Jesus College Nature Trail

Biodiversity in Jesus College, Cambridge

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Storms Ciara and Dennis

Two weekends in February, and two named storms, Ciara and Dennis.  Jesus College fared very well in the storms, perhaps due to the local firm of tree surgeons and the periodic surveying and maintenance that is done on our tree stock.

Storm Ciara caused the most damage, with our ‘Ivy’ tree coming down in the strong winds by the glade in the woods.  I am not sure what tree this was originally, but it has been a trunk completely covered in Ivy for as long as I have known it.  It has been a haven for birds rushing into cover when you walk past, and the ivy flowers have also been a good source of nectar for late insects when most of the other sources have dried up in late autumn.  Hopefully the gardeners will leave it in situ for the sake of the wildlife and the ivy will root around the tree.

‘Ivy tree’ taken from the path by the glade.

The other casualty from the storm is a Balsam poplar in the corner of the Fellows’ Garden.  This tree fell on Tuesday 11th February, after the main storm but when there was still gusty weather around.  The gardeners said that they saw and heard the tree moving for half an hour before it finally fell.  That gave them enough time to warn the people nearby in Wesley House.  The tree fell with a great crack (disturbing a supervision in First Court) and it fell away from Wesley House and into the garden.  The tree fell neatly through the Yew hedge creating just a small gap in the hedge.

The gardeners quickly cut up most of the tree and shredded it for use on paths; the larger pieces of trunk they left for the tree surgeons and their large chain saw.

Storm Dennis came on the next weekend and there was no more damage – apart from one of the cricket practice nets being lifted up onto an adjoining one.  The trees will be surveyed again this week to check for uplifting.  The gardeners have also got to do a great deal of picking up of small twigs and branches around the grounds.

We have been very lucky in Cambridge.

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When daffodils begin to peer… (William Shakespeare)

Bank vole in the sunshine

The posts that get the most attention on the wildlife facebook site are those with pictures of or information on the two Foxes (Vulpes vulpes) in Jesus.  I have had several people spotting them and sending in photos for social media.  They haven’t been seen regularly, even by the porters or housekeeping staff who are around when it is dark, but they have been spotted often enough so that we know they are still around in College.   There seems to be either a new den, or a new entrance to the existing den by the cricket practice nets.  It is about 25/30 feet away from the main entrance and it seems to have been excavated over the past month. Unfortunately the dog fox was seen on January 30th limping badly.  He seemed to be running on three legs and not using his front right leg.  Luckily a student saw the fox from the library on Sunday 2nd February and he was still limping, but he was running on all four legs.  He was also seen from Housekeeping on 5th February, again using all four legs.  Hopefully he is getting better. [Thanks to everyone who has been sending me sightings and photos].

It has been a mild dry winter so far and that means that, on sunny days at least, there have been lots of birds singing and invertebrates out flying.  Thursday 6th February seemed to be the first day of Spring.  It had been warm for a few days previously and, on this day, the birds were flying in couples, the insects were flying and it made me realise how quiet and empty the winter had been.  It actually surprised me when I found myself ducking to avoid a cloud of midges flying above the nature trail.  I saw four Buff-tailed bumblebees (Bombus terrestris) queens flying about; there were several hoverflies – both Eristalis tenax and Episyrphus balteatus; even the Ladybirds seemed to emerge that day.  The large Sarcococca plant at the back of Garden Court had seven Pine ladybirds (Exochomus quadripustulatus) and eight 7-spots (Coccinella septempunctata) on the leaves.  I saw Pine ladybirds in College for the first time last year – again in early Spring, on the same plant.

I also have an Angle shades (Phlogophora meticulosa) pupa in a jar on my desk at work.  I found it as a caterpillar on 14th January in the middle of the Library Cloisters and brought it inside.  I tried a variety of plants – it is said not to be fussy when eating, but I don’t think it ever did eat anything.  I came back to work on the weekend on 20th January to find it had pupated. That is maybe why I found it in the cloisters away from any vegetation – it was looking for somewhere to pupate.  I am keeping the jar moist and hopefully it will emerge as a moth soon (although it might take up to three months). [Edit – the moth emerged on Satuday 8th February].

