1. New high-speed rail-road SEA between Tours and Bordeaux
Evaluation of the use and effectiveness of underpasses implemented to maintain optimal permeability for semi aquatic mammals
P. Fournier, T. Charlemagne, D. Quintard, C. Bout, F. Gillet, E. Laoué, V. Maurie, N. Tranchant, L. Palussière, V. Leduc, A. Bigot, J. Michaux and C. Fournier-Chambrillon

2. LGV SEA Tours-Bordeaux underpasses Introduction
Context
Construction of 302 km of new hight-speed rail-road between Tours and Bordeaux (Sud Europe Atlantique).
High level of mitigation measures for continuous connectivity and permeability for semi-aquatic mammals (European mink, Otter).
Equipment with wildlife passages of every steam, from little ditches to main watercourses.
173 hydraulic bridges or culverts equipped with various types of walkways.

3. LGV SEA Tours-Bordeaux underpasses Introduction
Types of walkways depending of the hydraulic configuration:
Natural banks (NB).
1 to 3 concrete steps (S), on an unique or on both sides.
Pipes (P) drying out quickly.
Steps locally with hiding places or hiding lateral channels for micro mammals. NB NB
1S + 1S
3S + 3S 1S P

4. LGV SEA Tours-Bordeaux underpasses Introduction
A long term monitoring to evaluate the use and effectiveness of underpasses for micro to medium sized mammals, before and after commissioning.
A first 5-years monitoring of 159 underpasses, including 10 underpasses monitored every year to evaluate the evolution of effectiveness with time.
45 underpasses monitored in 2015 (3 x 30 days).
2012
2013
2014
2015
2016
2017
2018
2019 ….
2024
2025
Start of levelling works
Construction of the rail-road
Commisio-ning tests
Normal train traffic
Field work survey
Monitoring of corridors during diversion
10 underpasses (method’s adjustments)
10 underpasses monitored every year
149 underpasses monitored once
....
every 5 years
End of diversion

5. LGV SEA Tours-Bordeaux underpasses Evaluation of use and effectiveness
Material and methods
Five complementary methods for mammal detection:
Monitoring of Otter spraint places.
Ink footprints traps, targeting all micro to medium-sized mammals.

6. LGV SEA Tours-Bordeaux underpasses Evaluation of use and effectiveness
Material and methods
Hairs-trap tubes targeting small mammals.
Faeces-trap tubes targeting shrews.
Camera traps, to study the behaviour of the animals.
Faeces-trap tube
Hair-trap tube

7. LGV SEA Tours-Bordeaux underpasses Evaluation of use and effectiveness
Results: Specific monitoring of Otter
45 underpasses, 252 spraint places, 474 “check-places”.
All underpasses are used where the species is common, as long as habitats upstream are substantial and attractive.
Ongoing recolonisation
Rivers where the species is common

8. LGV SEA Tours-Bordeaux underpasses Evaluation of use and effectiveness
Results: Ink footprints traps
33 underpasses: 91 steps, 1 pipe, 48 riverbeds where walking is possible.
Checking every 10 days, identification of species or groups (23 items), specific diversity, number of crossing.
18 non-domestic species (2 to 11 Sp/udp; Mean = 7  2 Sp/udp).
3853 crossings through all underpasses and 133/140 walkways.

9. LGV SEA Tours-Bordeaux underpasses Evaluation of use and effectiveness
Results: Ink footprints traps
483 crossings of small carnivores in 31/33 underpasses and on 70/140 walkways.

10. LGV SEA Tours-Bordeaux underpasses Evaluation of use and effectiveness
Ink footprint traps: Different walkways’ level preferences according to the species. (² test, conformity with theoretical distribution of number of crossings walkway significantly preferred, trend but too small sample to be tested.)
Genet
Stone & pine marten
Micro mammals
PRA 2546
Otter
Weasel

11. LGV SEA Tours-Bordeaux underpasses Evaluation of use and effectiveness
Results: Hairs- and Faeces-traps tubes
23 underpasses: 835 faeces-traps tubes &1020 hair-trap tubes, on the walkways and outside the underpasses, genetic species identification.
10 micro mammals species.
6 detected on the walkways.

12. LGV SEA Tours-Bordeaux underpasses Evaluation of use and effectiveness
Conclusions :
Preliminary positive and promising results, with good complementarities between the monitoring methods:
All underpasses used by the Otter where it’s common, as long as habitats upstream are substantial and attractive.
All underpasses used at least by 2 non-domestic species (mammals + amphibians).
31/33 underpasses used by small carnivores (at least 5 species detected), with some walkways’ level preferences according to the species.
6/10 detected micro mammals species used the underpasses.
7 underpasses monitored both in 2014 and 2015, showed an increase with time of the number of detected species.
The 5-year study of 159 underpasses will be essential to correctly evaluate and compare the crossing of the species through the infrastructure.

13. LGV SEA Tours-Bordeaux underpasses Evaluation of use and effectiveness
Thank you for your attention
Photos : GREGE, Robert Luquès (European mink)