Body
The aim of this protocol is to give a guidance for measuring the habitat suitability of ponds for Great Crested Newts in particular for the reserve 'Woodhouse Washlands'.
It is meant to work alongside newt population surveys from March until end of June.
A further goal is to identify specific habitat management priorities to strenghten the area as a potential hotspot for Great Crested Newt populations. A total 9 of 14 ponds (2;3;4;5;6;;11;12;13;14) have to be surveyed at Woodhouse Washlands (see map attached).
Key attributes
- 0.9ha of open water habitat (ditches, ponds and scrapes). (Not to be measured in these surveys, will be done in future surveys using remote camera footage analysis of drone recordings).
- 8 ponds with HSI score of ≥0.7 based on Natural England guidelines.
- Population of great crested newt estimated between 11-100 individuals (or larger)
Skill level
Most of the measurements don't need a high skill level but some basic estimation abilities. Pond permanence should be estimated by a person with a higher knowledge of the local environmental conditions and seasonal changes of the ecosystem appearance. Some skills in identification of animal and plant species may be useful but are not essential. As the surveyed areas are very likely to be uneven, slippery and boggy, the surveyors can't be severely physically limited.
Materials/equipment
- Map
- Weather writer and pen/pencil
- survey sheets
- Instructions/Criteria
- waterproof clothes
- rubber boots or chest waders
- disinfectants
- throw line
Timing
From March until the end of June
Method
This method is just a summary because of the sensitivity of GCNs
GCN Survey Method
The GCN surveys took place at Woodhouse Washlands reserve on 6 visits from March until the
end of June.
A total of 10 ponds were surveyed per visit (2;3;4;5;6;7;;11;12;13;14) (Figure 1).
Before sunset bottle traps were set and an egg search was conducted at each pond.
Each pond was torched 1 hour after sunset and the number of each target species was
recorded.
The next morning bottle traps were checked and the number of each target species recorded.
Target species include:
Great crested newt, Triturus cristatus
Smooth newt, Lissotriton vulgaris
Palmate newt, Lissotriton helveticus
Common frog, Rana temporaria
Common toad, Bufo bufo
Habitat suitability index
The Habitat Suitability Index (HSI) by Oldham et al. (2000), modified by ARG UK (2010), is used to evaluate the quality of a surveyed pond as a potential habitat for Great Crested Newts. The HSI is a numerical index between 0.01 and 1, values close to 0 (not less than 0.01) indicate unsuitable habitat, 1 presents optimal habitat.
HSI Pond suitability
< 0.5 - poor
0.5-0.59 - below average
0.6-0.69 - average
0.7-0.79 - good
> 0.8 - excellent
The HSI is a geometric mean of ten factors, all of which are known to affect this species.
HSI=(SI1 x SI2 x SI3 x SI4 x SI5 x SI6 x SI7 x SI8 x SI9 x SI10)1/10
But as explained later in this protocol, one of the indices (SI4) should be omitted from the calculation, so the following formula will be used to calculate the HSI:
HSI = (SI1 x SI2 x SI3 x SI5 x SI6 x SI7 x SI8 x SI9 x SI10)1/9
Three of the indices can be achieved by desk studies under use of GIS or alternative programs. The other six indices have to be worked out on site.
Factors:
- Geographic location
- Pond area
- Pond count
- Permanence
- Water quality (not surveyed as part of our monitoring protocol)
- Shade
- Waterfowl
- Fish
- Terrestrial habitat
- Macrophytes
References
ARG UK (2010). ARG UK Advice Note 5: Great Crested Newt Habitat Suitability Index. Amphibian and Reptile Groups of the United Kingdom.
Oldham R.S., Keeble J., Swan M.J.S. & Jeffcote M. (2000). Evaluating the suitability of habitat for the Great Crested Newt (Triturus cristatus). Herpetological Journal 10(4), 143-155.