Cooler, wetter July leads to a mixed breeding season
July had a lower mean temperature and over 60 per cent more rain compared to June.
In comparison to July last year, this July's mean temperature was down 1.5 degrees and there were 26 days in which it rained, compared to 20 last July.
The cooler, wetter July had an impact on the breeding success of some visiting summer birds, particularly those that rely on airborne insects to feed young.
Looking at the proportion of adult to young birds from information gathered by licensed bird ringers, willow warbler had a poor breeding season, while the similar chiffchaff, which had bred earlier, had a good breeding season.
Whitethroat had a poor season, whereas sedge warbler and blackcap, relying less on flying insects, had a good season.
Similarly, the early breeding, single brooding sand martin had a good season, but the jury is still out on the double brooding house martin and swallow.
The weather in August may determine their overall success.
As reported in the June notes, garden birds seemed to thrive and seed eating birds including lesser redpoll, siskin and goldfinch all had successful breeding seasons.
Other signs of a successful breeding season included: 110 shag and 14 Arctic tern at their colonies on Pladda on July 2; young great spotted woodpecker at Machrie on July 3; 50 black guillemot between Imachar and Whitefarland on July 4; a pair of mute swan with five young at Port na Lochan on July 5; a creche of 10 eider off Levencorrach on July 6; a family group of seven greenfinch at Kilpatrick on July; three young kestrel on Maol Donn on July 11; four young spotted flycatcher in Glenkiln on July 18; five young stonechat on The Ross, also on July 18; two adult common guillemot, each with a young bird, off Pirnmill on July 23 and three large young shelduck at Port na Feannaiche on July 25.
Healthy vole populations in some areas sustained good breeding numbers of barn owl, hen harrier and short-eared owl.
On the downside, with the easing of some lockdown restrictions, there was increased human activity on shores, with many ignoring notices of breeding birds and allowing their dogs off leads which disturbed breeding shore birds.
There was concern more people walking on the hills near lochans was adversely affecting breeding red-throated divers and reports of diminishing numbers of breeding curlew and fulmar is a continuing cause for concern.
July marks the end of the breeding season for some birds. It can be an interesting time looking for northerly breeding species heading south from their breeding grounds, many still in their breeding plumage. Reports included: four turnstone on Pladda on July 2; two sandwich tern at Porta Buidhe on July 13; 39 golden plover at Machriewaterfoot on July 21; four dunlin on Blackwaterfoot shore on July 22; two whimbrel on Sliddery Shore on July 24 and a greenshank on
Cleats Shore on July 29. After breeding, many species flock together. Reports included: 150 woodpigeon at Mossend Pond on July 7; 42 red-breasted merganser in Machrie Bay on July 8; 47 raven in Clachaig on July 16; 70 house sparrow at Sannox on July 23; 400 linnet in Sliddery on July 24 and 41 curlew and 60 pied wagtail at Port na Feannaiche on July 26.
More than 100 species were reported in July. The appearance of a rose-coloured starling in a Shiskine garden on July 20 was a particular highlight.
This is the fourth year in a row this rare vagrant has turned up in Arran in July.
A few days later, on July 24, a wood sandpiper was seen and heard flying over Bennecarrigan and Sliddery. This is only the second record for Arran of this rare passage migrant.
Other highlights included: a dipper in Rodden on July 7; a swift over Sliddery on July 15; seven red grouse on Mullach Buidhe on July 17; two twite on Sliddery Shore on July 24; two water rail in Corriecravie on July 25 and off Whitefarland on July 29 an estimated 60 Manx shearwater joined 100 gannet in a feeding frenzy.
In June's Bird Notes I wrote: ‘Cuckoos, whose decreasing numbers are a cause for concern nationally, seem to be thriving on Arran. Throughout May and June there have been many widespread reports. People need no prompting to report the first Cuckoo. How about reporting when you hear or see the last Cuckoo this year?'
My thanks go to everyone who has responded. By now the adults will have left the UK, leaving the young to be brought up by their foster parents. The young have a distinctive white spot on the nape of the neck.
The latest date I have had so far for young Cuckoo is July 17 when one was seen with a pipit on the shore close to Lochranza pier.
Enjoy your birding and keep safe.
Please send any bird notes with ‘what, when, where’ to me at Kilpatrick Kennels, Kilpatrick, Blackwaterfoot, KA27 8EY, or email jim@ arranbirding.co.uk I look forward to hearing from you.
For more information on birding on Arran, the Arran Bird Report, The First 40 Years, which includes the annual report for 2019, is available to buy and visit www.arranbirding.co.uk