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Burrow Question: |
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Vicar Senior Member Joined: 02 Sep 2004 No. of posts: 1181  View other posts by Vicar |
Posted: 07 May 2005 I was strolling across Frensham common the other day, when I came upon a neat 2" hole dug into the sand. I supposed it was some kind of rodent burrow, as the diameter was very large compared with common lizard burrows I have seen. Anyway, I sat quietly for 10 minutes, and this is who appeared ! - is this a usual size burrow ? or was this an opportunistic squat ?
Steve Langham - Chairman 
Surrey Amphibian & Reptile Group (SARG). |
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GemmaJF Admin Group Joined: 25 Jan 2003 No. of posts: 2090  View other posts by GemmaJF |
Posted: 07 May 2005 Steve I know very little about sand lizard burrows, but I remembered one in Tony's pic from the ID page, looks similar?
Did you mean to say common lizard burrows above? I mostly see L.vivipara on grassland/bracken do they burrow in sand?? Gemma Fairchild, Independent Ecological Consultant |
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Tony Phelps Forum Specialist Joined: 09 Mar 2003 No. of posts: 575 View other posts by Tony Phelps |
Posted: 08 May 2005 Fresh sand lizard burrows are characteristicaly ovoid in shape but get eroded with use. Another thing sand lizards do is to use a rabbit burrow, perhaps a few cm down and then dig into the side.so a sort of 'secret' burrow. I think I posted a pic of male outside 'his'rabbit burrow last year. This weather is pretty good is it not? Yesterday at Hartland was particularly for good last years sand lizard babies - counted 28 in about an hour - also lots of males searching and females lying 'waiting'. Another female was very thin and sluggish - took off 32 ticks (always carry tweezers and alcohol)hope she survives, saw her last year mating, and also the year before T Tony |
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Vicar Senior Member Joined: 02 Sep 2004 No. of posts: 1181 View other posts by Vicar |
Posted: 08 May 2005 Gemma, Over this last winter, I had 2 Lvs at home, some kids had caught them mid october, both very young juveniles, thin and without tails. One appeared to have a broken leg (maybe from being caught ?, I'll never know). Both fully recovered (even the leg !). At one point the female dug a small burrow in the sandy part, and for a while, spent the nights in there, rather than in the stone or heather cover. The burrow was approximately 15mm in diameter (looked quite a squeeze), but she seemed happy enough. It was very intresting having them, as I noticed they would not eat ants nor beetles, but much prefered spiders and grasshoppers or crickets together with the occasional woodlouse. I have no idea how this ties up with accepted beliefs, this was purely from observation. I often see the same La at Frensham appearing from a Rabbit burrow, so I'll take a sneaky look inside to see if there is any obvious side burrow. Tony, Fantastic weather atm !, am seeing far more juveniles than previously!, often in groups of upto 5-6 within a few feet of eachother. Any obvious reasons for such grouping ?
Steve Langham - Chairman
Surrey Amphibian & Reptile Group (SARG). |
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GemmaJF Admin Group Joined: 25 Jan 2003 No. of posts: 2090 View other posts by GemmaJF |
Posted: 10 May 2005 Hi Steve, I've seen captive L.v burrow in very lose sand also (I will own up to keeping a pair over 30 years ago) I was wondering if this was due to a lack of cover or if burrowing is a normal activity for them on sandy heathlands. I wouldn't observe this activity in bracken/grassland habitats as it would normally be out of sight. The point being that L.a presumably burrow primarily for egg laying. I've always thought of ground spiders/grasshoppers as suberb indicator for L.v and am sure you are right that they form a large part of their natural diet - an interesting point for consultants undertaking translocations where low numbers of animals already occur, do they check to see if this natural food supply is available in abundance? Jo's post moved to http://www.herpetofauna.co.uk/forum/forum_posts.asp?TID=1000&PN=1 Post regarding invert surveys before translocations moved to avoid this thread going off-topic (my fault I should have started a new thread on the subject) any one else wishing to reply regarding invert surveys before translocation, please use the link above. Gemma Fairchild, Independent Ecological Consultant |
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Vicar Senior Member Joined: 02 Sep 2004 No. of posts: 1181 View other posts by Vicar |
