Category Archives: Project Blog

This blog will record the progress of the project as we go along.

I got it wrong ….. moving swiftly on to some September records!

The ducks on the edge of Hobson’s Park were not Garganey but Teal; I got it wrong – several birders contacted me …. moving swiftly on!
(left) Teal! Hobson’s Park – 7th September

Cattle Egret – Mare Fen (left)

 

Confrontational Robin (right)

A Peregrine on St Luke’s Church on 12th September (Ben Greig) was a good find. Disbursed birds from the City’s breeding pairs could be hanging around any of our tall building and, in the past, have been seen on the Catholic Church, St Giles Church, St Andrews and St George’s churches in Chesterton and the Riverside chimney. A female Marsh Harrier over the NIAB’s Trials Ground in the north of our project area on 13th September was unusual and a new bird for the site and probably our project area. It fits the pattern of most adult birds leaving local breeding sites over winter and returning the following spring. A brown juvenile Hobby was also seen there on the same day.

There are still Chiffchaffs about; 13th September was a beautiful day and three were singing along the river between Chesterton and Fen Ditton and one, possibly two, feeding in the tit flock in the rear gardens of the Doctors’ surgery in Fisher’s Lane, Cherry Hinton on 24th September. A Blackcap was in Logan Meadow willows on September 29th.

Simon Gillings tweeted recording night time passage of Tree Pipit, Golden Plover and Robins on September 13th. (@simon_gillings).

The Swallows that bred under the A14 bridge near Horningsea were still feeding over the river on 13th September but had gone a week later on 20th September. Six were over Fen Ditton meadows on October 1st. The first Siskin paid a fleeting visit to the garden feeders on 14th September but I have not seen it since. The confrontational Robin, far from being at ease with him?self, continued to attack his reflected image in the second and third floor bedroom windows. He has given that up and now chases away any other songbird that appears near the garden feeders up to Blackbird size.

A Meadow Pipit, low over Hawthorn Way on 19th September, was unusual. A skein of about 120 Greylag Geese and 25 Canada Geese flew over Fen Ditton towards Milton County Park on 20th September. It’s always worth a look into geese flocks for Barnacle Geese (probably from the feral population that breeds freely on the Suffolk coast) and Pink-footed Geese. Pink-feet have been seen in the north of our project area in the past and will be wanderers from North Norfolk. Olwen saw a distant ring-tailed harrier opposite the Beechwoods on 19th September; it was probably a Hen Harrier but two ring-tailed Pallid Harriers have turned up not far away: one at the Wildfowl and Wetlands reserve at Welney and one in nearby Herts around Therfield Heath and Greys (Cambridgeshire Bird Club Autumn Bulletin 2018).

The Herons feeding along the river at Riverside can be very confiding if not intimidating! I have seen an adult walking on the concrete embankment just meters from pedestrians and cyclists. On 29th September, I saw a Carrion Crow killing and eating a Woodpigeon on Midsummer Common. I have never seen predation by a crow like this before; it grimly stabbed it to death with its bill. Perhaps the pigeon was sick or injured or had been stolen by the crow from a Sparrowhawk but there was no sign of one.

A raptor survey on the edge of our project area on 22nd September produced no visible bird of prey passage but a strong southerly movement of about 100 House Martins in the allocated one-hour watch.

On 23rd September Chris Brown saw a flock of 19 Spoonbills flying over Stetchworth Ley heading west towards our project area (www.cbcwhatsabout.blogspot.com). At some point, they changed direction and turned south and were next recorded in Greater London in the Beddington area ( www.surfbirds.com)! Six Cattle Egrets have been present on the Wildlife Trust reserve at Mare Fen, between Swavesey and Over, for much of the month and are probably part on the recent influx into southern England. They seem to have disbursed and are quite likely to turn up around the cattle on our riverside commons; the bird found by Jon Heath in April 2016 with cattle off the Fen Road was probably the wandering long staying bird from a site in Suffolk.

Simon Gillings recorded overflying night migration of Sandwich Terns on five occasions during the month including at 21:33 on 22nd September and 04:51 the following morning (@simon_gillings).

Redwings are now arriving from Scandinavia and their nocturnal flight call were heard on September 26th. There is an excellent website – www.xeno-canto.org – that has recordings of bird songs and calls.

A recent report from the RSPB proves that persecution of raptors continues and is widespread; we know this – one of our local Peregrines was shot and injured last year but was taken into care at the Raptor Foundation near St Ives and recovered and was released. If you want an excellent a day out with the children/ grandchildren/by yourself/with another visit the Raptor Foundation.

The BTO wants Tawny Owl hooting records – www.bto.org/owls. I have records from five probable breeding sites in our project area and plan to submit these. The popular “toowit toowoo” rendition – is, I think, an amalgamation of the female “keewick” and the male hooting “towooo” calls.

Small Copper  (left)

 

Migrant Hawker (below)

 

Honey Bee? (below) feeding on Ivy flowers

I’m a great fan of Ivy – except growing up my house walls! There is a fine tree in Ainsworth Street shrouded in ivy – the City Council claims the tree is unstable and must come down. Ivy certainly does increase wind resistance during storms but is a wonderful late pollen and berry source for insects and birds especially city House Sparrows. It would be better to trim the ivy rather than fell the tree. There is a full wall of ivy behind the Cherry Hinton Doctors surgery that was full of bees during mid-September. The best House Sparrow nest colony in the City was in the ivy covering the front of a house in Radegund Road but it was removed and the sparrows were forced to move on.

