Horn growth in male pronghorns Antilocapra americana: selection for precocial maturation in stochastic environments

• Autorzy: Mitchell C. D. , Maher C.R.
• Języki publikacji: EN

Abstrakty

EN

PronghornsAntilocapra americana (Ord, 1818), the sole member of a family unique to North America, grow rapidly and reproduce at an early age. Recent studies have found male pronghorns can grow large horns by 2 to 3 yrs of age. This pattern contrasts with many other ungulates, and it has profound implications for life history strategies. We examine 5 hypotheses that might explain precocial horn growth: (1) sampling bias, (2) nutrition, (3) phylogenetic inertia, (4) reproductive benefits conveyed by rapid horn growth alone, and (5) rapid horn growth as part of a suite of characteristics acquired due to precocial maturation. Hypotheses 1, 2 and 3 do not imply any natural selection, whereas hypotheses 4 and 5 do. We reject hypotheses 1, 2 and 4, and we cannot evaluate hypothesis 3. We conclude that hypothesis 5 most likely explains precocial maturation in male pronghorns, and mortality related to frequent, severe weather events may drive this pattern. We suggest several experiments to further examine relationships between age, size, and horn growth.

• Wydawca: -
• Czasopismo: Acta Theriologica
• Rocznik: 2006
• Tom: 51
• Numer: 4
• Opis fizyczny: p.405-409,ref.

Twórcy

autor

Mitchell C. D.

• U.S.Fish and Wildlife Service, 74 Grays Lake Road, Wayan, Idaho, USA 83285

autor

Maher C.R.

Bibliografia

• Begon M., Harper J. L. and Townsend C. R. 1990. Ecology. Individuals, populations and communities. Blackwell Scientific Publications, Boston: 1–945.
• Bekenov A. B., Grachev I. A. and Milner-Gulland J. E. 1998. The ecology and management of the saiga antelope in Kazakhstan. Mammal Review 28: 1–52.
• Bowyer R. T. 1986. Antler characteristics as related to social status of male southern mule deer. The Southwestern Naturalist 31: 289–298.
• Bowyer R. T., Stewart K. M., Kie J. G. and Gasaway W. C. 2001. Fluctuating asymmetry in antlers of Alaskan moose: size matters. Journal of Mammalogy 82: 814–824.
• Brown D. E., Fagan W. F. and Turner B. 2003. Pronghorn sheath growth, age and precipitation on a ranch in southern New Mexico. Pronghorn Antelope Workshop Proceedings 20: 17–23.
• Bubenik A. B. 1990. Epigenetical, morphological, physiological, and behavioral aspects of evolution of horns, pronghorns, and antlers. [In: Horns, pronghorns, and antlers. G. A. Bubenik and A. B. Bubenik, eds]. Springer-Verlag, New York: 3–113.
• Byers J. A. 1997. American pronghorn. Social adaptations and ghosts of predators past. University of Chicago Press, Chicago and London: 1–300.
• Byers J. A., Byers A. A. and Dunn S. J. 2006. A dry summer diminishes mate search effort by pronghorn females: evidence for a significant cost of mate search. Ethology 113: 74–80.
• Byers J. A., Moodie J. D. and Hall N. 1994. Pronghorn females choose vigorous mates. Animal Behaviour 47: 33–43.
• Charlesworth B. 1994. Evolution in age-structured populations. 2nd ed. Cambridge University Press, Cambridge: 1–306.
• Clutton-Brock T. H. 1988. Introduction. [In: Reproductive success. T. H. Clutton-Brock, ed]. University of Chicago Press, Chicago and London: 1–6.
• Clutton-Brock T. H., Guiness F. E. and Albon S. D. 1982. Red deer. Behaviour and ecology of two sexes. University of Chicago Press Chicago: 1–378.
• Clutton-Brock T. H. and Pemberton J. 2003. Soay sheep. Dynamics and selection in an island population. Cambridge University Press, Cambridge: 1–383.
• Fandos P. and Vigal C. R. 1988. Body weight and horn length in relation to age of the Spanish wild goat. Acta Theriologica 33: 339–344.
• Festa-Bianchet M., Coltman D. W., Turelli L. and Jorgenson J. T. 2004. Relative allocation of horn and body growth in bighorn rams varies with resource availability. Behavioral Ecology 15: 305–312.
• Gavin T. A. 1991. Why ask “why”: the importance of evolutionary biology in wildlife science. Journal of Wildlife Management 55: 760–766.
• Geist V. 1971. Mountain sheep. A study in behavior and evolution. University of Chicago Press, Chicago: 1–383.
• Geist V. 1998. Deer of the world. Stackpole Books, Harrisburg: 1–421.
• McCorquodale S. M., Eberhardt L. E. and Sargeant G. A. 1989. Antler characteristics in a colonizing elk population. Journal of Wildlife Management 53: 618–620.
• Menzel K. 1980. Weights and horn measurements of Nebraska pronghorns: first seasons and twenty years later. Pronghorn Antelope Workshop Proceedings 9: 279–284.
• Mitchell C. D. and Maher C. R. 2001. Are horn characteristics related to age in male pronghorns? Wildlife Society Bulletin 29: 908–916.
• Min S. E. 1997. Variation in sexually dimorphic traits of male pronghorns. Journal of Mammalogy 78: 31–47.
• O’Gara B. W. 1990. The pronghornAntilocapra americana. [In: Horns, pronghorns, and antlers. G. A. Bubenik and A. B. Bubenik, eds]. Springer-Verlag, New York: 231–264.
• O’Gara B. W. 2004a. Physical characteristics. [In: Pronghorn ecology and Management. B. W. O’Gara and J. D. Yoakum, eds]. University Press of Colorado, Boulder: 109–143.
• O’Gara B. W. 2004b. Behavior. [In: Pronghorn ecology and Management. B. W. O’Gara and J. D. Yoakum, eds]. University Press of Colorado, Boulder: 145–194.
• O’Gara B. W. 2004c. Mortality factors. [In: Pronghorn ecology and Management. B. W. O’Gara and J. D. Yoakum, eds]. University Press of Colorado, Boulder: 379–408.
• O’Gara B. W. 2004d. Reproduction. [In: Pronghorn ecology and Management. B. W. O’Gara and J. D. Yoakum, eds]. University Press of Colorado, Boulder: 275–298.
• Pérez-Barbería F. J., Robles L. and Nores C. 1996. Horn growth pattern in Cantabrian chamoisRupicapra pyrenaica parva: Influence of sex, age and phaenology. Acta Theriologica 41: 83–92.
• Schaller G. B. 1977. Mountain monarchs. Wild sheep and goats of the Himalaya. University of Chicago Press, Chicago: 1–425.
• Stearns S. C. 1992. The evolution of life histories. Oxford University Press, Oxford: 1–264.
• Stewart K. M., Bowyer R. T., Kie J. G. and Gasaway W. C. 2000. Antler size relative to body mass in moose: tradeoffs associated with reproduction. Alces 36: 77–83.