Warning: imagejpeg(C:\Inetpub\vhosts\kidney.de\httpdocs\phplern\25122227
.jpg): Failed to open stream: No such file or directory in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 117 Proc+Biol+Sci
2014 ; 281
(1792
): ä Nephropedia Template TP
gab.com Text
Twit Text FOAVip
Twit Text #
English Wikipedia
Cryptic cuckoo eggs hide from competing cuckoos
#MMPMID25122227
Gloag R
; Keller LA
; Langmore NE
Proc Biol Sci
2014[Oct]; 281
(1792
): ä PMID25122227
show ga
Interspecific arms races between cuckoos and their hosts have produced remarkable
examples of mimicry, with parasite eggs evolving to match host egg appearance and
so evade removal by hosts. Certain bronze-cuckoo species, however, lay eggs that
are cryptic rather than mimetic. These eggs are coated in a low luminance pigment
that camouflages them within the dark interiors of hosts' nests. We investigated
whether cuckoo egg crypsis is likely to have arisen from the same coevolutionary
processes known to favour egg mimicry. We added high and low luminance-painted
eggs to the nests of large-billed gerygones (Gerygone magnirostris), a host of
the little bronze-cuckoo (Chalcites minutillus). Gerygones rarely rejected either
egg type, and did not reject natural cuckoo eggs. Cuckoos, by contrast, regularly
removed an egg from clutches before laying their own and were five times more
likely to remove a high luminance model than its low luminance counterpart. Given
that we found one-third of all parasitized nests were exploited by multiple
cuckoos, our results suggest that competition between cuckoos has been the key
selective agent for egg crypsis. In such intraspecific arms races, crypsis may be
favoured over mimicry because it can reduce the risk of egg removal to levels
below chance.