The fine weather also brought out Small Copper butterflies in our project area which, it seems, have had a bad year and Migrant Hawker dragonflies in our sector of Milton Country Park.

Bob Jarman bobjarman99@btinternet.com

1st October 2018

September Sightings 2018

What do plants and their leaves do in autumn? Mostly, change colour, go spotty and fall off, I hear you say. Therein lie a number of interesting stories. Sam reports, “I found galls of the mite Aceria tristriata on Walnut Juglans regia in Chesterton. This is a very local species, and apparently new to Cambridgeshire, according to the British Plant Gall Society.” I was curious about the term “mite” and found they were minute maggoty things, indeed arachnids, but with only 2 pairs of legs. (In the first picture A. tristriata has caused the smaller pustules, while the larger brown patches are remnants of galls of a much commoner mite, Aceria erinea.)

Galls of the mites Aceria tristriata  and A. erinea on Walnut leaves         Sam Buckton

 

Aceria tristriata mites

UKRBIN (Ukrainian Biodiversity Network)

 

Then Mark Hill found Gymnosporangium sabinae (European Pear Rust) in Cavendish Ave. It produces very conspicuous yellow, orange or red leaf spots on the upper side of the pear leaf, with bumps followed by conical structures below. Chris Preston has since found it in a few other sites in Cambridge and there is some in Newnham. Can you they can find any on your local pear trees before the leaves fall? A photo with details of the site would be great, either to me or him (<cdpr@ceh.ac.uk>). It is one of the rusts with an alternation of hosts, two stages of the life cycle on pear and two stages on junipers (usually cultivated bushes). Does anyone have has any experience of it on juniper, where it produces gelatinous orange masses on old twigs (most conspicuous when wet)? These are probably produced in spring but there are very few British records from juniper and none from Cambridgeshire. (The only juniper I can think of is in the Botanic Garden, but there must be more.)

Gymnosporangium sabinae on pear    Olwen Williams

It has been a strange year for many plants. May found a mature Rowan (Mountain Ash) tree had lost half of its leaves by June, but with some watering it revived and in the middle of September burst into bloom at the same time as the fruit was ripening.

Rowan fruiting and in bloom          May Block

It has also been a great year for apples, hops and particularly walnuts, where even the crows and the squirrels are overwhelmed.  Sue reports an oak tree where nearly all the acorns have been turned into Knopper Galls – a parasitic wasp is the culprit here.

This lovely moth (Angle Shades Phlogophora meticulosa) was found indoors and released, while the Goat Moth caterpillar (Cossus cossus) was ambling across the towpath. Thanks Peter for these.

Angle Shades Moth                            Goat Moth caterpillar                       

Peter Woodsford 

Pam noted a Speckled Wood butterfly and a late dragonfly in the garden at the end of the month. I had a visit from a Western Conifer Seed Bug (Leptoglossus occidentalis).  This Leaf-footed Bug resembles a shield bug, but is much bigger and has expanded hind tibias, hence the name. It is another new-comer, a US native only found in UK since 2007. Its larvae attack the immature cones of several conifer species.

 

Western Conifer Seed Bug        Olwen Williams

 

Paul reports Ivy Bees (Colletes hederae) enjoying the late flowering Ivy. This solitary bee was new to science in 1993, arrived at UK in Dorset in 2001 and has been slowly spreading north since then. It is the latest solitary bee to emerge and on the wing as late as November. Mark reports seeing dozens, burrowing into a steep bank. So if you have nearby ivy in flower, check it out – you will find all sorts of other insects there too.

Ivy Bee    Paul Rule

A quiz from Mary: which one of these is a Hornet (Vespa crabro) and which the hornet mimic Hoverfly Volucella zonanaria? Both were feeding on ivy.  V. zonanaria is the largest hoverfly in the UK, another fairly recent addition to the UK fauna, very rare before the 1940’s, but now common in the SE and spreading northwards. CLUE The Hoverfly has much bigger eyes and smaller antennae than the Hornet (also has no sting, but then male hornets don’t have a sting either).

Mary Wheater

A dead young Badger on Grange Rd and the presence of a badger latrine on one of the local playing fields reminds us that these nocturnal mammals can flourish in suburbia. Newnham college has had a colony for some years and several of the College Head Gardeners say that they have been seen in the grounds.

We should not forget the river. Guy reports that electrofishing the Rush Stream (Sheep’s Green) produced two mature Brown Trout 260mm, so potential breeders! Also a 600mm Eel on her way to the sea, Spined Loach, Bullhead and lots of Roach, Perch, Minnow, Chubb and Dace of all ages. Kingfishers were seen taking advantage of this lovely small stream and its other new inhabitant is a Terrapin! A recent bat punt through Sheep’s green and Paradise detected two Noctules, several each of Soprano and Common Pipistrelles and four Daubentans, with a bonus of a bat-hunting Sparrowhawk low over the punt. However, I gather that the Cambridge Angling and Fish Preservation Society have given up having matches in the Cam because the fish have all gone – they blame this on the recovery of the Otter population, which have even found their way into Robinson College lake to feed on Swan Mussels.

