Category Archives: Project Blog

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

October Sightings

Lots of volunteers this month!  Thank you to all contributors.

Birds! One observer reports an adult dark bellied Brent Goose with a Greylag flock on Pond 1 at Hobson’s Park, next to Addenbrooke’s. It was ringed, but its origin is not yet known. Locally, the first sight of a couple of fieldfares, feeding on hawthorn berries, indicates the onset of winter. Similarly, the early morning and teatime noisy flock of rooks and jackdaws are a winter treat. They are keen to see off any passing buzzards. An early morning rower describes two sightings of a kestrel along the river to Fen Ditton, a heron, a pheasant, ducks, swans, moorhens and also cormorants flying, diving, surfacing at different places along the river. In Newnham, our pair of swans still have 7 of their original 8 cygnets, so are doing well. On a more sombre note, a juvenile peregrine is in rehab, having been shot with ˑ22, recovery uncertain. This is likely to be a locally bred bird. I will not add Bob’s comments on the perpetrator.

One quite accidental finding was the pupa of the Orange Ladybird – we were identifying trees and found it on the leaf of a field maple. I have never seen the adult, which is orange with 12-16 white spots, but the pupa is unmistakable, black with yellow markings.







Pupa                                                                         Graham Callow


The UK Ladybird Survey states: “Considered an indicator of ancient woodland until 1987. Has become widespread since it became common on sycamore trees. Recently has also moved onto ash trees and appears to be increasing in abundance”.  The site was along the footpath to the Grantchester Meadows, an hedgerow possibly 500-600 years old, as are many of the hedges in W Cambridge.

At the beginning of the month, there were quite a few fungi – Stinking Parasol (Lepiota cristata), Wood blewit (Lepista nuda), and Slippery Jack (Boletus badeus) on the playing fields and in Paradise a beautiful patch of Honey Fungus (Armillaria mellea) and Chicken of the Woods (Laetiporus sulphurous). Then the warm weather returned and most things have disappeared again.

Another sign of the unseasonal weather – Ivy Broomrape has appeared in Chesterton, most unusual in October, as they are said to flower in June/July. These plants are parasitic and totally dependent on the roots of ivy plants, having no chlorophyll of their own.

Ivy Broomrape

Another unusual plant was the Shaggy Soldier (Galinsoga quadriradiata) found on the allotments at Empty Common. Introduced in 1909, it appears to be spreading and apparently likes allotments. It has daisy-like flowers and leaves with coarse hairs. (Quatriradiata seems an odd name for something with five main petals!)


Roger Horton has been doing some detective work: “The first I noticed was a red bloom on the duckweed in the race at Newnham Mill. It didn’t take long after that to trace Water Fern (Azolla filiculoides) to Crusoe Bridge and Laundress Green. Taking advantage of a bright autumn morning, I followed the trail down river as far as Baits Bite Lock, encountering on the way a dense growth of Floating Pennywort at Fen Ditton, near the railway bridge. Next day, upstream the fern was evident at Byron’s Pool and further up at the crossing of the M11. This spans the entire length of river in the NatHistCam area!”      Another invasive alien in the Cam has to be bad news – the Pennywort is back with a vengeance, in spite of major efforts to remove it last year.








Muntjac are often sighted in the city, with reports from Hills Rd and also from Grange Rd, where one was found dead after being hit by a car. A black squirrel was seen in Chesterton – we are interested in any more reports of this melanistic variant. Reports of hedgehogs continue to arrive – most recently in Glisson Rd, found dead (it should have stayed in Highsett Gardens!), in Arbury, where two lucky ones turn up for mealworms and sunflower hearts every evening and several in a garden in Chesterton following release from the sanctuary.

Olwen Williams


Autumn thugs and the gentle passage to Winter

Skuas (Jaegers in the USA) are the dark mean-looking gull-like thugs of the seas that terrorise  gull and terns into regurgitating food for their own consumption. From 1990 to 1995 local birdwatchers staked out the rivers Ouse and the Nene mouths at the south of the Wash to observe Skua passage. Hundreds were seen passing south down the rivers.

