Abstracts below
Snyder-Mackler, Noah& DJ White (2011) The developmental ecology of acoustic
reactions: approaches to song playbacks by male cowbirds change across their first
year of life. Behaviour 148: 747-764.
Fernandez-Vargas, M., Z Tang-Martinez& SM Phelps (2011) Singing, allogrooming,
and allomarking behaviour during inter- and intra-sexual encounters in the
Neotropical short-tailed singing mouse (Scotinomys teguina). Behaviour 148: 945-965.
Abstracts:
Snyder-Mackler, Noah& DJ White (2011) The developmental ecology of acoustic
reactions: approaches to song playbacks by male cowbirds change across their first
year of life. Behaviour 148: 747-764.
We examined whether captive, wild-caught juvenile male cowbirds (/Molothrus
ater/)
would react to playbacks of vocalizations of conspecifics and
heterospecifics and if so, whether those reactions would vary across
development. We played five different types of vocalizations to
juveniles: adult male cowbird song, adult female cowbird chatter,
juvenile male cowbird plastic song, songs from species that are common
cowbird hosts, and songs of species that cowbirds do not parasitize. We
played the vocalizations to different groups of juvenile males at four
times during their first year of life (summer, autumn, winter, and
spring). Juveniles approached the playback speaker in response to
broadcasts of specific vocalizations, but these responses differed
across the seasons. Early in summer, young males approached the speaker
more often when adult conspecific vocalizations were played. In the
autumn, subjects approached the speaker more often during broadcasts of
juvenile cowbird plastic song. In the winter, juveniles approached
conspecific and heterospecific vocalizations equally. In the spring,
they once again approached adult conspecific vocalizations more than any
others. Also, only in the spring, the time subjects spent near the
speaker during the male cowbird song playbacks was positively related to
the song's attractiveness to females (its ability to elicit copulation
solicitation displays from females). These responses suggest that song
reactivity may serve several functions across development, including
species recognition, song learning, and group organization.
Fernandez-Vargas, M., Z Tang-Martinez& SM Phelps (2011) Singing, allogrooming,
and allomarking behaviour during inter- and intra-sexual encounters in the
Neotropical short-tailed singing mouse (Scotinomys teguina). Behaviour 148: 945-965.
In this study we determine whether brief interactions with unfamiliar
conspecifics stimulate audible singing behaviour in the Neotropical
short-tailed singing mouse (/Scotinomys teguina/). Specifically, we
examine whether intra- or inter-sexual interactions elicit singing in
males in a neutral-arena design. We conducted two experiments. In
experiment 1, we recorded singing behaviour of male subjects both before
and after a brief exposure to a female mouse. Males significantly
increased their singing behaviour after the exposure to the female, as
compared to prior to the exposure. In experiment 2, we compared the
singing behaviour of male test subjects after a brief exposure with one
of three different treatment animals: a male, a non-oestrous female and
an oestrous female. We found that males are most likely to sing after an
interaction with a female, regardless of her reproductive condition.
Male subjects sang significantly less following an interaction with
another male. Although spontaneous singing is known to occur in males
and females, opposite sex elicited-singing behaviour was found to be
sexually dimorphic. An interaction with a male was not effective in
eliciting singing in females. In experiment 2, we also recorded
incidences of allogrooming and allomarking by males during the
interactions with males, non-oestrous females, and oestrous females.
Male allogrooming and allomarking behaviours using the mid-ventral
sebaceous gland tend to occur more frequently during interactions with
females as compared to males, but were significantly different only in
the case of allogrooming. Thus, this study clearly suggests sex
differences in singing, allogrooming and allomarking, and a likely
relationship between these behaviours and courtship in this Neotropical
rodent.
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