Thursday, 31 October 2013

October Summary

River Mole grasslands

The hysteria breaking out over the False Widow Spider was like watching the inevitable conveyor-belt-of-death scene in a Bond movie. Not everyone can be expected to know about individual spider species, but when something supposedly concerns public health then journalism should be better researched, factual and responsible. This very exaggerated and misleading press was damaging to arachnophobes and spiders alike! The truth about these False Widows is that they can nip, but then so do ants, bees, wasps and household pets. This article from Buglife concisely puts the record straight: Falsehoods about False Widows.
   Spiders play an important role in our ecosystems by keeping other invertebrates in check. Only since attempting to identify some out in the field, have I come to really appreciate the beauty and diversity in their colour, patterning and textures. I believe that the tabloids should be made to apologise to all UK spiders in person.
Walnut Orb-Weaver (Nuctenea umbratica), bedded down in the moss of a dormouse box

In more local news, Gatwick Greenspace Partnership (GGP) have a new team member in the form of Tom Simpson - a skilled countryside ranger and volunteer co-ordinator. This is fantastic news for our habitat management plan as there is a lot to be done and Tom is already on the case! He joins the GGP team consisting of Pete, Kev and Tom Forward who are based over at Tilgate in Crawley.

Tom Simpson - Assistant People and Wildlife Officer

This month has been the biggest so far in terms of our habitat management, with coppicing works on the River Mole in the North West Zone and thinning the young woodland in the Land East of the Railway Line. GGP led two departments from the airport, picking up the work at Goat Meadow which had been started several years ago; it is great to see it back underway. Two teams - BT Openreach and the BDO of City Place - were led by West Sussex County Council Volunteering, focusing on opening up the ride into Upper Picketts Wood and creating a dead-hedge. This makes a real difference through creating structural diversity, allowing more light to hit the ground and increasing the floral diversity. A massive thank you to all!

BT Openreach team building - Ashley's Field

GAL Planning and Development Team - Goat Meadow

GAL Communications Team and Corporate Sustainability and Affairs - Goat Meadow

Dead-hedge running along the footpath at Upper Picketts Wood, creating
 shelter for a variety of invertebrates, small mammals and birds

BDO Tax Team - Upper Picketts Wood

Recently, while collecting invertebrates from our Malaise trap, a local couple stopped to chat to me and were carrying with them this awesome gadget... a remote control helicopter with GPS tracker and high resolution camera mounted underneath for taking low-height aerial photos, picking up all the detail in the landscape. This could make my job somewhat easier! I want one.

Helicamera, aka my Ecology Drone

And finally... after discovering a population of Harvest Mice in the North West Zone, we will be carrying out nest searches and contributing to a study by the Sussex Mammal Group. Also, looking ahead to November we have a Fungi survey (not foraging for the cooking pot, but instead learning about the diversity of species) and a Winter Thrushes survey, supporting research by the British Trust for Ornithology. Seeing the Fieldfares and Redwings arriving will be a welcome reminder that life is still out there in the colder darker seasons.

Juvenile Harvest Mouse - River Mole Grasslands

Monday, 28 October 2013

Searching for the Micro-mouse

...can be the proverbial needle in a haystack. When managing a particular habitat, we need to bear in mind which species might be occurring there. Last year, while surveying grasslands in the North West Zone with ecologist Laurie Jackson, we came across a tiny nest.

It looked rather typical of Europe's smallest rodent: a Harvest Mouse (Micromys minutus). This then got Laurie to thinking!

Somewhere, out there, deep in the River Mole grasslands... 

Harvest Mice are listed as a Biodiversity Action Plan (BAP) species because their habitats are being reduced and populations almost certainly declining. Jim Jones and his colleagues at the Surrey Wildlife Trust are conducting a Harvest Mouse Project to boost the ecological data on these often overlooked rodents. Laurie Jackson belongs to the Sussex Mammal Group and, as Gatwick is on the boundary of two counties, I was fortunate to have two pros involved in Gatwick's first small mammal survey.

