Wildwatch September - December 2019

Centre for nature and green living

Wildwatch September – December 2019

St Nicks in early sunshine 23rd October 2019
St Nicks in early sunshine 23rd October 2019

Highlights

Winter birds disappoint, but many new invertebrates found and nine shieldbug species liven up the reserve. Plus a botanical oddity, plenty of fungi and galls.

 

Weather

A mixed bag. The wet Autumn’s heaviest rain fell on non-Wildwatch days. September walks were mainly cloudy following overnight rain. October, November and December brought us a number of frosty bright days with just occasional wet mornings on the reserve.

 

Bullfinch

Bullfinch

Birds

As in the summer, the Wednesday Wildwatch group averaged 20 species per week for the remainder of the year, with a total of 36 species seen on or over the reserve during the period. In addition there was an unconfirmed report (York Birding Twitter pages) of three Waxwings seen flying over the reserve on 18th November. Winter visitors were scarce, with only a few Redwings and no Fieldfares seen – not surprising in view of UK’s airstream this autumn which came from the south, the west and the north, but hardly ever from the east!  Despite careful searching we saw no Siskins or Redpolls among the small flocks of Goldfinches in the many Alder trees on the reserve.  An overwintering Chiffchaff was found on November 27th.

Bird counts rose once the leaves had fallen, which enabled small elusive birds like Goldcrests to be seen most weeks. Treecreepers, absent during the summer, were often seen and heard during the autumn while on the becks Grey Wagtails were observed on many of our walks, but only one sighting of a Kingfisher. Mallard and Moorhen were regularly seen.

Great Spotted Woodpecker

Great Spotted Woodpecker on its favourite perch at the top of a Larch tree by the Environment Centre

Birds on our core species list were seen most weeks – Carrion Crow, Magpie, Woodpigeon, Collared Dove, Great-spotted Woodpecker, Blackbird, Song Thrush, Robin, Wren, Dunnock, Blue Tit, Great Tit, Long-tailed Tit, Chaffinch, Goldfinch, Greenfinch, Bullfinch and House Sparrow.  Starlings and Pied Wagtails are rarely seen, and didn’t appear this autumn. Coal Tits are scarce (there are few conifer trees on the reserve) but we had one or two sightings.

Birds seen flying over the reserve this autumn included feral Greylag and Canada Geese, Black-headed, Common and Herring Gulls, Buzzards, Sparrowhawks, Jackdaws and, on September 18th, six House Martins.

 

Invertebrates

A number of sunny Wildwatch mornings this autumn enabled many of the invertebrates on the reserve to remain active well into November. New species for the St Nicks list turned up regularly (approximately 80 for the year) but the many autumn sightings of both our regular and occasional species are far too many to list here. Here are just a few of the highlights…

Clockwise from top left: Iron Prominent Moth larva; Pink-barred Sallow Moth adult; Oak Bush Cricket; Snail-killing Fly Coremacera marginata

Clockwise from top left: Iron Prominent Moth larva; Pink-barred Sallow Moth adult; Oak Bush Cricket; Snail-killing Fly Coremacera marginata

The last dragonfly sighting was of a Common Darter on October 2nd, but adult butterflies were flying on the reserve until October 23rd when two Speckled Wood were seen. Our 2019 butterfly sightings totalled 19 species, one fewer than in 2018 but happily with a considerable increase over that year in the number of individuals seen. Oak Bush Cricket Meconema thalassinum in late September was only our second record of this species

Hoverflies were still being found until our last Marmalade Episyrphus balteatus (St Nicks most abundant hoverfly species) on November 6th. Hoverflies had a generally good year with 30 species seen, two of them new records for the reserve including Platycheirus pelteatus in September, bringing our total St Nicks hoverfly species list to 55.

Clockwise from top left: Bluebottle Fly; Common Darter dragonfly; Hawthorn Shieldbug; Birch Shieldbug

Clockwise from top left: Bluebottle Fly; Common Darter dragonfly; Hawthorn Shieldbug; Birch Shieldbug

Autumn 2019 was notable for sightings of true bugs, and particularly shieldbugs. A total of nine shieldbug species was recorded for the autumn (eleven for the year) with as many as eight found on one morning in September, and some still being seen in December. Bordered Shieldbug Legnotus limbosus in mid-October was only our second record of this species. It was good to find St Nicks third record of the Mirid Bug Pantilius tunicatus in early November while birch trees held a good population of both adult and nymph Birch Catkin Bugs Kleidocerys resedae. A Tree Damselbug Himacerus apterus was a nice find on October 9th.  Many species of Leafhopper were seen, notably the attractive little Evacanthus interruptus (pictured) and a green-coloured Kybos species

 

Several day-flying moths were seen, either as adults or caterpillars, including the amazing larva of the Iron Prominent and a pretty adult Pink-barred Sallow, both pictured.

Beetle sightings included Orange Ladybird (only our third record of this species) and among several new species was this pictured Strawberry Blossom Weevil Anthonomus rubi.

