 |
|
|
Posts by David Bird: |
| Author | Message |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515  View other posts in this topic |
Posted: 17 Feb 2003
Topic: Inbreeding depression
The only effects of inbreeding that I have seen that occur in Amphibians are the strange colours that one finds in the Common Frog Rana temporaria and are often reported in the local press with some reference to global warming or radiation in Cornwall. These nearly always occur in garden ponds which are often colonies that are started with a batch of spawn or tadpoles from another garden pond and therefore usually with a small gene pool. There are at least 2 colonies of albino frogs in the Bournemouth area. Most of the other British amphibians and reptiles are not great travellers and some such as the Smooth Snake Coronella austriaca may in some localities spend the whole year in less than 100 square metres. One does not seem to see any visible signs of inbreeding in these colonies. Even in captive species that are often inbred for many generations now to provide colour varieties there does not seem to be any literature on inbreeding depression. Conversely however there is quite a lot of information becoming available , mostly fish and insects unfortunately, as to outbreeding depression when animals from other areas are released into wild populations. It seems that each population may have evolved for particular microclimates and other microecological factors. Any reports to populations which do show inbreeding depression would be very welcome as this could be very useful for the Sand Lizard Lacerta agilis recovery program. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 21 Feb 2003
Topic: B.H.S.Cons.cttee tasks
The British Herpetological Society Conservation Comittee runs conservation tasks every other Sunday from the end of September through to March. These are held at the moment in Dorset and Hampshire. The tasks remaining for this year are 2nd March, Branksome Dene Chine. 16th March Ham Common Poole 30th March Green Pool nr.Wareham. April a survey Sunday will be held going to several reserves around Bournemouth. The work will consist of scrub removal from heathland or areas next to heathland to increase the growth of Heather for the Sand Lizard and Smooth Snake as well as the more common species. Anyone interested in helping out with habitat management with the oldest reptile & amphibian conservation group in the country contact David Bird for furter details British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 27 Feb 2003
Topic: Alien or not?
I did not realise when I saw the title of this section the other day that it was not to do with Alien species of herpetofauna. Alien Aquatic Macrophytes are however a subject very close to my heart and sadly neglected by herpetologists and especially pond owners who are the cause of many of the problems. I would like to say that the fringed water lily Nymphoides peltatus is thought to be native in the Thames Valley and East Anglia having been known since the 1500Æs, the present distribution is due to deliberate movement of wild plants and the release of cultivated stock which is probably from European stock. Although this species does form large dense masses I do not know of any problems with the amphibian or invertebrate population where it occurs in Dorset. I do have slides of close ups of the plant and also extensive cover of ponds in Dorset and the New Forest if they are of any use to the site and anyone has a scanner. The species which is causing a problem in Hampshire and elsewhere is the New Zealand Stonecrop Crassula helmsii which can survive in water of varying depths growing across the surface of deep water and growing up to the surface30 cm from the bottom in ponds and even on dry gravel and heathland soil under gorse in the New Forest. I t produces a dense monoculture and is a problem for rare British aquatic plants and does seem to reduce the amount of invertebrates in a pond, it also seems to dry out non permanent ponds faster in the summer which may not give some amphibians enough time to metamorphose. It is almost impossible to eradicate and can be spread by animals and on footwear. It is still being sold by garden and aquatic centres and being released into wild ponds by ôwell meaningö pond owners when they clean out there own ponds at home..Again I have slides of this species. A species that is becoming a problem in the home counties is the floating pennywort Hydrocotyle rannunculoides from N.America that is now a problem in S. & C.America. It does form huge mats and can be a problem for boats on canals and rivers but as we do not have it yet in Dorset or Hampshire I cannot comment on its effect on amphibians or aquatic invertebrates but do not think it is going to have a positive effect. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 11 Mar 2003
Topic: Rate of neoteny in smooth newts?
