The Warbler Factory

Posted by Graeme Lyons , Thursday 25 April 2019 08:07

Butcherlands. The most exciting, unpredictable and consantly changing Common Bird Census I have ever done. This is the eighth year I have carried out the four visit CBC there and it's amazing how much it's changed. Eighteen years ago this was all arable on Wealden Clay and was fenced and left to be restored to something more natural with pulse grazing by cattle currently pretty much the only management. No planting occurred and there are at least 30,000 oaks out there alone. Before looking at some of the detail though I am gonna cut right to the chase and tell you about what happened yesterday morning. First though a recap from my first visit on the 3rd April 2019. I had a Hawfinch fly over (my first since the previous winter's influx) and then surprisingly a male Dartford Warbler called repeatedly from a bramble bush. Not all that unusual to pick them up in bramble scrub away from the heaths outside of the breeding season (I've seen them in Sheepcote Valley on the edge of Brighton for example). 

Yesterday morning, the warblers were in full song. Whitethroats were EVERYWHERE. I recorded 44 singing males across the site. So when I got to the exact same area and heard Dartford Warbler calling again, I was pretty shocked. "It's holding territory!". I bungled the video last time so I got a quick video of it calling and you can see it fly from the bush to the left.

I thought I really should try and hear it singing, so I headed a few bushes away and crouched down out of view. It didn't work and the bird came towards me, scolding me from just a few metres away. I grabbed another video as it did so and it started singing a tiny bit. However what happened next was incredible. A female popped up out of the same bush! "THEY'RE HOLDING TERRITORY!". Some context here, there isn't any heather at Butcherlands, there is however hectares of low bramble scrub. This part of the site is on the edge of a sea of undulating bramble. It's also south west facing with a slightly sandy soil (more Common Bent/Cat's-ear than Heather). So it's hot, dry and with a structural component close to heather/low gorse. I never thought that this would be a thing at Butcherlands but these birds are much less fussy abroad. It may well be that this structural type and temperature envelope is rarely provided outside of the heaths in the UK.

Has anyone else encountered this in the UK before?

Yesterday morning my brain was totally fried from all the warblers. After this encounter I was doubting every Whitethroat that called, after all, if one pair of Darties could nest there, why not more? I really doubt I would have picked them up with so many Whitethroats there if I hadn't found the male three weeks ago. So many questions. So exciting!

I actually recorded over 75 singing warblers yesterday! My rule for difficult species pairs is this: if you're not sure, it's the commoner one. Think I'll call that 'Lyons' Razor'. It certainly came in handy with a few Blackcaps today. A Blackcap AND a Garden Warbler taking turns to sing from the same willow nearly made me lose my mind though.

Whitethroat - 44
Chiffchaff - 11
Garden Warbler - 8
Blackckap - 8
Lesser Whitethroat - 4
Dartford Warbler - 1

That's 76 warblers in all. Plus ten Nightingales and a Cuckoo. 

How has this changed over the last eight years though? With provisional data from yesterday's visit (this will change) the warblers look like this. A highly significant increase from linear regression. Only Chiffchaff and Blackcap came out as stable (as they are probably at capacity in the hedgerows and fields edges - for now).

And then like this if you break them down to species.

It's not all winners though. Nightingales have dipped a bit (although this trend is not significant) and Skylarks have nearly disappeared completely (a significant decline), they are still holding on this year though.

But look at the overall number of territories for all species (no suggested data here for 2019) shows a significant increase.
If you break the data down to Red & Amber listed Birds of Conservation Concern and compared to the Green listed, there is no significant trend with the scarcer birds but a highly significant one with the green birds. Showing that the generalists are doing better/quicker than the specialists. You would expect this though. This graph would look very different if Whitethroat was still amber listed but that is not something to wish for!

Species-richness of birds holding territory looks like this from 2012 to 2018 and shows no trend being about as level as it could be.

Linnet and Dunnock are two of the other species that have colonised the centre of the fields and have rocketed up significantly over the period. However the star of the show is yet to arrive. Last year FOUR Turtle Dove territories were noted and this chart shows how they have fared over the period. Wow, wasn't expecting to analyse the whole data set. Got a bit carried away there with linear regression.

