The Great Meadow has not been grazed this summer, as the floods earlier this year took the fencing, which has yet to be repaired. It was time to monitor this area again, by our wildlife survey volunteers and we wondered what our findings would be, as the grass was very long. We hoped for wasp spider, and we found many, with their stripey vests and webs with the characteristic zig-zag. Also, the large 4 spot Orb spiders were plentiful. Other spiders had made traps by tying grass together. The first Ivy Mining bee was noted and various parasitic wasps, such as the Brachonid wasp. Also, grasshoppers, the most I have seen all year. We are able to name many of these insects because some of our group take close-up photographers. Ann Miles took this photo of Ormyrus ntidulus. Ormyrids are often recorded in association with plant galls, but are not gall-formers themselves; rather, they are parasites of the insect larvae that formed the galls (usually flies of other wasps). What an amazing place the insect world is! As the morning warmed up, more dragonflies were also seen, especially migrant hawkers.
The lakes are still quite empty this month of birds. The autumn influx of duck has yet to happen. However, there is some pleasing news about our breeding birds. Read on to find out. Also, which birds, do you think are our top 10 breeding birds and what were they in 2003. There are definite losers and winners.
Paxton Pits 2021 Breeding Bird Survey (BBS) Summary
This year 2021 returned to some normality with the three surveys for April, May and June running to plan. The weather was also kind without any disruptions. Interestingly, April was one of the coldest months for many years with spring migrants arriving at Paxton Pits later than most years. However, most species had arrived by the May count and in good numbers. The two later arrivals, turtle doves and spotted flycatchers, are no longer found as breeding birds at Paxton with the former not being recorded in 2021 (at time of writing). This must be the first year since human activity that turtle doves have not been seen at Paxton Pits!
A total of 101 species were seen during the three surveys, similar to past years. There was only one non-regular bird recorded being a mandarin duck, one of the best looking birds in breeding plumage. There were a possible 68 breeding species at Paxton Pits in 2021 being slightly down on last year of 71. The main omission was no reports of lapwing sitting or raising young, although they were seen displaying. A bird that was successful, previously lost to Paxton Pits, which was found outside the surveyed areas was a pair of ringed plovers. They raised three chicks on the new workings near Diddington.
The data from the surveys and other sightings outside the BBS are recorded by route and date to produce an estimated number of breeding birds. By using a consistent approach provides the capability to see the number of possible territories by route for each species – the example attached shows the distribution of nightingales around the Reserve. Also attached is the estimated number of territories by species compared to the past two years and ten years ago (2011).
The aim of this summary is to provide a brief update on the results of the surveys. A fuller account of the results will be issued in the annual report planned for issue in early 2022.
Non-passerines
Similar to past years, the breeding records of non-passerines is a combination of the Breeding Bird Surveys (BBS) and other sightings reported to myself. In past years, a third source was the sightings reported in the Visitor Centre’s log book but this has not been resumed since the first COVID lockdown.
The breeding success of most ground nesting species was slightly better than last year which was affected by heavy predation – mink being the likely culprit. This year also benefited from the anchoring of the tern rafts which was halted last year due to COVID, plus they had added protection of electric wiring around the top. The failures of the past two years and the lack of vegetation clearance on the islands, with working parties unable to meet due to COVID, meant wader, gull and tern breeding numbers remained low.
Most of the breeding records of waterfowl are gathered outside the BBS with only confirmed records included, either birds nesting or with young. The likelihood is this is an underestimation as many species nest over a lengthy period with some broods unreported. There were nine confirmed records of mute swans breeding, all on different pits. Greylag and Canada geese reported family groups of 13 and 7 respectively was down on last year but always difficult to assess as they gather into large flocks. The total number of geese on the Reserve was similar to past years. There were two pairs of Egyptian geese seen on the Reserve with one pair on Sailing Lake having ten goslings. Duck numbers were similar to last year with 11 mallard broods and 6 tufted broods reported. There were no gadwall broods seen this year.
The number of possible breeding great crested grebe of 25 was up on last year. Also, there were more confirmed sightings of eight compared to five from 2020. The success rate over the past two years equates to a third of possible breeding pairs. A pair of little grebes were seen regularly on Lodge pit with a juvenile being reported over the summer. Cormorant nests of 65 was slightly higher than last year although it is always difficult to see all the nests on the Heronry South island. Grey heron nests in past years have been an estimate based on the number of birds seen. This year we were able to find the nesting location and counted six nests. However, still no evidence of little egrets breeding on the Reserve although they were more numerous during the summer months than past years. Moorhen and coot numbers were similar to recent years and, unlike last year, no water rails were heard over the breeding season.
Raptor numbers of sparrowhawk, kestrel and buzzard remain similar to past years with circa two pairs breeding on or around the reserve. Again there were no records of breeding red kite and hobby. The little owls continue to inhabit the area around Broughton Lodge with the pair again being successful. Barn owls were scarcer this year with no evidence of successful nests. A bird was found dead near the A1 during the May BBS.
