RAUK - Archived Forum - Surveying for Adders

Hi all,

In recent threads I mentioned my missing Adder population. This inspired me to take a couple of intrepid walks around the area to see if they had simply moved. I came across this south-facing slope covered in laying bracken:

Couple of questions, does it look to those with more experience to be a likely place to start looking, and if so, how would you go about surveying it? It is bone dry and the slightest foot movement makes enough noise to scare anything within half a mile!

The missing Adders used to be seen on similar piles of dry bracken lower in the valley to the left of the picture.

Hi Gemma,

Habitat looks very similar to a number of Surrey sites which all have reasonable adder pops. Look for the areas with best cover, usuallu at the base of birch, any mossy clumps for basking, hiding. Mating season is coming to an end and soon adders will disperse and be more difficult to find.

If we get sun after the rain that is forecast later this week then a good search around mid-morning should reveal something. Other hints are if this is post-fire regen, how long ago, and also what is the nature of the surrounding habitat.

If you cannot get out now, look later for preggie females.

Tony

Hi Tony,

I will take a good look at the end of the week for sure.

The area hasn't seen a major fire since the 40's, to the north of the original picture the ground drops away steeply into mixed woodland, so the site is the south face of an arete.

The lower slope becomes a slightly sinister looking woodland, here's a picture,

ground cover here is heavy layers of bluebells and dry leaf litter. The valley floor is damp with mostly bluebells, later in the year replaced with heavy bracken growth. Large pond, then to the west large open meadow.

Hi Gemma,

Should have mentioned it - the area looks good for grass snakes too, is it?

Tony

Hi Wolfgang,

Firstly welcome to RAUK, we do have a naughty word filter operating, it seems that heathland management, or lack of, is the most likely issue to provoke the use of expletives, we usually turn a blind eye but it might be replaced by red stars by the moderator if too heavy.

Morning Wolfgang , everybody.

I'm affraid that's not so on my regular patches. Natrix natrix is also in decline where I walk.

It's not my ability to find either , as during the 80's I could find absolutely looooads! So many that I stunk to high heaven . My favourite game would be to sit in the passenger seat of my friends car on the return home , dampen my hands with water to refresh the smell , then place them infront of the airvents pointing in his dirrection :¼D!!

I read elsewhere on this forum a post from Tony saying a population of large specimins is often an indication that they are infact in decline. Well , in the eighties all these natrix were large thick set specimins. I rarely see these now , usually just thin 2-3 footers.

Cheers,

Alan

PS Looking forward to your pics from this past weekend.

I returned to the site today looking for my missing Adders. Weather was not what I would usually associate with a good snake spotting day, cool, strong wind and overcast. I followed Tony's advice for features to lookout for, and at 2:40 PM sighted the first pair of Adders I had seen in this area for over 10 years. (They used to be common in the lower valley that is perhaps now less suitable)

Male with yellow background and greenish markings and typically marked female basking coiled side-by-side on an open patch of moss at the base of some bracken-covered sticks. The female made off quite quickly, male slowly made his way off a minute or so later.

I returned an hour later, I thought much more quietly and carefully. I spotted the male moving through a gap under the piled bracken and sticks about 2 ft from the original basking spot (so I guess I wasn't quiet enough). What happened next was a first for me, he came round in an arc of about 8ft radius, stopping to watch me now and again until he arrived about 6 inches from my feet.

Male when first sighted moving through bracken on return to original spot

Male as he approached me (he is there to the left of the green bracken stem)

Sorry about the poor pictures, but I guess it gives some idea of how snakes appear in the wild.

So a big thanks to Tony . If I'm reported missing in the next week or so, guess where I am

Nice one Gemma!.

We searched and searched today ,but found only two slow-worms.

Cheers,

Alan

Hi Alan,

as you mentioned "we", I thought I better introduce my trainee herpetologist,

Harvey, aged 5 on way back today  

Aaaaawee! What a cute little Guy, thanks Gemma.

Alan

Hi Gemma,

Sounds like your male adder was mate-searching. When you find what looks like a fat female its worth sitting down and just watching. I do this all the time during April and early May, its also a good way of not disturbing the surrounding habitat. Most of my own observations are gleaned in this lazy but fruitful way. Itys the best way to see combat, and also note how many males actually attempt to mate and which is the dominant male. You follow this up in the same spot for a few days and observe the top guy mate-guarding. Watching this over many years strongly suggests that multiple matings are rare, on my sites anyway. This mating strategy contrasts with that of the grass snake which has a strategy described as 'scramble system' sometimes manifesting in impressive mating balls. If you see this you may be surprised at just how small some of the males are; dwarfed by the one female the centre of all the attention.