I found a brown shieldbug on the same Sarcococca bush (I always check it in passing as it is such a good source of invertebrates).  It turned out to be the winter colour of the Common green shieldbug (Palomena prasina) .   I hadn’t realised that they changed colour in winter, although only some of them turn completely brown.

The most interesting find this month has been a yellow coral fungus in the woods behind the Maintenance Department.  Ramaria fungus are difficult to identify properly – but it has been identified by the County plant recorder as either Ramaria curta, or something very similar.  Ramaria curta is seldom identified in the UK so even the chance of it begin this fungus is exciting.  It is also the first coral fungus that I have seen in College.

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In the Bleak Midwinter



The weather has not been particularly frosty so far, as we have only had a few mornings that have seen any frost, but we are in ‘midwinter’ so the title of this blog seemed appropriate.  We have had rain, cold, some sun, but mainly ‘dreich’ weather and, today, an awful lot of rain, so it certainly qualifies as ‘bleak’!

Looking back at the photographs I have taken over the past few weeks it is surprising how many sunny days we have had, and how I am now used to all the grey days at this time of the month.  The Foxes (Vulpes vulpes) have usually been seen in the dark, although they have occasionally been spotted during the day patrolling around College.  The dog fox is certainly more tame than the vixen, although she is also amazingly tolerant of people with cameras.

Insects have been hard to see this season but we definitely have at least one winter nest of the Buff-tailed bumblebee (Bombus terrestris).   I have also managed to get someone to identify a new opilione for the species list, a harvestman Dicranopalpus sp. (sp. as the species was split into two in 2015 and you can’t distinguish between them properly in the field).

No new birds have been seen, although Duane did see a pair of Peregrine falcons (Falco peregrinus) fly over the pond last week.  They were heading towards St. John’s College chapel tower – a well-known feeding station for the pair that live in the city centre.  I saw one of them a week later calling from the top of the University Library tower. The Goldcrests (Regulus regulus) have been more visible than usual, at times I have seen six or seven of them around the woods.  There have also been at least one large (20+ birds)  flock of Goldfinches (Carduelis carduelis) around.  They seem to stay up in the highest trees, mainly the Plane trees in College, but they can be easily heard – the RSPB describes it as a liquid twittering sound.

It has been a good year for fungi, with another new mushroom spotted near to the Maintenance building, a gigantic Stubble rosegill (Volvopluteus gloiocephalus) which has the volva visible at the base which helps with identification.  I have seen many more logs covered with Jelly ear (Auricularia auricular-judae) this year than I saw last year – they dry out in the dry weather and they almost disappear and then, as soon as there is rain, the ears appear again looking like new ones.  I have also found a lot more Candlesnuff (Xylaria hypoxylon) and Turkeytail (Trametes versicolor) fungi in late autumn than I did in early autumn –  two names that are perfect for Christmas!


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When yellow leaves, or none, or few, do hang… (Sonnet 73, William Shakespeare)

At the beginning of October and the start of the Michaelmas term time tends to speed up and there is little time left for other things.  I have still been walking round the College grounds and taking photos but I haven’t had a chance to write a blog for a while.  We are well into autumn now and it is time I got around to highlighting the changes in wildlife I have observed during this season.

Autumn is a time for fungi and it has been a particularly good season for these this year.  We have had a lot of the usual species, but one new one in College which was found by Duane Keedy is the Red cracking bolete (Xerocomellus chrysenteron) which he found in the triangle at the western end of the woods.  He performed a spore test to confirm his identification.  He also found some Scotch bonnet – aka Fairy ring Champignon mushroom (Marasmius oreades) – in a fairy ring on Library Court.  I often find fungi growing in the same place as the previous year and so they can be easy to identify, but new finds are more difficult to id.