A Longworth mammal trap made up of two chambers; a tunnel at the front and a chamber at the back with bedding and food. Mounting it onto a stake is an idea plagiarised from the study at Thundry Meadows. 

Longworth traps are humane, weight-triggered traps, stuffed with enough hay and food (such as oats, mealworms and carrot) for an overnight mammal stay. We check them every 12 hours, meaning that the survey is rather intensive and takes some planning. As days go by, the mammals tend to acclimatise to the traps and our hit rate increases. Below are some photos from our first and pretty successful trapping sessions:

Jim and Laurie demonstrate to assistants how to carefully bag up and empty a closed trap

Our first species was this Common Shrew (Sorex araneus) 5-14g. One of the UK's smallest mammals

An adult Field Vole (Mircotus agrestis) 20-40g. Scruffing mammals is the gentlest way
 to hold them in order to determine gender and breeding condition

A juvenile Field Vole (Mircotus agrestis). At this age they can seem almost tame

Wood Mouse (Apodemus sylvaticus) 13-27g. This particular female was both lively and pregnant

Then a bonus find in the form of a juvenile Harvest Mouse (Micromys minutus)! 
Britain's smallest rodent tips the scales at around 4-6g

It was Jim who found Gatwick's first Micro-mouse on both mine and Laurie's day off, scoring 1-0 to Surrey. This of course was quite unacceptable, so another surveying effort was needed. This time we raised the traps off the ground on stakes, hoping to target the acrobatic Harvest Mice climbing up amongst the grass stalks instead of the anxious little Common Shrews.

Chumming for Harvest Mice -  a selection of porridge oats, mealworms, apple and 
peanut butter placed in each trap to hopefully generate a feeding frenzy

I didn't go as far as baiting traps with live blowfly larvae, but I did raise the game with peanut butter and apple chunks. After setting up in the morning, we hooked our first Harvest Mouse that very evening!

A glimpse of my first wild Micro-mouse

Scruffing these little mites certainly takes some skill

We trapped two different adult Harvest Mice on consecutive days, and not that it's a competition... but I do believe that makes 2-1 to Sussex! The survey came to an abrupt end as the stormy weather began to close in; on the final evening we had a very good turn out of mammologists and a rather poor turn out of small mammals.

20 longworth traps on stands, all un-triggered. You win some, you lose some

All in all the effort was very worthwhile, so we hope to have another crack at it in spring. Many thanks to Tom Simpson and Kevin from Gatwick Greenspace for their help with the trap stands, to Laurie for her precious time and sourcing equipment, to Jim for his help and good advice, and finally to Katie, Jamie, Heather, Anthony, Martyn, Row, Pete, Reka, Rachael, James and Sue for coming along to help out on a rather damp and intensive survey.

*NB: In the defence of Surrey, it was a bit weighted towards the Sussex side in terms of people. Jim has therefore demanded a rematch!

Monday, 21 October 2013

Dormouse update: Tenants wanted

...must be small, fuzzy and with a fluffy ginger tail.

Sliding-top Dormouse box: unlike bird boxes, the entrance hole is on the side which rests against the tree trunk, discouraging larger species or predators from using the boxes.

After carrying out regular box checks this year at Gatwick, we are yet to get a glimpse of the sneaky Hazel Dormouse (Muscardinus avellanarius). All the signs are there - a good woodland understory, including all their favourite food plants and even an old nest was found. Earlier this year, only a month after installing new boxes, we found bits of honeysuckle had been dragged inside (a typical dormouse behaviour), but alas, the weather suddenly turned cold again and there was no more activity. Pretty frustrating!

Equivalent to Hazel Dormouse graffiti: I waz 'ere... but not for long! 

On the left: a small grassy Harvest Mouse nest. On the right: larger Hazel Dormouse nest largely made up of stripped honeysuckle bark

Dormice are a protected species, but it is difficult to know how these small mammals are really faring as they are quite elusive, turning up in some odd places and in certain years seem scarcer than in others. Early in September I attended a dormouse ecology course with the Sussex Wildlife Trust to hear the latest science and thinking on these vexing little... critters.