    Brown trout  Guy Belcher

For many years, there has been a flock of white (feral domestic) Geese in Newnham. Originally more than 20, they are now down to about 10, with one succumbing to a recent killing and BBQing on the bank. The scorched remains were not a pleasant sight. They are quite inbred, some with a genetic wing disorder preventing flight. Val reports the dramatic appearance of a male Sparrowhawk, which landed on the balcony while they were still in bed. I heard an Osprey calling from the other side of the Cam, but did not get a view. Then the next day, out at Beechwood Reserve in Wort’s Causeway, I saw a Hen Harrier, perhaps on migration, quartering a field of stubble. Never mind all these big raptors! Susan reports the sight of a flock of around twelve Long Tailed Tits, together with four juvenile Blue Tits descending on the feeders, where they fed feverishly for about ten minutes and then flew away, never to be seen again. A similar wave of mixed tits swept over my breakfast chair in the back garden today.

On the local river, Swans with five cygnets had spread themselves over the footpath in Paradise. But the best news is that the Paradise Rooks are back! At 6.23am on Sept 23rd, the first winter flock appeared and summer is officially over.

Olwen Williams                      olwenw@gmail.com

 

 

 

 

New Bird Species for Cambridgeshire over our Project Area

Sound recording night time migration over the City has produced sensational results (see August Blog: NocMig). Jon Heath set up his recording equipment in his garden in north Cambridge on the night of 28th August. The next day when he played back the recording, there appeared to be the call of an Ortolan Bunting at 02:57am. He set it up again the next night and, incredibly, recorded another set of Ortolan Bunting calls. He checked with other experienced bird call recordists and all agreed: Ortolan Bunting. This is likely the second and third records of Ortolan Bunting for Cambridgeshire and our project area after Simon Gillings, of the British Trust for Ornithology, recorded the first from his east Cambridge garden last year. These records add to the theory that Cambridgeshire and the skies above our project area may be an important migratory flyway highway for birds.

Ortolan Buntings breed in central Europe and Scandinavia and are rare east coast migrants, mostly in autumn. They have never been seen in Cambridgeshire; these are the very first records. Ortolan Bunting is known to be a nocturnal migrant and an autumn flight path over southern England was suspected after a sequence of recordings over Dorset in 2016. Both Simon’s and Jon’s records have yet to be ratified by the Rarities Committee of the Cambridgeshire Bird Club.

Whitehall contingency planning for a no-deal Brexit has been named after another bunting – Operation Yellowhammer.
Yellowhammers have become one of our most threatened farmland birds; I assume the names of the Whitehall operation and the status of Yellowhammers are intended! There are three breeding territories of Yellowhammers near the Histon Road/Huntingdon Road footpath close to the Darwin Green Development.

 

 

 

Garganeys – Hobson’s Park 7th Sept 2018 (above)

Local patch birding is a new enthusiasm amongst bird watchers …. as well as chasing rarities on the Norfolk coast! If I lived nearer to Hobson’s Park that would become my local patch. It’s a brilliant park in our NatHistCam study area, with a nature reserve established by the Cambridge City Council. It’s the best place I know for Corn Buntings and nearby, on 7th Sept, in small ponds by Long Road Bridge, there were two Garganeys; an unusual species for an urban location.

There were also two Yellow Wagtails, House and Sand Martins, the House Martins presumably from the Addenbrookes colony. What I like about Hobson’s Park is the “big sky”: Addenbrooke’s in the distance looks like a nuclear power station and the new low-rise development of Great Kneighton is on the opposite horizon!

I have a new and very territorial Robin (left) in my garden. It spent two days attacking its own image in the kitchen window and eventually flew into the kitchen to sort out this competitor. He (probably not a “she” as the sexes cannot be separated easily) flew out of the kitchen in terror and now lives at ease with his own image …. very male!

Ortolan Bunting in Greece – Jon Heath (left); Corn Bunting – Hobson’s Park Spring 2018 (right)

I often wonder what lives on Elder (Sambucus nigra). The larvae of some moths do but I never see any evidence of eaten leaves. Text books say it’s especially frequent near rabbit burrows and badger sets because both species find elder distasteful. The berries often go uneaten but I saw a bush behind the Grafton Centre completely stripped of berries by a mob of Starlings, which I have never seen before. Maybe that accounts for its distribution as seedling and saplings appear everywhere presumably from flyover bird droppings.

During this (hottest on record) summer I often heard crickets. On a mid-August evening, I heard one on Castle Hill and then another outside my house in Chesterton, which I recorded. I matched the recording with an excellent free app called: iRecord Grasshoppers and related insects. They were non-native House Crickets (Acheta domesticus) and have been heard in Cherry Hinton, Trumpington and Grantchester. I have heard them before at Addenbrooke’s by the heating systems. I understand they are escaped food for pet reptiles and this hot summer has brought them out from torpor.

Watch flocking Long-tailed-Tits. The frenzy of the flock often attracts other bird species and its always worth a look to see what else has been drawn in. Flocks usually have a lead species – in the UK it’s often Long-tailed Tits and flocks may circulate around a feeding territory as a “bird wave”. In the tropics and semi-tropics these flocks draw in both aerial feeding species and ground feeders.

The Common Lizard colony at Orchard Park has a stay of execution. Development of the site may not now take place until spring 2019 and hopefully a translocation site will be found.

Bob Jarman bobjarman99@btinternet.com

10th September 2018

August sightings 2018

On August 10th after two full months of drought, there was rain at last, a couple of inches altogether over a week. The vegetation has responded vigorously, nettles sprouting anew and the grass green again.