What type of ponds were these neotenous newts found in ? I remember having several ponds on an industrial site that was previously an army camp just west of Taunton, Somerset. It had brick lined emergency water supplies for fire fighting which were about 4 metres deep and walls about 1 metre above the ground so were probably only topped up by rain water and not that easy to climb out of. The species involved were Smooth Newts but these soon lost all gills when put into normal tap water so was probably due to the lack of vital minerals in the pond water. I visited a similar pond where I had been informed that neotenic Great Crested Newts had been seen but this pond had several new looking holes in the brick wall and only a few normal specimens were seen. This was in S.E.Somerset on an old Quarry site that had been infilled with domestic refuse and leachate was being sprayed into the air close by and probably containing all sorts of nutrients and other chemicals. I then found specimens of neotenic Palmate Newts in a pond, possibly a dew pond, on the top of a chalk hill in central Dorset. The field was ploughed and was used for growing cereal each year, there was just a band of marginal plants around the pond a few feet wide so very little suitable terrestrial amphibian habitat. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 11 Mar 2003
Topic: Wall Lizard [I]Podarcis muralis[/I]
Dorset has several colonies of Wall Lizard that seem to have been fairly recently set up (less than 10 years). Several of these are in fairly isolated areas with very few native reptiles. One however is in an area where Sand Lizards used to occur. These now have not been seen for a number of years although the habitat is difficult to survey and it is not known if they are still present in areas where one cannot reach or if habitat changes that have occured may be responsible for their disappearance. Habitat management has been carried out recently and a more thorough survey will be made in the spring. Has anyone else seen any reduction in native reptile species where Wall Lizards are now found British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 13 Mar 2003
Topic: Fate of Frogs Spawn in Temporary Pools?
I have always considered wet winters or early spring to be bad for the Common Frog. Whilst on their way to larger ponds they will stop off and breed in the shallowest of water. In Poole I have found frog spawn in the flooded goal mouth of a football pitch with just a few centimetres of water, on one local nature reserve I often find spawn in a wood in damp leaves where there is at the most 1 centimetre of surface water after periods of rain although a marshy area that has had deeper areas dug out specifically for spawning is only a metre or so away. I have found that none of this spawn has a chance to produce small frogs as if the eggs or tadpoles do not dry up or are rescued the tadpoles usually become food for local birds. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 14 Mar 2003
Topic: Fate of Frogs Spawn in Temporary Pools?
Gemma I have seen several lots of spawn in the last few days in shallow pools in a quarry I have been clearing gorse from. The tadpoles are still in or on the egg mass and seen to be feeding on the algae that has turned the surface of the albumen green. I think they also feed on the decaying albumen. I moved some tadpoles from one pool that I knew was not permanent and quite shallow with just a small Yoghurt pot the only thing I had to hand. The tadpoles were on the top of the albumen in the centre and easily flowed into the pot when I carefully lowered it into the mass. One batch had tadpoles that still had their gills whilst another was older with no external gills so you may be lucky if there has been no disturbance to the eggs. Take a freezer box or bucket rather than the small pot I used and you may be able to scoop up the whole egg mass with all the tadpoles. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 18 Mar 2003
Topic: Early adder sightings
I Adder seen on a bank where I know there are several more on 21 February nr Wareham Dorset. Bright sunny day also out on 24 February so individual animals do vary when they come out of hibernation. Another site on Poole Harbour had 3 adult and 1 juvenile Adder out on 2 march Sand Lizards also on the same site and numerous Wall Lizards on a site close by were also out. This last species comes out on any sunny day throughout the winter. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 29 Mar 2003
Topic: rescued tadpoles
Feeding Tadpoles.. I have always found that when growing tadpoles it is best to feed vegetable material for as long as possible and often I give no animal protein at all. This is not just for Common Frog tadpoles but others such as Fire-bellied toads and treefrog tadpoles. The reason for this is that the use of animal protein seems to speed up the process of metamorphosis and one gets very small newly metamorphosed froglets which require very small live food. On plant material the tadpoles will grow larger and develop into larger froglets which are able to feed on a larger size range of live foods. I have always used Beet Spinach which is also known as Perpetual leaf Spinach or Chard which one can buy in supermarkets as a bag of frozen leaves or cubes of chopped leaves. This is the food that the Amphibian unit of Hiroshima University used. Some animal material can be given once the back legs are growing and this can be fish flakes or pellets or earthworms or meat in small amounts. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 31 Mar 2003
Topic: rescued tadpoles
Gemma The plant looks like Water Starwort Callitriche sp. Have never found this to grow too well when transferred to a fish tank or pond at home. It does damage quite easily and the tadpoles are probably eating the leaves as they begin to die. The spinach is par cooked before being frozen and the tadpoles get straight on to it. The one thing we always did at Poole Aquarium was to remove any fast growing tadpoles from the trays and put them together as they will inhibit the growth of the smaller ones and eventually feed on them so if you can always keep similar sizes together and do daily 1/4water changes to remove inhibitors and cannibalism should be almost non existant. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 01 Apr 2003
Topic: Is the Common Lizard thriving?
