Category Archives: Project Blog

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

The Birding Account: Winners and Losers

An excellent article by Paul Brackley in the Cambridge Independent (Jan 3-9th 2018) talks about how ineffective governance is a threat to biodiversity. He also mentions how targeted recovery programmes by conservation charities e.g. the RSPB and the Wildlife Trusts have helped rare birds re-establish thriving breeding populations. It got me thinking: what is Cambridge City’s balance sheet – winners and losers of breeding birds over the last decades? It is one of the questions our NatHistCam project will explore but for birds the stories are reasonably well known.

The bird story is good: probably more winners than losers. Let’s start with the losers. The main losers are specialised woodland species which fit into a national pattern, not just Cambridge. Hawfinches which once bred in the Botanic Gardens and along the Backs are long gone; Lesser-spotted Woodpeckers (LsW) once our commonest woodpecker and in the 1980s often seen in Romsey Town gardens and orchards near Histon Road are gone. So have Spotted Flycatchers which bred in Whitehouse Lane off Huntingdon Road and went when the Elms died from Dutch Elm disease. The LsW is  sparrow sized and may have died out from predation by Grey Squirrels or from the larger Great-spotted Woodpeckers. The Lesser Redpoll, a finch of cool northern pine forests, has gone; the last confirmed breeding in the City was in 2002. Nationally this small finch has withdrawn north and west probably as warmer summers have disrupted its insect food supply to chicks in the south of its range.

Our Rook survey has shown that numbers have dropped in the City by 90% since the 1960’s; rookeries along the Backs and in college gardens in west Cambridge have gone. Rooks are birds of open farmland and pasture and their decline mirrors the decline in numbers of many bird species in the farmed countryside. A major shift in farming from spring crops to winter crops from the late 1970’s ended the availability of over-winter weedy stubbles as a source of food. Our local Rookeries are now on the northern and eastern edges of our project area adjacent to neighbouring farmland.

Now for the plus side! Other corvids are doing well, probably due to less persecution. Most morning I’m woken by the belly-aching croaks of Carrion Crows. For several years a pair nested immediately above the Mill Rd/East Rd junction – probably the most polluted part of the City! After food fairs on Parkers Piece up to 60 can be seen clearing the dropped food and takeaways (likewise early mornings); Magpies and Jays are now frequent garden visitors.

The Little-ringed Plover is an enigmatic species that colonises temporary wet sites around gravel and sand workings. It used to breed regularly in Cherry Hinton but the site became the David Lloyds Health Centre and a Holiday Inn Hotel; I recently heard birds over the Eddington development and it has cautiously re-established in Trumpington.

Grey Wagtails have become common across the City, not just near waterside habitats; I’m sure a pair raised young on the rooftop of M&S in the Market Square in 2017. Woodpigeons now breed commonly across the city (perhaps the countryside is too full of them!); they are one of the few species that can rely solely on vegetation to feed their squabs (or is it squibs!) and do not need high protein insect food to raise their young.

Little Egrets can now be seen across the city where ever there is open water or a stream. Another wetland species, the Cetti’s Warbler, can now be heard in the ditches in Barnwell in the shadows of Cambridge United’s football ground. The number of overwintering Blackcaps continues to increase. Lapwings attempted to breed on the northern edge of our project area, the first time for at least 50 years in 2017 and may do so again in 2018.

Common Terns can be seen feeding from Jesus Lock and Riverside to Horningsea from April to July; but where do they breed?

Lapwing at a potential breeding site at the north of our
project area

The real success has been in birds of prey as Duncan’s photographs of Buzzards over East Road show. Peregrines were thought of as rare birds of rugged cliffs and haunted moorlands; there are now more Peregrines breeding in our project area than on the Shetland Isles (2 v 1!). Buzzards have arrived in the last 15-20 years; they probably do not breed in our project area but certainly do on the very northern edge. Red Kites have successfully bred in our project area and may also account for the “eagle” seen in a Cherry Hinton garden! Sparrowhawks are now as frequent as they have ever been (they were extinct as a breeding species in Cambridgeshire from 1960 to 1985) and breed in the very centre of the City in college gardens. As an example of just what can happen if habitat is right: the area in the City boundary between Huntingdon Road and Histon Road that is now being developed as Darwin Green was left vacant for about nine years. In that period a big population of Field Voles established and over winter 2015/2016 up to four Short-eared Owls and over winter 2016/17 a female Hen Harrier hunted over this area. In the past Merlin has been seen here. The problem is that alongside the presence of these wonderful birds of prey comes illegal persecution.

What of the future? Grey Partridges are holding on in the farmed margins of our project area: two breeding pairs in the north but the population faces extinction in the south due to development near Nine-Wells. Stonechats may become breeders in the new country parks around Trumpington. Firecrests, might, just might turn up and breed; they like Holly bushes in winter and Douglas Firs to nest!

What have I missed?

Bob Jarman

bobjarman99@btinternet.com

 

 

 

 

 

Bob Jarman

December 2017

Kissing under the Mistletoe and all that!