Clockwise from top left: Strawberry Blossom Weevil; Cream-spot Ladybird; Leafhopper Evacanthus interruptus; Cinnamon Bug

Clockwise from top left: Strawberry Blossom Weevil; Cream-spot Ladybird; Leafhopper Evacanthus interruptus; Cinnamon Bug

The frequently sunny Autumn of 2019 at St Nicks was a glorious mix of moths, bugs, beetles, flies, bees, sawflies, wasps, harvestmen, spiders, springtails, millipedes, woodlice, slugs and snails and more – all helped and supported by skilled and sympathetic management of the habitat of this amazingly diverse nature reserve half a mile from York’s city centre.

 

Plants

Last summer’s warm and rather damp weather continued into September. Consequently many of St Nicks’ meadow flowers bloomed well into autumn. These included knapweeds, thistles, Ribbed Melilot, Field Scabious, Yarrow, Tufted Vetch, and Bird’s-foot-trefoil. Typical late-flowering plants such as Buddleia, Hemp Agrimony, Canadian Goldenrod, and Common Ragwort also flourished. All provided abundant food for pollinating insects. September also saw Common Toadflax – sown in recent years – put on a good show in a couple of places. A single Deadly Nightshade popped up; but, as this was in a vegetable bed, it had (alas) to be humanely destroyed.

Clockwise from left: furrow bee sp. on ragwort, Common Toadflax, Deadly Nightshade

Clockwise from left: furrow bee sp. on ragwort, Common Toadflax, Deadly Nightshade

Autumn really only felt like it was properly under way in October. Ideal growing conditions earlier in the year meant there appeared to be a bumper crop of seeds, nuts and fruit of all kinds. Very much a season of “mellow fruitfulness”, as Keats put it. Rose-hips, hazelnuts, apples, the berries of Hawthorn, Rowan, Yew and Holly, the keys of maples and Ash – all these, and more, are packed full of nutrients and are a vital source of food for all sorts of creatures. We saw many birds (and Grey Squirrels) take advantage of this bounty; but it’s worth remembering that many more elusive animals, from voles to weevils, depend on it as well. And, of course, a few of the seeds get to become the next generation of plants – despite, or because of, their eaters.

Clockwise from top left: Rowan, Field Maple, Hawthorn, burdock (with Hawthorn Shieldbug), rosehips, Wild Carrot

Clockwise from top left: Rowan, Field Maple, Hawthorn, burdock (with Hawthorn Shieldbug), rosehips, Wild Carrot

viviparous Teasel

viviparous Teasel

Botanical oddities of the month for November were tiny Teasel seedlings sprouting from within their parents’ seed-heads. This unusual viviparous germination has been recorded around the UK in recent weeks, and is probably due to particularly mild and wet weather conditions. More expected this month was the peak of autumnal colours, as leaves turned brilliant hues of copper, red and gold. It might just be down to plants breaking down their green chlorophyll, thus revealing their carotenoid and anthocyanin pigments – but it was all gloriously colourful anyway.

winter Gorse

winter Gorse

Some evergreen plants have evolved different strategies for getting through the winter. Two of them at St Nicks, Gorse and Ivy, even regularly flower throughout December, as we observed. White Dead-Nettle was another plant still in bloom, together with the occasional out-of-season flower such as Tansy and Wood Avens.

There’s plenty to enjoy botanically at St Nicks, even in the depth of winter. The first Hazel catkins are already out – a sign that there’s so much to look forward to in this New Year.

 

Fungi

Twenty species of fungi were observed on 17 October during an informative Fungus Foray led by Malcolm Greaves (follow the link for pics). Unfortunately, all of us regular Wildwatch volunteers struggle with fungal ID. Nevertheless, we found plenty of interest every week – from delicate Candlesnuffs to Jelly Ears, Crystal Brains and Turkeytails. Most popular were Collared Earthstars – which not only appear distinctly B-movieishly extra-terrestrial, but emit little puffs of spores when poked. What (entirely legal) fun there’s to be had with mushrooms!

L-R: Candlesnuff and Earthstar

L-R: Candlesnuff and Collared Earthstars

 

Lamproderma slime mould

Lamproderma slime mould

Other Organisms

It’s easy to ignore all the life out there that isn’t a familiar animal, plant or fungus. Stuff like bacteria, viruses, algae, water-moulds, etc. Stuff that’s mostly invisible, and little-known by most of us, but is just as important for a functioning ecosystem. Two of our keen-eyed volunteers spotted this little gem in December. It’s the spore-producing body of a slime mould, possibly a Lamproderma species. (Not that the “slime mould” name does these extraordinary creatures any justice: if you’re interested, watch this TED talk).

