Early winter bird surveys 2016 (Part 2)

North West Zone grasslands

The survey start-off was signaled by a group of 9 Pied Wagtail, which must have just emerged from their communal roost. Plenty of Reed Bunting and Wren were calling around the River Mole reed beds, and the occasional Song Thrush giving a high-pitched 'tseep'.

Snipe explosion / spontaneous combustion

After yesterday's survey Snipe joys, this ominous pile of Common Snipe feathers is a bit of a sorrowful sight. Still, there is a good population around at the moment and the Sparrowhawk (presumably the culprit) has got to feed too.

We stopped in our tracks as we got closer to the reed beds, scratching our heads over this one call...

For a moment there we couldn't put our finger on it. However, later on and further downstream, we heard the more familiar, squealing cry...

Water Rail is the weirdest thing you will hear along the River Mole (except maybe for Tom Forward's imitation of a Water Rail).

Water Rail (Rallus aquaticus). RSPB

A pair of Common Buzzard called to each other, one gliding towards the woodland with a Carrion Crow in wing-flapping pursuit. On the far side of the river, along the woodland strip, we scanned the gorse and bramble scrub for any movement...
   Luke then spotted a new species for the Gatwick surveys!

Stonechat (Saxicola torquata) male. RSPB

Stonechats are a stunning little bird, slightly smaller than a Robin. Its name comes from the call which sounds a bit like two pebbles being bashed together. The pair we saw are probably temporary winter visitors to our sites.

A scatological interlude to look at some mystery poop...

Too small for Fox, but containing lots of fur... A Stoat or a Mink perhaps?

The tell-tale cigarette ash poo of Green Woodpecker

Mistle Thrush made their machine-gun calls as they shot past overhead. Fieldfare were the loudest though; I love how they sound on the verge of hysteria.

Fieldfare (Turdus pilaris) RSPB

In the north of Brockley Wood, Chaffinches were calling loudly; it makes a nice change as we are usually a bit light on finches here. A flock of Redwing were busy in the understory and a Coal Tit called from the canopy.

As we rounded the bend on the river, two Roe Deer stood motionless only meters away. Just a little further along, the gang caught a view of a top predator - Sparrowhawk! Unfortunately, I was too busy predating on rich tea biscuits and missed it.

Towards the end of the transect we were closer to the tree line; Ring-necked Parakeets started up their cry, disturbing another Common Buzzard. A lonely Little Egret took off downstream in lumbering flight. Although we didn't find Katherine a promised birthday Kingfisher, we did get a lovely Grey Wagtail zip along the river and land up next to us. 

   We start with wagtail, we finish with wagtail.

Winter shrubs: Bramble, Field Rose, Gorse and Spindle

Our species list from the day; 37 is a new record I think! Our total species recorded on our timed transects at Gatwick since 2012 stands at 79.

1	Blackbird	Turdus merula
2	Blue Tit	Cyanistes caeruleus
3	Bullfinch	Pyrrhula pyrrhula
4	Buzzard	Buteo buteo
5	Carrion Crow	Corvus corone
6	Chaffinch	Fringilla coelebs
7	Coal Tit	Periparus ater
8	Dunnock	Prunella modularis
9	Fieldfare	Turdus pilaris
10	Goldcrest	Regulus regulus
11	Great Spotted Woodpecker	Dendrocopos major
12	Great Tit	Parus major
13	Green Woodpecker	Picus viridis
14	Grey Wagtail	Motacilla cinerea
15	Jackdaw	Corvus monedula
16	Jay	Garrulus glandarius
17	Kestrel	Falco tinnunculus
18	Little Egret	Egretta garzetta
19	Long-tailed Tit	Aegithalos caudatus
20	Magpie	Pica pica
21	Meadow Pipit	Anthus pratensis
22	Mistle Thrush	Turdus viscivorus
23	Pied Wagtail	Motacilla alba subsp. yarrellii
24	Redwing	Turdus iliacus
25	Reed Bunting	Emberiza schoeniclus
26	Ring-necked Parakeet	Psittacula krameri
27	Robin	Erithacus rubecula
28	Rock Dove	Columba livia
29	Roe Deer	Capreolus capreolus
30	Song Thrush	Turdus philomelos
31	Sparrowhawk	Accipiter nisus
32	Stock Dove	Columba oenas
33	Stonechat	Saxicola rubicola
34	Treecreeper	Certhia familiaris
35	Water Rail	Rallus aquaticus
36	Woodpigeon	Columba palumbus
37	Wren	Troglodytes troglodytes

