Transcript PP Presentation

MAPPING ANIMAL FITNESS
ONTO SEASONAL CLIMATE CHANGE
F. Stephen Dobson
Department of Biological Sciences
College of Science & Mathematics
• GENERAL TOPIC: PHENOLOGICAL RESPONSES TO
CLIMATE CHANGE
• GENERAL PATTERN: earlier dates of spring phenology
with warming - including species at different trophic
levels in the same habitats
• PROBLEM: because trophic links are involved, there
may be mismatches between resources &
reproduction for some of the species
specifically, breeding and peak resource periods may not match up
e.g., peak insect abundances and nestling feeding by breeding birds
often coincide
Evidence of trophic
interactions
Budburst
Typical story of timing
across trophic levels
Caterpillars
1985 - 2005
This study compared
plant growth
insect development
4 species - song birds
an avian predator
Both et al. 2009, JAE
Sparrowhawks
• GENERAL TOPIC: PHENOLOGICAL RESPONSES TO
CLIMATE CHANGE
• SPECIFIC QUESTION: how much of the changes in
timing is due to:
• Plastic responses of phenotypes
• Genetic adaptations to new conditions
Breeding
Date
A
B
cool
warm
Spring temperature
Pattern:
Laying date is a week later than 20
years ago (b = 0.35 ± 0.05, p <
0.0001)
[due to lower fish food abundance]
Heritability = h2 = 0.36 (± 0.05)
Selection gradient = S = -0.10
Breeder’s equation: R = h2  S
Conclusion 1:
•natural selection favors earlier
breeding, not later breeding!
Conclusion 2:
•later breeding due to phenotypic
plasticity
Snow melted off significant later
Emergence from hibernation delayed
OVER 20 YEARS:
•Emergence 9.4 days later
Heritability = h2 = 0.23 (± 0.05)
Selection gradient = S = -0.14
Breeder’s equation: R = h2  S
Lower fitness with later emergence
Conclusion 1:
•natural selection favors earlier,
not later emergence from
hibernation!
Conclusion 2:
•later emergence due to
phenotypic plasticity
Population grew, then declined
Δ Fitness & Δ Climate:
Temperature: 28 June - 18 July
Summer temperature has gone up:
3.00
+4.4°C, mean = 16.5°C
2.50
Annual Fitness
Summer rainfall has gone down:
-3.7mm, mean = 2.5mm
Fitness has gone down:
y = -0.0977x + 2.9276
R² = 0.1833
2.00
1.50
1.00
0.50
r = -0.428 (P = 0.05), with temp
0.00
r = 0.548 (P = 0.01), with rain
11
12
13
14
15
16
17
18
19
20
Temperature °C
July Rain &
Temperature
Nov – Dec
Snowfall
3.00
0.468*
0.047
-0.032
December
Snowpack
April
Snowfall
after
Rainfall: 28 June - 11 July
0.046
-0.223
2.50
Annual
Fitness
Annual Fitness
April
Snowfall
before
2.00
1.50
1.00
y = 0.1201x + 1.0147
R² = 0.3
0.50
0.00
0
1
2
3
4
Rainfall °C
5
6
7
8