It has become clear over the past few decades
that activity patterns in primates can no longer be classified
simply as diurnal or nocturnal. The term now generally employed by
primatologists to describe the exploitation of both diurnal and
nocturnal phases is "cathemeral". In the 1970s, studies
in the field and in captivity on Eulemur sp. (family Lemuridae)
pointed to the regular occurrence of activity throughout the
24-hour cycle and this type of activity was also observed in owl
monkeys, Aotus azarai, in the Paraguayan and Argentinian Chaco in
the 1980s. Recent field studies have provided a wealth of data
collected on lemurids and owl monkeys throughout the 24-hour
period and a complex picture is beginning to emerge. In this
symposium we aim to elucidate the proximate role of environmental
cues and the functional relevance of cathemerality and, hence, its
adaptive value and evolution. This will be accomplished through
individual presentations investigating links between cathemerality
and (1) abiotic cueing mechanisms; (2) predation; (3) diet; (4)
thermoregulation; (5) mating / social systems. In addition, we
will present a chronobiologist's analysis of cathemerality and
investigate the visual systems of cathemeral primates. In order to
take a broader view of the evolution of primate activity patterns,
the effects of moonlight and darkness on nocturnal primates will
be assessed and a presentation on polyphasic activity patterns in
small mammals will provide the link to other mammalian strategies.
Tattersall
I.
“The
concept of cathemerality: history and definition”
Halle
S.
“Polyphasic
activity patterns in small mammals”
Nekaris
K.A.I., Bearder S.K., Curtis D.C.
“A
re-evaluation of the role of moonlight on the activity rhythms of
nocturnal primates”
Russell
H.
“Why
be diurnal?”
Erkert
H.G.
“Chronobiological
background to cathemerality.”
Donati
G., Borgognini Tarli S.M.
“Abiotic
cueing mechanisms and cathemerality”
Fernandez-Duque
E.
“Cathemerality
and lunarphilia in owl monkeys of the argentinean chaco”
Mutschler
T.
“Food
availability, diet, and cathemerality”
Colquhoun
I.
“Predation
and Cathemerality”
Curtis
D.J., Rasmussen M.A.
“Evolution
of cathemerality in primates”