I am constantly amazed by the variety of wildlife reported to us – many thanks to everyone! It seems to have been a good (or perhaps bad?) year for bats. A dead Pipistrelle in my kitchen was followed by an email from a neighbour, saying she had found a dead bat in the house too. However, the accompanying photo showed the most enormous ears and it turned out to be a Brown Long-eared Bat – equally tiny, but the ears almost as long as the body. Mo also reported some from Trumpington : they are reasonably common but new to me.

Brown Long-eared Bat Olwen Williams

Red Underwing Moths have been abundant : Peter found this one indoors and released it outside. Duncan also noted Old Lady and Vine’s Rustic Moths. Paul’s micromoths have become too numerous to comment on, but he has promised a moth blog sometime!

Red Underwing Moth Peter Woodsford

Liza reported three Oak Bush Crickets in Alpha Rd.  Until the last three years, they had been regular since 1981,  often coming into the house on warm nights when windows are open. She was very pleased to see them again.

On August 13th, Colin, “Woke to see a Fox moseying around in the bushes a few yards outside my window. Rather small and dowdy with a bushless tail.” Then on August 14th, “Different fox this morning (5.36am) – bigger and silvery-bushy-tailed lolloping across my lawn. We’re infested!” (West Chesterton)

We have been doing a survey of the College Gardens and on a visit to Queens’, Duncan was introduced to a huge Chichester Elm Tree. Propagated by Gilbert White’s brother in 1770 it is undoubtedly one of the largest surviving elms in the country. Steve Tyrell, the head gardener, is standing by the trunk.

Chichester Elm Queens’ College Duncan McKay

From huge to tiny – weeds flourish even in the city centre! Valerian Verbena officinalis grows beside John Lewis in Downing St and there is Gallant Soldier Galinsoga parviflora (a small-flowered daisy family plant) in several locations including Mud Lane (off Parkside) and on Trumpington Road alongside the Botanic Garden.

Along Cherry Hinton Brook, there have been two reports of a Kingfisher and several sightings of Water Vole. Still on a watery theme, Colin reports swimming at the Newnham Riverside Club (balmy at 19 degrees C, as it has been for much of the summer). However, at the top of the steps he saw a floating dead Fish, about four inches long and lying on its side, quite motionless. Not liking the idea of it rotting in the river, he dipped his hand in to hoick it out, when it suddenly sprang to life, wriggled free and disappeared into the depths. What, he asks, was it doing – sun-bathing? My reply was that I had no idea! Any suggestions welcome! However, while I was talking to a lady by the learners pool, her daughter brought a dead Wasp which she had fished out of the pool with a net. I picked it up, inspected it, showed it to them and put it in the top of my thermos for proper Id at home. When I opened the top, a perfectly alive-and-well wasp walked off along the counter. Colin’s comment, “I must introduce your wasp to my fish – they are clearly soul-mates!”

Paul writes, “Late August is a great time to look for spiders. Many species have reached maturity and males can be found roaming around looking for a mate. Lots of spiders hide away during the daytime, so a night time search of your garden is likely to throw up species you never knew you had. Here are a few I found in my garden recently.”

A male Zygiella x-notata was found courting a female who had made her home at the base of a bird feeder. These spiders make very distinctive webs, very similar to the familiar common garden spiders webs, but with a triangular section missing (which is why they are called Missing Section orb web spiders).

Male and female Zygiella x-notata  Paul Rule

Nuctenea umbratica (Walnut Orb-weaver Spider) spends the day hiding in any convenient crevice. This one is living under the window frame of the shed.

Nuctenea umbratica Paul Rule

This Pholcus phalangioides  (Daddy long legs spider) was found on the outside of the shed, but they are mainly found indoors and responsible for most of the webs found on your walls. Despite the webs they are good to have around as they eat insect pests.

Pholcus phalangioides  Paul Rule

And finally, a couple of really beautiful spiders! A Big Butterfly Count at the end of July turned up a Cucumber Green Orb-weaver (Araniella cucurbitina) in the Meadow of British Antarctic Survey site.

Cucumber Green Orb-weaver Spider

Then this amazing Wasp Spider is living on Ditton meadows –  another species moving steadily northwards as the climate warms.

 Wasp Spider Duncan McKay

Olwen Williams     olwenw@gmail.com          August 2018

Flyway Highway

The more we learn about bird migration from satellite tracking and the night time recording of over-flying birds the more remarkable the story becomes; as if it wasn’t remarkable enough anyway!

Guy Belcher recorded 43 Whimbrels over Little Shelford on 20th August – they were likely Siberian birds moving south and they probably passed over our project area. The north westerly winds today (25th August) will probably produce a show of Arctic and Great Skuas (Bonxies) on the north Norfolk Coast. The curious thing about these birds is they appear to fly west and into the Wash rather than follow the coast east then south on their southerly migration. Observations suggest they exit the Wash at the mouths of the rivers that flow into it – the Great Ouse and the Nene – and continue a south-westerly overland migration following these river valleys. They continue south-west to join the Severn estuary and so “short-cut” the route round south-east England and arrive into the Atlantic much quicker.

The Whimbrels were possibly following the same track. A comparable spring migration has been observed with skuas following the Great Glen north-east from the Atlantic to the North Sea avoiding the route around the north of Scotland. I once saw an unseasonal immature Arctic Skua fly out of the mist in mid-January 1985 at a farm reservoir in our project area.

