IBYME   02675
INSTITUTO DE BIOLOGIA Y MEDICINA EXPERIMENTAL
Unidad Ejecutora - UE
artículos
Título:
Consequences of local Allee effects in spatially structured populations
Autor/es:
CASSINI MH
Revista:
OECOLOGIA
Editorial:
SPRINGER
Referencias:
Año: 2011 vol. 165 p. 547 - 552
ISSN:
0029-8549
Resumen:
The ideal free distribution model incorporating
the Allee eVect was published by Fretwell and Lucas
(1970), but went almost unnoticed within the ecological literature.
The model is relevant to populations distributed
among patchy habitats. It predicts a sporadic but substantial
decline in populations at high densities, which in turn
induces the rapid growth of new populations. In this paper,
I show that the simple process explained by this model can
be used to change our view of several phenomena within
the Weld of population ecology, behavioural ecology and
conservation. The ecological consequences of the model
are well known. A key feature of Fretwell and Lucass
model is what I call the Allee paradox: there is a range of
local population densities at which local individual Wtness
is less than the potential mean gain that could be obtained
in the environment; however, individuals cannot disperse.
This paradox can be used to explain why helping appears
before suitable breeding areas are fully occupied, and why
breeding females aggregate when male coercion is a reproductive
cost. The model also predicts high clustering
between related populations, and, in conservation biology,
it can identify unfounded concerns about the dangers of
extinction, delays in recolonisation processes after humaninduced
population decline, and latency periods in the
initial phases of expansion of invasive species.