| to eject or to abandon? life history traits of hosts and parasites interact to influence the fitness payoffs of alternative anti-parasite strategies. | hosts either tolerate avian brood parasitism or reject it by ejecting parasitic eggs, as seen in most rejecter hosts of common cuckoos, cuculus canorus, or by abandoning parasitized clutches, as seen in most rejecter hosts of brown-headed cowbirds, molothrus ater. what explains consistent variation between alternative rejection behaviours of hosts within the same species and across species when exposed to different types of parasites? life history theory predicts that when parasites decrease the ... | 2006 | 16910987 |
| cuckoo-hawk mimicry? an experimental test. | the similarity between many old world parasitic cuckoos (cuculinae) and accipiter hawks, in size, shape and plumage, has been noted since ancient times. in particular, hawk-like underpart barring is more prevalent in parasitic than in non-parasitic cuckoos. cuckoo-hawk resemblance may reflect convergent evolution of cryptic plumage that reduces detection by hosts and prey, or evolved mimicry of hawks by parasitic cuckoos, either for protection against hawk attacks or to facilitate brood parasiti ... | 2008 | 18467298 |
| egg colour mimicry in the common cuckoo cuculus canorus as revealed by modelling host retinal function. | some parasite cuckoo species lay eggs that, to the human eye, appear to mimic the appearance of the eggs of their favourite hosts, which hinders discrimination and removal of their eggs by host species. hitherto, perception of cuckoo-host egg mimicry has been estimated based on human vision or spectrophotometry, which does not account for what the receivers' eye (i.e. hosts) actually discriminates. using a discrimination model approach that reproduces host retinal functioning, and museum egg col ... | 2008 | 18595836 |
| outcomes of brood parasite-host interactions mediated by egg matching: common cuckoos cuculus canorus versus fringilla finches. | antagonistic species often interact via matching of phenotypes, and interactions between brood parasitic common cuckoos (cuculus canorus) and their hosts constitute classic examples. the outcome of a parasitic event is often determined by the match between host and cuckoo eggs, giving rise to potentially strong associations between fitness and egg phenotype. yet, empirical efforts aiming to document and understand the resulting evolutionary outcomes are in short supply. | 2011 | 21559400 |
| color plumage polymorphism and predator mimicry in brood parasites. | plumage polymorphism may evolve during coevolution between brood parasites and their hosts if rare morph(s), by contravening host search image, evade host recognition systems better than common variant(s). females of the parasitic common cuckoo (cuculus canorus) are a classic example of discrete color polymorphism: gray females supposedly mimic the sparrowhawk (accipiter nisus), while rufous females are believed to mimic the kestrel (falco tinnunculus). despite many studies on host responses to ... | 2013 | 23663311 |
| cuckoos, cowbirds and the persistence of brood parasitism. | brood parasites provide a particularly good opportunity for the study of host-parasite evolution because they directly affect the reproductive success of their hosts. two parasitic species, the common cuckoo (cuculus canorus) and the brown-headed cowbird (molothrus ater), differ widely in their relationships with their hosts, yet share the attribute of having been particularly well studied by biologists. recent work on the cuckoo and the cowbird has resulted in new answers to the question begged ... | 1999 | 10441306 |
| evolution of defence portfolios in exploiter-victim systems. | some organisms maintain a battery of defensive strategies against their exploiters (predators, parasites or parasitoids), while others fail to employ a defence that seems obvious. in this paper, we shall investigate the circumstances under which defence strategies might be expected to evolve. brood parasites and their hosts provide our main motivation, and we shall discuss why the reed warbler acrocephalus scirpaceus has evolved an egg-rejection but not a chick-rejection strategy as a defence ag ... | 2007 | 17265120 |
| social transmission of a host defense against cuckoo parasitism. | coevolutionary arms races between brood parasites and hosts involve genetic adaptations and counter-adaptations. however, hosts sometimes acquire defenses too rapidly to reflect genetic change. our field experiments show that observation of cuckoo (cuculus canorus) mobbing by neighbors on adjacent territories induced reed warblers (acrocephalus scirpaceus) to increase the mobbing of cuckoos but not of parrots (a harmless control) on their own territory. in contrast, observation of neighbors mobb ... | 2009 | 19498167 |
| the common cuckoo cuculus canorus is not locally adapted to its reed warbler acrocephalus scirpaceus host. | the obligate avian brood parasitic common cuckoo cuculus canorus comprises different strains of females that specialize on particular host species by laying eggs of a constant type that often mimics those of the host. whether cuckoos are locally adapted for mimicking populations of the hosts on which they are specialized has never been investigated. in this study, we first explored the possibility of local adaptation in cuckoo egg mimicry over a geographical mosaic of selection exerted by one of ... | 2011 | 21054625 |
