Estimating the volume of woody debris

I was recently asked by the New Zealand Forest Owners Association to critique the statistical methods that are commonly used to estimate the volume of woody debris at a site. This work arose out of the need to assess the proportion of woody debris (by volume) that came from forestry operations after Cyclone Gabrielle hitContinue reading “Estimating the volume of woody debris”

Model averaging for split-plot designs

I recently published a paper (which can be found here) with Peter Dillingham, Chuen Yen Hong and others on the use of model averaging when analysing data from a split-plot design. In some split-plot studies the whole-plot variance component may be small relative to that for the sub-plots. When this is the case, we proposeContinue reading “Model averaging for split-plot designs”

New Online Courses

I now have four online courses running at the Center for Wildlife Studies: Sampling and Experimental Design This course provides a thorough overview of the principles and techniques that are vital for designing a good research study, both observational and experimental. Generalised Linear Models This course provides an introduction to a large class of statisticalContinue reading “New Online Courses”

Report on fisheries bycatch risk to marine mammals in New Zealand

My work on estimating maximum population growth rate for New Zealand marine mammal populations has recently been published as part of a report produced by Proteus Wildlife Research Consultants for the New Zealand Ministry of Primary Industries. This report provides an assessment of the risk to marine mammal populations from fisheries in New Zealand waters,Continue reading “Report on fisheries bycatch risk to marine mammals in New Zealand”

Single-fit Bootstrapping paper

Tim Jowett and I have just published a paper on single-fit bootstrapping, which provides a simple means of calculating a confidence interval for a non-linear function of model parameters. The idea is not new, but we thought it should be more widely known, as it is simpler and more reliable than a Wald interval basedContinue reading “Single-fit Bootstrapping paper”

Modelling the population dynamics of tītī

I am part of a research group led by Phil Lyver at Manaaki Whenua (Landcare) that is working with the Rakiura Tītī Islands Administering Body on the population dynamics of tītī (sooty shearwater). Our most recent work has recently appeared in the following papers: David Fletcher, Jamie Newman, Sam McKechnie, Corey Bragg, Peter Dillingham, Rosemary Clucas, DarrenContinue reading “Modelling the population dynamics of tītī”