Allonursing in Captive Guanacos, Lama guanicoe: Milk Theft or Misdirected Parental Care?
Author
dc.contributor.author
Zapata, Beatriz
Author
dc.contributor.author
González, Benito A.
Author
dc.contributor.author
Ebensperger, Luis A.
Admission date
dc.date.accessioned
2019-03-11T12:57:40Z
Available date
dc.date.available
2019-03-11T12:57:40Z
Publication date
dc.date.issued
2009
Cita de ítem
dc.identifier.citation
Ethology 115 (2009) 731–737
Identifier
dc.identifier.issn
01791613
Identifier
dc.identifier.issn
14390310
Identifier
dc.identifier.other
10.1111/j.1439-0310.2009.01660.x
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/164800
Abstract
dc.description.abstract
Females in several ungulates transfer milk to non-filial (NF) offspring, in
a process known as allonursing. This behavior is less common in monotocous
species, including most ungulates, and it has been associated with
parasitic behavior of calves or mothers who have lost their own offspring.
To examine whether the calves ‘steal’ milk from the females or
whether females fail to discriminate their own calves in guanacos, allonursing
behavior was observed. If milk theft drives allonursing, mothers
should reject NF offspring, they should search for their own calves, and
calves attempting to suckle from alien mothers should adopt parallel (as
opposed to the anti-parallel) position during allonursing. Alternatively,
if allonursing is caused by mothers unable to discriminate own offspring,
mothers are not expected to reject NF offspring, and alien calves should
use parallel and antiparallel position similarly when allonursing. Allonursing
was investigated during the first 3 mo of lactation in two groups
of captive guanacos composed of 15 and 14 mother-calf pairs, respectively.
While 40% and 62.5% of mothers in groups 1 and 2 performed
allonursing, high individual variation prevailed; some females exhibited
this behavior infrequently (4.1% and 6.5 % in groups 1 and 2). The
rejection rate to NF nursing attempts was threefold higher than the
rejection rate to filial nursing attempts. The occurrence of nursing to NF
was associated to a parallel posture by the calves. Our findings suggest
that ‘milk theft’ is a more plausible hypothesis to explain allonursing in
guanacos than ‘misdirected parental care’.