Autumn 2020

Autumn is nearly here! Pam says that the Tawny Owls are calling in the night. I know this because the Swallows and House Martins have gone and the Jackdaws and Rooks are beginning to flock together in the tall trees of Paradise Island, morning and evening.

The newly planted Black Poplar near the Owlstone Rd gate is thriving. Earlier in the year, Victoria was worried it was dying of drought and asked us to water it. Now there has been enough rain to rescue it. The lake has not dried out this summer, unlike the last couple of years. Jeff drew my attention to the Southern Migrant Hawkers holding territory over the water : these medium/small dragonflies were first recorded in UK in 2006 and are steadily moving north. Paul took this picture in Paradise – really difficult, as they never seem to settle.

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I came across an interesting article in Nature in Cambridgeshire about the Bats on Coe Fen and Sheep’s Green. Entitled, “Impact of Bat-Friendly Lighting on Bat Activity and Bat Species Diversity at Coe Fen and Sheep’s Green, Cambridge”, it investigated the impact of the low-level lighting studs provided for cyclists in 2017. Studs were provided with “Bat Hats” – a central opaque disc designed to minimise light spill upwards.

Surveys were done before (2017) and after (2020) the studs were put in place, to see whether there had been any adverse effect. Results interestingly showed that before the studs were inserted, there were 4 bat species, while afterwards 8 species were recorded. There was also a non-significant increase in overall bat activity.

The 8 species identified by the second survey were Common Pipistrelle, Soprano Pipistrelle, Nathuseus’ Pipistrelle, Brown Long-Eared Bat, Serotine, Noctule, Barbastelle and Daubenton’s Bat.  This diversity makes Newnham a veritable Bat Hot Spot!  Daubenton’s bat flies low over the Cam and for this reason, lights were not placed over the bridge. Common Pipistrelle, Soprano Pipistrelle and Noctule were all relatively common, with Common Pipistrelle increasing at the expense of Soprano after the lighting.  The other species are rarer; Nathuseus’ Pipistrelle and Barbastelle had not been previously recorded here. This Brown Long-Eared Bat turned up in Owlstone Rd in 2018.

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This survey confirmed that there had been no adverse affect and that the objective of preserving bat-friendly territory had been achieved.  However, we need to stay alert to the danger of light pollution around Paradise and the adjoining green spaces.

Chesham, J. (2020) Impact of Bat-Friendly Lighting on Bat Activity and Bat Species Diversity at Coe Fen and Sheep’s Green, Cambridge. Nature in Cambridgeshire, 62:56-61.

Someone asked me whether the “Mile-a-Minute” Russian Vine on the edge of the wood, near Queens’ Hostel should be cut back. What do you think? It’s an invasive alien. Is it taking over too much?

PS  It is soon going to be fungus season again and there is already a new Chicken of the Woods. Overheard was an argument between a foraging couple and another passer-by. He calmly maintained that the fungus should be left for others to admire and she angrily defended her right to harvest wild food. Not sure where I stand on this! But they are stunningly beautiful.

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Olwen Williams September 2020