Bird nerd part 2: summary stats

So, having collected all this lovely data, what do I know about the birds that visit my garden? Here are some summary stats from the last three years of data collection.

  • In 2010-11 I saw on average 7 different species per observation day. In 2011-12 this went down to 6, and in 2012-13 it went up to 8.
  • In 2010-11 I saw on average 14 individual birds per observation day. In 2011-12 that went down to 12, and in 2012-13 it went up to 15.
  • These averages hide quite a bit of seasonal variation: September is generally pretty quiet, while the bird table is unsurprisingly busy in December and January.
  • The most regular avian visitors to the garden were: bluetits in 2010-11, being seen on 55 out of 64 observation days, starlings in 2011-12, being seen on 35 out of 43 observation days, and woodpigeons in 2012-13, with only one observation day out of 44 when they didn’t make an appearance.
  • The most numerous visitors to the garden were starlings by far (which won’t surprise anyone who has seen hoardes of them descend on a bird table), although in the last year house sparrows have almost managed to catch them up.

    Bluetit
    Bluetit gathering nesting material

Changes in which species visit over time

As I mentioned in the first ‘Bird nerd’ post, altogether I’ve seen 26 different species of bird in the garden, although never all in the same year. In 2010-11 I saw blackcaps on 15 observation days (in the winter), but only once in 2011-12 and once in August 2012-13 (which is a shame, as they are pretty birds).

There have been no records of jays since 2010-11, but even then they were not frequent visitors. Other birds missing in 2012-13 that I have seen (infrequently) in other years include crows, greenfinches and siskins.

On the bright side, in 2012-13 I saw chaffinches and some kind of warbler for the first time. It’s quite encouraging that 4 years after moving here we’re still spotting new species.

Future analysis to be done

The few stats I’ve presented here are only the tip of the iceberg in terms of what I could examine from my data. One question I would like to look at is how the weather affects bird numbers. I’ve got very basic data on weather for most observation days, but only as far as whether it was sunny, snowy, rainy or overcast. Since we had solar panels installed last June I now have data on sunlight. My theory is we get more bird visits on sunny days than rainy or overcast (controlling for the month of the year), but we’ll see if the data supports that…

Let me know if there are any other questions you would like me to look at – for example, if you’re interested in a particular species or comparison over time…

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