Chadwick et al. (2021) examined a novel method to determine the abundance of Signal Crayfish (*Pacifastacus leniusculus*) in an isolated portion of a stream. At one experimental location their novel method resulted in the removal of 1477, 133, and 46 crayfish in three successive samplings. Use these data to answer the following questions.

- What is the best estimate and 95% confidence interval for the population size?
- What is the best estimate and 95% confidence interval for the probability of capture for each sampling period.
- Is there evidence that the probability of capture differed after the first pass?

## References

Chadwick, D. D. A., E. G. Pritchard, P. Bradley, C. D. Sayer, M. A. Chadwick, L. J. B. Eagle, and J. C. Axmacher. 2021. A novel “triple drawdown” method highlights deficiencies in invasive alien crayfish survey and control techniques. Journal of Applied Ecology 58:316–326.