All posts by Monica Frisch

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 Orni-thology, 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 it is a rare east coast migrant 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”: Addenbrookes 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 Addenbrookes 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

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 Granchester 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 Granchester 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 

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.