Whimbrel – wintering on Teneriffe October 2017

Skylark – Garth Peacock

Our project area could be a major flyway highway! In the 1960/1970’s Graham Easy observed Skuas over Milton but at a great height moving south west over the City. The trouble is that skuas usually fly too high to be seen and do not call so cannot be picked up by night-time sound recording (“noc-mig”). Migration height is another puzzle with some recent evidence that songbirds fly at altitudes of 5-6 km. This comes as no surprise. It was once assumed that Siberian migrants flew round the Himalayas to avoid flying at extreme altitude over the mountains and then filtered east and west to over-winter in the Indian sub-continent. In the 1970’s local birders camped in the Himalayas above the tree line noticed large early morning flocks of thrushes making land fall from the north. They had clearly come straight over nearby 6-7 km high Himalayan peaks.

It makes sense for the Whimbrels, Guy recorded, to follow the Ouse/Cam valley over our project area. Many winter in west Africa and on the Canary Islands and this is a much more direct route from Scandinavia than following the coast of England to the Atlantic. However, some do just that and I recently saw two groups of 10 and 15 flying south past Southwold.

Recent finds below the feeding perches of the City centre Peregrines include the severed head of a Moorhen and Black-tailed Godwit feathers! How the severed Moorhen’s head got there is anyone’s guess – an overhead migrant perhaps!? I don’t think I have ever seen a Moorhen fly any higher than 5 m! I suspect our City centre Peregrines hunt over the Ouse Wash. I have seen Peregrines heading north-east over Castle Hill/Huntingdon Road and between Girton and Impington and sitting in the aerial tower at Over. The general trajectory of travel seems to be towards the Washes and I have seen birds hunting at Chain Corner between Earith and Sutton Gault.

A recent article in The Observer (RSPB chief warns: we’ve got to protect our rare birds. 19.08.18) talks about the loss of 420 million birds in western Europe. The article specifically mentions Cirl Buntings which were occasionally recorded in our study area in the 1940’s and 1950’s (Bircham 1989). They are now only found in south Devon and Cornwall and were the subject of a successful RSPB recovery programme. Farmers there have combined to grow successions of spring crops leaving weedy over-winter stubbles on which the birds feed. Turtle Doves have declined by 90% which might be due, in part, to the loss of habitat in their African wintering grounds. This is the first year (in my birdwatching life-time) I have not seen a Turtle Dove.

The development at Darwin Green pushes our farmland birds: Skylarks, Yellow Wagtails, Yellowhammers, Linnets and Grey Partridges further to the edge of our project area whilst species like the Tree Sparrow have been lost. The devastation of adjacent landscapes and habitats due to the A14 widening might mean these species may require specific recovery programmes in the future like the Cirl Bunting.

Turtle Dove – Garth Peacock

Tree Sparrow

Watch for unexpected autumn migrants in back gardens. An easterly wind followed by rain could bring new birds to your local patch and garden. Two autumns ago, a mixed flock of tits included Willow Warblers, Chiffchaffs, a Lesser Whitethroat and a Reed Warbler in my very small Chesterton garden. Later in October, and if you are lucky, listen for the high pitched, rising “suwheet” call of Yellow-browed Warblers – they like Sycamores. Not to be confused with the contact calls of overflying Redwings, especially at night, that begin to arrive in numbers from the end of September – that’s a thin, high, flat “zeep”!

Bircham, P.M.M. (1985) The Birds of Cambridgeshire. Cambridge University Press.

Bob Jarman bobjarman99@btinternet.com

27th August 2018

Dragonflies in spring and summer

Female Emperor egg laying at Great Kneighton

With all the hot weather that we have had this year, the Dragonflies and Damselflies have been spectacular. I started the season watching Large Red Damselflies in late April this year, as they appeared in my garden, which is over 150 yards from Cherry Hinton Brook and lakes. I went on to look at Hobson’s Conduit as it flows across Empty Common and in front of the Botanical Gardens which is the perfect place to watch Damselflies and Dragonflies going about their short adult existence.

Late May and early June is the time when the number of species steadily climbs as more adults emerge from their aquatic larval forms to dance above the waters. Most adult dragons and damsels are relatively short lived and many only live for a few days. The larvae climb up onto a piece of emergent vegetation and then can be seen climbing out of their old skin to emerge in all their adult glory. They leave their old skin still attached to the vegetation and this exuvium can be collected and identified to species.  After emergence they have to disperse and mate, although since many emerge together, mating must often occur quite quickly. In June, there were so many Azure and Blue-tailed Damselflies mating and egg laying on the Conduit, I sometimes had numerous pairs in the frame of my camera.

Brown Hawker on a bulrush in the Science Park

The section of Hobson’s Conduit by the Botanical Gardens really is superb and sometimes Emperor, Four-spot Chaser or Brown Hawker Dragonflies will pass within just a few feet. Emperors are easy to identify, as they are the largest British dragonfly and have a green thorax (the bit between the wings). Brown Hawkers don’t come out until July and are identified by their brown bodies and orangey wing colour.

A Southern Hawker on Cherry Hinton Brook

A little later in July Southern Hawkers emerge, with their blue and yellow abdomen and broad yellow stripes on the thorax. These three are the biggest of our native species and are all magnificent as they hunt up and down the water course.

The Chasers and Skimmers are also present and early in the spring and summer the most common species is the Four-spot Chaser. The striking medium-sized beast has a brown body, much shorter than any of the Hawkers. It also has 4 black spots across the fore wings and another four across the hind wings, So I am not sure why it wasn’t called the eight-spot chaser.

