1. Ecological Mechanisms of Adaptation in Red Squirrels Andrew McAdam Michigan State University

2. Ecological and Evolutionary Functional Genomics (EEFG) GenesGenotypePhenotypePhenotype’ Evolution Q. Genetics Genomics Development Selection

3. Integrating Evolutionary Approaches GenesGenotypePhenotype Q. Genetics / Genomics Development Selection Genotype Phenotype Phenotype’ Evolution Traditional Q. Genetics

4. "What we understand best about evolution is mostly genetic, and what we understand least is mostly ecological." - E.O. Wilson

5. Integrating Evolutionary Approaches GenesGenotypePhenotype Q. Genetics / Genomics Development Selection Genotype Phenotype Phenotype’ Evolution Traditional Q. Genetics

6. Kluane Red Squirrels

7. Feeding Observations n = 15,309

8. 3m  ~450 trees distributed systematically  Monitored since 1988 Spruce Cone Counts

9. Variation in Spruce Cone Abundance 0 1 2 3 4 5 6 198819901992199419961998200020022004 ln (count + 1) Year: F 15, 4337 = 312.3, P <0.001 dbh: F 1, 452 = 90.0, P <0.001 457 trees counted in multiple years Checked for changes in tree id and dbh

10. 0 20, 000 40, 000 60, 000 80, 000 100, 000 120, 000 140, 000 160, 000 198819901992199419961998200020022004 Cones per squirrel 1 year RMR ln(cones/tree) = 1.185 x ln (cone count); Jalene 15 trees in 5m radius = 1401 trees/ha; midden condition Territory size = 0.2ha; Jalene 80 seeds/cone 2.2 mg/seed 6.62 kcal/g 4.2 kJ/kcal =4.89 kJ/cone 1 year 4x RMR

11. Winter Summer Reproduction Cone Production All squirrels conceive prior to the arrival of current year cones

12. Food abundance influences… Population density Sullivan 1990 Reproductive rate Sullivan 1990? Juvenile growth rate Boutin & Larsen & 1993 McAdam & Boutin 2003a,b Parturition date Réale et al., 2003 Bequeathal behaviour Berteaux & Boutin 2000 Juvenile survival Klenner & Krebs 1991 Humphries & Boutin 2000 McAdam & Boutin 2003a Costs of reproduction Humphries & Boutin 2000 Ignore what you read in Larsen et al., 1997

13. Food abundance also influences… Variation in growth McAdam & Boutin 2003b Selection on growth McAdam & Boutin 2003a Selection on parturition date?? Réale et al., 2003

14. Hypothesis: The abundance of spruce cones is an ecological mechanism of adaptation in red squirrels. Selection on red squirrel life history traits (e.g. parturition date, growth rates) is controlled by the abundance of food. Annual variation in the abundance of spruce cones results in fluctuations in natural selection that minimize sustained evolutionary responses to selection.

15. Conceptual Model Cones t-1 Cones t Selection Population Parameters (competition) Food Abundance

16. Food abundance affects territory vacancies Vacancies estimated from changes in population density in core areas Over-winter (OW) vacancies = fall (t-1) - spring (t) New vacancies = fall (t) - fall (t-1) OWNew r 2 = 0.30, n = 16, P = 0.03 r 2 = 0.49, n = 16, P = 0.002 2000

17. Food affects offspring production Age at first reproduction - Boutin et al., unpub. Reproductive rate - Boutin et al., unpub. Litter size All influenced by future and not previous year’s cones

18. Food affects litter size 1081 litters 16 years Factorest.sedftP Cones t 0.130.04133.2 0.007 Cones t-1 0.030.04130.7 0.51 Age0.240.0710633.5< 0.001 Age 2 - 0.030.011063- 3.3< 0.001

19. Conceptual model Cones t-1 Cones t OW vacancies - 0.11 New Territories # Competitors +* -* +** +* => Selection?

20. ~25 Days Nestling Growth Rate (g/day) 1-2 Days

21. Food affects offspring growth rates Factorest.sedftP Cones t-1 0.130.023145.7< 0.001 Food Add0.760.12614006.1< 0.001 Sex0.040.01114003.8< 0.001 Cones t-1 x Food Add - 0.290.0391400- 7.4< 0.001 2167 offspring 764 dams within years 16 years

