Autumn Notes from the Commons
The autumnal months recorded, consisting of September, October and November, seem a long while ago as we settle into the winter season. The autumn weather was rather unremarkable apart from the increasing amount of rainfall and generally mild conditions. Very few ground frosts were seen and wintery showers were rare. Leaves remained on the trees until quite late and the autumn colours were brilliant, especially the yellow-gold of the Silver Birches. Mark Clements and I continued recording the wildlife of the Commons throughout the period and the following are some of the more interesting sightings we spotted plus a few others of note from visiting naturalists.
A Humming-bird Hawk-moth was noted (01 Sept) and a Willow Emerald was spotted by John Furse. Willow Emeralds are a recent colonist, arriving first in the south-east of Norfolk in 2009 where it had spread from Suffolk (2007). By 2015 it was found throughout eight counties in south-east England and the following year had moved to inland counties such as Northamptonshire and Buckinghamshire. It is an unusual damselfly as it does not lay its eggs directly into submerged water plants as most do but the eggs are laid into incisions in the bark of overhanging branches, which can result in distinct oval galls forming in the bark. The eggs develop rapidly for a few weeks and then enter a diapause state. In this state the eggs development is very slow and it is in this state that the eggs overwinter. The following spring the eggs hatch, the larvae drop into the water and start to develop in a similar way to other damselflies. Mark found two Grass Snakes, a Box Bug and four Willow Emeralds (02 Sept) and the next day (03 Sept) I recorded my earliest return of Pink-footed Geese as a skein of 30 passed east , which contrasted well with a party of five Swallows heading west seen earlier. This was a visible changeover of outgoing summer and incoming winter migrants. Butterflies were still in good numbers with Red Admiral, Painted Lady and Speckled Wood being in the highest numbers. An Ivy Bee was also seen, the first of many males to emerge from the nesting area. The bees mainly visit Ivy flowers, hence its name and in the six years since it was first recorded in Norfolk it has become well-established throughout the county. The North East Norfolk Bird Club paid the site a visit (07 Sept) and although birds were scarce other wildlife made the morning interesting, especially the Ivy Bees which were emerging in greater numbers. There were 50+ males patrolling the nest site (10 Sept) and as soon as a female emerged she would be immediately surrounded by a bunch of males, from which one would be lucky and fly off with his female prize. Another migration event was witnessed by Mark (14 Sept) when a flock of 27 Buzzards drifted across the site. Mark also had a Red Kite drifting east (21 Sept) as well as finding some migrant warblers including Lesser Whitethroat and Garden Warbler. Three pairs of Willow Emeralds were attempting to oviposit into Hemp Agrimony, a waterside plant that appears to be a new species used for egg laying in UK (26 Sept) and visiting naturalist Tony Moverley found a female Bog Bush-cricket on heathland, which is not typical as its normal habitat on this site is the damp heather areas of the central mire.
The first Redwings were reported by Mark (03 Oct) as well as a Kingfisher and the following day he found a Yellow-browed Warbler. Another Yellow-browed Warbler, a Brambling, a Fieldfare and about 100 Redwings were noted by Mark (07 Oct). Up to three Yellow-browed Warblers were present (10 Oct) and Mark also saw the Kingfisher back on the pond (15 Oct) plus 15 Brambling overflying west. A Green Sandpiper was reported for the site on the NENBC webpage by Christopher Mason (16 Oct). Further movement of birds was recorded by Mark (17 Oct) with a Ring Ouzel, two Tree Sparrows and up to 50 Jays heading west. Also that day two Adders and two Grass Snakes were seen basking. An overnight recording to monitor nocturnal migration (21 Oct) picked up a Barn Owl ‘screech’ as it hunted over the site. The mild and damp weather produced a number of fungi including Blackening Waxcap, Rosy Bonnet and Golden Spindles.
Fieldfares had generally been scarce this autumn but three flocks were observed heading south (03 Nov) which totalled about 100 birds and as evening approached over 100 Jackdaws headed east towards a roosting site. Three Siskin were seen singly (09 Nov) and a pair of Common Darter dragonflies were ovipositing at the main pond with another male in attendance. The enigmatic Giant Willow Aphid was located (16 Nov) on willows not previously used by this strange insect. They appear on willow branches in dense patches for a few weeks in the autumn then disappear. The colonies are made up of females who give birth to live young who are genetically clones of their mother. No male Giant Willow Aphid has ever been found. It is still a mystery as to where these aphids go when they leave the tree although one possibility is that they go down into the root system.
As the winter season passes will the mild wet weather continue or will some ‘beast from the east’ return and catch us and the wildlife out as we await spring?
Hon. Warden – Beeston Common SSSI/SAC