| egg phenotype matching by cuckoos in relation to discrimination by hosts and climatic conditions. | although parasites and their hosts often coexist in a set of environmentally differentiated populations connected by gene flow, few empirical studies have considered a role of environmental variation in shaping correlations between traits of hosts and parasites. here, we studied for the first time the association between the frequency of adaptive parasitic common cuckoo cuculus canorus phenotypes in terms of egg matching and level of defences exhibited by its reed warbler acrocephalus scirpaceus ... | 2012 | 22237911 |
| reed warbler hosts fine-tune their defenses to track three decades of cuckoo decline. | interactions between avian hosts and brood parasites can provide a model for how animals adapt to a changing world. reed warbler (acrocephalus scirpaceus) hosts employ costly defenses to combat parasitism by common cuckoos (cuculus canorus). during the past three decades cuckoos have declined markedly across england, reducing parasitism at our study site (wicken fen) from 24% of reed warbler nests in 1985 to 1% in 2012. here we show with experiments that host mobbing and egg rejection defenses h ... | 2013 | 24299407 |
| are cuckoos maximizing egg mimicry by selecting host individuals with better matching egg phenotypes? | avian brood parasites and their hosts are involved in complex offence-defense coevolutionary arms races. the most common pair of reciprocal adaptations in these systems is egg discrimination by hosts and egg mimicry by parasites. as mimicry improves, more advanced host adaptations evolve such as decreased intra- and increased interclutch variation in egg appearance to facilitate detection of parasitic eggs. as interclutch variation increases, parasites able to choose hosts matching best their ow ... | 2012 | 22384060 |
| geographic variation in parasitism rates of two sympatric cuckoo hosts in china. | rates of brood parasitism vary extensively among host species and populations of a single host species. in this study, we documented and compared parasitism rates of two sympatric hosts, the oriental reed warbler (acrocephalus orientalis) and the reed parrotbill (paradoxornis heudei), in three populations in china. we found that the common cuckoo (cuculus canorus) is the only parasite using both the oriental reed warbler and reed parrotbill as hosts, with a parasitism rate of 22.4%-34.3% and 0%- ... | 2014 | 24470456 |
| experimental shift in hosts' acceptance threshold of inaccurate-mimic brood parasite eggs. | hosts are expected to evolve resistance strategies that efficiently detect and resist exposure to virulent parasites and pathogens. when recognition is not error-proof, the acceptance threshold used by hosts to recognize parasites should be context dependent and become more restrictive with increasing predictability of parasitism. here, we demonstrate that decisions of great reed warblers acrocephalus arundinaceus to reject parasitism by the common cuckoo cuculus canorus vary adaptively within a ... | 2006 | 17148357 |
| host genotype and age have no effect on rejection of parasitic eggs. | egg rejection belongs to a widely used host tactic to prevent the costs incurred by avian brood parasitism. however, the genetic basis of this behaviour and the effect of host age on the probability of rejecting the parasitic egg remain largely unknown. here, we used a set of 15 polymorphic microsatellite loci, including a previously detected candidate locus (ase64), to link genotypes of female great reed warblers (acrocephalus arundinaceus), a known rejecter, with their egg rejection responses ... | 2014 | 24718778 |
| experimental shifts in egg-nest contrasts do not alter egg rejection responses in an avian host-brood parasite system. | obligate brood parasitic birds exploit their hosts to provide care for unrelated young in the nest. potential hosts can reduce the cost of parasitism by rejecting foreign eggs from the nest. observational, comparative, and experimental studies have concluded that most hosts use the coloration and patterning of eggshells to discriminate between own and foreign eggs in the nest. however, an alternative hypothesis is that birds use the colour contrasts between eggshells and the nest lining to ident ... | 2015 | 26118673 |
| dynamic egg color mimicry. | evolutionary hypotheses regarding the function of eggshell phenotypes, from solar protection through mimicry, have implicitly assumed that eggshell appearance remains static throughout the laying and incubation periods. however, recent research demonstrates that egg coloration changes over relatively short, biologically relevant timescales. here, we provide the first evidence that such changes impact brood parasite-host eggshell color mimicry during the incubation stage. first, we use long-term ... | 2016 | 27516874 |
| wild birds, frequent carriers of extended-spectrum β-lactamase (esbl) producing escherichia coli of ctx-m and shv-12 types. | to get a better insight into the role of birds as reservoirs of extended-spectrum β-lactamase (esbl) and plasmidic ampc β-lactamase (pampc) escherichia coli producers, 100 fecal samples belonging to 15 different wild avian species from northern spain were analyzed. cefotaxime-resistant (ctx(r)) e. coli isolates were identified in 16 of the 100 tested birds, which corresponded to 9 animal species (gyps fulvus-griffon vulture, larus michahellis-yellow-legged gull, milvus migrans-black kite, milvus ... | 2016 | 26687342 |
