Chine Birds 2013,4(1):51–56DOI 10.5122/cbirds.2013.0004
ORIGINA L ARTICLE
小提琴姿势3B j F y U y O S y
Received 19December 2012;accepted 20March 2013f (W L )@Eggs mimicry of Common Cuckoo (Cuculus canorus)utilizing Ashy-throated Parrotbill (Paradoxornis alphonsianus)host春节时间
半音和全音的区别
Canchao Y ANG,Y an CAI,Wei LIANG
Ministry of Education Key Laborator y for Tropical Animal and Plant Ecology ,Colleg e of Life Sciences,Hainan Normal University ,Haikou 571158,Chinaban的用法
A bstrac t Polymorphism in egg coloration is prominent in the Common Cuckoo (Cuc ulus cano rus)and a common host,the Ashy-throated Parrotbill (Paradox ornis alphonsianus).Egg polymorphism has probably evolv ed as a conquence of frequency-dependent lection in both host and parasite,and has,according to human vision,resulted in discrete immaculate white,pale blue and blue egg phenotypes within a single population.However,egg mimicr y asssment is not always straightfor-ward,and previous studies have shown that human bad comparisons applied to the coloration of bird
eggs may be inadequate.Here,we objectively quantify egg color of both parasite and host by spectrophotometry and asss eg g mimicr y of the Common Cuckoo to the eggs of its Ashy -throated Parrotbill host.Our results revealed that egg re ectance spectra agree well with the asssment bad on human vision that cuckoo eggs mimic tho of the parrotbill host,in both visible (VIS)and ul-traviolet (UV)ranges.Howev er,the white cuckoo egg shows slightly poorer mimicr y than the blue cuckoo egg in corresponding host clutches.We suggest that the white parrotbill egg morph (and sub-quently the whitish cuckoo egg color)may have evolved after the evolution of the blue egg morph due to strong lection from parasites in the cuckoo-parrotbill system.K e ywords brood parasitism,egg coloration,egg re ectance,ev olutionary lagcat音乐剧
Introduct ion
T rait polymorphism in natural populations can evolv e as a conquence of frequency-dependent lection (Majerus,1998).This implies that parasites,preda-tors or other lectiv e agents impo variable intensi-ties of lection on the phenotype depending on the frequency in the population.Brood parasites and their hosts provide one such possible ca of frequency-dependent lection resulting in the ev olution of poly-morphic eggs in both host and parasite (Kilner,2006;
小数减法
汤圆都有什么馅金猪报喜病毒Y ang et al.,2010a).Obligate avian brood parasites lay their eg gs in nests belonging to other species of birds,thereby transferring the costs of parental care to their victims.As a conquence,hosts evolve defens to counter brood parasitism,which in turn lects for cor-responding counter-adaptations for better trickery of parasites (Davies and Brooke,1989).The well-known arms race between parasitic cuckoos and their hosts are regarded as a textbook example of co-ev olutionary interactions.Theoretically ,the cuckoo-host system,when acting in a frequency-dependent manner,should be able to produce polymorphisms in co-ev olved traits in the interacting parties.This hypothetical scenario has been found in the Common Cuckoo (Cuculus ca-norus)and one of its hosts,the Ashy-throated Parrotbill (Parado xornis alpho nsianus),in which both species hav e evolved matching egg polymorphism manifested in discrete immaculate white,pale blue and blue eg g phe-y (F ;Y ,),y y 201ei ing orestr niversit and C hina rnithologic al oc iet A uthor or correspondenc e ei iang E-mail:liangwei hainnu.e du
not pes within a single population ig.1ang et al.2010a .However egg mimicr asssment is not alwa s