I think the success of a project like this is when the site can sustain all of the species that the site has the potential to carry. So losing the red-listed Skylarks to the red-listed Linnets completely doesn't seem right to me just because we don't have an easy way of controlling the scrub. It's always early successional habitats that lose out without a constant effort to keep them open, that's why the associated species are rare. But I am also a fan of not trying to have everything everywhere all of the time. Additionally, scale is a factor here and it may not be possible to have all the successional states in 80 ha in a functional way. It shouldn't stop us trying though. How far back do you go though? After all, soon after the project started some 18 years ago (way before monitoring began) there were breeding Lapwing out there. The site would have to look very different to support them again, not something I would propose at all. You can go round and round with this. One thing is certain though, succession goes in one direction and never stops.

Over the last eight years I have recorded 73 species in the survey but this morning added another one to the list in the form of a pair of Egyptian Geese flying over. Whatever next?!

Endangered spider best birthday gift ever!

Posted by Graeme Lyons , Tuesday 23 April 2019 19:33

So last Tuesday I went hunting spiders at Levin Down and Iping Common on my birthday. I did pretty well but didn't really find anything I hadn't seen before. Until a few days later when I found a little thing in the bottom of my utility belt (it's not a bum bag) which I assumed was an immature in the field but clearly looked different enough for me to put it in its own tube. It took a while to figure out it was an adult female Scotina. Now I have seen Scotina gracilipes and celans only very occasionally and find them quite generic looking but this was found by sieving moss in chalk-grassland, so there was a chance it was the Nationally Rare and Endangered Scotina palliardii. I wasn't sure, so sent it off to Peter Harvey who confirmed it was today. There is one record for Shoreham with a vague date, which is the only other Sussex record. It's the 392nd spider recorded on a Sussex Wildlife Trust reserve and seems to be a genuinely scarce beast. It's the first larger spider I have added to the reserve list since year listing spiders became a thing this year (the only other species so far was Sintula corniger). Can we get to 400 spiders for the reserve network? Levin has some really good spiders, with 18.8% of the 64 spiders recorded there having conservation status.

A few nights later, I went over to see my mate Simon who has recently moved to Shoreham. Last year I did an invertebrate survey there for the Friends of Shoreham Beach that involved extensive suction sampling on vegetated shingle. I had another go for 10 minutes and found a spider genus (in good numbers - six at least) that I had never seen before. Zodarion. I also didn't have any genitalia diagrams of this genus so wasn't able to identify them, so I sent them to Peter along with the Scotina and he confirmed them as the most likely candidate, the Nationally Scarce Zodarion italicum which is a new species for West Sussex. They looked like very fast money spiders in the tray, also not far off a reddish Phrurolithus festivus in the way they moved (which I found them with). What's really strange is that I found so many of them so easily but didn't pick them up last time. The one big difference was it was at 7.30 pm at the end of a very warm day, so maybe they are more active at this time of day.

I end the day on 194 spiders for the year! Can I find another six spiders in seven days?

Bugs, borders and bugs with borders

Posted by Graeme Lyons , Saturday 20 April 2019 13:54

Bob Foreman and the SxBRC have updated the excellent Sussex Shield Bug Atlas with all our records. I have done a wee bit of analysis to show how much things have changed in the last year. It surprised me just how much better recorded shield bugs (and allies) are now we have the atlas. It's already out of date though, as yesterday I recorded Bordered Shieldbug Legnotus limbosus new to my home 1 km square as I was walking to the shops. Here is a rubbish phone shot.

Oh and here (and the top photo) are shots I took of one I collected in the suction sampler from Levin Down this week, first record there since 1997. You can see the detail on the clypeus here that separates it from the scarcer Lengotus picipes.

Anyways, back to the analysis.

Here is the overview before

And after the update

First off, the total number of species per 10 km square rose by over 10% from 15.7 to 17.3, That's pretty cool. Around 63% of 10 km squares showed increased species-richness of shield bugs.

The total number of records per 10 km square rose by nearly 22% from 80.8 to 98.3. That's really impressive. Around 90% of 10 km squares showed some level of shield bug recording in the last year. The biggest jump was in the most recorded square which went from from 676 to 777 records over the last year.

The most species-rich 10 km squares now contain 31 species, these being around Hastings and immediately north of Hastings. I wonder if this is mainly due to Derek Binns? Can we beat 31 species I wonder? The biggest jump is the square in the far north west of West Sussex where the partial square bordering Hampshire went from two species to 13 species in the last year. Who is recording in this part of the world I wonder?

Have a look at the rise of the Western Conifer Seedbug. It's now been recorded in nearly as many squares as Green Shieldbug and Dock Bug and has already been recorded in two more squares than Hairy Shieldbug?! Partly this is down to its striking appearance, people love to record it on iRecord!