| avian vision and the evolution of egg color mimicry in the common cuckoo. | coevolutionary arms races are a potent force in evolution, and brood parasite-host dynamics provide classical examples. different host-races of the common cuckoo, cuculus canorus, lay eggs in the nests of other species, leaving all parental care to hosts. cuckoo eggs often (but not always) appear to match remarkably the color and pattern of host eggs, thus reducing detection by hosts. however, most studies of egg mimicry focus on human assessments or reflectance spectra, which fail to account fo ... | 2011 | 21729055 |
| persistence of host defence behaviour in the absence of avian brood parasitism. | the fate of host defensive behaviour in the absence of selection from brood parasitism is critical to long-term host-parasite coevolution. we investigated whether new world bohemian waxwings bombycilla garrulus that are allopatric from brown-headed cowbird molothrus ater and common cuckoo cuculus canorus parasitism have retained egg rejection behaviour. we found that egg rejection was expressed by 100 per cent of bohemian waxwings. our phylogeny revealed that bohemian and japanese waxwings bomby ... | 2011 | 21493623 |
| egg phenotype differentiation in sympatric cuckoo cuculus canorus gentes. | the brood parasitic common cuckoo cuculus canorus consists of gentes, which typically parasitize only a single host species whose eggs they often mimic. where multiple cuckoo gentes co-exist in sympatry, we may expect variable but generally poorer mimicry because of host switches or inter-gens gene flow via males if these also contribute to egg phenotypes. here, we investigated egg trait differentiation and mimicry in three cuckoo gentes parasitizing great reed warblers acrocephalus arundinaceus ... | 2010 | 20345810 |
| rapid increase in cuckoo egg matching in a recently parasitized reed warbler population. | parasitic cuckoos lay eggs that mimic those of their hosts, and such close phenotypic matching may arise from coevolutionary interactions between parasite and host. however, cuckoos may also explicitly choose hosts in a way that increases degree of matching between eggs of cuckoos and parasites, with female preference for specific host phenotypes increasing the degree of matching. we tested for temporal change in degree of matching between eggs of the parasitic european cuckoo (cuculus canorus) ... | 2006 | 17040387 |
| strategic variation in mobbing as a front line of defense against brood parasitism. | coevolutionary arms races, where adaptations in one party select for counter-adaptations in another and vice versa, are fundamental to interactions between organisms and their predators, pathogens, and parasites [1]. avian brood parasites and their hosts have emerged as model systems for studying such reciprocal coevolutionary processes [2, 3]. for example, hosts have evolved changes in egg appearance and rejection of foreign eggs in response to brood parasitism from cuckoos, and cuckoos have ev ... | 2009 | 19185495 |
| nestling discrimination without recognition: a possible defence mechanism for hosts towards cuckoo parasitism? | one of the great evolutionary puzzles is why hosts of parasitic birds discriminate finely against alien eggs, but almost never discriminate against parasitic chicks. a theoretical model has shown that an adaptive host response to alien eggs can be based on learning. however, learned nestling discrimination is too costly to be favoured by selection in hosts of evicting parasites, such as the european cuckoo (cuculus canorus). indeed, parasitic chick rejection has never been reported for any europ ... | 2003 | 12952641 |
| internal incubation and early hatching in brood parasitic birds. | the offspring of brood parasitic birds benefit from hatching earlier than host young. a proposed but little-known strategy to achieve this is 'internal incubation', by retaining the egg in the oviduct for an additional 24 h. to test this, we quantified the stage of embryo development at laying in four brood parasitic birds (european cuckoo, cuculus canorus; african cuckoo, cuculus gularis; greater honeyguide, indicator indicator; and the cuckoo finch, anomalospiza imberbis). for the two cuckoos ... | 2011 | 20880882 |
| genetic identification for prey birds of the endangered peregrine falcon (falco peregrinus). | to reveal the dietary ecology of the peregrine falcon (falco peregrinus), we conducted a molecular analysis for mitochondrial genes (coi and cytb) to identify the prey species collected from a feeding place found on sasu island, south korea. the results from noninvasive genetic analysis showed that the sequences obtained came from nine species of birds (cuculus canorus, eurystomus orientalis, limosa limosa, microscelis amaurotis, oriolus chinensis, phasianus colchicus, sterna hirundo, streptopel ... | 2017 | 28071972 |
| conflict between egg recognition and egg rejection decisions in common cuckoo (cuculus canorus) hosts. | common cuckoos (cuculus canorus) are obligate brood parasites, laying eggs into nests of small songbirds. the cuckoo hatchling evicts all eggs and young from a nest, eliminating hosts' breeding success. despite the consistently high costs of parasitism by common cuckoos, great reed warbler (acrocephalus arundinaceus) hosts sometime accept and other times reject parasitic eggs. to explore the cognitive basis of this seemingly maladaptive variation in host responses, we documented differences in e ... | 2007 | 17279422 |
