Balearic Shearwaters through west Lyme Bay, 2017 a good year?
While seawatching at Berry Head recently I was asked what 2017 was looking like for Balearic Shearwaters off South Devon? I've been keeping a study going of numbers through west Lyme Bay while seawatching either Berry Head or Start Point for a few years now. So what's 2017 looking like? So far June-September 2017 I've logged 1060 birds in 146 hours watching. So taking into account effort that's 7.3 birds/hour (the best measure for comparison). This is much better than last year's 2.7 birds/hour, but there has been better. As a comparison of years I take the period June–November, which captures the majority WLB Balearic passage (so there will be data to add to this year, which may push the rate higher or lower). See the graph below:
As you can see so far 2017 is looking above average (mean for all years based on data so far is 4.5 birds/hr), but not matching the years 2011, 2013 and 2015; unless we get a big late surge, which is possible. Also we might not get any more big numbers and the 2017 rate will come down. What 2017 has showed so far was a big peak in the period from late July to early August and had my best July passage day of 185 birds on 28th. The best day so far was 3rd August with 203. So far there have been five three-figure counts and the general trend has been more birds moving through outer Lyme Bay - so bigger numbers at Start rather than Berry Head.