In the summer the birds and squirrels seemed to be in hiding (birds tend to moult in late summer and so hide from predators then), but they are beginning to become more obvious now that we are into autumn.  I think that we are also beginning to see some birds which have come over from the continent too; there seem to be many more young Blackbirds (Turdus merula) around now and I am also beginning to see pairs of Goldcrests (Regulus regulus) in the Yew trees around College.  Paul Stearn saw a Ring-necked parakeet (Psittacula krameri) flying past him when he was in the Orchard and it seemed to come out of the large copper beech there.  It flew northwards past North Court at about 11am on 5th November.  Bob Jarman says that there have been occasional records of parakeets in this county but not many (if any) in the city centre itself.  The corvids (usually a small group of crows but occasionally a group of jackdaws), have started digging up the lawns again, even the bits of the North Court lawn where the gardeners have replaced parts of the lawn with a dwarf Rye grass.  On  the North Court lawn you might also be able to see the remains of a 2.5m2 bare patch where a BSAF scientist recorded 500 chafer larvae in this small area.  They were a mixture of  Garden chafers (Phyllopertha horticola), Welsh chafers (Hoplia philanthus) and some Cockchafer (Melolontha melolotha) grubs.  No wonder the birds are digging up the lawns!

The three Moorhen (Gallinula chloropus) chicks from the pond are still around and they can usually be seen in the vicinity of the pond, even though the gardeners have cut down the old vegetation.  The juveniles are very similar to the adults now, although they don’t quite have that blueish black sheen on the breast that the adults have.

The most exciting find this autumn has been a new shieldbug for the site, the Southern green shieldbug (Nezara viridula).  Several nymphs (at least 10) were found on the Morning glory plants in First Court on 22nd August.  The instars are a mix of black, white, red and yellow colours, although the adults are all green.  This bug is rare for this part of the country (although someone else has spotted it in Mill Road cemetery) but the NBN atlas shows how rare it is outside London.


I saw the Willow emerald damselfly (Chalcolestes viridis) a few times near the ditch; we had a female that was often on the same twig over a week.  I have seen 10-spot ladybirds in the College before, but I have now seen a new colour variation of chestnut and cream.  I saw this 10 spot f bimaculata (Adalia decempunctata) on the Foxglove tree (Paulownia tomentosa) in the Fellows’ Garden on 15th October.

We have also found a couple of new moths for the College – the Garden pebble (Evergestis forficalis), and the Carnation tortrix (Cacoecimorpha pronuba).  Stewart Rosell examined a November moth agg. (there are 4 Epirrita species that are very difficult to tell apart unless you undertake male gen. det.)  for a study in Cambs this autumn and identified the November moth itself (Epirrita dilutata).  There have been several sightings of a Hummingbird hawkmoth (Macroglossum stellatarum) around College this autumn.  I have usually seen one on the brilliant blue Ceratostigma plants in Chapel and Library Courts, but I have also seen it on the red sage plants too.  Two types of caterpillars have also been found: seven large hairy caterpillars were in First Court in the Ageratum border; the caterpillars were a mixture ranging from black to chestnut colours and they were probably Ruby tiger moths (Phragmatobia fuliginosa) searching for somewhere to pupate for the winter.  I also found a tiny Double-striped pug caterpillar (Gymnoscelis rufifasciata) in the Japanese anemones outside the Roost café.  Both moths are ones that I have seen as adults in College, but it is good to see the caterpillars too.

A juvenile Water vole (Arvicola amphibius) was seen on 17th September in Jesus Ditch,  it was about half the size of an adult so it is good to know that voles are still breeding in the Ditch.   I saw a Tawny owl (Strix aluco) on 18th September when I came into work very early to try and photograph the foxes – there were no foxes that morning but I investigated the blackbirds and wrens making a lot of noise and was lucky enough to see the owl.  The Foxes (Vulpes vulpes) have been seen, though perhaps not as often in the wet weather as they were in the warm summer.  There also seems to have been some digging under a tree about 30 feet away from their cricket practice nets den. There have been some paw prints on the loose soil – maybe it is a new den.