The Mistletoe survey at the beginning of 2017 resulted in 122 records of Mistletoe in the NatHistCam area. The most common host trees are Poplars, Lime, Hawthorn and Apple. Mistletoes does not seem to like oaks; or perhaps oaks do not like mistletoe. These are visible locations and probably underestimates the actual distribution of mistletoe across the City; there are probably many more, out of sight, on garden hawthorns and apple trees. This is the next phase of the survey – to uncover the distribution in gardens although very little mistletoe has been found in the 21 gardens surveyed so far.

Please let us know if you have apple trees in your garden (and what varieties) and whether any of them have mistletoe growing on them.

The tree-top distribution of mistletoe is probably by thrushes, particularly Mistle Thrushes. In Chesterton I have seen a Mistle Thrush “hunkered-down” in a clump chasing off any visiting thrushes. The distribution in gardens maybe due to wintering Blackcaps. I have seen two male Blackcaps chasing off thrushes visiting a clump on a garden hawthorn then squabbling with each other over grazing rights! The birds wipe the sticky berries from their bills onto tree branches. Mistletoe seeds do not need any pre-germination treatment by passing through the bird’s digestive tract.

Mistletoe is a hemi-parasite – its roots infiltrate the host’s conductive tissue for water and nutrients absorbed through the host’s roots but the mistletoe’s green foliage actively photosynthesises. It is dioecious (“two-houses”) with separate female berry-bearing clumps and male pollinating clumps that produce no berries. Clarke Brunt has infected apple trees in the orchard at Milton Country park (on the northern edge of our project area) and says that aerial shoots of mistletoe appear after 3-4 months but its takes 2-3 years before significant growth is visible and the male plants produce pollen before the females bear berries.

Why kiss under the mistletoe? The two berries at the base of the leaf fork are supposed to represent male and female fertility. After each kiss, a berry is removed from the stalks; when the last berry is removed, the match for life of the kissing couple has been made. Mistletoe is the marriage matchmaker!

Mistletoe growing near Bethlehem, West Bank, Dec 2011 [below]
Mistletoe is associated with many superstitions especially in Nordic legends. In Christian legend, mistletoe was originally the crown of thorns forced onto the head of Jesus as he carried the cross through Jerusalem to Calvary. The Lord was so angry with the thorny rose bush that he transformed it into mistletoe – a flabby, parasitic, thorn-less shrub that grows at the tops of trees. The original crown of thorns (a Rubus bush) is supposed to grow only at St Catherine’s monastery in the Sinai but contemporary history says that it is a cutting from the original bush that grows in the Greek Orthodox archbishop’s garden in Jerusalem.

Berry bearing female clump, Chesterton, Dec 2017 [left]

Male mistletoe clump without berries Chesterton Dec 2016 [below]

Mistletoe is grown commercially in the fruit orchards of Kent and Worcestershire. Perhaps profits have reduced as  mistletoe establishes itself as wild plants but female berry-bearing clumps growing within easy reach in Chesterton seems to remain untouched.

Happy Christmas – under the mistletoe!
Bob Jarman
December 2017

 

More on Little Brown Jobs (LBJs) and Happy Christmas!

More on Little Brown Jobs (LBJs) and Happy Christmas!

Another Little Brown Job (LBJ) is the Redpoll (see December 2017 blog). It has a troubled taxonomic history. The species that breeds in England, Wales and (parts of) Scotland is designated the Lesser Redpoll. It has been separated from the Common Redpoll but in Ireland both “species” are considered the same – Common Redpoll.

Lesser Redpoll used to be a regular breeder in our project area; in spring displaying males could be heard in song flight over Romsey Town, Cherry Hinton and Petersfield. In 1989 a male was singing from the telegraph wires above Ridgeon’s wood yard in Cavendish Road. Within ten years it had disappeared as a breeding species in, not just Cambridge City but Cambridgeshire – the last confirmed breeding was in Coleridge in 2002, although a displaying bird was heard over Carlton Way/Gilbert Road in spring 2016.  A warming climate seems to be the reason this arboreal finch has receded north and west with a strong increase in Ireland. It is now a winter visitor to our project area and should be looked for feeding on Alder catkins – Newnham park play area and Milton Country Park near the apple orchard are good sites. It is a small Linnet-like Little Brown Job (LBJ) – the males have a red forehead (“poll)” and a black bib. It has a very distinctive flight call. Flocks may contain Common Redpolls which are paler with distinct whiter wing bars.

Siskins often accompany Redpoll flocks in winter and also feed on Alder catkins and visit garden feeders. They have distinctive yellow rumps and wing-bars. They breed in conifer woods, are common in the Thetford/Brandon Brecklands, but displaying males often linger in spring and singing birds have been seen in Cherry Hinton Hall park in late April.

Siskins in Chesterton
December
11-14th 2017

Another record of a single Stonechat from our project area – Trumpington, Country Park from Guy Belcher.

A walk along the Riverside will produce (Grey) Herons, Cormorants on the willows near Logan’s Meadow, possible Water Rail in Logan’s Meadow nature reserve, wintering Chiffchaff and Kingfisher (given away by its distinctive flight call – a loud “jeet”), winter plumage Black-headed Gulls and Green Woodpeckers often “grubbing” for ants.

Blackcap records for this winter period have come from Benson Street, Alpha Road and Longworth Avenue.

Male Sparrow Hawk sitting on a balcony rail, Riverside [left] and (Grey) Heron [right], Riverside (thanks to Nigel Fuller)