| discordancy or template-based recognition? dissecting the cognitive basis of the rejection of foreign eggs in hosts of avian brood parasites. | many avian hosts have evolved antiparasite defence mechanisms, including egg rejection, to reduce the costs of brood parasitism. the two main alternative cognitive mechanisms of egg discrimination are thought to be based on the perceived discordancy of eggs in a clutch or the use of recognition templates by hosts. our experiments reveal that the great reed warbler (acrocephalus arundinaceus), a host of the common cuckoo (cuculus canorus), relies on both mechanisms. in support of the discordancy ... | 2010 | 20472785 |
| competition with a host nestling for parental provisioning imposes recoverable costs on parasitic cuckoo chick's growth. | chicks of the brood parasitic common cuckoo (cuculus canorus) typically monopolize host parental care by evicting all eggs and nestmates from the nest. to assess the benefits of parasitic eviction behaviour throughout the full nestling period, we generated mixed broods of one cuckoo and one great reed warbler (acrocephalus arundinaceus) to study how hosts divide care between own and parasitic young. we also recorded parental provisioning behaviour at nests of singleton host nestlings or singleto ... | 2012 | 22521709 |
| naïve hosts of avian brood parasites accept foreign eggs, whereas older hosts fine-tune foreign egg discrimination during laying. | many potential hosts of social parasites recognize and reject foreign intruders, and reduce or altogether escape the negative impacts of parasitism. the ontogenetic basis of whether and how avian hosts recognize their own and the brood parasitic eggs remains unclear. by repeatedly parasitizing the same hosts with a consistent parasitic egg type, and contrasting the responses of naïve and older breeders, we studied ontogenetic plasticity in the rejection of foreign eggs by the great reed warbler ... | 2014 | 25024736 |
| continuous variation rather than specialization in the egg phenotypes of cuckoos (cuculus canorus) parasitizing two sympatric reed warbler species. | the evolution of brood parasitism has long attracted considerable attention among behavioural ecologists, especially in the common cuckoo system. common cuckoos (cuculus canorus) are obligatory brood parasites, laying eggs in nests of passerines and specializing on specific host species. specialized races of cuckoos are genetically distinct. often in a given area, cuckoos encounter multiple hosts showing substantial variation in egg morphology. exploiting different hosts should lead to egg-pheno ... | 2014 | 25180796 |
| experimental evidence for chick discrimination without recognition in a brood parasite host. | recognition is considered a critical basis for discriminatory behaviours in animals. theoretically, recognition and discrimination of parasitic chicks are not predicted to evolve in hosts of brood parasitic birds that evict nest-mates. yet, an earlier study showed that host reed warblers (acrocephalus scirpaceus) of an evicting parasite, the common cuckoo (cuculus canorus), can avoid the costs of prolonged care for unrelated young by deserting the cuckoo chick before it fledges. desertion was no ... | 2007 | 17164201 |
| narrow-front loop migration in a population of the common cuckoo cuculus canorus, as revealed by satellite telemetry. | narrow migration corridors known in diurnal, social migrants such as raptors, storks and geese are thought to be caused by topographical leading line effects in combination with learning detailed routes across generations. here, we document narrow-front migration in a nocturnal, solitary migrant, the common cuckoo cuculus canorus, using satellite telemetry. we tracked the migration of adult cuckoos from the breeding grounds in southern scandinavia (n = 8), to wintering sites in south-western cen ... | 2014 | 24421890 |
| how selfish is a cuckoo chick? | we studied the begging display of nestling cuckoos, cuculus canorus, reared by reed warbler, acrocephalus scirpaceus, hosts, to test various hypotheses for the cuckoo's unusually rapid begging call. the hypotheses are not mutually exclusive but focus on different parts of the chain: chick need-begging signals-provisioning by hosts. we reject two hypotheses. (1) cuckoo chicks do not use their exaggerated begging to counteract host rejection: begging displays varied with hunger and functioned enti ... | 1999 | 10512653 |
| pattern recognition algorithm reveals how birds evolve individual egg pattern signatures. | pattern-based identity signatures are commonplace in the animal kingdom, but how they are recognized is poorly understood. here we develop a computer vision tool for analysing visual patterns, naturepatternmatch, which breaks new ground by mimicking visual and cognitive processes known to be involved in recognition tasks. we apply this tool to a long-standing question about the evolution of recognizable signatures. the common cuckoo (cuculus canorus) is a notorious cheat that sneaks its mimetic ... | 2014 | 24939367 |
