Ecological Research

, Volume 25, Issue 3, pp 521–529

A demographic analysis of population responses to the manipulation of adult males in Calomys venustus (Rodentia, Sigmodontinae)

Original Article

DOI: 10.1007/s11284-009-0682-6

Cite this article as:
Priotto, J., Gómez, D. & Polop, J. Ecol Res (2010) 25: 521. doi:10.1007/s11284-009-0682-6
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Abstract

In many species of mammals, adults play an important role in influencing the survival and/or reproduction of juveniles. Adult males could have a negative effect on population density when their absence becomes a limiting factor in female fertilization. We tested the hypotheses that the absence of overwintering males (adult males) reduces the population growth rate through a delay in the onset of reproductive activity of Cohort 1 females in Calomys venustus populations. The study was carried out in two control and two experimental enclosures (0.25 ha). Adult males were removed after their offspring were born. Weekly trapping sessions were carried out from spring to autumn. To estimate population growth rates (λ), apparent survival (ϕ) and seniority probability (γ) were estimated using capture–mark-recapture models. Models were constructed with these two parameters and recapture probability (p) constrained to vary as a function of time, enclosure and/or treatment. We derived estimates of population growth rates through the estimates of ϕ and γ. The best models for ϕ and γ did not show a treatment effect. Variability between the four enclosures was greater than between control and experimental enclosures. Enclosures had different growth rates at the beginning of the study but were equaled at the end. Temporal variation in population growth rates was a result of temporal variation of γ. The two controls showed the highest growth rates earlier in time. The results did not support the hypothesis tested in this study. It seems that the number of overwintering males do not affect the population growth rate.

Keywords

Population growth Seniority Sigmodontinae Small mammals Survival 

Supplementary material

11284_2009_682_MOESM1_ESM.doc (206 kb)
Supplementary material 1 (DOC 206 kb)

Copyright information

© The Ecological Society of Japan 2009

Authors and Affiliations

  1. 1.Departamento de Ciencias Naturales, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)Universidad Nacional de Río CuartoRío CuartoArgentina
  2. 2.Departamento de Ciencias NaturalesUniversidad Nacional de Río CuartoRío CuartoArgentina

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