 

Plant Galls 2019

Systematic gall hunting got off to a late start this year. By way of compensation, we spent a bit longer than usual looking for things that ought to be there but haven’t yet been recorded. This (along with a couple of bits of luck) brought eleven new records. We’re unclear whether this is “Wow, eleven!” or “Only eleven?” Either way there are quite a few more common St Nicks plants that could, probably should, be hosting galls that we haven’t found. Must work harder!

poplar aphid probably P spyrothecae

Aphid P. spyrothecae on Poplar

Starting with the new ones, we found little pimples on Oak leaves caused by a Psyllid, Trioza remota. This is the first first Oak gall we’ve found that isn’t caused by a wasp. A fungal gall on Pear, Gymnosporangium sabinae, could easily have been overlooked in previous years because our only Pear tree is located in the Centre garden, and we tend to walk past it. Likewise we only recently started examining the Poplars on the Rawdon Avenue boundary, where we found Aphid gall Pemphigus bursarius alongside last year’s P. populinigrae and P. spyrothecae. Another new Aphid gall was Cryptomyzus ribis which crinkles and often reddens Redcurrant leaves. It was news to some of us that there are so many highly specialised species of Aphid. The Black Poplar group don’t just confine themselves to breeding in Poplars – they’re picky about which bit of a leaf to use!

Cleavers mite galls

Mite gall on Cleavers

There were five new Mite galls, all but one characterised by blotches, blisters and pimples: Acalitus brevitarsus on Alder, Aceria erinea on Walnut, Aceria tetanothrix on Willow, Phyllocoptes populi on Aspen. The exception is Cecyophides rouhollahi which causes the leaves of Goosegrass aka Cleavers to roll into almost surreal curls. We found this in just one location, and wondered about the possibility of spreading the mites around the reserve as a control measure.

Midge gall on Germander Speedwell

Midge gall on Germander Speedwell

A fungal gall, Protomyces macrosporus, on Ground Elder, and attractive Jaapiella veronicae midge-induced galls on Germander Speedwell complete the tally of new records.

There is a small group of galls that we have found every year since records began in 2013, and a couple more that have turned up every year since we first found them. Mites Eriophyes laevis and Eriophyes inangulis cause pimples on Alder leaves , the former scattered all over the leaf, the latter neatly lined up along the mid-rib in the angles where the veins join. Another mite, Eriophyes tiliae, causes red “nail galls” on the leaves of Common and hybrid Lime.

oak marble gall

Oak marble gall

Three Oak galls are regulars. Common Spangle and Silk Button galls occur on the underside of leaves. These are caused respectively by wasps Neuroterus quercusbaccarum and Neuroterus numismalis. Another wasp, Andricus quercuscalicis, lays its eggs in developing acorns, giving rise to unmistakable knobbly Knopper galls. Regular they may be, but all is not well. This year we found Knoppers more or less as usual, but after a peak in 2015, numbers of Spangles have fallen to the point where they have to be searched for, and not more than half a dozen leaves had Silk Buttons. We also found a few Oak Marble galls (Andricus kollari), Cola-nut galls (Andricus lignicolus) and just a couple of under-developed Ramshorns (Andricus aries). Several other rarer wasp galls were missing altogether. These tiny wasps have a fascinating two-generation lifecycle – see our Spotlight article for more details. So one possible explanation is that conditions in winter or spring adversely affected the first generation. Other possibilities are increased parasitisation of larvae, or quite simply that our young oaks keep growing but the gall hunters don’t – though we do scan with binoculars and it doesn’t look as though there are much larger numbers higher up.

 

Another wasp, Diplolepis rosa, is responsible for one of our best known galls – the fluffy red Bedeguar or Robin’s Pincushion on Dog Rose. There have been fewer of these this year though the one or two we found were impressive – unfortunately well out of camera range.

 

Whatever affected the gall wasps didn’t bother the Willow Sawfly Pontania proxima. There were lots of aptly named Bean Galls on the long, narrow leaves of Crack Willows.

The other regular is Urophora cardui, a picture-winged fly that induces remarkable urn-shaped swellings in the stems of Creeping Thistles. Maybe uniquely in our records, the gall hunters find the gall, and the bug hunters find the fly. Mostly the galls are our only indication that an insect is present, but we also have a few records of insects found regularly on the reserve without ever tracking down their galls. We keep trying…

Aside from questions raised by distribution and abundance, what we don’t find is sometimes as interesting as what we do. We’ve searched Tansy in vain for the intriguing vase-shaped galls of the Midge Rhopalomyia tanaceticola. We seem to find this one in very small numbers one year in three, so we wait with interest to see whether it reappears in 2020. In 2016 another midge, Wachtliella persicariae, produced its distinctively curled pink and purple leaf galls on nearly every Bistort plant on the reserve. We’ve never seen one since. Evidently we still have a very great deal to learn about the fascinating process of gall formation and the organisms that start it off.


Post written by St Nicks Wildwatch members who meet every Wednesday to record wildlife in the nature reserve. All photos were taken at St Nicks by volunteers.

31 January 2020 | Categories: Wildwatch | Tags: ash, autumn, berries, Candlesnuff, Chiffchaff, Deadly Nightshade, Earthstar, fungi, galls, Godlcrest, gorse, Grey Squirrel, Grey Wagtail, Hawthorn, hazel, House Martins, ivy, Lamproderma, Oak Bush Cricket, Ragwort, Rowan, Shieldbug, Slime mould, Strawberry Blossom Weevil, teasel, Toadflax, Treecreeper, Wildwatch