I leave you with one of my favourites, the Rhombic Leatherbug which I have added new to the square containing East Head already this year. Happy shieldbug recording! By the way I am thinking of year listing Heteroptera next year as I have had so much fun doing the spiders if anyone is up for it.

I've seen more than a quarter of the UK's spiders already this year!

Posted by Graeme Lyons , Wednesday 17 April 2019 07:11

As it was my birthday I decided to have the day off. What this ended up being was me going to Levin Down and Iping Common to look for spiders. One thing I have learned though is if it FEELS like a day off, then that's OK. I had a few targets in mind and Xysticus bifasciatus was soon on the list. I love this photo as you can identify it from the palps. This area is always really good for this massive crab spider. Ozyptila nigrita evaded me though.

I have a confession to make. I really hate the genus Theridion. Well, I mean all the new names they have been split up to too. Not big enough to be real spiders, they have boring palps and also, no novelty heads like money spiders either. They are also only adult for about 30 seconds each year. Theridion mystaceum or whatever it is called now...

The real rarity was Phaeocedus braccatus though. I found these spiders at Levin in an area of moss a few years back and the young females were abundant yesterday. You can only just make out the six spots but they are there.

A novelty headed spider in the form of Hybocoptus decollatus which is abundant on the Juniper there. The highlight for me though was finding a beetle new to the reserve network, the tiny weevil Tychius squamulatus in the suction sampler. Violet Weevil was also new to the site.

Then I dashed off to Iping. It was cooler there sadly so my target species of a certain chevron-headed jumping spider was not to be found. I did add Hypomma cornutum, Evracha arcuata and Xerolycosa nemoralis though. It was however a male Araniella displicata that stole the show. What a beauty!

Another one I recorded months ago this year but a real beauty was Philodromus histrio. Here a pair were swept from the place I usually see them.

I recorded a total of eight new species for the year, making my spider list 172 species or 25.2% of the list. Collectively, the UK Spiders Facebook page has now recorded over a third of all the spiders too. Is it possible that I can get to 200 species in the first four months of the year?! Right, now I am off to set up a new survey in Surrey...

The importance of a baseline

Posted by Graeme Lyons , Monday 15 April 2019 15:25

I have just got back from a fantastic weekend setting up monitoring at an exciting project in Norfolk. The Ken Hill Estate are planning to restore around 400 ha of farmland and woodland, predominantly through rewilding, and thanks to Penny and Dave Green I was able to get involved in setting up a baseline before any changes took place. This month saw the beginning of the invertebrate survey, the start of some BBS transects and of course lots of casual recording. It's really great that the Estate have been able to pull this baseline together in time and that I was in just the right place going part-time freelance too. It will be a great way to measure the huge biodiversity gains that are expected from this change in direction.

But before you can do that, you need to know what's there. You also need to do that in a way that's standardised where possible, simple and easily repeatable.

The highlight for me was finding two Heath Shieldbugs Legnotus picipes (nationally scarce). In Sussex, this has only ever been recorded from the Crumbles, I have looked for it many times (I even have a day this month pencilled in to look for it again). At Ken Hill, the two I found were on an area of open acid-grassland/heathland but both of them were found on small scrapes and it's great that this might continue. One was found in the suction sampler, the other found under a stone. 

On the first scrape, I also 'sucked' a single Ant-tiger Euryopis flavomaculata (also nationally scarce), which appears to be only the second record for Norfolk after Steve Lane found one in 2018 at Roydon Common. Overall I recorded 146 species last Friday, which was pretty good as it wasn't all that warm. That doesn't even include most of the beetles and bugs which have gone in vinegar until the winter. Spiders are currently at the number one slot with 46 species (but they have all been identified already), followed by beetles at 29 (this will overtake the spiders from this visit alone though). I'm expecting well over 600 species at this rate from this survey.

Oh and Gymnocheta viridis, a new tachind for me (thanks for confirming Tony), was everywhere. Wonder why I have not seen this in Sussex before?

I ended the weekend on 164 species of spider for the year too and added a few nationally scarce species from the dunes there that all seem to be new 10 km square records. Thanatus striatus, and Xerolycosa miniata (those were new for me this year) as well as Zelotes electus and Crustulina sticta.

