1. Life-history of a population of Cottonmouths in east-central Alabama Scott Boback, Matt Greene, Roger Birkhead, Matt Williams, and Dave Koons

3. How do organisms respond to environmental variation?

4. Comparative life-history can help us understand how organisms respond to variation in the environment.

6. A. p. piscivorus A. p. leucostoma A. p. conanti

9. Methodology

14. Results Four years of sampling every two weeks 391 captures of 198 individuals 49% adults

15. SVL (cm) 30405060708090 Number of Snakes 30 25 20 15 10 5 0 5 Males Females Body Size 67.9 62.6

16. Body Mass (g) 0100200300400500600700 Number of Snakes 30 25 20 15 10 5 0 5 Males Females Body Size 336.8 277.0

17. Mean Male SVL (cm) 50 55 60 65 70 75 80 ARNCVA AL AR SC 67.9 Body Size

18. SSD Index -0.6 -0.7 -0.8 -0.9 Equal ARNCVA ARSCALFL -0.92 Sexual Size Dimorphism

19. Sex Ratio (F:M) 0 1 2 3 4 5 6 7 2001200220032004 March – June 15 June 16 – October 1:1 Sex Ratio 95 29 67 21 69 35 38 41 Sex Ratio

20. Cormack-Jolly-Seber estimator for open populations Survival = probability that a snake alive in week i survived and did not permanently emigrate from study area in week i+1 Recapture = probability that a marked snake alive in week i did not permanently emigrate and was captured in week i+1 Survival Analysis- MARK

21. Recapture Probabilities SVL (cm) Weekly Recapture Probability Annual survival = 0.79 Recapture probability higher in first year Strong effect of transient individuals

22. Litter size = 4.1±1.5 (N=11) RCM = 26.2±9.3 (N=7) Frequency of pregnancy from 91% - 15% Reproduction

23. Mean Litter Size 2 3 4 5 6 7 8 TXNCVAFLARSCALFLTXVA 4.1 Litter Size

24. Midpoint SVL (cm) 30405060708090 Growth Rate (cm/month) 0 1 2 3 Growth – Field Data Males Females

26. Midpoint SVL (cm) Growth Rate (cm/month) Growth – Lab Data Males Females

27. 2030405060708090100 -2 0 2 4 6 8 10 Midpoint SVL (cm) Growth Rate (cm/month) Growth – Field versus Lab Field Lab

30. J F M A M J J A S O N DA S O N D SVL (cm) 20 40 60 80 100 200120022003 J F M A M J J A S O N D Polyphasic Growth

31. Summary High annual survival Likely a long-lived species Frequency of reproduction highly variable Small litter size Slow growth but capable of extremely rapid growth when resources are abundant

33. Acknowledgements