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Jesus College Fox, by Jamie Andersen

Fox in the Cricket practice nets

Mint moth in the East House garden. One lunchtime I counted 32 of these moths in the garden.

Common blue butterfly in Chapel Court seen during the very hot weather. This is only the 2nd I have seen in College.

Canary-shouldered thorn moth

Mouse moth, new for site.

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In June as many as a dozen species may burst their buds on a single day. No man can heed all of these anniversaries; no man can ignore all of them. (Aldo Leopold)

Marmalade hoverfly in the St Radegund Garden

The June weather has been mixed, with all sorts of different weathers, from boiling hot days to torrential rain showers and a lot of cloudy days.  The warm, dry days have resulted in a flourishing of wildlife with new flowers, new species, fledgling birds seemingly emerging all at once.

It seems to be another influx year for Painted lady (Vanessa cardui) butterflies, with several being seen around College nectaring on the lime tree flowers and several of the flower heads in the borders.  The Meadow browns (Maniolo jurtina) and Ringlet (Aphantopus hyperantus) butterflies have also emerged this month; they can usually be seen in the wild area with long grass to the west of North Court although I have found a few Meadow browns on the flower beds too.

Other new invertebrates in College have been a Mottled rustic (Caradrina morpheus) moth and a beetle with a wonderful name, the Fairy-ring longhorn beetle (Pseudovadonia livida), the Artichoke beetle (Sphaeroderma testaceum), and I found several Variegated carpet beetles (Anthrenus verbasci) on the yarrow near the cricket practice nets.  I have also had fun raising a caterpillar this month.  I found a tiny Vapourer (Orgyia antiqua) moth caterpillar about 1cm long on a fallen rose petal near North Court.  I brought it back to the office and put it in a jar; it originally fed on rose petals, but it also ate hawthorn.  It has just spun a cocoon this weekend (I was hoping to see this happen, but I did take a photo on Friday before I left work for the weekend).  The Head Gardener has agreed to look after them when I am on holiday.  I say ‘’them’’, as a student also gave me one in a cocoon before he left for the summer.  Vapourers are sexually dimorphic, as the females are wingless, whereas the males have wings and are attracted by the pheromones that the females emit.  The females stay on their cocoons when they hatch, emit pheromones and then lay eggs nearby after mating.  Adult moths emerge from their cocoons after 8-15 days, so I will probably miss the emergence of my moth, as I shall be on holiday.   There has also been a patch of nettles with well over 20 Peacock (Aglais io) butterfly caterpillars in the scrub behind the cricket practice nets.

I have seen a few leaf-cutter bees this month, a first for the College.  I managed to get a few photos of one on the geranium plants outside P staircase and it has been identified as a Willughby’s leafcutter bee (Megachile willughbiella).  A nice Cambridge connection, as this bee was named after Francis Willughby (1635-1672), a Trinity student and a friend of the naturalist John Ray, and who is often called the first ornithologist.  Francis Willughby also studied leaf cutter bees and one was later named after him.

There have been many more birds fledging this month.  All 7 blue tits from the College nestbox fledged on 1st June, and there seem to be an especially large number of fledgling Blackbirds and Wrens around this year.  I have on occasion walked round the nature trail and had 5 or 6 tiny wrens burst from the undergrowth by the path and fly off in all directions.  Duane Keedy saw a Little egret (Egretta garzetta) flying over College on 4th June.

The foxes have been seen around College on most days.  One has taken to sleeping throughout the day in the flower border near the library.  He usually gets up and leaves about 3-3.30pm every day and saunters off to the woods.   Our two foxes are still around the grounds and even the May Ball did not drive them away.  Apparently they were seen going around the stalls on Chapel Court the following morning looking for food as the stalls were being packed away.