Howard, I have a site which never had any Common Lizards on only Sand Lizards until a few years ago, we now do see them on most survey days. I have certainly seen reasonable numbers on some of the small urban sites but not so many on some of the larger heathland sites as I remember seeing in the past. I am sure that the reduction by grazing of some of the Molinia and other grass areas, where I used to see most of them may have helped the decline. Dave British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 04 Apr 2003
Topic: Common Frog Identification & Sightings
6.3.03 Common Frog Tadpoles on Spawn 5 clumps Quarry nr Wareham Dorset. 28 .3.03 Common Frog Tadpoles Many in pond and many in water filled holes in meadow about 20 metres away all drying out. Tadpoles moved into larger pond . Broadstone. David Bird British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 05 Apr 2003
Topic: Early adder sightings
Had a report earlier in the week of male adders dancing from the warden of a local nature reserve. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 06 Apr 2003
Topic: Bull Frog Information required
Had 2 calling adult males in June 1993 Hatch pond L.N.R. Caught one in a pond dipping net the other one was not captured up to July and disappeared. Tried seine net, boat and trying toshoot it. I did have it hanging on to a dead sand eel tied on fishing line on a roach pole and had it about 1 metre above surface but it dropped off as I tried to get it over reeds and get a net under it obviously a 2 man job. Had about 6 from garden ponds from 1992 -5 none since. Most of the people who had them did not put them in their pond but it was neighbours who had the tadpoles in their garden. Have slides and tape recording of very noisy call. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 09 Apr 2003
Topic: Is Aesculapian snake still around?
Aesculapian Snake. I have never been to the North Wales site and have no up to date information but a friend told me about a colony in central London at one of the royal parks a few years ago where he had found immature specimens showing breeding had occured. In all the years I have been visiting the Balkans with hundreds of days in the field I have only seen one adult specimen and found an area in Croatia where quite a few juvenile individuals were seen, so they are not that easy to find in the wild from my experience. Wall Lizard Podarcis muralis all the colonies I have visited Isle of Wight, Somerset, 4 in Dorset, Hampshire and the Sussex coast are of this species. Some look like the Italian subspecies Podarcis muralis nigriventris syn. P.m.brueggemanni whilst a few look like populations from France which are P.m.brogniardi. There is a paper Quayle ,A. & Noble,M. 2000 The Wall Lizard in England British Wildlife Dec.2000 99-106 and a small folded A4 leaflet produced by Ventnor Regeneration Forum,Island 2000 Trust and Wight Wildlife on the Wall Lizard at Ventnor. I do not know of any other species of Podarcis that have become established, I know several people have tried with Podarcis sicula in gardens in the past but they have all disappeared from the site of introduction extremely quickly never to be seen again. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 10 Apr 2003
Topic: Wall Lizard [I]Podarcis muralis[/I]
The release of any non native species is against the law. Wildlife & Countryside Act 1981 Pt 1 section 14 (1) Subject to the provisions of this part, if any person releases or allows to escape into the wild any animal which- (a) is of a kin which is not ordinarily resident in and is not a regular visitor to Great Britain in a wild state; or (b) is included in Part 1 of schedule 9. he shall be guilty of an offence. The common Wall Lizard is on the list in Pt.1 of schedule 9. of animals which are established in the wild. From a personal point of view I do not consider that colonies that are on the coast on rocky cliffs or on shingle beaches and garden walls are a threat to any native species. Some people have tried to proove that some populations are relict native populations and as such should be given strictly protected status. I do not think the introduction onto heathland cliffs in Dorset where the endangered Sand Lizard lives was a good idea and I am rather worried that the Wall Lizard is thriving possibly at the expense of the Sand Lizard. Certainly with the Wall lizard the numbers of young that can be produced each year by a female I do not feel that if people do go to any of the sites and collect a few specimens to keep at home they are going to have much effect on the population. Obviously it is illegal and irresponsible to release any specimens caught anywhere else in the wild. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 11 Apr 2003
Topic: Is Aesculapian snake still around?