Four-spot Chaser on Hobsons Conduit

The Broad-bodied Chaser seems a more elegant creature altogether with a  pale blue abdomen with little yellow spots down the side. The thorax is essentially brown with paler markings.

Male Broad-bodied Chaser on Hobson’s Conduit

In Grantchester Meadows and also in the ditch around the new bird ponds at Great Kneighton, one can find the Black-tailed Skimmer. The male looks a bit like the Broad-bodied Chaser but with a striking black end to its abdomen and lacking the yellow spots. The female is yellow in colour with two lines of black markings down the abdomen.

Female Black tailed skimmer on Grantchester meadows

In July and August, Southern Hawkers, Migrant Hawkers, Ruddy and Common Darters all make their appearance. So the summer is constantly interesting with new species to observe.

Common Darter: The insert shows the yellow stripe on the foreleg that does not occur in the very similar Ruddy Darter

One of the most spectacular dragonfly events takes place in Cherry Hinton chalk pits in August. Many Migrant Hawkers and Southern Hawkers can be found hunting in the bushes in the pit on sunny days. Then as the sun begins to go down, a shadow sweeps across the bottom of the pit and the dragonflies move to keep in the sun, so slowly the numbers flying just ahead of the shadow can be very great and hundreds of Dragonflies are amassed together following the setting sun.

There are some other really good sites to see Dragons and Damselflies in Cambridge, the list includes: The ditch across Coe Fen, The complex of ditches in Ditton Meadows, Banks of the River Cam just north of Fen Ditton, Logan’s Meadow, Science Park lakes, Barnwell Pit, Botanical Gardens ponds, Skaters Meadow and Sheep’s Green. Some of the smaller Cambridge nature reserves also have ponds which have good potential, but in the 2018 heat,  these have tended to dry up due to lack of water supply.

I will write more about Damselflies in my next blog.

Duncan Mackay

NocMig (Nocturnal Migration) the new Birding and the wader passage

Most of my birding is done by sound not by sight, but it depends where you are. In the City, gardens and woodlands it can account for 90% of records, which can then be checked out visually: flyover Peregrines, Common Terns along the river, singing/calling warblers, thrushes passing overhead at night when they arrive from the end of September onwards, even when sea watching – passing waders and the distinctive flight call of some gulls, especially Mediterranean Gulls.

The New Birding is to set up sound recording equipment at night, in a quiet spot away from peripheral noise and capture the flight calls of night-time migrants. Records can be confirmed from listening to play-backs or converting sounds to sonograms and comparing these to standard samples for comparisons; it’s called NocMig! I have heard Whimbrels and Green Sandpipers over Cambridge on clear dark nights in August, but this new technique is more systematic. Highlights this July have included a Whimbrel, Quail and, remarkably, a Bittern over our project area. Now is the time for active wader migrations and, with or without recording equipment, it’s worth listening on clear dark nights (especially if the wind is from the north or east).

A day-time Whimbrel was recorded over Trumpington Meadows on 27th July (Iain Webb). It also confirms that  urban Peregrines hunt at night and the remains of over 100 species of birds have been found in their pellets, many of which must be on overnight migration e.g. Quail, Nightjar, Water Rails. 

Wimbrels – Donegal 2017

Until the late 1960’s the Cambridge Sewage Farm was THE local hotspot for wader watching – especially during the autumn and spring passages. I remember seeing and hearing my first Temminck’s Stint and Wood Sandpipers there. One rarity recorded was the Red-necked Phalarope. The latest edition of British Birds describes its migration, which must be one of the most remarkable. After breeding on Fetlar, Shetland, male phalaropes fly north and west to Greenland, then south along the east coast of North America to the Caribbean, cross central America to winter off the coasts of Ecuador and Peru …. and then back again the following spring! WHY? Did they start to do this before the continents moved apart, or because food and therefore breeding conditions were so much better in Shetland?!

Most of our Swifts have gone; a few remained over Chesterton on 6th August. Swallows are still feeding young in Ditton Meadows (right) and Horningsea. Rooks may be having a tough time. They are birds of damp north–west Europe where they can probe soft earth for grubs and insects.

The baked soils due to the hot weather must have cut off much of their accessible food supplies. The Rookery count next spring will be a measure of how many Rooks survived this exceptionally hot summer.

 

Rook probing solid ground baked hard by the sun

A specific search for Meadow Pipits on agricultural land in the north of our project area found none. This is the first time in 30 years that no breeding pairs have been found. Meadow Pipits are Red Listed (50% population decline without any signs of recovery). I have no explanation other than loss of an insect food supply – in winter there is often a flock of 20+ birds.

Accompanying the Meadow Pipits in winter are Pied Wagtails (right). From now on they begin to assemble in overnight roosts. There used to be a roost of about 150 birds in the trees outside Carlucci’s Café by the Grand Arcade (Lion Yard!).

 Left: You are being watched! Roe Deer in the north of our project area

Chiffchaffs and Blackcaps are still calling in the heat of the mid-day sun.

I hope this exceptional summer has been good for butterflies. The following photographs were taken in Chesterton at the end of July. The Butterflies of Cambridgeshire (Field, Perrin, Bacon and Greatorix-Davies) features the Grizzled Skipper on the back cover. This butterfly is now a County rarity but in the 1960’s and early 1970’s it was common on brownfield sites in the north of the City: Arbury and Chesterton.