The theory is that they migrate overland at a great height following the north-east/ south-west trajectories of the Ouse/Cam and the Nene river valleys to the Severn estuary – a migration short cut. The theory suggests they pass over our project area but too high to be visible.

Arctic Skua (courtesy Bill Schmoker) (above)

Great Skua (right)

Illustration by Graham Easy of Skua migration over Cambridgeshire (1990 Annual Report of the Cambridgeshire Bird Club No 64)

Graeme Easy produced a very evocative drawing of Skuas over Milton (left)

Recently birds have been seen passing overland through the Great Glen in Scotland on a path from the Irish Sea to the North Sea on their way to their breeding grounds in our northern Isles and Scandinavia. Look up on a stormy day with strong NE winds! On 14th September this  year (2017) Jonathan Taylor saw 62 Great Skuas heading south into Cambridgeshire at Foul Anchor, north of Wisbech. There is at least one record of a Skua in our project area: a juvenile Arctic Skua at a local farm reservoir in January!

Ten Common Buzzards high over Huntingdon Road on 6 October were probably passage birds; a Chiffchaff singing in Logan’s Way had probably lost its way! Redwings heard over Cambridge on 1st Oct and a Brambling over Cambridge on 8th October (reported by Jon Heath) are early winter visitors; a Common Redstart was seen at Eddington.

(Grey) Herons are tough cookies! There is one heronry in our project area in Newnham. Little Egrets often breed in heronries but where our local Little Egrets breed is an enigma. Garden ponds stocked with ornamental fish are regular targets for herons, especially young birds.

Grey Heron (left)  watchful, waiting, for the chance and poised to fly down to a garden pond in Chesterton (below)

The Tawny Owl survey in our project area has found 5 nest sites, 4 in west Cambridge in the Newnham/Grange Road area. Please send me any records of breeding or single birds. Sparrowhawks (see September blog) are now probably commoner in urban areas than the wider countryside where farmland birds have declined.

October 2017

September sightings

Lots of comments from observers this month. Even in the middle of the city, wildlife can be found – in this case a verbena plant in a tiny crack in the pavement by the John Lewis store.







Five common buzzards were seen together from the Huntingdon Rd area and a group of three sparrowhawks were observed circling above Owlstone Rd, Newnham. Late butterflies at this site included several large whites and two red admirals. At Addenbrooke’s Hospital, an area of grass has been damaged, the suspected culprits being badgers in search of chafer grubs, as at the Botanic Garden. Finally, several baby toads appeared in a Chesterton garden.

One of our current surveys is of tawny owls and on the night of 11th, I heard a male calling in the middle of the night, near to the river. The male and female have a duet – she says “tuwhit” and he says “too-whoo”, so the two calls may be heard either together or separately. Please let us have details of any more!

At the allotments, it has been a good year for apples. However, gone are the days when many had damage from grubs, as we have eliminated most of our insects. I did see a 7-spot ladybird and also a rather sleepy noonfly, Mesembrina meridiana – one of the largest blowflies, with orange patches on the wings. It is one of the many flies which breed in and depend on cattle dung.

By Simon A. Eugster

On Sept 13th, the City Council and Environmental Agency carried out electro-fishing of the newly regenerated brook – The Rush – which runs between the main river and the Newnham millpond across Sheep’s Green and under Fen Causeway. What had been a sluggish and overgrown stream is now running freely through a narrower channel and a fish gate has been installed at the top. I went to see what was happening and talked to a fisherman on the main river who had just caught (and then lost) a perch. He was using mealworms as bait and said he was hoping for dace or chub

At the brook, one man carried a loop attached to a battery, which delivered a weak electric shock in the water, followed by two with nets to scoop up the ‘catch’ for counting and measuring. By the time of counting, the fish were very frisky and were returned to the stream.

Counting and measuring fish at The Rush stream

The whole stream was fished twice from the millpond to the river.      I was surprised how many fish had been caught. I saw about 40-50, but the total for the two runs was 203, which meant there were about 20 fish per 10m stream. Most common were gudgeon (bottom feeders) and dace, with numerous perch, chub, roach and minnow, occasional pike, 3-spined stickleback and eel. They ranged in size from 4-15cm (2-7in). In the process, a larger eel had also been spotted, but not caught.

