As with most things on this topic, I invite people to notice that Pages 40 to 42 of The GBS Report describes in detail (with 7 graphs), aspects relating to
how many species are recorded on GBS charts and some of the variables involved in this aspect. Although that includes a bigger scope than by not including those nearby and overhead. Overall, for the charts for the first 21 years, the average number of species
per chart (i.e. a site per year or part thereof) is 41. There are many sites that include over 60 per year and those that record high number or low number or middle number of species per year are typically consistent. That is, most show very little variation
in the number of species recorded per year.
Philip
From: Wayne Gregson [
Sent: Friday, 14 December, 2018 9:29 AM
Cc:
Subject: Re: [canberrabirds] "Anthony Overs is not lying"
31 spp in two hours is very impressive!
I just checked my own records for birds actually IN our Duffy yard over 45 years (excluding those nearby and overhead) and could only get to 42 spp.
could have something to do with our rather meagre garden of course!
