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Newts in Canals: |
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David Dodds Member Joined: 24 Jul 2004 No. of posts: 7  View other posts by David Dodds |
Posted: 18 May 2005 Hi Not sure why I didn't think of this last year, but... Whilst bat surveying along the Union Canal west of Edinburgh in August last year I encountered large numbers of small newts on the towpath one evening. At the time I assumed they were that year's young, leaving the canal in the same way as froglets and toadlets do. Thinking about it now, the canal must be the worst possible habitat for newts:
On the plus side the canal is host to a thriving and diverse invertebrate population, so there's no shortage of food. Can they really be breeding there? Any thoughts gratefully received! David |
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rhysrkid Senior Member Joined: 14 Nov 2003 No. of posts: 98  View other posts by rhysrkid |
Posted: 18 May 2005 I have found smooth newt to breed in and amongst reed beds of lakes as well as reedbeds which are contained within concrete walls (a polluted runoff treatment system - an equally unlikely location!). So they may also use marginal vegetation of canals such as reed beds, although I have never had the chance to observe this so cant say it definitely happens. Also on canals such as the Shropshire Union and Llangollen canal, one bank is often vegetated rather than a retaining wall. This often leads to small 'bays' and cut-off pools which could support amphibians. Vegetation can become quite diverse in these areas, especially if fenced off from livestock. Perhaps there are no other suitable water bodies and the newts are using the canal as an alternative? Alternatively, could they have dispersed from a nearby pond that was out of sight? Often along canals there are ponds and small balancing reservoirs designed to take overflow when water levels rise. These can sometimes be situated down slopes or in woodland and so be difficult to spot. What was the surrounding habitat like? Rhys |
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calumma Senior Member Joined: 27 Jun 2003 No. of posts: 351 View other posts by calumma |
Posted: 18 May 2005 Whilst growing up in Manchester, I would regularly find smooth newt breeding in the Rochdale Canal. Small newt species are able to tolerate a wide range of aquatic conditions. Lee Lee Brady Kent Herpetofauna Recorder | Independent Ecological Consultant |
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rhysrkid Senior Member Joined: 14 Nov 2003 No. of posts: 98 View other posts by rhysrkid |
Posted: 19 May 2005 Lee What sort of impact do you think the high levels of suspended solids have on their courting behviour? Or are they less dependent than crested newts on clearer water for the male displays/pheremone wafting? Canals are often very murky with poor visibility - even though water quality is usually quite good. Cheers Rhys |
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David Dodds Member Joined: 24 Jul 2004 No. of posts: 7 View other posts by David Dodds |
Posted: 19 May 2005 Surrounding habitat for the stretch of canal I described is: - Well-established cattle pasture on one side - Towpath, 3' retaining stone wall with open deciduous woodland behind on the other The nearest body of water is around 500m, though there may be small ditches etc. I've missed. The newts were on the towpath so they had emerged from the canal or the stone wall or climbed down the wall from the woodland. The wall has very little mortar left and is well-used by toads as a refuge - most nights theres one every metre or tow on the towpath. |
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calumma Senior Member Joined: 27 Jun 2003 No. of posts: 351 View other posts by calumma |
Posted: 19 May 2005 I'm not sure the high turbidity will have much of an impact on the newts. I regularly record newts from waterbodies that have high turbidity. The suspended solids probably have much more of an effect on our detectability of the animals. When I surveyed canals for newts in my younger days, animals were very often found along the towpath, usually between the grass verge and structures such as brick walls etc. Available suitable newt habitat along the Rochdale canal was limited to say the least! Lee Lee Brady Kent Herpetofauna Recorder | Independent Ecological Consultant |
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rhysrkid Senior Member Joined: 14 Nov 2003 No. of posts: 98 View other posts by rhysrkid |
Posted: 20 May 2005 Thanks Lee - i guess so long as they are able to detect each other it doesn't matter - would be a bit like blind date though! I would have said that from David's description, the surrounding habitat would be good with woodland for foraging and hibernation. Cheers Rhys |
- Newts in Canals |