Bombina variegata in Alsace (France). Results of the three ... · Long-term site occupancy...

Long-termsiteoccupancymonitoringoftheyellow-belliedtoad

(Bombinavariegata)inAlsace(France).Resultsofthethreefirstsessions.

Jean-Pierre Vacher1, Hugo Cayuela, Julie Reynaud, Julie Lambrey

1BUFO, 8 rue Adèle Riton, 67000 Strasbourg. jpvacher@gmail.com

Bern,2.12.2107

Introduc@on

International

•  Loss of biodiversity

•  Amphibian decline

National and regional

•  Integration in the Natura 2000 network

•  Integration in conservation schemes: green corridors, “ZNIEFF”…

Introduc2on Materials&Methods Results Discussion

VUVulnerable

LCLeast

Concern

Introduc@on

Introduc2on Materials&Methods Results Discussion

Introduc@on

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NTNearlythreatened

Introduc@on

Introduc2on Materials&Methods Results Discussion

Questions

•  What is the population trend of the yellow-bellied toad in Alsace?

•  What are the variables that influence detection and occupancy?

•  3 natural regions

•  150 plots

•  Random selection of 4 subplots (n=600)

•  Binary response (0/1)

•  Biennial

Introduc2on Material&Methods Results Discussion

Sampledesign:Siteoccupancy

300m

300m

Introduc2on Material&Methods Results Discussion

Sampledesign:Siteoccupancy

Introduc2on Material&Methods Results Discussion

Occupancyanddetec@on

•  Occupancy (each year and between years)

•  Detection probability (each year and between years)

•  Extinction rate (between years)

•  Colonization rate (between years)

Package unmarked in R

2013 2015 2017 2019 …t

Introduc2on Material&Methods Results Discussion

Detec@onvariables

Cayuelaetal.2015(Pop.Ecol.)

Introduc2on Material&Methods Results Discussion

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•  Air temperature

•  Number of water collections per subplot

Detec@onvariables(fieldwork)

Occupancyvariables(GIS)

Introduc2on Material&Methods Results Discussion

•  Agricultural area (sampling plot + 1500m buffer)

•  Path density (sampling plot)

•  Habitat fragmentation (1500 buffer)

1500m buffer Sampling plot

Occupancyvariables(GIS)

Introduc2on Material&Methods Results Discussion

Softwares: GIS (R or QGIS) + FRAGSTATS

Results:monitoring

Introduc2on Materials&Methods Results Discussion

Results:GISanalysis

Introduc2on Materials&Methods Results Discussion

Occurrence Extinction

Sampling plot

Introduc2on Materials&Methods Results Discussion

Results:GISanalysis

1500m buffer

Occurrence Extinction

Discussion

Introduc2on Materials&Methods Results Discussion

2015 2017

Nochangeinlandusebetweenyears

Discussion

Introduc2on Materials&Methods Results Discussion

20

30

40

50

60

70

80

90

Mean precipitations in Alsace - 2017

Month

Me

an

(m

m)

Jan.

Feb.

Mar.

Apr.

May

Jun.

Jul.

Aug.

Sep.

Oct.

Nov.

Dec.

Alsace 2017

Seasonal norms

Discussion

Introduc2on Materials&Methods Results Discussion

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2015 2017

Droughtin2017

Perspec@ves

Introduc2on Materials&Methods Results Discussion

Distribu2onofBombinavariegata

2000-2015

Perspec@ves

Introduc2on Materials&Methods Results Discussion

Adjustments to the protocol

•  How many plots?

•  Where to place the plots?

•  Who will do the analyses?

Acknowledgements

For their help on the field in 2017:

•  Sarah Baouch (BUFO)

•  Aurélie Berna (BUFO)

•  Léa Merckling (RNN Petite Camargue Alsacienne)

For providing permits to access the forests

•  Office national des forêts

ThankyouforyouraNen@on!