directly affect the fitness of the host, typically by killing or competing with the host's offspring, thus directing resources away from reproductive success of the host [1-5].
Naturalists have ventured that cowbirds adapted to this nomadic existence by becoming brood parasites
and depositing their eggs in nests built and incubated by birds of other species.
Bronzed cowbirds are generalist brood parasites
, with 101 species victimized, and 44 species documented raising cowbird young, despite limited and uneven research coverage throughout the species' range (Friedmann, 1929; Carter, 1986; Sealy et al., 1997; Ellison and Lowther, 2009).
Cowbird removals unexpectedly increase productivity of a brood parasite
and the songbird host.
"I don't think that the results are broadly applicable to brood parasites
in general," says Stephen Rothstein of the University of California, Santa Barbara.
Other "hot" brood parasite
research topics of particular interest to ecologists that are given short shrift in this volume, at least relative to recent research emphases, include landscape-based host selection strategies and the evolution of shortened incubation periods.
In such instances the word cuckoo refers to the adulterer rather than his victim, by analogy with the bird's behaviour as a brood parasite
. Although The Manciple's Tale has been used to validate the supposed pun in The Boke of Cupide, and vice versa, there is no pun in either.
As the likelihood of multiple substitutions of nucleotides within a site is higher within the species groups that are less closely related and have higher interspecific genetic distances, the values of estimated genetic distance will underestimate the distances between the host species, which were greater than those between the brood parasite
The brown-headed cowbird (Molothrus ater), an obligate brood parasite
, had previously shown greater resistance to infection with WNV, lower viremia and faster recovery when infected, and lower subsequent antibody titers than the red-winged blackbird (Agelaius phoeniceus), a close relative that is not a brood parasite
The brown-headed cowbird is an obligate brood parasite
that lays its eggs into nests of >200 species (Friedmann and Kiff, 1985).
In conclusion, magpies that respond to parasitism by great spotted cuckoos by accepting the parasite egg do not have lower reproductive success than ejectors or abandoners, because ejection frequently results in nest predation by the brood parasite
. This provides support for the Mafia hypothesis, which suggests that the hosts of brood parasites
are forced to accept parasitism.
Red-winged Blackbirds (Agelaius phoeniceus, hereafter blackbirds) respond to cowbirds as a brood parasite
rather than as a nest predator (Neudorf and Sealy, 1992; Gill et al., 2008) with aggression that may temporarily deprive cowbirds of access to the nest (Strausberger, 2001).