| first-time migration in juvenile common cuckoos documented by satellite tracking. | being an obligate parasite, juvenile common cuckoos cuculus canorus are thought to reach their african wintering grounds from palearctic breeding grounds without guidance from experienced conspecifics but this has not been documented. we used satellite tracking to study naïve migrating common cuckoos. juvenile cuckoos left breeding sites in finland moving slowly and less consistently directed than adult cuckoos. migration of the juveniles (n = 5) was initiated later than adults (n = 20), was dir ... | 2016 | 28005960 |
| the common redstart as a suitable model to study cuckoo-host coevolution in a unique ecological context. | co-evolutionary arms-races result in spatio-temporally dynamic relationships between interacting species, e.g., brood parasites and their avian hosts. however, majority of avian co-evolutionary studies are limited to "snap-shots" of a single breeding season in an open-nesting host. in a long-term study (11 breeding seasons), we explored a unique system between the brood parasitic common cuckoo (cuculus canorus) and its host, the common redstart (phoenicurus phoenicurus) which is exceptional amon ... | 2016 | 27887566 |
| sex-specific defence behaviour against brood parasitism in a host with female-only incubation. | nest protection against intruders is an indispensable component of avian parental care. in species with biparental care, both mates should evolve nest defence behaviour to increase their reproductive success. in most host-parasite systems, host females are predicted to have more important roles in nest defence against brood parasites, because they typically are primarily responsible for clutch incubation. male antiparasitic behaviour, on the other hand, is often underestimated or even not consid ... | 2009 | 19154783 |
| egg eviction imposes a recoverable cost of virulence in chicks of a brood parasite. | chicks of virulent brood parasitic birds eliminate their nestmates and avoid costly competition for foster parental care. yet, efforts to evict nest contents by the blind and naked common cuckoo cuculus canorus hatchling are counterintuitive as both adult parasites and large older cuckoo chicks appear to be better suited to tossing the eggs and young of the foster parents. | 2009 | 19907639 |
| chick loss from mixed broods reflects severe nestmate competition between an evictor brood parasite and its hosts. | hatchlings of the obligate brood parasite common cuckoo cuculus canorus typically evict eggs and nestmates but, rarely, host and parasite nestlings may grow up together. as part of previous experiments, we manipulated host clutches by inducing two great reed warbler acrocephalus arundinaceus and one parasite young to share a nest from 4 days posthatch, when the cuckoo's eviction behaviour is thought to cease. we documented that in mixed broods typically at least one nestling eventually fell out ... | 2010 | 20117189 |
| egg rejection in blackbirds turdus merula: a by-product of conspecific parasitism or successful resistance against interspecific brood parasites? | traditional theory assumes that egg recognition and rejection abilities arise as a response against interspecific brood parasitism (ibp). however, rejection also appears in some species that are currently not exploited by interspecific parasites, such as turdus thrushes. recent evidences suggest that rejection abilities evolved in these species as a response to conspecific brood parasitism (cbp). to test these two alternative hypotheses, we performed an experimental study by parasitizing nests o ... | 2016 | 27073406 |
| ancient origin and maternal inheritance of blue cuckoo eggs. | maternal inheritance via the female-specific w chromosome was long ago proposed as a potential solution to the evolutionary enigma of co-existing host-specific races (or 'gentes') in avian brood parasites. here we report the first unambiguous evidence for maternal inheritance of egg colouration in the brood-parasitic common cuckoo cuculus canorus. females laying blue eggs belong to an ancient (∼2.6 myr) maternal lineage, as evidenced by both mitochondrial and w-linked dna, but are indistinguisha ... | 2016 | 26754355 |
| first evidence of regular common cuckoo, cuculus canorus, parasitism on eastern olivaceous warblers, hippolais pallida elaeica. | coevolution is defined as specialized relationships between species that lead to a reciprocal evolutionary change. a particularly suitable model system for studying coevolution is the interactions between obligate avian brood parasites and their hosts. the common cuckoo (cuculus canorus, hereafter cuckoo) is a well-known brood parasite, which utilizes a range of smaller passerines as hosts. however, warblers of the genus hippolais have rarely been reported as being victims of cuckoos, and furthe ... | 2007 | 17160581 |
| a host-race difference in begging calls of nestling cuckoos cuculus canorus develops through experience and increases host provisioning. | the structure of common cuckoo nestling begging calls differs between the two host-races parasitizing reed warblers (reed warbler-cuckoos) and dunnocks (dunnock-cuckoos; longer syllable duration, lower peak and maximum frequency, narrower bandwidth). cross-fostering experiments demonstrated that this difference is not genetically fixed but develops through experience. when newly hatched reed warbler-cuckoos were transferred to dunnock nests, they developed begging calls more like those of dunnoc ... | 2006 | 16928637 |