Box checking in the woodlands in Crawley, West Sussex

Course tutor Laurie demonstrating how to 'bag up' a box containing a potential nest

The course was attended by an enthusiastic bunch of environmentalists, keen naturalists or people simply wanting to get involved in monitoring local Dormouse populations and the better management of woodland habitats. We had a bright and charming course tutor in Laurie who has a lot of hands-on experience with these and many other wee mammals. 

Bag 'o Dormouse - the weight and general health of each individual is recorded

This nest contained very new dormouse babies called 'pinkies', which are just visible in the centre. We only took a quick glance and then the box was placed back on the tree to minimise disturbance.

My highlight of the day was seeing a Dormouse run up a tree, showing off some brilliant arboreal acrobactics. There is a surprising amount to know about this superb little mammal, too much to sum up here and as I don't want to give away all the secrets from the course, here is a selection of the stranger dormousey facts we have learned:

1. There are many species of Dormouse - the Hazel Dormouse is the only one native to the UK
2. Adult females sometimes pool their young together in creches, possibly so that they can take it in turns to go out foraging. 
3. They do not just eat hazel nuts (which are seasonal and they don't bother storing), they also tuck into various flowers, pollen, nectar, fruit, aphids, caterpillars and teacakes*
4. They are descended from one of the most ancient rodent families
5. When handling dormice (under supervision of a qualified handler) it is advisable to roll up your sleeves
6. There are few reports of people being bitten by dormice, except for one unfortunate PhD student I know who must be finding particularly irritable ones.

* one of these facts might not be verified

(Muscardinus avellanarius) the Hazel Dormouse. 
In latin the word dormir means 'to sleep'

I used to be a bit cynical about how much small mammals could tell us, but I now see that by putting in a decent survey effort they can give an indication of the current condition of our woodlands for other wildlife. The next step in Gatwick's dormouse work is to carry out some Hazel coppicing and to increase our survey effort by installing more boxes. You can find out more about these and other UK small mammals here:

Tuesday, 8 October 2013


I find it quite fun making up unofficial biological terms (many people don't know I coined the word 'ecologising', spelt the UK English way.) Sadly, the JS Agriculture team know me pretty well and, more often than not, I get called on it.

A snake 'hibernaculum' - Illustration by Larry Eifert ( Demonstrating a pit
 filled with a mixture of rubble and deadwood, with a growing top layer of vegetation

I should stress though that hibernaculum is a real word; a place where beasties such as cold-blooded reptiles and amphibians like to bed down for the winter. These 'hibernacula' (as Jake pointed out is the pluralisation, not 'hibernaculars' ...thankyouverymuch) are structures which can be natural or created, even sometimes accidentally, as a refuge. It is based on very simple principles - a mound or pit filled with clean or natural materials with holes and gaps to squeeze/curl up amongst/wedge into, where the temperature remains fairly constant and the frost cannot get in.

 Expert Hibernacularist, Jake of JS Agriculture

A pit was dug on slightly sloping ground, about 30cm-90cm deep. The base was
 broken up with the pick, with sand and plenty of rubble added

'La belle monticule pour les amphibiens' - the concise French term for hibernaculum.
 (I may have made that up too)

The finished article is pictured above - 5 star luxury accommodation, bordered by a sunny mound for those short, opportunistic spring days of sunbathing. A rambling rose garden with bramble scrub is available for hiding away in should any birds of prey pass by, or pesky humans with their nosy dogs.

The next one is situated in a more wooded habitat, close to our newt ponds:

Lauren - our smallest but very enthusiastic hibernacularist 

A pile of broken bricks topped with deadwood, bark chips, logs and nearby brash

'Le hibernacle'. The actual and rather dull translation into French by Google

Another luxury 5 star winter holiday home available to rent; this one with more of a woodland character, containing a nice warming, rotting logpile and large pool just out the back. The varying locations of our hibernacula affect the decor: this one under more tree cover contains a larger amount of wood and vegetation, whereas the one in the grassland has more stone and turf. We will continue to add natural materials to these structures as our nearby habitat management continues.