Estimate rate of iteroparity for American shad from latitude based on Leggett and Cascardden (1978) and Bailey and Zydlewski (2013).

Function used to extract river-specific latitude from built-in data sets.

Usage

make_iteroparity(latitude)

Arguments

latitude

Latitude, in decimal degrees. Can be queried for each river using make_lat.

Value

Probability of repeat spawning. A numeric vector of length = 1.

References

Bailey, M.M., and J. D. Zydlewski. 2013. To stock or not to stock? Assessing therestoration potential of a remnant American shad spawning run with hatchery supplementation. North American Journal of Fisheries Management 33:459-467.

Leggett, W., and J. E. Cascardden. 1978. Latitudinal Variation in Reproductive Characteristics of American Shad (Alosa sapidissima): Evidence for Population Specific Life History Strategies in Fish. Journal of the Fisheries Research Board of Canada 35:1469-1478.

Examples

make_iteroparity( make_lat(river = 'Susquehanna', species = 'AMS') )
#> [1] 0.333116