for testosterone and corticosterone (or their metabolites). Sex differences and variability within each measure, and correlation of values across measures were compared. For both hormones, plasma samples showed greater variation than faecal samples. Males had higher mean corticosterone concentrations than females, but the difference was only statistically significant in faecal samples. Plasma testosterone, but not faecal testosterone, was significantly higher in males than females. Correlation between sample types was poor overall, and weaker in females than in males, perhaps because measures from plasma represent hormones that are both free and bound to globulins, whereas measures from faeces represent only the free portion. Faecal samples also represent a cumulative measure of hormones over time, as opposed to a plasma 'snapshot' concentration. Our data indicate that faecal sampling appears more suitable for assessing baseline hormone concentrations, while plasma sampling may best define immediate responses to environmental events. Consequently, future studies should ensure they select the most appropriate matrix and method of hormone measurement to answer their research questions.

Australian magpies (Gymnorhina tibicen) have been recorded as predators at nests of other birds in New Zealand but their importance as a predator in rural areas, where they are most common, has not been previously quantified. We continuously monitored 38 nests of seven species in rural areas over two successive breeding seasons using time-lapse video recording to determine the proportion that were preyed on by magpies compared to other animals in this ecosystem. Twenty-two lethal events were recorded over the two breeding seasons; magpies were responsible for only one of these. A further eight scavenging events were also recorded; magpies were not responsible for any of these. Harriers (Circus approximans), ship rats (Rattus rattus), and cats (Felis catus) were the main predators and were responsible for 36, 32, and 23% of lethal events respectively. A pukeko (Porphyrio porphyrio) was also recorded preying on nest contents on one occasion. Other known nest predators such as Norway rats (Rattus norvegicus), possums (Trichosurus vulpecula), hedgehogs (Erinaceus europaeus) and ruru (Ninox novaeseelandiae) did not Z05031; appear in any recorded frame although present in the study areas. Our results suggest that magpies are not serious nest predators in rural areas in comparison to ship rats, cats, and harriers, and that controlling magpies in rural areas will not significantly improve the nesting success of other birds.