In such as your bracken site Gemma in a months time it will look like a jungle and the head high bracken looks most unsuitable for snakes; i e too shady.

However, if you take a bird's eye view you will see that there are still open areas for basking and that many of the snakes are still there, its just that we feeble humans can't get to them easily without crashing through this jungle fighting off horseflies. 

Another reason why bracken should be controlled and not totally eradicated.

Keep watching, and waiting.

Tony Phelps

Hi Tony,

I've only once observed a Grass Snake mating ball, this was at this site during May back in the late 80's. 2 small males with the female, I was drawn to them because of the amount of noise that they were making in the dry leaf litter by a bank in the lower valley as they rolled about.

Now I've located the Adders again, a couple of days laying around nearby sounds good to me . I know all about horseflies , last year I observed Grass Snakes quite often in clear patches in the bracken later in the year as you describe.

Never seen a mating ball as such , but did surprise a mating pair of grass snakes in a ditch full of water once.

Poor old male , they were as surprised as I was , and she , being the larger snake shot of in the ditch dragging him along by his privates, "OOOOUCH!"

Alan

Interesting Alan, were the GS actually mating in the water?, I have never seen that, close to water, but never doing it in the water.

Beena great day for little adders - went to my urban heath site this afternoon - 6 adders , 2 last years babies, both males, and a third season male, 280mm, and 3 immature (4th season) females. These young ones are so precious for research. This is a strange site. The site is just under 50ha and the adders here occur in four distinct sub-populations. Two of these exhibit an imbalanced sex ratio, females outnumber the males 3:1.

The other two sup pops are where I find the little ones and these have a more normal sex ratio and reproductive cycle although females breeding every third season appears to be the case. The first  mentioned pops have very large females one monster at over 80cm several around the 70cm mark.

I have in three years only found one gravid female in this group.

I have a total of 78 adders ID'd here, including immatures, and I get a high recapture rate of adults, particularly the females, around 70-80% each season. This is surprising because this site has suffered serious fires, especially during 2001 when 40% of the site was affected. Many adults have signs of fire trauma, scarring, etc. The most common is 'stubby' tail syndrome, about 20% of adults have bits of tail missing.

Tony Phelps 

Hi Tony,

Yup, in the water . I saw this in Bisley , There is a large field that I cross to gain access to an area of heath with adders. I had never seen any snakes in this field till then and that is why both I and the snakes where surprised as I was walking normally.

The ditch ran the length of the field along the edge and was full of rain water. But the grass snakes could actually lie on the surface as there was alot of long grass in the water . I've never thought anything of this except "Ouch", as they are the only mating grass snakes I've come across.

Glad you've had a good day , that certainly sounds like a good site.

Acouple of questions for you Tony. How can I tell the difference between Male female neo adders without probing? Also , have you ever witnessed a fem adder in the proccess of giving birth? The reason I ask this second question is, I think this might be what a friend and I came across in the late 90's. We found a gravid Fem Berus curled up in a hollow at the base of a tree. Her movements were awkward and she was reluctant to move on even though she knew we were present. Unfortunately Time did not allow us to wait and see and we had to return home. I suppose we'll never know.

Cheers ,

Alan

Thanks for that Alan.

Yes I have seen and photographed the birth in the wild. Typically the female becomes restless and moves slowly throught the heather whatever, pauses, and drops a baby, then moves on. She usually moves in a circle of a few sq metres so this is why you see babies together soon after, sometimes basking with mum in a favoured spot.

When neo adders moult you can tell in good light by colour males are more greyish and bolder pattern and lateral markings - thats a rough guide. Subcaudal counts have some overlap so can be misleading - but tail length to SVL is the best way. Some say that under a lens the colour of the eye is obvious the males being more red - take your pick.

 I have got some pix of male and female neos, close ups that show colour difference clearly. Might post them soon as some kind person has offered me a scanner.

Cheers

Tony

You're welcome Tony, and thanks for the info on neos, something that's been bugging me for years.

Sounds as though this fem berus we saw was acting differently. She was turning in circles , but staying within the hollow. interesting stuff though.

Anyhow, thanks again , I look forward to your neo pics.

Cheers,

Alan