22. Conceptual model - Growth Cones t-1 Cones t OW vacancies Selection - 0.11 New Territories # Competitors +* -* +** +* -**

23. Parturition Date

24. Food affects timing of breeding n = 16 years Factorest.sedftP Cones t 1.991.14131.7 0.10 Cones t-1 -10.571.1413- 9.3< 0.001 Age-11.401.241279- 9.2< 0.001 Age 2 1.250.1712797.3< 0.001 1297 litters 16 years

25. Selection on Parturition Date Factorest.sedftP OW vac.0.410.21132.00.07 NEW vac.0.280.15131.90.08 …also positive effects of mean parturition date and year

26. Conceptual model - Parturition date Cones t-1 Cones t OW vacancies Selection - 0.11 New Territories # Competitors +* -* +** +* +’

27. Goal: To perform a replicated food supplementation experiment across multiple generations to test the hypothesis that food abundance controls life history adaptation in red squirrels Mimic ‘mast’ conditions for all individuals in each of 3 populations for the next 5 years

28. Kluane Red Squirrel Experiment 0 20, 000 40, 000 60, 000 80, 000 100, 000 120, 000 140, 000 160, 000 1988 19901992 1994 1996 1998 2000 2002 2004 Cones per squirrel 2006 20082010 2012 2014 food addition

29. Kluane Red Squirrel Experiment 0 20, 000 40, 000 60, 000 80, 000 100, 000 120, 000 140, 000 160, 000 1988 19901992 1994 1996 1998 2000 2002 2004 Cones per squirrel 2006 20082010 2012 2014 8 kg peanut butter

30. One experimental population 49 females 100 middens supplemented 1kg peanut butter added to each feeder in October 2004

31. NSF Plan Add 2 (or 3) new grids –(SU, KL, AG, Food1, Food2, Control?) Supplement all individuals (~100) on each food grid Follow standard monitoring protocol –Add 2 (or 3) spring technicians –Add 2 or 3 grad students –Add 2 or 3 summer assistants

32. Quantitative predictions based on correlations from the past 17 years of data. ResponseControl (± se)Experiment Food (ln count+1) 2.4 ± 0.44.0 ± 0.0 Fall density (sq./ha) 2.6 ± 0.23.0?? OW vac. (ha -1 ) 0.32 ± 0.110.15 New vac. (ha -1 ) - 0.02 ± 0.160.0 Litter size3.0 ± 0.063.2? Parturition date (Julian) 117.6 ± 4.1101.1 Growth rate (g/day) 1.81 ± 0.052.0

33. Conceptual Model Cones t-1 Cones t Selection Population Parameters (competition) Food Abundance

34. Quantitative Genetic Predictions - Growth ScenarioCones t Cones t-1 Predicted  h2h2 Response (g·day -1 /gen) 1040.620.570.18 2440.220.570.06 3--0.580.570.17 19940.694.180.370.570.10 Predicted response of 0.12 - 0.36 sd/gen

35. Predicted changes in growth rates

36. Quantitative Genetic Predictions - Parturition Date ScenarioCones t Cones t-1 Predicted  h2h2 Response (days/gen) 104- 0.340.16*- 0.98 244- 0.130.16*- 0.38 3--- 0.290.16*- 0.85 19940.694.18- 0.730.16*- 2.13 Réale et al. 2003 --- 0.240.16*- 0.70 * Effects of food addition are unknown Predicted response of 0.02 - 0.05 sd/gen

37. Predicted changes in parturition date

38. Test Predictions Selection –Adults: lifetime selection –Juveniles: survival to breeding age –Adults: offspring surviving to spring Evolution –Phenotypic changes (corrected / common garden) –Changes in breeding values (animal model)

39. Sub-projects Experimental and observational approaches to Genotype x Environment Local adaptation, gene flow and introgression Inbreeding and outbreeding depression Adaptation of energy acquisition and expenditure