Common Snipe (feathers)

Early winter bird surveys 2016 (Part 1)

Land East of the Railway Line: December 8th

Dawn breaks over the Gatwick Stream, and Tom Forward is about to have a date with destiny...

Actually, the date is with a Snipe, but this is not just any old Common Snipe (although we did see 7 of those); it's a little bit scarcer than that. He wanders along the wet flushes, keeping out a sharp eye...

A sudden burst of wings from the ground and it's off like a shot - a Jack Snipe! Another new record for our bird list at Gatwick.

Jack Snipe (Lymnocryptes minimus) RSPB

Common Snipe (Gallinago gallinago) RSPB

Much quieter than Common Snipe, the Jacks have a shorter bill and are a shorter, dumpier bird in general. The Common types will shoot off up into the air before you can get close, but Jacks can hold on until you almost step on them, then dropping onto the ground again after a short, low flight.
  A small flock of Meadow Pipits bounced past us through the air, and a Grey Wagtail descended rapidly down into the river channel.

 

Our next new discovery for this site is a Barn Owl roost in our 'Little Owl-Oak'. Not sure if the little-er owls would think much of their new neighbour....

White wash (owl wee) on the tree above what might be the Little Owl nesting hole

Barn Owl pellet

Poking our heads over the bank of the Gatwick Stream by the sluice gates, and were surprised to see a dark, sleek mammal gamboling in the water. American Mink are insatiably curious and this one actually came towards us, then hid in a small clump of rushes to check us out.

Not much of a photo of course.
How to tell apart Otter and Mink - a handy Wildlife Trust fact sheet.

Dashing back over grasslands to the next transect, and we were stopped in our tracks by a pair of Kingfishers zooming low over the grass. Although strongly associated with water courses, they are known to sometimes cut corners and even head into woodland habitat to do so. Hey, I would too!

Into the woods and a flock of Redwing were busy foraging in the understory. Winter thrushes vary what height they forage at depending on available food source. Towards the end of winter they feed more on the ground.

More white-wash beneath a mature oak - favored perching point for a Common Buzzard?

A Song Thrush sang from a distant hedgerow. A Wren and Robin were also in song; only a few birds do this through winter.
   At Dunnock corner, there were constant loud calls which signified the usual debauchery. They always seem to get louder in winter, kind of like my own family. I guess domestic drama helps to keep small birds warm. I still get Dunnock and Kingfisher calls mixed up, which after 4 years of these surveys Tom F. must be getting fed up with.

Through the woodland strip and out into Lower Picketts Wood, mixed flocks were abound of Long-tailed Tits, Blue Tits and Goldcrests. We checked a little closer through the binoculars but sadly couldn't turn any of them into a Firecrest. At the end of the transect, our trusty Treecreeper finally called.

The final species count for the morning was 33 (not 34, as I only recorded Common Buzzard when I returned to site at the end of the day):