The birds were really exciting with sightings of Spoonbill, Great White Egret, Barn Owl, Marsh Harrier, Red Kite and more Grey Partridge than I see in a decade. I was typically seeing around 50 Brown Hares a day and the Lapwings were also very plentiful. Quite something!

Back on the little scrapes where I was photographing the Heath Shieldbug, I noticed a few plants of Field Mouse-ear in flower, always love seeing this. Then I noticed in the same scrape I was literally kneeling on a patch of Shepherd's-cress (Near Threatened). I love the little 'jigsaw-puzzle' leaves of this little crucifer, always a good indicator. Was lovely seeing plants that I used to see much more in the RSPB days like Shrubby Seablite, Mossy Stonecrop and Flixweed too. I can't wait until the next visit.

Oh and a new skull! A Muntjac (minus the fangs though). It looks like they fall out easily.

Who wants my job?

Posted by Graeme Lyons , Thursday 11 April 2019 16:14

If you're reading this, chances are you've seen quite a bit of what I get up to, the wildlife and the amazing reserves I work on at Sussex Wildlife Trust. I have decided to head out on my own as a freelance consultant entomologist and ecologist - well three days a week at least. I am moving on in the next couple of months to a new part time role at the Trust too. That means my current job will be up for grabs. Part of my new role will be mentoring and supporting my replacement, so I'll be around some of the time. I'll also be continuing with some of the more complex surveys and tasks, such as the invertebrates etc. The Land Management team are a great bunch and the Trust is a great pace to work. And what can I say, East and West Sussex are just the best counties with some amazing wildlife.

If this sounds up your street, have a look here and good luck!

WARNING: This spider is too cute for you to handle!

Posted by Graeme Lyons , Monday 8 April 2019 17:50

Meet Sitticus saltator. He's only 2.5 mm long. He's just had his hair cut by his Mum for his first day of school.
"The other kids sure are bigger than me".

"I better start taking some notes with my shiny new pencil".

There are not many spiders with a cephalothorax bigger than their abdomen, it looks like a head on legs. And boy can they jump. Actually it's more like a bounce. Such little characters.

OK enough mucking about, this spider though. Could it be any cuter?! I have only seen it twice before, back in 2014. In Sussex, it's known only from Camber Sands and Climping Dunes. It's nationally scarce and a dune specialist (mainly) and hasn't been seen at East Head since 1971 as far as I can tell. We saw three yesterday, all found by suction sampler. If you think the above photos are cute, you might just lose it when you watch this video of it cleaning its face. You have been warned!

Yesterday I started a survey for the National Trust at East Head with Lee Walther and a team of trainee volunteers. I said we should look out for Phlegra fasciata as I know Chris Bentley found it on a bioblitz a few years back. We found five! Having only seen one before at Rye Harbour, I was very pleased by this. This females of this nationally rare dune specialist are like a furry little humbug.

And another one that Chris had there a few years back, Crustulina sticta. We had one of these in the dune slack. Another nationally scarce species.

I actually had nine new spiders for the year and two were lifers! I didn't identify these until I got home. They were another coastal specialist which we recorded on the saltmarsh by sieving tidal litter, Zelotes electus (nationally scarce) which was recorded on the site back in 2007.

And also known from the site was Ceratinopsis romana, a nationally rare coastal species. This sieved from Marram litter on the mobile dunes. 

I ended the day on 151 spiders in all. Others new for the year were: Pardosa proxima (NS), Stemonyphantes lineatus, Walckenaeria vigilax and Cheiracanthium erraticum.

But there's a lot more than spiders there! The commonest bee by far was Colletes cunicularius which Mike Edwards tells me is likely to be a first for West Sussex! Here is a male, they were feeding on gorse and willow.

And what I'm pretty sure were their burrows. There were lots of females buzzing around here, a long way from where we saw the males.

My third lifer for the day though was a real surprise. We sieved this huge Broscus cephalotes from a pile of tidal debris, it's more of a surprise that I could see 1300+ species of beetle without seeing one of these to be fair. We do have very little of this habitat in Sussex though. What a beast though!

Later on in the mobile dunes, I sieved another one from Marram litter. I was convinced that it was dead but it wasn't! It's front two pairs of legs were clamped together, holding tightly to a Marram grass stem, while its back pair of legs were held backwards at 45 degrees. The head was back and jaws were wide open. It was utterly motionless as we took photos. Then it dropped off and ran away, an amazing experience!

And a new 10 km square for the awesome Rhombic Leatherbug! What a day! I can't wait until the next visit.

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