Notes from Olwen’s recent presentation on Newnham Habitats and Wildlife

Summary notes from ‘Newnham Habitats and Wildlife’: a talk given by Olwen Williams on 16 March 2026

Newnham lies on the edge of Cambridge, surrounded by playing fields, agricultural fields and water meadows to the south. It also lies on the junction of green sand and chalk, with Jurassic clays surfacing at Boltons‘s Pit, where excavations for brick building have left a substantial lake.  Remnants of ancient hedges can be seen along current field boundaries and tracks, for example each side of the Driftway and the track to the bathing place.  The oldest woodland is on Paradise Island.  Three nature reserves — Paradise, Skaters’ Meadow and Sheep’s Green — contain some of the original biodiversity.

There has been a huge loss of invertebrates over the last 80 years. Most mammals are now nocturnal. There is a rich bird population. 

The river corridor joins the city centre to Grantchester Meadows and supports fish, bats, birds, water voles and otters.  Newnham is at its narrowest point and sadly Queens’ College’s new development at Owlstone Croft has narrowed it still further.  

Sheep’s Green has many veteran willows and the flooded water meadows contain lots of unusual plants, including butterbur, first recorded in Paradise in the 1660s.  

Paradise has nearly 200 species of invertebrate recorded, but many more wait to be found. The river contains 14 species of fish, ranging from minnows to pike and including sea trout and eels.  

Grass snakes flourish and can be seen swimming in the river. Paradise has eight species of bat, including the rare barbastelle. These are threatened by the loss of trees along the boundary and by light pollution from Queens’ development.  

Badgers flourish, which means, sadly, that we no longer see hedgehogs. Hares romp on the fields above Grantchester Meadows. Stoat and weasel are occasionally seen, as are water voles and otters. 

Jackdaws and rooks flock in large numbers in the winter, before the herons and egrets take over the woods. There is a growing swift colony in Newnham, based in Owlstone Road. In winter, there is a murmuration of starlings over the lake at Bolton’s Pit.  We have lost the feral white geese, but gained the very elegant white egret. Other newcomers include Cettis Warbler and recently Firecrests. Sadly, we have lost many of the chaffinches and green finches.  

To maintain biodiversity, we need to preserve habitats – woodland, ancient hedges, nature reserves, and especially garden biodiversity. We need to fight encroachment by new developments.  CPPF have taken over the management of Grantchester Meadows and plan to do a survey of visitor opinion, increasing tree cover, increasing marshy areas and controlling cattle grazing. 

Private gardens are crucial. We can all help by avoiding chemicals, growing plants for pollinators, increasing trees and ponds and bird boxes. Recent advice is not to feed birds in the summer and to clean feeding stations very regularly. 

We have many strengths – including the South Newnham Neighbourhood Plan, Green Party councillors and the iconic status of Grantchester Meadows.  Threats come from planning authorities who are weak in resisting developers such as the University and its colleges. Pollution from pesticides and herbicides and also light pollution offer further threats. 

Activism works, untidy verges, and gutters are okay, no chemicals!

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Olwen’s slide presentation.