Category Archives: Project Blog

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

Peregrines – update June 2017

The City centre Peregrines have reared two chicks. One fell onto the pavement below and was rescued. The second chick is fully feathered and now glowers down onto the street below waiting for the parent birds to return with prey.

Below: Juvenile Peregrine photographed on 17th June 2017

The second city pair has two healthy chicks. At the beginning of June a dead Buzzard was found close to their nest site. At some nest sites Peregrines have been seen to kill Common Buzzards – presumably they see them as a predatory threat. This dead Buzzard appeared uninjured and on close examination turned out to be a Honey Buzzard!

Honey Buzzards are rare breeding birds with about 50 breeding pairs in the UK and very occasional annual passage migrants over the City in the first weeks of May. A June record is exceptional. Could this be one of a pair that is breeding locally?

The Peregrines at this second city site often nest with a pair of Kestrels and Stock Doves nesting closely nearby without any apparent antagonism!

A female Black Redstart has been seen at a central City location – no male has been seen or heard so it’s likely this lone individual is an unpaired female on an early return migration. But its show they maybe about in the City; central Cambridge, around the colleges and churches, is a likely location.

Bob Jarman 19th June 2017

June sightings

High summer!! A alternating mixture of rain and heat has provided an excellent growing season and some spectacular flowers. In my garden, bumble bees are investigating the honeysuckle and foxglove flowers. In particular, the Common Carder (Bombus pascuorum) and the Garden Bumblebee (B. hortorum) have long tongues and are able to reach into the deeper flowers. I have also seen the Early Bumblebee (B. pratorum) here.

In Paradise, there is a nest of Tree Bumblebees (B. hypnorum), recognised by its combination of ginger thorax, black abdomen and white tail. The nest is in a willow tree about 8 ft off the ground and is patrolled by ardent males, waiting for the virgin queens to emerge. These bumblebees are relative newcomers to UK, having arrived only in 2001 from Continental Europe, but are spreading widely and have reached both Ireland and Scotland.

Tree Bumblebee Bombus hypnorum

In the heat, the river is a popular place to swim. However, there is a warning of the “river itch”, especially on hot days. This is caused by the larvae of a flatworm, whose primary host is a snail. The free-swimming larvae seek their secondary host, a duck, but may mistakenly attack a swimming human. Apart from an irritating rash, the larvae are harmless to us.

There seem to be exceptional numbers of singing Blackcaps and I am also hearing Chiffchaff locally. The Song Thrushes are still vocal and a little pile of broken snail shells indicates where they are feeding.  Skylarks sing over the Grantchester fields, but I have not heard a Yellow Hammer there this year. The local Herons are noisier than ever, now that the young are hatched and courting is overtaken by childcare duties.

In the house, I disturbed a very large House Spider (Tegenaria domestica). I left him there, hoping his diet includes my current plague of Clothes Moths. There seem to be very few flies for him this year. A recent publication* states that there has been a

decline of about 80% in the biomass of insects over the last few decades (since 1989). I wonder why?

Olwen Williams


Winter in Mozambique or catching pigeons in the Market Square?

One of our most exciting spring migrants is the Hobby, a swift-shaped falcon. Satellite tagging has shown they spend their winters catching termites in Mozambique. One or two pairs probably breed on the edges of our project area; hunting birds are often over the City and were recently seen over Huntingdon Road and Chesterton. In the early 1960’s this species was confined to the New Forest and Dorset heaths. Slowly, it expanded its range and by 1964 there may have been 1-2 pairs nesting in Cambridgeshire. Until the 1960’s this species was a target for bird nesters. It uses disused crows nests and is faithful to suitable breeding sites; a breeding site in the north of our project area has probably been used for the last 25 years. It nests late and entire clutches were stolen to order. Once taken the birds did not usually lay again and if they did the eggs were often stolen for a second time.

The ban on egg collecting and more importantly enforcing the ban enabled the Hobby to expand from its New Forest strong-hold. Crows were less persecuted so the number of potential nest sites increased. The extraction of gravel in the Home Counties and into Cambridgeshire created open water gravel pits for it to feed on one of its favourite prey items – dragonflies.

While Hobbys are away in winter chasing termites in southern Africa, the City’s Peregrines are catching feral pigeons in the Market Square or wildfowl on the Ouse Washes.