Earlier, the team had found and briefly captured a grass snake, before releasing it into the brook. Note the yellow collar, distinguishing it from an adder. Guy Belcher (in the picture) mentioned the offensive smell on his hands after handling it.








Grass snake





Nearby, a willow, in apparently poor condition, was secreting a sticky sap that was attracting both Harlequin ladybirds and also wasps, which were feeding on the trunk. Periodically, a hornet circled, hunting the wasps, catching them in the air and biting off their heads!

On September 17, at 11am, the air was alive with noise – the rooks and jackdaws were back in the trees by the river at Newnham. It sounded just like the first day back at school. Rooks – enormously social birds – form large flocks in the winter, with gathering sub-stations like the Paradise woods and a huge roost at Madingley. In the summer, they hardly appear here at all, but spend their time at their rookery where chicks are raised.

Olwen Williams


Autumn Watch and Eddington

A few late Swifts were recorded, probably passage birds: 1 over Huntingdon Road on 3rd September, 5 over Addenbrooke’s, the next day, September 4th, and 6 over Chesterton on 15th; September Swifts are unusual. A Chiffchaff was singing in the rain in Fulbrooke Road on the 15th September and a Hobby over Huntingdon Road on the same day.

Keep an eye open for unusual migrant birds that find safety in numbers amongst flocks of tits coming to garden feeders. A very small garden can attract passage Whitethroat, Lesser Whitethroat, Willow Warbler, Reed Warbler even a Yellow-browed Warbler. In a week to ten days, over-wintering Redwings will be heard flying over at night with their high pitched “sseep, sseep” contact call.

Cambridge has a new suburb (or is it a new village?) on the north- west of the city – Eddington; named after the astronomer and mathematician Arthur Stanley Eddington (1882-1944). Between the buildings and the M11 are a group of balancing ponds to mitigate flooding. They already have breeding Little Grebes; Kingfishers have been seen and in the early stages of the project the bare soils and gravels attracted breeding Lapwings and Little Ringed Plovers. In 2015 only 8 breeding pairs of Little Ringed Plovers were found in Cambridgeshire. Kestrels bred on one of the housing blocks under construction, which stopped work until the chicks fledged. Some Swift and House Sparrow nest boxes have been integrated into the build. It an impressive sustainable development and well worth visiting and is part of our project area.

Just a mile away to the east on farmland in our project area, five pairs of Lapwings nested on a field of short barley stubble in spring 2015 – the first time on this site for at least 50 years! Sadly, all nests failed probably due to predation by corvids and despite careful farm operations that marked each nest.

I try hard to like Crows – it’s respect more than like. A paper in the recent British Wildlife (Stoate, 2017) says that controlling nest predators such as Carrion Crows and Magpies increases nest survival rates for vulnerable species such as Song Thrushes, Blackbirds and Spotted Flycatchers. It makes uncomfortable reading!


Little Egret (left); Cattle Egret (right) – Chesterton Fen April 2016

Until 1988 sightings of Little Egrets were so rare that records required a written description to be accepted. (“Medium sized pure white heron with a black bill and legs and bright yellow feet. Period!”) In 1989, 40 turned up along the south coast of England and the remarkable colonisation of the UK began.; they first bred in Dorset in 1996; in 2016, 82 were counted at Burwell Fen near Wicken. Last year I saw two fly over Arbury where I lived as a boy; such an occurrence would have been unthinkable then. Where they breed is enigmatic! They can be seen regularly in Coe Fen and Newnham and along Snakey Path between Romsey Town and Cherry Hinton – almost any shallow water area, ditch or dyke. But beware, amongst farm stock it could be a Cattle Egret! In April 2016 Jon Heath found a Cattle Egret in our project area on Chesterton Fen. It is slightly smaller with a yellow bill and yellowish/green legs and feet.

Three Tawny Owl records so far: two in the Newnham/Coe Fen area and one in Sidgwick Avenue. Please send Tawny Owl records to  or to me at the email the address below giving date, location – street name. All records will be confidential and also forwarded to the County Bird Recorder.

