Dr Nick Isaac
Macroecologist (Biological Records Centre)
Background and research interests
I am interested in questions about the abundance, distributions, diversity and extinction risk of species. My background is in comparative evolutionary biology and conservation biology of mammals. These days I work mostly on the distribution and abundance of UK insects.
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 working with hierarchical models to explore patterns at a range of scales, from populations in space to species and higher taxonomic levels.
Extracting trends from distributional data
Biological recording represents a vast source of data for exploring trends in species distributions. The potential of these data is only now being realised, thanks to new methods that account for the variation in the effort of recorders, most of whom are volunteers. I am currently engaged in three areas of research:
Scale-dependence in biodiversity
Biodiversity is inherently scale-dependent: many well-known patterns change with the spatial, temporal and taxonomic scale over which they are examined. My current research asks whether local abundance can be predicted from large-sale patterns of species’ distributions, and whether it is possible to derive a scale-independent measure of species’ range size. Key collaborator: Bill Kunin.
Abundance, energy and space use
I am interested in revealing the factors determining variation in abundance among and within species. I use data on mammals and butterflies to test whether these patterns are consistent with theories such as metabolic theory and unified theories of biodiversity. Key collaborator: Chris Carbone.
Large-scale datasets play an increasing role in biodiversity research. With Kate Jones I manage 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. I am developing similar traits datasets for UK invertebrates.
Selecting priority species for conservation remains a major issue in conservation biology. My research in this area contributed to the Edge of Existence programme at the Zoological Society of London (ZSL).
Education & Employment
2008–present: Macroecologist, CEH
Preprints available through the NERC Open Research Archive.
Isaac, NJB, Storch, D & Carbone, C (2012) The Paradox of energy equivalence. Global Ecology & Biogeography in press. DOI: 10.1111/j.1466-8238.2012.00782.x
Roy, HE, Adriaens, T, Isaac, NJB et al. (2012) Invasive alien predator causes rapid declines of native European ladybirds. Diversity & Distributions 18: 717-725. DOI: 10.1111/j.1472-4642.2012.00883.x
Isaac, NJB, Carbone, C & McGill, BJ (2012). Population and Community Ecology. pp 77-85 in: Metabolic Ecology: A Scaling Approach (Sibly, Brown & Kodric-Brown, eds). John Wiley & Sons, Ltd. DOI: 10.1002/9781119968535.ch7
Isaac, NJB, Cruickshanks KL et al (2011). Distance sampling and the challenge of monitoring butterfly populations. Methods in Ecology & Evolution: 2: 585-594. DOI: 10.1111/j.2041-210X.2011.00109.x
Isaac, NJB, Girardello, M, Brereton, TM & Roy, DB (2011). Butterfly abundance in a warming climate: patterns in space and time are not congruent. Journal of Insect Conservation 15: 233-240. DOI: 10.1007/s10841-010-9340-0
Jones, KE, Blackburn, TM & Isaac, NJB (2011) Can unified theories of biodiversity explain mammalian macroecological patterns? Phil. Trans. R. Soc. Lond. B. 366: 2554-2563. DOI: 10.1098/rstb.2011.0119
Isaac, NJB, Storch, D & Carbone, C (2011). Variation in the size-density relationship challenges the notion of energy equivalence. Biology Letters: 7: 615-618. DOI: 10.1098/rsbl.2011.0128
Isaac, NJB & Carbone, C (2010). Why are metabolic scaling exponents so controversial? Quantifying variance and testing hypotheses. Ecology Letters 13: 728-735. DOI: 10.1111/j.1461-0248.2010.01461.x
Cowlishaw, G, Pettifor, RA & Isaac, NJB. (2009). High variability in patterns of population decline: the importance of local processes in species extinctions. Proceedings: Biological Sciences 276: 63-69. DOI: 10.1098/rspb.2008.0767
Isaac, NJB & Cowlishaw, G (2004). How species respond to multiple extinction threats. Proceedings: Biological Sciences. 271: 1135-1141. DOI: 10.1098/rspb.2004.2724