Wader species at Paxton over recent years have not fared well. Oystercatchers seem to be the only regular wader that rear young most years. Little ringed plover are almost as successful but are more dependent on the excavation areas outside the Reserve. There was no sightings of young redshank and lapwing this year – both were relatively common 10 years ago! And, avocets did not return after the previous poor year.
The gull and tern colonies have been decimated over recent years with the colonies on Sailing Lake and northen pits all failing. This year a few lesser blacked-backed and black-headed gulls nested on the islands with the former raising some chicks. However, the islands were not conducive for breeding gulls and terns as the vegetation was too high. The common terns and the few black-headed gulls which nested on the tern rafts seemed to have had a successful year with numerous juveniles reported.
There were no records of kingfisher breeding on the Reserve although a nest hole was seen on the river but unfortunately failed due to high rainfall resulting in the hole being flooded. Green and great-spotted woodpeckers continue to do well at Paxton with many reports of juvenile birds. Cuckoo is another bird which seems to fare well at Paxton, probably helped by the good number of reed warblers and the accessibility to the small reedbeds.
Passerines
The BBS is the main source on the number of possible breeding passerines. The other notable source is from David Bale’s survey of nightingales. This year seems to have been a good year at Paxton for the smaller passerines with total numbers reported being 10% up on the past two years. Certainly some species had a better year and others continuing to increase.
Nightingales must have had a good year in 2020 as good numbers returned to the scrub north of Pumphouse East. The number of birds heard by David in different locations over the first weeks was 20 which was higher than last year. David’s surveys for the period to June were recently sent to the BTO for verifying numbers but initial numbers are likely to exceed 20 territories. This area is very restricted with limited habitat for expansion which may explain the apparent spread of single birds in other locations throughout the Reserve. There were another 10 birds heard plus two further birds just outside the Reserve. Great news as numbers seem to be back to levels historically heard around the Heronry Lakes.
There was again no evidence of hirundines breeding within Paxton Pits. There was a large colony of sand martins with circa 50 nest holes on the quarry dig south of Diddington. Swallows were relatively numerous around Diddington village and house martins again nested in good numbers in Little Paxton. Similar to previous years, pied wagtails were regularly seen around buildings on the peripheral of the Reserve and grey wagtails were often reported near Little Paxton weir.
The robin has always been the most conspicuous bird at Paxton but this year it appeared to be more numerous. The BBS reinforced this view with 144 possible territories, almost 25% higher than last year! The robin was the second most common bird with the wren remaining top with 154, similar to past years. The other common resident birds of the blackbird, dunnock and song thrush all bred in good number. The latter two species showed a 33% increase over past years. It seems 2021 was a good year for resident birds probably helped by a mild winter.
Warblers returned in good numbers with the BBS counts being similar or better than last year. Sedge warbler territories were 50% down in 2020 but numbers bounced back in 2021 with 50 singing birds similar to previous levels. Whitethroat showed a notable increase with numbers counted being the highest over recent years, and chiffchaff continued their seasonal increase with 120 singing birds – a 50% increase over 5 years. All the other species, Cetti’s warbler, reed warbler, lesser whitethroat, blackcap, garden warbler, willow warbler and goldcrest, were at similar levels to recent years. Blackcap with 138 singing males is now the third common breeding species overtaken by the robin.
Tit numbers were similar to past years apart from great tit which was well down on the peak year of 2019. Blue tit numbers seemed to have plateaued at 127 territories. Treecreeper numbers of 11 possible territories was slightly up with a number of family parties seen in late spring.
Finch and bunting numbers apart from the reed bunting are found at lower densities than other passerines. The chaffinch, once a common bird, seems to be clinging on at Paxton with 15 males reported. All the other species apart from goldfinch were recorded at similar or slightly better numbers than last year.
The general conclusion from the 2021 BBS survey is non passerine ground nesting birds are struggling to raise young at Paxton with some species at critically low levels whereas passerine species seemed to have had a very good year. Only the great tit and goldfinch showed a notable decline with all other passerines recorded at similar or better counts than last year.
Finally, I must thank everyone who participated in the surveys. Again, it was a good turnout. This was the 24th year of surveys which have seen some notable changes over the period with the loss of some species but gains from others.
If you have any further breeding information outside the surveys, then please email details to friends@paxton-pits.org.uk or myself at neal.parkin@hotmail.co.uk.
Neal Parkin
27/08/21
Top 10 Breeding Birds of Paxton Pits
| 2003 | 2021 | |||
| 1 | Chaffinch | Wren | ||
| 2 | Wren | Robin | ||
| 3 | Sedge warbler | Blackcap | ||
| 4 | Coot | Blue tit | ||
| 5 | Garden Warbler | Chiffchaff | ||
| 6 | Blue tit | Blackbird | ||
| 7 | Blackbird | Garden Warbler | ||
| 8 | Blackcap | Dunnock | ||
| 9 | Reed warbler | Rook | ||
| 10 | Willow warbler | Reed warbler |