Below: Battered migrant – Painted Lady

Right: Peacock

 

Right: Speckled Wood

 

Bob Jarman         bobjarman99@btinternet.com

6th August 2018 

July Sightings 2018

As I begin to write this month’s account of Cambridge wildlife, we had thunder and the first rain since the end of April, nearly 3 complete months. However, about 20 minutes of rain will do little for the yellow grass and nothing at all for my allotment. Chris reports Strawberry Clover (Trifolium fragiferum) coming into flower at the beginning of Wimbledon on Jesus Green. It has been present there for at least 26 years and is always more obvious in a hot summer, as it is very drought resistant. Then, in a ditch at Great Kneighton, Trumpington, Cotton Grass (Eriophorum angustifolium), which is normally found in acid bog habitat, was fruiting well in a ditch – clearly planted during the development of the site.

Strawberry Clover  Chris Preston


 

Cotton Grass        Alan Leslie

 

 

 

I have had several reports of beasties which seem to be moving north, as the climate warms. The Horse-chestnut Leaf Miner (Cameraria ohridella) is the 4mm invasive Moth that is doing all the leaf damage to our conker trees. It was first reported in the UK in 2002 in Wimbledon, and has since spread north, south and west to most of England and parts of Wales. In continental Europe, it was estimated to have spread at 60 km/yr.  This pest has only a minimal effect on host tree vigour but causes very unsightly damage. A Jersey Tiger Moth was reported from Trumpington and again, these appear to be extending northwards. One was spotted by my 4 year old granddaughter, Rosa, in Tonbridge Kent.

Horse-chestnut Leaf Miner

Paul Rule

 

 

Jersey Tiger Moth      Rosa Williams

 

 

Ben’s Tree Lichen Beauty Moth has previously been known as a summer migrant, but may now be breeding in UK.

 

 

Tree Lichen Beauty               Ben Greig

Then Garret reports a Plane Tree Bug (Arocatus longiceps) from Jesus Green. Another recent immigrant to UK, it was first noted in 2007 and is now abundant on plane trees in parts of London

Plane Tree Bug

 

Guy reports successful Kestrel breeding: 4 youngsters fledged from the box on Stourbridge Common and at least 3 on Sheep’s Green. Swifts are also doing well – In Newnham the maximum number of adults seen was 12, with 4 nesting pairs. CCTV shows an older larger chick spreading its wings and doing press-ups in readiness for the long flight ahead. The Newnham heronry is alive with yelps and clacking beaks as the adults fly in with food. Jill’s second brood of Robins is now being fed, thankfully with masses of cabbage white caterpillars available for them. A glimpse of a Kingfisher at Grantchester Meadows and the sight of a Common Tern fishing there were bonuses for swimmers and punters. Swans with seven cygnets were doing well, though may be threatened by the Pike in the Cam: one 40 cm pike was seen along Garret Hostel Lane.  Other birds included Nuthatch and Grey Wagtail at Byron’s Pool, Tawny Owls, Buzzards, Long Tailed Tits,  oversexed Wood Pigeons, a Green Woodpecker (heard but not seen), 2 Hobbies and a Red Kite. At the Sewage Works (aka Anglian Water Recycling Works!) I noted Black Headed Gulls, a pair of Stock Doves, a Pied Wagtail and about 200 roosting Starlings. This was a fascinating visit, where I learned how they process about 1300 litres/sec (a decent-sized river), produce enough Methane to generate 40% of their electricity, sell the sewage sludge for fertiliser and then return the water to the Cam.

Bill reports a Spruce tree full of new cones being attacked, probably by squirrels. Lots of animals must have struggled in this dry weather. Two Hedgehog introductions took place in Newnham this year. George appears to have wandered off, but Spike is still around and two infants were recently found on the pavement nearby. Even though fully spiked, at only 2.5 ozs, they were taken to the Shepreth Hedgehog Hospital for care and feeding.

Spruce cones Bill Block

 

Spikelet (Infant hedgehog) Jill Newcombe

 

Elephant Hawk Moths have been abundant this year and one Red Underwing Moth was seen. It has been an excellent year for both Large and Small White Butterflies. More unusually, Guy noted a White Letter Hairstreak and a Small Copper at Byron’s Pool. Small Blue, Holly Blue, Meadow Brown, Comma and Peacock butterflies were seen across the city. Then various reports of damsel and dragonflies. Duncan saw Brown Hawker, Southern Hawker, Ruddy Darter, recently emerged Common Darter, Emperor, Four Spot Chaser, Scarce Chaser and Black Tailed Skimmer all present along the Cam. Sue heard buzzing in her kitchen and found Buff-Tailed Bumble Bees using an old vent in the wall. Wasp mimic Hornet Hoverflies were noted by Martin. I had one comment about lots of Hornets, but I have seen none this year and very few wasps.

White Letter Hairstreak

                       Hornet Hoverfly

 

 

But how about these two pictures?!

Paul took this one of a female Glow Worm (Lampyris noctiluca) at Cherry Hinton chalk pit. These static flightless female beetles sit in the grass and supply landing lights for the males. (“Very hard to photograph if you want to shoot the glowing tail and the rest of the insect – a 5 second exposure with fill-in flash for these shots.”) The Wildlife Trust organises Glow Worm walks around the chalk pits.

And then Ben reports a female Gasteruption jaculator Wasp in Oxford Rd (with a wonderful white-tipped ovipositor and a great name).