Stoate, C. 2017. The Allerton Project’s first 25 years. British Wildlife 28:392-397.

September 2017

Late August in the Botanical Gardens

A visit to the gardens last Friday in order check out late summer dragonflies and damsel flies, turned out to be one of the best trips for wildlife I have had to this site. Starting out at the fountain we had our first dragonfly species, a single female Southern Darter ovipositing on the pond vegetation, along with a lone Blue-tailed Damselfly.

On the main lake there was plenty of dragonfly activity in the form of Common and Ruddy Darters, Brown Hawkers and hovering Migrant Hawkers. There were also small numbers of Common Blue Damselflies. The main entertainment here however was provided by a pair of Kingfishers who performed a number of flybys over the lake.

On the western edge of the lake we found two Water Voles, one of which was content to feed just a few feet from us allowing great views and photo opportunities.

Water Vole (Paul Rule 2017)

At about this time last year, I had photographed a pair of mating Willow Emerald Damselflies which was a first for this site and I was hoping to find evidence that they had become established here. We found one male specimen  in the exact location the pair had been seen the previous year, and the following day another observer found five. This along with other sightings suggests this species is now well established in Cambridgeshire.

Willow Emerald Damselflies (Paul Rule 2016)

Other observation of note  were a number of Speckled Wood butterflies, good views of one of the resident Jays and an unknown species of wolf spider walking on water carrying  her bundle of eggs behind her.

Paul Rule

The Swifts have gone – 2017

Swifts breeding in our study area have mostly gone – there seemed to be major overnight departures on Tuesday 1st and Saturday 5th August but a few remained over Chesterton until 12th August. Since then occasional birds are probably over-flying migrants moving south but about 10 were feeding with swallows over Midsummer Common on 20th August. Two pairs used the Swift Tower on Logan’s Meadow and at least 10 nest boxes on Edgecombe Flats, near Campkin Road, were occupied. A Chiffchaff, singing in Huntingdon Road on 12th August, was probably a passage bird confused by a spring-like sunny day.

August is wader passage time. Overflying night migrants that often call include Whimbrels, Godwits and Green Sandpipers. On a clear night listen for their contact calls especially if the prevailing winds are from the north or east. An examination of prey from Peregrine Falcons nesting in Nottingham found the remains of night migrants such as Water Rails, Nightjars and waders.

The two pairs of nesting Peregrines in our project area both reared two young. One of the young from the City centre crash landed in Caius College and spent five days R&R at the Raptor Foundation near St Ives. It was then successfully reunited with its parents in the City.

Our project has four new surveys and we are asking for records. One of these surveys is for Tawny Owl records. From August young Tawnies are ejected from parental territories and attempt to set up their own home patch. They can fetch up in any wooded area, including our gardens, especially if near open ground where they can hunt small mammals and earthworms – Tawny Owls are great worm eaters! The “tuwit too- wooo” is an amalgam of the female call – “tuwit” or better a sharp “kerwick” and the male call – “ too-whoo”. There is a breeding pair with well fledged young in Sidgewick Avenue.

Please send Tawny Owl records to or to me at the email the address below giving date, location – street name. All records will be confidential and also forwarded to the County Bird Recorder.

Sparrowhawk (left)
© Frank Bell 

Another raptor common in the City is the Sparrow hawk. A male was displaying over Logan’s Meadow Chesterton at the beginning of August – why? Probably, like the Chiffchaff, inspired by a warm day rather than a late nesting attempt. Sparrowhawks were our commonest raptor until 1960 but agricultural pesticide poisoning caused them to become extinct in Cambridgeshire for 25 years until a nesting pair was discovered in a wood in the west of the County in 1985. Since then numbers have recovered and now they are probably as common as they ever were. It is difficult to estimate their current population in our project area but it is possibly 10-15 breeding pairs.

Little Egret on the Snakey Path (left)  © Bob Jarman

Future bird projects in our study area will include, (Grey) Herons, Little Egrets and wintering thrushes: Redwings and Fieldfares. Redwings will be with us very soon – early birds arrive on the coast at the beginning of September. Redwings are frequent night migrants and can be heard passing overhead with a high, drawn out, “seep” contact call.