1	Blackbird	Turdus merula
2	Black-headed Gull	Chroicocephalus ridibundus
3	Blue Tit	Cyanistes caeruleus
4	Bullfinch	Pyrrhula pyrrhula
5	Buzzard	Buteo buteo
6	Canada Goose	Branta canadensis
7	Carrion Crow	Corvus corone
8	Coal Tit	Periparus ater
9	Dunnock	Prunella modularis
10	Goldcrest	Regulus regulus
11	Goldfinch	Carduelis carduelis
12	Great Spotted Woodpecker	Dendrocopos major
13	Great Tit	Parus major
14	Grey Heron	Ardea cinerea
15	Grey Wagtail	Motacilla cinerea
16	Jack Snipe	Lymnocryptes minimus
17	Jackdaw	Corvus monedula
18	Jay	Garrulus glandarius
19	Kingfisher	Alcedo atthis
20	Linnet	Linaria cannabina
21	Long-tailed Tit	Aegithalos caudatus
35	Magpie	Pica pica
22	Mallard	Anas platyrhynchos
23	Meadow Pipit	Anthus pratensis
24	Mistle Thrush	Turdus viscivorus
25	Pied Wagtail	Motacilla alba subsp. yarrellii
26	Redwing	Turdus iliacus
27	Robin	Erithacus rubecula
28	Siskin	Spinus spinus
29	Snipe	Gallinago gallinago
30	Song Thrush	Turdus philomelos
31	Starling	Sturnus vulgaris
32	Treecreeper	Certhia familiaris
33	Woodpigeon	Columba palumbus
34	Wren	Troglodytes troglodytes
	American Mink	Neovison vison
	Eastern Grey Squirrel	Sciurus carolinensis

Barn Owl (roost)

Tyto alba

Still searching for Micromouse

We have conducted 3 consecutive seasons of mammal surveying now, targeting Harvest Mice for the Surrey Mammal Group genetics study. I can only describe the feeling as 'incredibly disappointed' when you do finally capture one of your target species, then it perishes on the survey.

Eurasian Harvest Mouse (Micromys minutus), deceased adult male

Ecological surveys help us to target our conservation efforts, providing important data for reports such as the State of Nature. We do not wish to put animals through undue stress, and it was unclear why this individual died in the Longworth trap. As per the best practice protocols, traps were generously stocked with bedding, food, sources of moisture and checked within the regulated times. Harvest Mice do however have very short life spans, so it could be this individual was just reaching the end of his natural life. 

And so, after this one and only capture of a micro-mouse plus several discussions with other Harvest Mouse surveyors, these are the things I have learned:

1. Harvest Mice are difficult to survey, despite finding plenty of nests on our site. The fluctuating weather, changing habitat use and population crashes could all be impacting on our struggle to catch these little critters.

2. Despite this unfortunate mortality, Harvest Mice are fairly resilient; after speaking with other surveyors it seems very few casualties occur with Longworth traps. The overnight temperatures were above the minimum recommended for surveys, so cold was unlikely to be a factor, but we still took the precaution of providing extra insulation for the traps.

Longworth trap on stand with bubble wrap plus layers of grass

3. Wood Mice are relentless. I've seen more Wood Mice this year than craneflies. Their adaptability and climbing skills are to be commended, and they are certainly not deterred by the experience of temporary captivity! In fact, they mostly seem to find the traps before the other mammals can get a look in...

4. Shrews are awesome and sometimes I wish we were studying Shrews instead.

Lucy Groves, keeper at British Wildlife Centre with a Pygmy Shrew

Shrews love these castors (fly pupae)

5. Tube traps are a faff and take about 3 times longer to clean than Longworth traps.

6. On this survey, the average occupancy of Longworth traps was 49.71% whereas tube traps were 42.33% 

Collating trap data

Adrian Ashley is a handy chap to know - he's both an ecologist and a bespoke jeweller! He has kindly serviced the Longworth trap mechanisms which were not working so well.

7. Traps stands can definitely help to reduce the number of Common Shrew captures, but do not deter Wood Mice one little bit!

Tom Simpson often raids the set of vampire films for us 

Traps off the ground are more likely to tempt in Harvest Mice and appeal less to Common Shrews

8. Let the record stand that Martyn Cooke has still never seen a live Harvest Mouse in the wild.

Our survey data ends up in 3 places; on the internal Gatwick database, online on iRecord (which feeds into the National Biodiversity Network Gateway), and with the Surrey and Sussex Mammal Groups. We will be discussing the merits of continuing these surveys and any new approaches we might take next year.

Below are a few of our mammal records from the past 2 weeks (photos by Martyn Cooke):

Pygmy Shrew (Sorex minutus)

Bank Vole (Myodes glareolus)

Wood Mouse (Apodemus sylvaticus)

Surprise! Not a mammal: Wren (Troglodytes troglodytes)

A huge thanks to all who have helped out these past two weeks of surveys, and to Jim, Lucy and Laurie for all your advice.