The Effects of Climate Change on the Breeding Behavior and Migration Patterns of Birds and Mammals. Dr. Susan Longest Colorado Mesa University

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1 The Effects of Climate Change on the Breeding Behavior and Migration Patterns of Birds and Mammals Dr. Susan Longest Colorado Mesa University

2 How much do we know? 1 st paper on climate change in birds in 1991 (Peter Berthold) In 2010 alone almost 300 papers, much of it descriptive Causation versus correlation Intensification of agriculture Forestry and fisheries Urbanization (fragmentation) Increased pollution

3 How do animals react and adapt when their environment changes? Intra- and interspecific variation Earlier timing of migration Breeding earlier in spring Longer annual breeding cycles Breeding at higher elevations Altered patterns of departure from breeding grounds (autumn migration) Wintering grounds and breeding grounds shifting northward

4 How do animals react and adapt when their environment changes? Problem: Rapid climate change Adaptations that may have been possible for gradual climate change cannot keep up with this pace Natural selection vs. Phenotypic plasticity Evolutionary change vs. individuals adapting to changing conditions during their lifetime

5 Outline Climate Change and Changing Sea Levels Migration Breeding Behavior Citizen Science/Next Steps Mammals in South Africa

6 Climate Change and Rising Sea Levels Global temperature increase of 0.7 C during last century (mostly last 100 years) Temp. increases distributed unevenly across globe Dramatic increases at high altitudes and latitudes Sea levels rose by cm in last century Arctic ice sheet Avg. decrease of 7.4%/decade since 1970s Several records in ice melt in recent years Advancing spring phenologies due to decrease in snow cover in northern hemisphere Climate Change Working Group 2007, Masson-Delmotte et al. 2003

7 Climate Change and Rising Sea Levels Subtropics: temperature and precipitation mostly affected Increase in dry conditions and accelerating desertification Tropics: modest changes in temperature Changes in sea level and frequency of tropical storms Negative impacts on birds in coastal areas Affects oceanic islands with high #s of endemics Climate Change Working Group 2007

8 Climate Change and Rising Sea Levels

9 Climate Change and Rising Sea Levels

10 Climate Change and Rising Sea Levels

11 Climate Change and Rising Sea Levels Mountain ranges Shift of species to higher altitudes Low-altitude vegetation and associated fauna shift north High-altitude species have no other place to go

12 Migration Adaptation to exploitation of seasonal environments As temps increase, migrants can change to residents over a few generations (Berthold 2001) Hooded crow, common blackbird, European robin

Southern ocean Increased natal dispersal distances by 75km over 60

13 Long-Distance Migrants Arctic Tern Breed in temperate & Arctic regions of northern hemisphere Winter in Antarctic parts of Southern ocean Increased natal dispersal distances by 75km over 60 years Related to climatic conditions on breeding grounds and wintering grounds

14 Long-distance migrants respond less to climate change than short-distance migrants Long-distance migrants may arrive later b/c: Timing of migration may be under influence of conditions in winter grounds (often 1000s of km away from breeding areas) Weak or absent response of endogenous rhythms for determining departure for breeding areas

15 European Pied Flycatcher Steadily advancing breeding dates over past 20 years No advance in spring arrival date Winters in western Africa Breeds in Europe & Asia

16 Early Spring Arrival Due to faster migration, earlier autumn departure, & use of wintering grounds closer to breeding areas Many North American species migrate more quickly across US in warmer years (Marra et al. 2005) Northward shifts in wintering grounds (Ambrosini et al. 2011) Barn swallows and European pied flycatchers now in Mediterranean versus tropics

17 Early Spring Arrival Study on spring arrival dates of 455 species over durations of years 82% showed tendency for earlier arrival Earlier arrival by 0.28 days/yr for 1 st arrival dates Significant effects of species and geographic regions Lehikoinen & Sparks 2010

18 Why does arrival date matter? Early-arriving individuals have higher mating and breeding success (Moller 1994) Bird migration under intense selection Matching between timing of breeding and peaks in food supply (Lack 1954) With increasing temps, food supply shifts Some species match, some mismatch (Dunn et al. 2011)

19 Mismatching in Great Tits Charmantier et al. 2008

20 Earlier Laying Dates 59% of 68 species from Europe & North America have significantly advanced their laying date (Dunn & Winkler 2010) 79% advanced their laying date during last few decades when temps increased Advance date by 0.13 days/yr Differences across populations based on temperature

21 Number of Clutches Per Year Single most important factor explaining advancement in laying date Species with multiple clutches advance laying date less Harder to time clutches to peak food abundance

22 Variation in Early Breeding Selection for early breeding has increased in recent years in only ½ the studies European pied flycatchers, great tits, common murres, arctic terns Equal # of studies show no evidence of change in directional selection Dunn & Winkler 2010

23 Barn Swallows Started breeding earlier in recent years Increased interval b/t 1 st and 2 nd clutch by more than 10 days over 40 years Allows females time to recover Reproductive success almost doubled between clutches with shortest and longest intervals between two clutches

24 Duration of Breeding Season Interspecific variation Analyzed 20 bird species in Denmark Breeding season +/- 36 days Directly related to mean temp during month when breeding started

25 What We Know Different species vary in their response to climate change The advancement in arrival date is clear and highly significant Geographical patterns of advancement in arrival date follow geographic patterns of climate change

26 Next Steps Further research and identify problems Problem: Lacking long-term datasets on birds of known breeding origin (banded birds) Census efforts for monitoring populations over time = Bird Counts!

27 Upcoming Bird Counts Dec. 15 th : Christmas Bird Count May: Spring Migratory Bird Count Grand Valley Audubon Society

28 Citizen Science Data Some issues with sampling effort Crucial resource for monitoring bird populations ebird.com Western Slope Birding News listserv (wsbn)

29 18 species studied Citizen Science Data Shift in arrival date of 0.8 days earlier for every C increase in spring temperature Species with earliest arrival dates: Migrate more slowly Short-distance migrants Broader climatic niches Hurlbert & Liang 2012

30 Golondrinas de las Americas

31 Tachycineta Locally

32 Lajuma Research Center

33 Lajuma Research Center

34 Interested in Getting Involved? Susan Longest Grand Valley Audubon Society WSBN

Foreword. Climate Change and Birds. Introduction

Foreword. Climate Change and Birds. Introduction Foreword Climate Change and Birds Introduction Mean annual specific net balance (mm w.e.) 2-2 -4-6 -8-1 -12-14 -16 198 1982 1984 1986 1988 199 1992 1994 Year 1996 1998 2 22 24 26 Figure 1 Melting of glaciers