 

Gasteruption jaculator    

Ben Greig

 At the allotment, I found a dead Mole lying next to a Hare’s foot! I can only think that the hare was enough for the fox and this was the remains of dinner. Jill found a Grass Snake skin on the back porch, a reminder that reptiles (though cryptic) are still around. Blackberries are starting to ripen. After a brief thundery interlude, the drought looks ready to continue, but in Pam’s small pond, the Frogs are enjoying the cool water. Will it rain in August?

                                                   Frogs          Pam Gatrell

 

 

 

Mid-July 2018 – I was wrong! …… about the Common Terns

I was wrong about the Common Terns not appearing this year. Two pairs were feeding along The Reach at Fen Ditton on 11th July and one pair headed off high due south with food, as if to feed young. I have never worked out where they breed, but this pair were heading towards Cherry Hinton Pits or even Hobson’s Park.

Common Tern on The Reach 1st July                       Reed Warblers were still feeding young on Ditton Meadows on 1st July, but where are the Sedge Warblers this year? Perhaps the “Beast from the East” stalled their north-wards migration this year. Some years ago, I photographed a Sedge Warbler at Little Wilbraham and only noticed on the photo, it was ringed; closer examination showed it had a French ring. Perhaps that’s where their migration north stopped this year.

I guestimate there are 10 pairs of Kestrels in our project area and perhaps the same number of Sparrowhawks. Jon Heath has a wonderful film on Twitter of Sparrowhawk chicks in a nest in the north of the City; Barry Sims has photographs of a nest in Romsey town (below). Sparrowhawks became extinct in Cambs in the early 1960’s due to toxic agrochemicals. They were extinct in the County for about 25 years but returned in 1985.

Peregrine at the second City site  Common Buzzard over Ditton Fields  Female Sparrow-hawk with chicks Romsey

One Peregrine fledged at the second breeding site in the City (photo Richard Johnson). I guestimate five pairs of breeding Buzzards in our project area; in July, whilst watching the City Centre Peregrines, a pair of Buzzards were circling over the city in the same binocular view. Just five years ago I would not have thought this possible!

We have had no rain since the 29th May; in Queen Edith’s Way Goldcrests come to drink at a garden pond and “skitter” across the lily pads. A Garden Warbler is still singing in the Orchard in Milton Country Park, on the very northern edge of our project area and Chiffchaffs, Blackcaps and Song Thrushes were still in song in mid-July. Two territorial male Yellow Wagtails were located at a farm site also on the northern edge of our project area.

Yellow Wagtail Song Thrush by The Rush

A Quail heard at night over the City is, I suspect, a first for the City and hints at the nocturnal movement and migration of birds that goes unnoticed.

 

 

 

 

Himalayan Balsam (above), an aggressive coloniser of river and stream banks, is well established in the south-west corner of Ditton Meadows. Eighty-Five Ivy Broomrapes were counted in the central reservation in Longworth Avenue and lots in St Giles (Ascension) Cemetery in deep shade, but none in Newnham College grounds this year.

Lots of Swifts are screaming over their nest territories. Interesting data from Clarke Brunt’s Swift nest boxes in Milton:

  • Birds return from 5th May to 7th May; first eggs are laid from May 14th to May 25th
  • They lay two or three eggs (2 or 3 days apart); hatching is approximately 19 days from the last laid eggs; from hatching to fledging is approx. 42 days. Fledging is from July 19th to August 2nd.
  • If an adult is lost and the remaining bird attracts a new mate and lays a new clutch, fledging can take place from August 16th to 18th but one exceptionally late pair fledged young on September 9th. In the field, a September Swift sighting is unusual.

Thank you Clarke – I hope I have those figures correct! See – http://www.viridis.net/animals/swifts.html

The excellent photograph of the fledged Peregrine is by Richard Johnson – his Facebook page is: https:/www.facebook.com/Richard-Johnson-Wildlife-Artist-318774484888727/.

The photo of the Romsey Sparrowhawk with chicks is by Barry Sims. Thank you, Richard and Barry,

Bob Jarman bobjarman99@btinternet.com 17th July 2018

Cambridge moths

To the amateur naturalist moths can be a fascinating subject to study. They are an incredibly diverse group with over 2,500 different species recorded in the UK (71 species of butterfly recorded in the UK seems meagre in comparison!). Though often dismissed as brown and drab, many moths are quite the opposite, showing just as brightly coloured wings and a great deal more variance in terms of shape and body size than butterflies.

What makes moths such an interesting group to study? Well, for me it is the fact that a large diversity of species can be observed in a small area, such as an ordinary back garden. The most effective way to assess the moth population of a site is to run a ‘light trap’ overnight. This technique attracts moths in large numbers by exploiting their tendency to become disorientated by bright light. Moths enter the trap where they rest on egg trays and are unable to get out. The next morning, the ‘catch’ can be studied and once identified and recorded the moths are released unharmed. Using this method to date I have recorded over 400 species of moths in my north Cambridge garden.

Actinic Mercury Vapour
moth trap
Privet Hawk

There are many spectacular and beautiful moths to be found in the Cambridge study area. The most impressive group are the Hawkmoths, which are medium to large moths, often brightly coloured. There are seven species which can be regularly recorded in Cambridge city which include the enormous Privet Hawkmoth (as large as a mouse!), bright pink Elephant Hawkmoth and stunning Eyed Hawkmoth. Late May to July is the best time to look for Hawkmoths and this year has been particularly good with a larger than normal number recorded.