Breeding Bird Population Changes (2020-2021) at Saltfleetby-Theddlethorpe NNR

Cliff Morrison

Natural England volunteer and regular Dynamic Dunescapes bird blogger from Lincolnshire Cliff Morrison explores the changes seen in the breeding bird populations at his local Saltfleetby NNR.

A review of all recorded breeding species on the NNR from 2000 to 2020 was presented to the national Dynamic Dunescapes team in March 2021. Some 63 breeding species have been recorded over that time. In 2020, 54 species were recorded, with the same number in 2021, but ringed plover was lost, whilst stonechat was a new breeding species. Actual estimated numbers for 2020 are presented in a document available to download here, along with an estimated numerical change for 2021.

A small brown bird sits on a stick with a clear sky background.
A small brown bird with a dark head sits on a twig with a yellow background

Stonechat juvenile and adult. Pair raised 3 young in buckthorn along foredunes. First breeding record for reserve. Birds of Lincolnshire state scarce and sporadic breeder. 1 pair Gib. Point 2020 and 1 pair Saltfleet 1980

Following a promising start to the breeding season at the end of March, the weather took a turn for the worse for most April with cold onshore winds, whilst May continued to be 2-3 degrees Centigrade below average, but it was also unduly wet. There is no doubt that the weather had a significant impact on early breeding success, with few juveniles being noted. Nationally, both blue and great tits were noted for their nesting failures due to the cold with both lack of flying insects and caterpillars being washed from the bushes. Fortunately, the summer months were kinder than spring and many young warblers, robins and dunnocks were to be seen, but it will be interesting to see the overall impact in numbers next year.

Whilst most species had stopped singing in early July,  last cuckoos were heard calling during the first few days of the month, whitethroats still be heard into the middle, skylarks to the end of the month, but wood pigeons and turtle doves continued to almost the end of August. Cuckoos have maintained their position of strength here on the coast, with at least 4 pairs, but turtle doves seem to have increased from an estimate 6 to 7 or even 8 pairs in 2021. Only 1 juvenile bird has been seen to date and several purring males shifted their calling perches several times, probably suggesting nesting failures. This reserve now seems to be holding the only breeding population along the whole Lincs coast from the Wash to the Upper Humber, species which has declined by 98% nationally.

Due to climate change willow warbler numbers have been generally declining in England, but whilst they had maintained a healthy population here at around 24, they declined by over 60% to perhaps 10 pairs this year. Sedge warbler and grasshopper warbler showed similar declines, but all other warblers were at normal levels and there were 2 pairs of Cettis warblers at either end of the reserve. 2 pairs of garden warblers were also the first to breed for many years.

A long-eared owl was seen in suitable breeding habitat in June and has been an occasional breeder here, the last time in 2015, when a juvenile was seen. 2-3 pairs of barn owls nested close to the reserve boundaries, adults make use of the reserve for hunting, as did a pair of kestrels with their 3 young. Likewise with 2 pairs of great-spotted woodpeckers and their young. 1-2 pairs sparrow hawks were also present but can be very secretive when nesting. A pair of marsh harriers raised 3 young and another female probably also attempted to nest.

Up to 4 pairs of avocets could be seen incubating around the edge of the outer Rimac lagoon, but high tides and heavy rain took their toll. However, 1 pair was seen with 3 young. The failed birds renested on an adjoining grazing marsh scheme with some success.