Yes urbanisation could be a driver. I am only using the data from the PDFs on the COG website but these do not contain enough detailed data to test this theory.
Steve
From:
David McDonald (personal) [
Sent: Saturday, 24 June 2017 4:13 PM
To:
Subject: Re: FW: [canberrabirds] Skinks as a food resource in winter
Fascinating, thanks Steve.
Here at Wamboin we record the Grey Butcherbird in most weeks, but in the decade I have been here I have never recorded a Noisy Miner.
Perhaps it is ecological processes in urban areas, specifically, that drive the (statistical) relationship wrt reporting rates?
David
On 24/06/2017 7:55 AM, Wallaces wrote:
Thanks Geoffrey. Your comments prompted me to look at the seasonal reporting rates as I would expect that skink activity is lower in winter. The graph below shows the general COG data (with dotted second degree
polynomial lines). The trend is for increased reporting rates in all seasons with winter, spring and summer moving at similar levels and rates of increase. In most years the autumn reporting rate is higher (1990, 1998, 1999 being the exception) resulting in
a noticeably higher and increasing trend. Based on the increasing reporting rates, something is working in the butcherbirds favour.
Steve