| flexible navigation response in common cuckoos cuculus canorus displaced experimentally during migration. | migrating birds follow innate species-specific migration programs capable of guiding them along complex spatio-temporal routes, which may include several separate staging areas. indeed, migration routes of common cuckoos cuculus canorus show little variation between individuals; yet, satellite tracks of 11 experimentally displaced adults revealed an unexpected flexibility in individual navigation responses. the birds compensated for the translocation to unfamiliar areas by travelling toward popu ... | 2015 | 26549318 |
| egg color variation, but not egg rejection behavior, changes in a cuckoo host breeding in the absence of brood parasitism. | interactions between parasitic cuckoos and their songbird hosts form a classical reciprocal "arms race," and are an excellent model for understanding the process of coevolution. changes in host egg coloration via the evolution of interclutch variation in egg color or intraclutch consistency in egg color are hypothesized counter adaptations that facilitate egg recognition and thus limit brood parasitism. whether these antiparasitism strategies are maintained when the selective pressure of parasit ... | 2014 | 25360264 |
| nest defenses and egg recognition of yellow-bellied prinia against cuckoo parasitism. | parasites may, in multi-parasite systems, block the defenses of their hosts and thus thwart host recognition of parasites by frequency-dependent selection. nest defenses as frontline may block or promote the subsequent stage of defenses such as egg recognition. we conducted comparative studies of the defensive strategies of a host of the oriental cuckoo cuculus optatus, the yellow-bellied prinia prinia flaviventris, in mainland china with multiple species of cuckoos and in taiwan with a single c ... | 2014 | 25011416 |
| host responses to interspecific brood parasitism: a by-product of adaptations to conspecific parasitism? | why have birds evolved the ability to reject eggs? typically, foreign egg discrimination is interpreted as evidence that interspecific brood parasitism (ip) has selected for the host's ability to recognize and eliminate foreign eggs. fewer studies explore the alternative hypothesis that rejection of interspecific eggs is a by-product of host defenses, evolved against conspecific parasitism (cp). we performed a large scale study with replication across taxa (two congeneric turdus thrushes), space ... | 2014 | 24834103 |
| "cu-coo": can you recognize my stepparents?--a study of host-specific male call divergence in the common cuckoo. | the presence of multiple host-specific races in the common cuckoo cuculus canorus has long been recognized as an evolutionary enigma but how this genetic divergence could be maintained is still equivocal. some recent studies supported biparental genetic contribution in maintaining the host-races, implying the necessity that they should recognize and mate assortatively with those who belong to the same host-race. one potential mechanism to accomplish this is that males may produce distinctive cal ... | 2014 | 24603770 |
| brood parasites lay eggs matching the appearance of host clutches. | interspecific brood parasitism represents a prime example of the coevolutionary arms race where each party has evolved strategies in response to the other. here, we investigated whether common cuckoos (cuculus canorus) actively select nests within a host population to match the egg appearance of a particular host clutch. to achieve this goal, we quantified the degree of egg matching using the avian vision modelling approach. randomization tests revealed that cuckoo eggs in naturally parasitized ... | 2014 | 24258721 |
| modelling the evolution of common cuckoo host-races: speciation or genetic swamping? | co-evolutionary arms races have provided clear evidence for evolutionary change, especially in host-parasite systems. the evolution of host-specific races in the common cuckoo (cuculus canorus), however, is also an example where sexual conflict influences the outcome. cuckoo females benefit from better adaptation to overcome host defences, whereas cuckoo males face a trade-off between the benefits of better adaptation to a host and the benefits of multiple mating with females from other host-rac ... | 2013 | 24070171 |
| rapid change in host use of the common cuckoo cuculus canorus linked to climate change. | parasites require synchrony with their hosts so if host timing changes with climate change, some parasites may decline and eventually go extinct. residents and short-distance migrant hosts of the brood parasitic common cuckoo, cuculus canorus, have advanced their phenology in response to climate change more than long-distance migrants, including the cuckoo itself. because different parts of europe show different degrees of climate change, we predicted that use of residents or short-distance migr ... | 2011 | 20843848 |
| cuckoos combat socially transmitted defenses of reed warbler hosts with a plumage polymorphism. | in predator-prey and host-parasite interactions, an individual's ability to combat an opponent often improves with experience--for example, by learning to identify enemy signals. although learning occurs through individual experience, individuals can also assess threats from social information. such recognition could promote the evolution of polymorphisms if socially transmitted defenses depend on enemy morph frequency. this would allow rare variants to evade detection. female brood parasitic co ... | 2012 | 22859487 |