The male Peregrine of our city centre nesting pair on watch some distance from the nest on 15th May – it’s a good sign! The heavy rain the next day on the 16th is a worry as the nest was partially water-logged last year and one chick was lost.

Common Terns have returned and are regularly fishing from Jesus Green to Riverside to Horningsea and Bait’s Bite. Where they breed is a mystery but in August young birds can be seen harassing the adults for food.

The Common Terns below Elizabeth Way Bridge; one of them swallowing a fish about half the size of the bird itself!

There are at least two singing Whitethroats in bushes along the river on Logan’s Meadow. It’s probably our commonest “scrub” warbler; its pleasant short scratchy song is often the prelude to a towering song flight, a rather clumsy hover and then parachute descent into a bush. Nearby are Treecreepers nesting in one of the nest boxes put up by the Council.

 Male Yellow Wagtail                                Whitethroat

Yellow Wagtails are much less common than they used to be. They are birds of meadows and damp pasture. This bird was photographed in a wet puddle near the Histon Rd/Huntingdon Road footpath on the 11th May. They have adapted to agricultural arable crops and occasionally nest in oilseed rape in the north of our project area. A study by Bill Jordan for the Cambridgeshire Bird Club found fenland birds often nested in potato and pea crops.

Male Yellow Wagtails have (probably) the dullest song of all our passerines: “slurp, slurp, slurp” or if you are lucky: “slurp, slurp, slurp, slurp”, but their striking yellow plumage says it all!

So far no definite sight or sound of Black Redstarts in the City.

Couldn’t resist a couple of butterfly pics; a Brimstone, left, on a Primrose and a rather battered Speckled Wood that had probably emerged from hibernation; both taken near Histon Road.

Bob Jarman

17th May 2017

May sightings

The early UK spring foliage and flowers cannot be beaten – returning from a trip to the tropics, I found Cambridge spring in full flood. Elderflower is now adding to the heady scent of the May blossom and cow parsley. Lots of migrant warblers are here now, but it was a great delight to hear a Cuckoo from my back doorstep on May 2nd.

“The cuckoo comes in April,                                                                                           He sings his song in May.                                                                                               In June, he changes his tune                                                                                      And in July he flies away.”

Then on May 10th, the first screams of airborne Swifts, returning for their summer holidays. The UK must be the only place they ever touch down, as they nest and rear young here, but otherwise live their lives on the wing. I expect Bob will tell us where in Cambridge they are nesting.

Mayflies have hatched in Paradise, Newnham’s local nature reserve. The new pond there provides quiet water and lots of emergent vegetation, while excluding large predatory fish. For a few days each spring, evening swarms can be seen as the males search for a female before ending their brief adult lives.

Above the gate and near the chapel in Trinity Great Court, House Martins are busy flying in and out from their nests. By the river in Newnham, a Grey Wagtail investigated the waterside vegetation.

A massive effort was made to clear the invasive Floating Pennywort from the upper river last autumn. At one point, it had spread right across the river. Happily, there is no sign of it at the moment.

My spider of the month is Araneus diadematus.  This well known Garden Spider is generally associated with autumn, but at breakfast on May 18th, I found a newly hatched mass of spiderlings in a communal web.  Yellow and black, there must have been about one hundred of them, clustered together. When disturbed, they fell away on individual threads like golden raindrops and then gradually reassembled. Within a few hours, they had climbed up into the tree and disappeared.

On 31st May, while swimming in the river, I saw a barn owl crossing the river to the Skaters Field nature reserve in Newnham. It was early evening and the owl was moth-like and white in the sunshine. I had been told that they were about, but this was the first time I had seen one.

Olwen Williams

The Unloved 2 – Pigeons and more on Corvids!

What’s the point of Woodpigeons? What do they do? What are they for? The UK breeding population increased by 169% between 1967-2010 (Bird Atlas 2007-11, Balmer et al) probably because of agricultural intensification and boosted by the move to winter oilseed rape and winter cereals from the late 1970’s. The UK population is estimated at 5.4 million pairs and its abundance is probably because of the birds’ ability to survive on green vegetation unlike other granivores (BTO Birdtrends 2014)

More recently Woodpigeons have become dominant garden birds (RSPB Garden Birdwatches) probably as countryside habitats become “full” of resident birds. Despite this their breeding biology and ecology are poorly studied.