August 2017

August sightings

Migrants are beginning to slip away. Swifts arrive in early May and depart in August, a shorter visit than most of the summer migrants. A Newnham neighbour has an established swift colony, with both boxes and adapted bricks being used. Behind the bricks are nesting boxes with a glass back, to allow photography and monitoring.  She reports, “We last saw them on August 15th, the adults went in the evening and then the chick fledged sometime in the night … empty box on August 16th. On August 17th I saw a solitary swift swooping round our house briefly, before it flew up and away.”  Swifts have also been using the Swift Tower in Logan’s Meadow, Chesterton since 2011. The main constraint on these birds must be the availability of flies, whose numbers have plummeted over the last 30 years.

Another neighbour recently found a large toad in her garden, also a humming-bird hawk-moth. At the allotments, there has been a superb crop of blackberries, the best for some time. In the local playing fields, cooler nights and lots of rain produced an interesting crop of fungi: a field mushroom, some boletus (Slippery Jack) and some horse mushrooms (larger version of the field mushroom). I did not eat the latter, as there was a suggestion of yellow-tingeing on the broken surface, but enjoyed the others. The boletus is dependent on the adjacent pine trees, which sadly have just been felled, so presumably that will be the end of these at this site.

Relaxing over coffee in the graduate centre, a peregrine falcon came past at eye level – a lovely sight.  One evening, by the river, a kingfisher zipped its way through the swimmers, going upstream.     A lesser stag beetle (with the wonderful Latin name of Dorcus parallelipipedus) turned up on the pavement outside the social club in Newnham. On August 27th, I heard a snatch of chiffchaff song, as well as the contact calls. I wondered if he was calling to gather up comrades for his migration flight.

At Cherry Hinton Hall, workmen were clearing away the remains of the Folk Festival – squares and rings of paler grass indicating the presence of tents over the weekend. Jays called in the woodland and in the lake were yellow patches of marsh marigold.

The spider of the month is this fellow, whom I found in the bath….

Larger than the house spider (Tegenaria domestica), this giant house spider (recently renamed Eratigena atrica but previously T. duellica) is also common and just as harmless.  The female body size can reach 18.5 mm in length, with males slightly smaller at around 12 to 15 mm. The female leg span is typically around 45 mm while the leg span of the male is highly variable, between 25 and 75 mm. This one has enlarged, club-like pedipalps, so is a mature male, with body 13mm and leg span 66mm. He was doubtless looking for a mate when he fell into my bath. (I will leave a towel over the edge, so he can get out unaided next time.) Once mated, he will remain with the female and eventually become her dinner – the ultimate recycling event!

 Olwen Williams

The Water Vole and the Folk Festival

I was cycling along  Cherryhinton brook one afternoon last week and heard the music from the Folk Festival drifting over the alotments, a nice lilting melody mixing with the sounds of nature all around. As I rounded one of the bends in the footpath I noticed a little water vole sitting mesmerised on a patch of Greater pond sedge (Carex riparia) .  I am sure it was feeling just as mellow as I was. It knew I was watching but went about its nibbling for some moments. Then plunged into the water and dived down to the bottom of the stream. A great cloud of mud billowed up as the vole started an excavation process. It was digging at the base of the sedge plant and eventually resurfaced with a length of white succulent rhizome in its mouth. It then resumed its meal and had soon consumed this prized moursel. I imagine the rhizomes must contain lots of stored starch, so the vole was getting a much better meal than it gets from endless nibbling of the leaves.  It was a very young vole and quite small, so I wonder how it learnt to expertly dive and excavate in this way so early in its life. Presumably by watching its parents.
I have discovered that if you want to see a water vole, the easiest way of spotting them is to look out for unusual ripples on the water surface. The voles sit under the bank and nibble food. The frequency of their nibbling is much faster than other animals, so the ripples they produce are a shorter wave length than say a moorhen or a mallard, which are also found along the brook. I think the ripples come from the vibration of their tummies as they nibble. They are very enthusiastic nibblers and they are always eating. I can often find the hidden voles right in the middle of a sedge bed in this way. You just hang around a while and the vole is sure to appear.

