INVESTIGADORES
MAHLER Bettina
artículos
Título:
Host switching in cowbird brood parasites: how often does it occur?
Autor/es:
DOMINGUEZ, M.; DE LA COLINA, M. A.; DI GIACOMO, A. G.; REBOREDA, J.C.; MAHLER, B.
Revista:
JOURNAL OF EVOLUTIONARY BIOLOGY
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2015
ISSN:
1010-061X
Resumen:
Avian obligate brood parasites lay their eggs in nests of host species, which
provide all parental care. Brood parasites may be host specialists, if they use
one or a few host species, or host generalists, if they parasitize many hosts.
Within the latter, strains of host-specific females might coexist. Although
females preferentially parasitize one host, they may occasionally successfully
parasitize the nest of another species. These host switching events allow the
colonization of new hosts and the expansion of brood parasites into new
areas. In this study, we analyse host switching in two parasitic cowbirds, the
specialist screaming cowbird (Molothrus rufoaxillaris) and the generalist shiny
cowbird (M. bonariensis), and compare the frequency of host switches
between these species with different parasitism strategies. Contrary to
expected, host switches did not occur more frequently in the generalist than
in the specialist brood parasite. We also found that migration between hosts
was asymmetrical in most cases and host switches towards one host were
more recurrent than backwards, thus differing among hosts within the same
species. This might depend on a combination of factors including the rate at
which females lay eggs in nests of alternative hosts, fledging success of the
chicks in this new host and their subsequent success in parasitizing it.