        Woodpigeons nesting in
Dorchester town centre

Woodpigeon left;
Collared Dove right


A maize stubble field in the north of our study area attracted a flock of 1,480 (counted from photographs) in winter 2015/16. UK birds are almost entirely resident but Woodpigeons in northern Europe do migrate and movements of autumn birds have been noted on the north Norfolk coast. Woodpigeons to birdwatchers are an irritating fact of life! Lone birds can resemble Sparrow Hawks and distant flocks can look like Golden Plovers.

Stock Doves (or Stock Pigeons) are smaller discrete versions of the clattering, bulky Woodpigeon and lack the white wing and white neck patches. They are usually seen singly or in pairs but, unusually, a flock of c100 were feeding on Oil seed Rape stubble from harvest 2016 awaiting spring barley 2017 drilling in the north of our project area.

Feral pigeons: escaped homers, urban vandals, building defacers – these general nuisance birds are thought to derive from wild Rock Doves which are now confined to rocky northern and western cliffs on the very margins of the UK.

These feral birds should now be controlled by urban Peregrines. Cambridge has its own nesting Peregrines (see below); London has 26-30 breeding pairs – the second highest urban Peregrine population in the world behind New York.

Hopefully Peregrines will breed again in the City this year; the female is more strongly barred and bigger than the male by about an additional 1/3rd; they have been seen mating.

Male Peregrine (above)

Female Peregrine (right)

Corvids – the crows – are also unloved (see March blog). The local newspaper in Royston, Hertfordshire is the “Royston Crow” but the crow on the paper’s logo is not the corvid we are familiar with – it’s a Hooded Crow. Hooded Crows used to be considered conspecific with the Carrion Crow but have been granted species status. They used to be frequent winter visitors in flocks of 30+ in Cambridgeshire but are now exceptionally rare – 1 or 2 per year in Norfolk and occasional single strays into the north of Cambs.

Hooded Crows replace Carrion Crows in Ireland and central to northern Scotland and are the common crow in much of Fennoscandinavia and central Europe. Milder winters have probably resulted in these birds remaining resident with little need to move south or west, to the UK, to avoid freezing conditions.

A scruffy Hooded Crow!

The Rook survey in our NatHistCam project area is now 108 (apparently) active nests. Rather like House Sparrows the biggest numbers are in the Cherry Hinton area.

Another corvid is the Jay. This woodland species is a resident and predator of nests and nestlings and eater of slugs and snails. In Chesterton, breeding birds are summer visitors and the first arrived back on March 17th.

May 2017 Bob Jarman




Hoverflies appear

Now that things are warming up and at last we have a few sunny days, the first of this season’s Hoverflies are appearing all over Cambridge. As more plants come into flower their numbers will rapidly increase, assisted by migrating insects from the continent as summer progresses.


Over 270 species of hoverflies have been recorded in the UK and many of them are spectacular bee and wasp mimics, although all of them are totally harmless. Their larvae are well known as the gardener’s friend for eating aphids, but in truth only around 40% of  species do this.  Some feed on plants, some on decaying matter, while others live in the nests of ants, wasps and bees, either scavenging or feeding on the host’s own larvae.

Hoverflies will be with us right through to the autumn, when large numbers can be found feeding on the late blooming ivy flowers.


Paul Rule

Mob arrival of Warblers!

In mid April there was a mob arrival of our common woodland warblers. At present Blackcaps are singing across our project area in shrubby gardens and hedge rows. Our recent CNHS visit to Coldham’s Common found Blackcaps singing their rich 6 second warble in the bushes every 100 metres and Chiffchaffs singing their repetitive “chiff chaff” song also every 100 metres between the Blackcaps. Occasionally there is a Willow Warbler with its “beautiful descending sequence” (Martin Walters, Cambridge Independent April 2017); most are probably passage birds moving north. They can turn up anywhere and two were recently seen and heard in the street trees in Ditton Fields.

Chiffs and Willow Warblers are both small, very similar unobtrusive greenish warblers; Chiffs are usually duller with darker legs with a nervous habit of flicking their tail downwards. Just occasionally there is a “wiffwaff” ! These are Willow Warblers but with “chiff chaff” inserted into their song. There is one on Coldham’s Common at present (follow the path from Newmarket Road past the football stadium to where the bushes cross the path and on the left – in the bushes behind the allotments). This Willow Warbler has the “chiff chaff” notes at the end of its song; a bird at Little Paxton Local Nature Reserve near St Neots has clear “chiff chaff” notes at the beginning of its song. Both birds show the plumage characters of typical Willow Warblers.

