Peterhouse Leads the Way in Biodiversity

Dr Gerlach and members of the Peterhouse Biodiversity Group examining an insect net

Since 2017, Dr Justin Gerlach has been recording the biodiversity of Peterhouse gardens, with termly surveys of the gardens in College. The Peterhouse wildlife website currently records 781 species, although there are many more that have been recently recorded and will soon be added.

In April this year, Dr Gerlach set up the Colleges’ Biodiversity Working Group. This is an intercollegiate initiative aiming to assess the biodiversity of all the Colleges, in order to help them in managing and enhancing the environment of their properties. The Colleges vary greatly in their nature and extent of their land holdings, and also in their capacity and expertise in studying biodiversity.

It is quite striking that in the 815 year history of the university there has never been a comprehensive study of the animal and plant life of the University or of any of the Colleges. Only three Colleges have carried out much work in this area, and of those Peterhouse has the most extensive information. Accordingly Peterhouse is going to be used as a test case to demonstrate that comprehensive biodiversity assessment is practical and what it entails. To this end a ‘Peterhouse Biodiversity Group’ of College members who are interested in carrying out surveys - as pictured above. This has already pushed our recorded species number up to 823. The strangest find of the year so far has been the ‘pale giant oak aphid’ (pictured below) which is a small creature that feeds on the sap from tree trunks. In order to do so it has mouthparts that are up to three-times longer than it’s body. It is such an impractical creature that it has to be defended by ants (which it rewards with surplus sugar from the sap). A close up view of several of the pale giant oak aphid found in the College grounds

Peterhouse is also going to be a monitoring site for the ‘BIOSCAN Project’, sampling flying insects for 24 hours each month for the next 5 years. This national programme is monitoring the diversity of insects through sample collection and DNA barcoding. This will provide useful information on changes in insect life over the next few years and will help with our ability to record and identify many of the very difficult small flying insects.

In addition to studying the wildlife of College properties we are also improving conditions where we can. The ditch between Scholars’ Garden and Coe Fen has been dredged for the first time in 40 years. Over many years the Coe Fen cows had trampled down the banks and turned it into a shallow stagnant puddle, only appreciated by mosquitoes. Now that it is once again a permanent water body it will hopefully provide a better habitat for a more diverse range of species. Almost straight away we had a sighting of a kingfisher, though there are no fish so we do not see it becoming resident. A grass snake was also spotted recently. Grass snakes used to be seen more commonly but sightings have become rarer in the last decade; this one (pictured below) stayed on the croquet lawn for an entire day and startled a good number of people who passed by.

Grass snake in the grass