Posted: 10 May 2005 [QUOTE=GemmaJF]The point being that L.a presumably burrow primarily for egg laying.[/QUOTE] I've been wondering about this ! Is this the case ? or do L.a also dig at non-egg laying times, and/or use previous burrows for shelter/cover ? I'm still seeing courtship rituals between pairs of L.a at Frensham, so adding some gestation time, I would think we're a bit early for any egg laying just yet, although from the above pics, clearly this female was using the burrow. Are egg-burrows covered after the eggs are laid ? The burrow pictured above decends visibly for about 12 inches, I've not examined it more closely for fear of disturbing the occupant, this seems a bit deep for egg laying?, although I'm saying this from no scientific basis. I would greatly appreciate comments from those forum members more familiar with L.a behaviour. Steve Langham - Chairman
Surrey Amphibian & Reptile Group (SARG). |
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David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts by David Bird |
Posted: 12 May 2005 Hoping that this may answer some of the questions or points raised in the above thread. Lacerta agilis will have a burrow that it hibernates in and also uses for shelter for a few weeks after it has come out of hibernation. They will then move to other areas and use other burrows for shelter for the rest of the season. Some individuals will use just one hole and remain in this territory whereas other individuals move about or spread out to new areas that then become their territory. These holes are used at night or in the heat of the day. Hopefully the radio tracking work that is being carried out at the moment will give a clearer idea of how and where lizards spend their time during each day and through the season. Obviously where the population is sparse there may be enough holes produced by other animals to cope with the needs of the lizards, where there is a large population a lot of the lizards will have to dig their own burrows. There is a method of detecting adult female Sand Lizards that is used by some surveyors and that is to look for so called "test" or "dummy" burrows. Some have even used this as a quantitative method for estimating the number of females using a particular sand patch. I feel that these burrows are misnamed and prove very little other than where the female has been unable to lay her eggs due to the incorrect humidity of the sand or large stones stopping her from digging further. She does not waste her energy in filling them up or remaining in a vulnerable position away from vegetation cover. When the eggs are laid the burrow is filled in and the sand pressed down so that its position is not visible, in areas of good egg laying sand i.e particle size and humidity, the "test" burrows are not found. The actual burrow used for laying eggs is only just larger than the females body at the surface and is about the length of the female she digs down head first then when she has reached the required depth turns around and often sits with her snout just at the entrance whilst laying the eggs. The egg laying burrow will be out in open sand whereas burrows used for shelter will be mainly in vegetation or on small ridges or banks. David British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
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Vicar Senior Member Joined: 02 Sep 2004 No. of posts: 1181 View other posts by Vicar |
Posted: 12 May 2005 Excellent summary !, Many thanks David. Steve Langham - Chairman
Surrey Amphibian & Reptile Group (SARG). |
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Tony Phelps Forum Specialist Joined: 09 Mar 2003 No. of posts: 575 View other posts by Tony Phelps |
Posted: 13 May 2005 Yes, nice one Dave. In Dorset sand lizards also dig into clay, and even railway chippings, although this takes a lot longer. Also, in recent years there has been a noticeable overlap with mating/egg-laying (around 14 days)and this results in some interesting behaviour. Those of you who are lucky enough to have sand lizards on their patch note that much can be learned by just sitting and watching at this time. Useful refs. PHELPS,T.(2000): Reproductive behaviour of the sand lizard, Lacerta agilis, in south-east Dorset, with a note on habitat management. The Herpetological Bulletin.72: 21-25. FEARNLEY, H.(2002): A photographic study of reproductive behaviour un the Sand Lizard, Lacerta agilis, on a Dorset nature reserve. The Herpetological Bulletin. 82: 10-19. T |
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Vicar Senior Member Joined: 02 Sep 2004 No. of posts: 1181 View other posts by Vicar |
Posted: 13 May 2005 Funny you should say that :P Sat for about an hour the other day, watching the courtship of a pair of Sandies. The female seemd quite the tease, wiggling her tail in a 'come and get me' way, only to scoot off whenever the male approached. The brazen hussy even sat there and bent her rear legs over her back to egg him on. (I'm not joking !, pic attached). As far as I saw she was doing all the flirting, and all the male got was a healthy dose of fustration....how like my life :P
Steve Langham - Chairman
Surrey Amphibian & Reptile Group (SARG). |
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rhysrkid Senior Member Joined: 14 Nov 2003 No. of posts: 98  View other posts by rhysrkid |
Posted: 13 May 2005 Facinating picture - thanks! Rhys |
- Burrow Question |