| the evolution of host-specific variation in cuckoo eggshell strength. | cuckoo eggs are renowned for their mimicry of different host species, leading to the evolution of host-specific races (or 'gentes') defined by egg colour and pattern. this study aims to test the prediction that another property of parasitic eggs, namely shell strength, might also have experienced divergent selection within cuckoo species. host races of the common cuckoo cuculus canorus encountering stronger host rejection have thicker-shelled eggs than those parasitising less discriminating spec ... | 2010 | 20561139 |
| uncovering dangerous cheats: how do avian hosts recognize adult brood parasites? | co-evolutionary struggles between dangerous enemies (e.g., brood parasites) and their victims (hosts) lead to the emergence of sophisticated adaptations and counter-adaptations. salient host tricks to reduce parasitism costs include, as front line defence, adult enemy discrimination. in contrast to the well studied egg stage, investigations addressing the specific cues for adult enemy recognition are rare. previous studies have suggested barred underparts and yellow eyes may provide cues for the ... | 2012 | 22624031 |
| coevolution in action: disruptive selection on egg colour in an avian brood parasite and its host. | trait polymorphism can evolve as a consequence of frequency-dependent selection. coevolutionary interactions between hosts and parasites may lead to selection on both to evolve extreme phenotypes deviating from the norm, through disruptive selection. | 2010 | 20520815 |
| sex allocation in relation to host races in the brood-parasitic common cuckoo (cuculus canorus). | sex allocation theory and empirical evidence both suggest that natural selection should favour maternal control of offspring sex ratio in relation to their ability to invest in the offspring. generalist parasites constitute a particularly interesting group to test this theory as different females commonly utilize different host species showing large variation in provisioning ability. the common cuckoo (cuculus canorus) is a generalist brood parasite that lays its eggs in the nest of many differe ... | 2012 | 22615833 |
| modelling the maintenance of egg polymorphism in avian brood parasites and their hosts. | in avian brood parasitism, egg phenotype plays a key role for both host and parasite reproduction. several parrotbill species of the genus paradoxornis are parasitized by the common cuckoo cuculus canorus, and clear polymorphism in egg phenotype is observed. in this article, we develop a population genetics model in order to identify the key parameters that control the maintenance of egg polymorphism. the model analyses show that egg polymorphism can be maintained either statically as an equilib ... | 2012 | 22404333 |
| pattern mimicry of host eggs by the common cuckoo, as seen through a bird's eye. | cuckoo-host interactions provide classical examples of coevolution. cuckoos place hosts under selection to detect and reject foreign eggs, while host defences result in the evolution of host-egg mimicry in cuckoos. despite a long history of research, egg pattern mimicry has never been objectively quantified, and so its coevolution with host defences has not been properly assessed. here, we use digital image analysis and modelling of avian vision to quantify the level of pattern mimicry in eight ... | 2010 | 20053650 |
| climate change effects on migration phenology may mismatch brood parasitic cuckoos and their hosts. | phenological responses to climate change vary among taxa and across trophic levels. this can lead to a mismatch between the life cycles of ecologically interrelated populations (e.g. predators and prey), with negative consequences for population dynamics of some of the interacting species. here we provide, to our knowledge, the first evidence that climate change might disrupt the association between the life cycles of the common cuckoo (cuculus canorus), a migratory brood parasitic bird, and its ... | 2009 | 19443508 |
| geographic distribution of suitable hosts explains the evolution of specialized gentes in the european cuckoo cuculus canorus. | several types of selective forces can act to promote parasite specialization. parasites might specialize on some suitable hosts at the cost of decreasing effectiveness when exploiting other species of hosts, and specialization can be more easily selected for in hosts that the parasites will easily find. thus demographic characteristics of suitable hosts such as population density and its spatial consistency could be key factors predicting probability of parasite specialization and speciation. he ... | 2009 | 19405966 |
| a shared chemical basis of avian host-parasite egg colour mimicry. | avian brood parasites lay their eggs in other birds' nests and impose considerable fitness costs on their hosts. historically and scientifically, the best studied example of circumventing host defences is the mimicry of host eggshell colour by the common cuckoo (cuculus canorus). yet the chemical basis of eggshell colour similarity, which impacts hosts' tolerance towards parasitic eggs, remains unknown. we tested the alternative scenarios that (i) cuckoos replicate host egg pigment chemistry, or ... | 2012 | 21920975 |