July sightings

Our local pair of swans have hatched (and so far raised) eight cygnets – they are very attentive parents! Many of the songsters are too busy with offspring to sing much, but song thrush, chiffchaff and blackcap are still about and vocal. Swifts can also be heard (July 20th) but perhaps for not too much longer, as small groups appear to be heading south. In Paradise, there are reports of 3 egrets, in the company of a heron.  Then, in the river above Newnham, a common tern swooped between the swimmers to pick up a fish.

The dominant colours of the flowers in summer and autumn seem to be purple and red. Tufted vetch keeps company with knapweed, great willow herb, mallow, betony, spear and marsh thistle, bittersweet (woody nightshade) and woundwort. Even the white yarrow has taken on a pink colour in places. Much of the grass is yellow now, but the new growth of nettles more than makes up for this. Many of the nettles in Paradise lack stinging hairs. This is generally true of places where grazing animals have not been present for some time and so the stinging properties are unnecessary. Stinging hairs are costly for the plant to produce, so in this situation, there is selection pressure against them.

Among the nettles was a small (~1 cm) snail – one of the Amber snails – whose aperture is longer than the spire. Although there are two very similar species, I think this one was Succinea putris, which frequents wet places.

Spider of the month has to be the garden spider, Araneus diadematus Although most are not yet fully grown, they are actively renewing their webs every morning.

Olwen Williams

It’s been a good year for – Warblers

Blackcaps are still singing in Logan’s Meadow which suggests a second or even a third breeding attempt this year. In Rustat Road, in an unkempt patch about 3m x 3m at the end of a well-cared for garden, Chiffchaffs were feeding young in mid-July and others still singing in Huntingdon Road gardens. The Willow Warbler on Coldham’s Common with the “chiff chaff” notes at the end of its song was also still singing in mid-July.

Chiffchaffs have out-numbered Willow Warbler by about 10:1 in our project area this year. Apart from the Coldham’s Common bird, the only Willow Warblers I have heard have been along the river opposite Fen Ditton and three singing in the birch thicket near the new Cambridge North Station.

The July issue of British Birds has a paper which suggests Willow Warblers have declined in southern England while populations in the north have remained stable or have increased.

Willow Warbler – above

Blackcap (female) – below

The average shift north of 122 species of British birds is about 20.4 km or 1-km per year or almost 3m per day! (Pearce-Higgins 2017). A good example is the Spotted Flycatcher which used to be regular in our NatHistCam project area but is now a rarity. In Scotland, especially around sheep pastures, it is still common.

The Cambridgeshire Bird Club has a current project on the present distribution of the Spotted Flycatcher – if you have any recent records (from anywhere in Cambs) please let Michael Holdsworth know:

The reasons for this move north are probably related to climate change and a decline in insects. The BBC’s Farming Today reported that the banned neonicotinamide insecticides, that some believe are responsible for the decline in bee species, are still widely used on non-flowering agricultural crops such as sugar beet, turnips and kale to reduce aphids and the transmission of virus yellows.

Common Tern on Riverside (below)

A pair of Common Terns can still be seen regularly feeding along Riverside often heading down river with food; if you know where they are breeding please let the Cambridgeshire Bird Club know:

Marbled White on Coldham’s Common (left)

Has it been a good year for butterflies? The Marbled White is a species that has increased in recent years and has expanded its range from chalk grassland to grassy corners. This year I have seen them on a farm site in the north of our project area and on Coldham’s Common. There is an excellent book: The Butterflies of Cambridgeshire published by the Cambridgeshire and Essex Butterfly Conservation Branch that is well worth buying!

Field, R. Perrin, V. Bacon, L. Greatorex-Davies, N. (2006) The Butterflies of Cambridgeshire. Butterfly Conservation Cambridgeshire and Essex Branch – ISBN 0-9554347-0-X; 978-0-9554347-0-9
Pierce-Higgins, J.W. 2017. Birds and Climate Change.
British Birds 110:388-404.

Bob Jarman 24th July 2017