Dr Nick IsaacMacroecologist (Biological Records Centre)
Current Work and Research InterestsI am interested in questions about the abundance, distributions, diversity and extinction risk of species. My research generally involves statistical models using data that are structured in space, time and/or phylogenetically. I started out using the traditional approach in macroecology of taking one value per species, but recently I have been using with multilevel models to explore patterns at a range of scales, from populations in space to species and higher taxonomic levels. Inter and inter-specific patterns of abundance Abundance is a key variable in ecology. Studies on variation across species have generally ignored the variation within species, which is extensive and often correlated with environmental gradients. My research in this area uses data on mammals, butterflies and trees to reveal the intrinsic biological and extrinsic environmental determinants of abundance, and the interactions between them. Metabolic theory and energy equivalence The metabolic theory of ecology is a powerful framework linking physiology with ecology through energetics. Energy equivalence is the observation that organisms of markedly different sizes do not vary much in their energy use. My research in this area uses rigorous statistics to explore these patterns in detail, and test competing explanations for them. Spatial patterns in population parameters Do the way populations change over time exhibit characteristic patterns in space? PhD student Savrina Carrizo has revealed strong patterns in the way birds in the US have shifted their geographic ranges. The magnitude of these shifts varies markedly in space and also according to species biology. Ecological informatics of mammals Large scale datasets play an increasing role in biodiversity research. I am Co-PI on a global database of mammalian traits (YouTHERIA) that is spatially explicit and allows users to download large quantities of trait data with a choice of taxonomic arrangements. Conservation prioritisation Much effort has been expended on selecting priority species for conservation, but the species receiving most attention are not always those identified as priorities. My research in this area contributed to the Edge of Existence programme at the Zoological Society of London. |
Brief CV
Selected PublicationsSee also the NERC Open Research Archive. Sitas, N., Baillie, J.E.M. & Isaac, N.J.B. (2009). What are we saving?: developing a standardised approach for conservation action. Animal Conservation 12: 231-237 Cowlishaw, G., Pettifor, R.A. & Isaac, N.J.B. (2009). High variability in patterns of population decline: the importance of local processes in species extinctions. Proceedings: Biological Sciences 276: 63-69 Carbone, C., Cowlishaw, G., Rowcliffe, J.M. & Isaac, N.J.B. (2007). The scaling of consumer and resources abundance: implications for the Energy Equivalence Rule. American Naturalist 170: 479-484 Isaac, N.J.B., Turvey, S.T., Collen, B. & Baillie, J.E.M. (2007). Mammals on the EDGE: Conservation priorities based on threat and phylogeny. PLoS ONE: 1: e296 Isaac, N.J.B., Jones, K.E., Gittleman, J.L. & Purvis, A. (2005) Correlates of species richness in mammals: body size, life history and ecology. American Naturalist 165: 600-607 Isaac, N.J.B., Mallet, J. & Mace, G.M. (2004). Taxonomic inflation: its effect on macroecology and conservation. Trends in Ecology and Evolution 19: 464-469 Isaac, N.J.B. & Cowlishaw, G. (2004). How species respond to multiple extinction threats. Proceedings: Biological Sciences. 271: 1135-1141 Isaac, N.J.B., Agapow, P.M., Harvey, P.H. & Purvis, A (2003). Phylogenetically nested comparisons for testing correlates of species-richness: a simulation study of continuous variables. Evolution 57: 18-26 |