Tony Fulford, Behavioural Ecology Group,University of Cambridge is studying these Willow Warblers with aberrant songs to see if it helps teach us why birds sing. If you come across one such bird please contact with location details.

Willow Warbler                                             Chiffchaff  

In the same area on Coldham’s Common is a much less common marshland warbler – a Cetti’s Warbler. These birds are resident; they first bred at Radipole Lake near Weymouth in the late 1960’s but have now spread north to Lancashire and can survive our warmer winters. They look like Reed Warblers and nest in similar habitats. Reed Warblers are parasitised by Cuckoos but Cetti’s Warblers lay red eggs which Cuckoos cannot yet mimic – they have beaten the Cuckoo trap (see the excellent book Cuckoo Cheating by Nature by Nick Davies, Professor of Behavioural Ecology, University of Cambridge). Cetti’s Warblers are birds of dense reedy cover and are difficult to see but they have an unmistakable explosive song – a loud “chet chet cherweoweeoo”!

Although they are mainly resident – Cetti’s Warblers have distinctive stumpy short wings not designed for long distance migration unlike Reed Warblers – but a Cetti’s Warbler ringed at the Great Fen near Peterborough was re-caught at Leighton Moss in Lancashire.

Look out for Swifts – they are here!

Bob Jarman 6th May 2017

April sightings

April sightings

Spring seems to be advancing in fits and starts. We have had a series of night frosts and cold winds, with one magnificent hail storm. However, at the same time, sunny days mean that the spring is well advanced and most of the May blossom is out before May has even arrived. Cow parsley blooms at the same time, the two together providing a double layer of white and a sensational scent.

Cow parsley

My local Song Thrush is putting in overtime!  I hear him throughout the day – maybe a minute’s pause as he moves from one tree to another, to establish territory – but a continuous flow of small repeated phrases in a fluty whistle. He is still going at dusk! Last year was very good for slugs and snails, so hopefully he will be mopping up a few of these.

A family of Hedgehogs has been spotted in Arbury Rd and in Chesterton, there are reports of Toads in the garden.  All good news.

Olwen Williams




The Hirundines – Swallows and Martins

The Hirundines – Swallows, House Martins and Sand Martins – are some of our earliest summer migrants to return from sub-Saharan Africa to breed in the UK. Sand Martins are often amongst the very first with birds appearing from mid-February onwards, followed by Swallows from the end of March, then House Martins from the beginning of April. Unusually House Martins were recorded on the Suffolk coast in the first week of March this year.

These birds are the background to our summers and a reminder that, despite the weather, our annual seasonal cycles are constant and reassuring. But these birds are disappearing from England! House Martins have declined in England by 14% between 1995-2010 (BTO Atlas 2011) and are now a species of conservation concern. Regional variations are striking with a 26% decline in south eastern England. Sand Martins used to nest along Riverside in Cambridge but have long since disappeared. All three species are moving north east into Wales, Scotland and Ireland. Ireland experienced a 23% increase in House Martins between 1998-2010.

Why is this? Most believe these changes are driven by temperature, humidity and therefore food availability. All three species are insect eaters, catching prey on the wing, and our drier summers combined with agricultural insecticides may have reduced food availability. The disappearance of pasture and grasslands from eastern England that support insect communities, maybe another factor. The absence of available wet mud for nest building near favoured communal nesting sites may also affect House Martin distribution.

House Martins collecting wet mud for nest building

House Martins also present another dilemma. They nest under the eaves of houses and other buildings and make a mess! In the 1960s there was a large House Martin colony under the eaves of the old Milton Road infants and junior schools at the junction of Milton and Gilbert Roads (now that’s going back!). The nests were destroyed and the birds never returned.