Lee the book was probably Christopher Lever's The Naturalized animals of the British Isles. I will try to get a list together of books and papers on the introduced species in the next few days and post it with the other bibliographies. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 24 Apr 2003
Topic: Some neo shots
I have used a 135 mm or now use an Olympus 75-150 mm zoom usually with a No.1 or 2 extension tube so that one is not too close to the reptile to disturb it too much. I have found that by approaching calmly and quietly without too much direct eye to eye contact one can get shots where the animal is not staring at the lens. If the animal does look up one can stand, kneel or lay still for a few minutes often the animal will relax and look away in another direction. I never pose any animals for normal shots only for back patterns or head patterns for survey database. I do not like posed pictures which are usually the ones published and are often quite obvious with moss as a setting and fill in or worse still ring flash reflection from scales or eye. I personally would rather see a less sharp photograph or a shot taken from further away if it is an in situ picture showing some of the natural habitat, I also like to see photos of how one finds reptiles in the wild where they are often camouflaged or slightly hidden as this gives newcomers a better idea on what to look for when out in the field. Often when I go out with people they are surprised at how I see animals before they see me and they often say that they would never have seen them and often do pass by them until I point them out. I am sure they expect to see the animal standing out like they see in many books. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 28 Apr 2003
Topic: Drift fencing
Martin I always look upon drift fencing as being a way to move animals along to a central point where there is a bucket for capture at the tip of a funnel shape fence. The idea is to angle the fence to try to get the animals to move to the central point. An exclusion fence should be a closed structure and joined all the way round to stop animals getting in or out which ever is needed at the time. I know that some people do tend not to put up a fence where there is very unfavourable habitat such as concrete, tarmac or bare sand and gravel mainly to save money and the difficulty of putting up a fence on such a base. I do turn the fence back on itself in such a situation as it seems obvious to me you want to return the animal to its proper side of the fence and not allow it to crawl around it. I have seen many awful exclusion fences put up by people who are putting themselves about as experts in the consultancy and translocation field. I have seen fences made of geotextile which allows lizards to run up and over in both directions and ones that are put up on 1" by 1/2' roofing lathes that get broken by the local children within a few days and the fence lays on the ground for the rest of the operation. I cannot see how these fences are allowed by the powers that be who should keep an eye on this blatant shoddy unprofessional workmanship but it still seems to go on in Dorset. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
|
David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts in this topic |
Posted: 30 Apr 2003
Topic: Sad stuff folks
Did it look as though the site was previously solid trees with no heathland habitat underneath or was there heather underneath that could have sustained other reptiles. I am totally against the use of any machinery going anywhere on sites that may have suitable habitat hanging on and the possibility of reptiles on. It does not matter how careful the workers are supposed to be they are sitting high up in a massive machine where 20 cms of heather or even a 50 cm boundary bank means very little, they tend to want to move the quickest way from A to B and do not worry what is in between. When clear felling of forestry plantations is involved I am afraid economic considerations are looked upon as the most important, the price of timber is very low. The excuse one gets if one complains and if it is in the name of conservation rather than commercial forestry is that the end result will far outweigh the few animals that are killed or have their small amount of habitat destroyed. It is far too late in the season to be working on heathland sites for conservation purposes especially with machinery. Hope you have more success than I have had in the past. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
- Posts by David Bird |