Climate change and biodemographic performance in a

mountain ungulate

Warm temperatures are bad for Alpine ibex (Capra ibex)

1

Carole Toïgo

Daniel Blanc

François Couilloud

Daniel Maillard

©Rodolphe Papet

2

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Climate warming

Source: IPCC

3

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Climate warming

Particularly pronounced in arctic and alpine

ecosystems with the melting of the ice cap

4

Winter is the most critical period because of

food shortage, NRJ expenditures linked to

thermoregulation or moving in snow…

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Climate warming in alpine/arctic ecosystems

duration of the harsh period

>0

5

>0 impact

Garel et al. 2011

Richard et al. 2013

body mass

horn length

<0 impactBUT

Mason et al. 2011

body mass

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Climate warming in alpine/arctic ecosystems

Pettorelli et al. 2007

juvenile survival

Büntgen et al. 2013

horn length

Davis et al. 2016

survival

Plard et al. 2014

juvenile survival

6

• Idiosynchratic responses to climate change: species-, site-, trait-

dependent

• Many studies encompassing contrasted situations necessary to

understand the global impact of climate change

• In that context, we aimed at studying the impact of climate warming on

Alpine ibex performance, taking advantage of a long-term CMR monitoring

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Climate warming in alpine/arctic ecosystems

Alpine ibex performance, taking advantage of a long-term CMR monitoring

©Virgil Decourteille

©Pascal Ghiette

©Carole Toïgo

7

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Study area: the Belledonne massif

Haute Savoie

SavoieIsère

Haute Savoie

Savoie

Isère

DrômeHautes Alpes

Belledonne

Drome Hautes Alpes

Alpes de Haute

ProvenceAlpes maritimeNumbers of Ibex

1995 : 4630

2000 :

DrômeHautes Alpes

Alpes de Haute

Provence Alpes maritime

8

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� The study population

Reintroduction in 1983 of 7 males and 13

femelles from the Swiss population of

Mont-Pleureur

Altitude: 1200-2900m asl

~1000 individuals in 2017

99

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� The study area and spring/summer temperatures

6

7

8

9

10

11

12

13

1985 1990 1995 2000 2005 2010 2015

°C

year

April-May temperature

135

145

155

165

175

185

1985 1995 2005 2015ju

lia

n d

ate

date of the peak of plant

productivity (GDD 800)

Spring

earlier onset of vegetation growth

forage quantity +++

accelerated vegetation growth at

any elevation

forage quality ---

~ 2 weeks shift of the peak of

plant productivity

yearyear

1,8 °C in 30 years

forage quality ---

Summer

14

15

16

17

18

19

20

1995 2000 2005 2010 2015

°C

year

July-August temperature

2 °C in 20 yearsacceleration of plant

senescence

forage productivity

NRJ expenditure linked to

thermoregulation and

behavioural adaptations

Ibex

performance

??

<0

10

Captures each spring since 1986 From1986 to 2016

� ~ 1200 captures

� 350 females

� 680 males

� 153 recaptures

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� The study population: long-term CMR monitoring

individual identification body measurements

Survival rate

Individual reproductive successHorn length

11

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� The method: classical Capture-Mark-Resighting models

dies

survives

not seenyear t

seen

11100001100000000000000000000

00000011111111001101000000000

00000000000000000011111111111

etc…

not seen

E-SURGE with spring or summer

temperatures of the current year

year t+1

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

age-class

surv

ival

femalesmales

1 2-7 8-12 >12

Separated analyses for males and

females

4 age-classes classical for ungulates

temperatures of the current year

as external variables

12

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Sex-dependent impacts of spring and summer temperatures

Strong sexual size dimorphism:

Males and females have different NRJ requirements (Demment & Van Soest 1985)

Summer temperature

Su

rviv

al

Males

Males have lower survival rates during

1-8 yrs

8-12 yrs

>12 yrs

high quality foragehigh quantity of forage

+

strong NRJ expenditure

for thermoregulation

summer conditions

spring conditions

Males have lower survival rates during

years with hot summers

Spring temperature

Su

rviv

al

Females have lower survival rates during

years with warm springs

Females

1-8 yrs

8-12 yrs

>12 yrs

13

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Female individual reproductive success

Prime-age females (4-12 years)

Reproductive Success(RS):

for each marked female, whether she was seen

with a kid or not during summer

Mixed model:

lmer(RS~Tspring(t-1)+Tsummer(t-1)+Tspring(t)+1|individual)

RS=reproducing females whose kid survived the

neonatal period

ibex=capital breeder

female condition at conception

and for next gestation

female condition during

late gestation and early

lactation

14

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Reproductive success decreases after hot summers

Re

pro

du

ctiv

esu

cce

ss

Only the temperature of the previous

summer had a significant effect

Summer temperature

Re

pro

du

ctiv

e

During hot summers, food condition may be unfavorable for females to

recover sufficient body reserves to deal with next gestation

Female reproductive success decreased in years following hot summers

15

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Different measures of male horn length

age

tota

l ho

rnle

ntg

h(c

m)

Cohort effects

HL ~ Tspring + Tsummer

Total horn length (HL)- 1st increment

corrected for age

Annual horn increment (IL)

Horns=Indirect fitness components

honnest signals of individual quality

determinant of male Reproductive

Success

ageHL ~ Tspring(coh)+ Tsummer(coh)

Mixed model:

IL~lme(age+Tspring(t)+Tsummer(t)+1|individual)

0123456789

1011121314

0 1 2 3 4 5 6 7 8 9 10 11 12

cm

age

16

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Spring temperature negatively affects horn growthto

tal h

orn

len

gth

Incr

em

en

tle

ng

th

Total horn length:

Males born during warm springs will have

short horns throughout their life

spring temperature the year of birthspring temperature (°C)

Annual horn increment:

Each male grows shorter increments during

years with warm springs

Forage quality

horn growth of males through maternal

condition (cohort effects) or direct food

intake

17

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Warm temperatures are bad for ibex performance

• In our study site, warm springs or summers negatively affect survival rate

of both sexes, female reproductive success and male horn growth

• Food availability (quality and quantity) and NRJ expenditures linked to

thermoruglation may explain such negative correlations

• BUT further studies are necessary to confirm these hypotheses• BUT further studies are necessary to confirm these hypotheses

- Direct relationship between climate and vegetation

productivity at different altitudes (since 2013)

- Direct relationship between climate and ibex

behaviour and physiology: GPS with

accelerometers (since 2017)

18

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Where are ibex going to?

•Several species newly colonized

mountain habitats

©Virgil Decourteille

19

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Where are ibex going to?

•Several species newly colonized

mountain habitats

©Virgil Decourteille

20

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Where are ibex going to?

•Several species newly colonized

mountain habitats

• or moved towards higher altitudes

©Virgil Decourteille

21

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Where are ibex going to?

•Several species newly colonized

mountain habitats

• or moved towards higher altitudes

©Virgil Decourteille

22

Introduction - Site & Methods –Survival – Reproduction – Horn Length – Conclusion

� Where are ibex going to?

• In most sites, ibex already exploits

almost the whole available altitudinal

range

•Several species newly colonized

mountain habitats

• or moved towards higher altitudes

?

What future for the species???

• No possibility to follow the shift in the

suitable niche

range

©Virgil Decourteille

Thanks for attention23

©Nicolas Van Inghen