As delightful as these birds maybe there comes a time when property owners have to paint/repair, and may even remove nests to facilitate building maintenance. This is the issue at the Addenbrooke’s site, Cambridge, on the University buildings opposite Out-Patients. This has one of the largest House Martin nesting colonies in Cambridgeshire with over 100 nests. There are alternative to nest removal. Some nests can be retained, intact, to keep the core of the colony and encourage returning birds to rebuild breed and return again; artificial nests can be installed. Ideally, the work should have been started – and completed – in winter, well before the birds were likely to return. As a species of conservation concern House Martins have protection under the Wildlife and Countryside Act (1981). Members of the Natural History Society, alarmed by the destruction of nests at the Addenbrooke’s site have spoken to staff about their serious concerns who in their turn have undertaken to keep any nest removal to an absolute minimum.

Bob Jarman 11.3.17


More on Rooks, Peregrines, a museum of Waxwings and Blackcaps …!

In 1928 – the year of the first Cambridge Bird Club’s Annual Report – 662 Rooks nests were counted within a mile radius of Market Square, Cambridge. Numbers are much less now due to poisoning from agricultural pesticides (some deliberate), agricultural intensification and persecution. In 1975 it was estimated that 65% of Rooks nests in Cambridgeshire were in Elms and many nest sites were lost to Dutch Elm disease. Monica Frisch remembers young Rooks being sold on the game stall at Newcastle-upon-Tyne market about 25 years ago for Rook pie! Attitudes to Rooks today are more benign. It is still a common countryside bird and many local villages have a rookery in trees on the village green e.g. Cottenham, or in trees surrounding their parish church e.g. Teversham and Histon.

Rooks are now considered more a friend than foe to farmers. They probe for leather jackets, slugs, snails and worms but they do have a habit of taking cereal and field bean seedlings, as I know to my cost. When I worked at the National Institute of Agricultural Botany (NIAB), Rook Protection of our high value specialist cereal tests and trials cost me tens of thousands of pounds in Rook Protection netting, caging and labour.

In our NatHistCam project area we have counted 78 nests so far in four rookeries … we are still looking. Counts were made before and a week after storm Doris and the numbers remained the same. Please send any records of Rookeries in the NatHistCam project area to: Olwen Williams –

Museum of Waxwings opposite Vindis (left)

The museum of Waxwings (museum is the collective name for Waxwings!) may still be hanging around the guided busway but they have moved further along from the Vindis garage end towards the Cambridge Regional College.

Peregrine Cambridge City 4th March 2017

You may have noticed fewer pigeons in the Market Square recently. For the last three years Peregrines have nested in central Cambridge. Sit outside at Don Pasquales, have a cup of Mario’s excellent coffee, look out over the market square and you stand a good chance of seeing a hunting Peregrine Falcon. One has been seen chasing pigeons down Petty Cury. Peregrines used to be considered birds of open moors and rugged cliffs but we now have more pairs of Peregrines nesting in our NatHistCam project area than in the Shetland Isles (2!). If you think you know of, or find the site of, a Peregrine’s nest please keep it confidential and contact the County recorder, Louise Bacon, direct:

Male Blackcap (left)

In 1993 one of the County’s leading birders, Graham Easy, noted that Blackcaps had become increasingly common over winter; one of the first in our project area was in Manhatten Drive, Cambridge in 1993. The wintering Blackcap survey for 2017 has produced records from 23 locations in our project area, 22 within Cambridge City gardens. Two locations in built-up areas seem to have resident year-round birds that are probably nesting. Thank you all for sending me your records – they will be forwarded to the Cambridgeshire Bird Club Recorder – Louise Bacon (see above) and be duly credited. Keep them coming. I will end this “winter” count at the end of March 2017 – returning birds should be arriving in numbers by mid-April.

Male Black Redstart

The project is also keen to obtain any records of breeding Black Redstarts in the City.

Vince Lee, Chair of the Cambridgeshire Bird Club suggested this would be a valuable project. Birds were seen last year around the central city University buildings – The Old Schools and Pembroke College – and so far this year a bird has been seen on the roof of St Botolph’s Church in King’s Parade. Some years ago a juvenile bird was seen behind the Primark store in Burleigh Street and Anglia Ruskin seems a possible site too.

They have a distinctive two part song: a melodic part usually followed by a “scratchy” part – like small stones of gravel being dropped over a cheese grater! There is a good recording on Radio 4 Tweet-of-the-Day which is available on the BBC website with commentary by Bill Oddie. Black Redstarts like feeding and nesting around large buildings and an early morning cycle ride round the city centre, or wherever you live, listening for birds singing in the dawn chorus maybe a good way of locating them.

Bob Jarman 6.3.17