Sex ratios among anurans at breeding sites are routinely observed to be skewed toward males, which has implications for the strength of sexual selection in these animals. However, the relative numbers of males and females observed at breeding sites also depends upon their relative conspicuousness and the physical sex ratio of the adult population as a whole, which includes animals not present at breeding sites. Using intensive capture–recapture methods, I estimated abundances of both sexes of Fowler's Toads in a population at Long Point, Ontario, over a span of 14 years (1998 to 2011, incl.). Although males greatly outnumbered females at breeding sites, persisted there for longer periods of time, and were more readily re-captured, both sexes could be found in their lakeshore non-breeding habitat with equivalent reliability. Estimates of abundance were calculated for each sex based on 3,162 total captures of 686 females and 982 males. The abundances of males and females each year were not significantly different (P = 0.738), which was consistent with a 1∶1 physical sex ratio. Both sexes also exhibited large, but strongly correlated (P << 0.001; R2 = 0.838), variations in their abundance over the 14 yrs. Only 39% of total estimated males were found at breeding sites. The ratio of males at breeding sites to total males declined significantly (P = 0.002; R2 = 0.542) over the 14-year study, in parallel with a diminishing availability of breeding sites.
Skip Nav Destination
Article navigation
Life History, Behavior, and Ecology|
December 30 2013
Sex Ratio and Breeding Population Size in Fowler's Toad, Anaxyrus ( = Bufo) fowleri
David M. Green
David M. Green
1 Redpath Museum, McGill University, Montreal, Québec, Canada H3A 2K6; E-mail: david.m.green@mcgill.ca
Search for other works by this author on:
Copeia (2013) 2013 (4): 647–652.
Citation
David M. Green; Sex Ratio and Breeding Population Size in Fowler's Toad, Anaxyrus ( = Bufo) fowleri. Copeia 1 December 2013; 2013 (4): 647–652. doi: https://doi.org/10.1643/CE-12-104
Download citation file:
Sign in
Don't already have an account? Register
Client Account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.
Sign in via your Institution
Sign in via your InstitutionCiting articles via
Genomic Data Do Not Support the Species Status of the San Luis Valley Short-Horned Lizard (Phrynosoma diminutum)
Julianna Hoza, Hayden R. Davis, Adam D. Leaché
Two New Species of Suckermouth Catfishes (Mochokidae: Chiloglanis) from Upper Guinean Forest Streams in West Africa
Ray C. Schmidt, Pedro H. N. Bragança, John P. Friel, Frank Pezold, Denis Tweddle, Henry L. Bart, Jr.
Rates of Alloparental Care by Male Stickleback in Natural Lake Populations
Racine E. Rangel, Travis Ingram, Daniel I. Bolnick
Habitat Use by the Rock-Dwelling Karoo Dwarf Tortoise, Chersobius boulengeri
Victor J. T. Loehr