“As I roved out on a bright May morning”

Fox amongst the wildflowers

I have been enjoying my early walks round the nature trail this month.  I definitely see and hear a lot more if I walk around before work than if I walk around in the middle of the day.  The dawn chorus may be over but the birds are still a lot more active and vocal earlier on in the day.  I am also more likely to see the Foxes (Vulpes vulpes) as I walk around the College grounds.  I have had excellent views of the foxes patrolling along the trail, and also finding their breakfast, or should that be supper?  I have twice seen the young fox playing with a young rat on the football pitch.  I checked with someone from the the Cambridge Mammal Group and he confirmed it was a young rat and not a vole.

Foxes are termed crepuscular – mainly seen outside their dens in the early morning and late evening – although our foxes have been seen at all hours of the day or night.  I am often asked what is the best time and place to see them.  All I can say is that I have rarely seen them in the same place or time.  If you want to see them, then I would suggest either walking through the woods in the morning, perhaps before 8am, or taking a glance out on the sports fields on a warm day if there is sunlight and warmth early on.  The Head Gardener has seen them a couple of times there as he drove in to College in the morning – ‘sitting up and looking like sphinxes’, he said. I have also seen the larger, paler fox twice in the Master’s Garden in the late afternoon.  This garden is private, but it might be worth looking out over the garden from the library windows occasionally.  The fox has been hidden in the long grass and so she can be quite difficult to see, but you might get views of her.   I happened to meet Lukas Lang one morning in the woods and we saw the younger, darker fox travelling in both directions along the trail.  We took photos and Lukas kindly sent me in a set of photos for use in social media.  They are all on facebook and I have put a sample on here.

The Blue tits (Cyanistes caeruleus) in the nest box are growing fast and both parents are bringing in food.  I can’t tell the difference between the male and the female bird, but there have been occasions when we have seen both parents in the box at the same time via the Nestbox camera.  The chicks are slightly different sizes, but hopefully all seven will fledge very soon.

There seem to be lots of young birds around the woods at the moment.  Young Blackbirds (Turdus merula) (one sounding confusingly like a Cetti’s warbler to two people who were surprised when they saw which bird was actually calling); young Wrens, (Troglodytes troglodytes) Robins (Erithacus rubecula) and several Great tits (Parus major) in different parts of the College.  I was lucky enough to see one fledging –  I was walking near the large horse chestnut closest to the Victoria Ave gates and I heard a Great tit frantically calling. I looked up and there was a bird peeping out of the nestbox on the trunk nearby.  I took a quick photo and the bird immediately popped out of the box and flew to a nearby branch and I suddenly realised that it was a youngster that I saw fledging.  I left in a hurry so that I didn’t disturb the birds any more than I already had done.  We have had a family of Treecreepers (Certhia familiaris) fledging too.  They were in the old Hawthorn tree between First Court and the Orchard in a gap in the tree trunk.  I don’t have any photos of the birds, (the parent flew too fast into the trunk) but Rob got a video and I saw the parent taking in food too.  It also looks as if we might have a Starling (Sturnus vulgaris) nest in College – in the bole of a large Plane tree near Lower Park Street.  I have seen a bird going in and out of a hole several times.

We still have the Sparrowhawks (Accipiter nisus) around, they were both seen at Easter time, and we are still finding the evidence around College – lots of dead Woodpigeons and even one Swift.  The swift was found without a head in the Orchard which makes me think that it was taken by a raptor, so it was probably either a Sparrowhawk or a Tawny owl.   There have also been lots of sightings of Blackcaps (Sylvia atricapilla) this month.  I am not sure how far their territory extends, but I have seen males singing in six different places in College and I have also seen four females around.

We have also had a visitor to College – Duncan Mackay was walking alongside Jesus Ditch on the Jesus Green side and he saw a Cockatiel (Nymphicus hollandicus) in our woods.  He took a quick record shot with his phone and you can just see the grey, gold and orange coloured feathers in the middle of the photo.   An interesting addition to the College species list!