| alternative mechanisms of increased eggshell hardness of avian brood parasites relative to host species. | obligate brood parasitic birds lay their eggs in nests of other species and parasite eggs typically have evolved greater structural strength relative to host eggs. increased mechanical strength of the parasite eggshell is an adaptation that can interfere with puncture ejection behaviours of discriminating hosts. we investigated whether hardness of eggshells is related to differences between physical and chemical traits from three different races of the parasitic common cuckoo cuculus canorus, an ... | 2011 | 21561966 |
| genetic differentiation among sympatric cuckoo host races: males matter. | generalist parasites regularly evolve host-specific races that each specialize on one particular host species. many host-specific races originate from geographically structured populations where local adaptations to different host species drive the differentiation of distinct races. however, in sympatric populations where several host races coexist, gene flow could potentially disrupt such host-specific adaptations. here, we analyse genetic differentiation among three sympatrically breeding host ... | 2011 | 21068043 |
| evidence for egg discrimination preceding failed rejection attempts in a small cuckoo host. | given the high costs of avian obligate brood parasitism, host individuals are selected to reject parasitic eggs they recognize as foreign. we show that rejection may not necessarily follow egg discrimination when selective removal of the parasitic egg is difficult. we studied egg rejection behaviour in a small host of the common cuckoo cuculus canorus, the eastern olivaceous warbler hippolais pallida, by experimental parasitism with model and real non-mimetic cuckoo eggs and video recordings of ... | 2009 | 19126530 |
| habitat-dependent call divergence in the common cuckoo: is it a potential signal for assortative mating? | the common cuckoo (cuculus canorus) is an obligate brood parasite that mimics the eggs of its hosts. the host-specific egg pattern is thought to be inherited matrilinearly, creating female-only host-specific races. males are thought not to be adapted to their host and they maintain the species by mating arbitrarily with respect to host specialization of females. however, recent results suggest that male cuckoos may also show host-specific adaptations and these may require assortative mating with ... | 2007 | 17580296 |
| constraints on host choice: why do parasitic birds rarely exploit some common potential hosts? | 1. why are some common and apparently suitable resources avoided by potential users? this interesting ecological and evolutionary conundrum is vividly illustrated by obligate brood parasites. parasitic birds lay their eggs into nests of a wide range of host species, including many rare ones, but do not parasitize some commonly co-occurring potential hosts. 2. attempts to explain the absence of parasitism in common potential hosts are limited and typically focused on single-factor explanations wh ... | 2011 | 21244420 |
| short-, medium-, and long-chain chlorinated paraffins in wildlife from paddy fields in the yangtze river delta. | short-chain chlorinated paraffins (sccps) were added to annex a of the stockholm convention on persistent organic pollutants in april, 2017. as a consequence of this regulation, increasing production and usage of alternatives, such as medium- and long-chain chlorinated paraffins (mccps and lccps, respectively), is expected. little is known about the environmental fate and behavior of mccps and lccps. in the present study, sccps, mccps, and lccps were analyzed in nine wildlife species from paddy ... | 2018 | 29320169 |
| isolation by time and habitat and coexistence of distinct host races of the common cuckoo. | isolation by time occurs when different populations of a single species reproduce at different times and thereby reduce the probability of interbreeding, potentially causing divergent adaptation to timing of reproduction, eventually resulting in ecological species separated by timing of reproduction. we analysed extensive data on timing of reproduction by different host races of the common cuckoo cuculus canorus that is an obligate brood parasite laying eggs in the nests of many different specie ... | 2011 | 21214656 |
| how do cuckoos find their hosts? the role of habitat imprinting. | although a number of hypotheses have been proposed for how european cuckoo, cuculus canorus, females may find hosts belonging to their foster parents' species, clear evidence is lacking for any of them. here, we propose 'habitat imprinting' as an alternative mechanism for host selection and provide evidence that cuckoos are able to remember acquired information about a familiar habitat. we hand-reared seven cuckoos in one of five different artificial habitats and tested them as adults in habitat ... | 1998 | 9933539 |
| model eggs fail to detect egg recognition in host populations after brood parasitism is relaxed. | obligate brood parasites exert strong selective pressure on target hosts. in response, hosts typically evolve anti-parasitism strategies, of which egg recognition is one of the most efficient. generally, host egg-recognition capacity is determined using model eggs. previous studies have shown that some host species, which are capable of detecting parasite eggs, do not reject model eggs. however, it is unknown that whether the reaction to model eggs varies among distinct populations of the same h ... | 2020 | 32426018 |
| a comparative study of host selection in the european cuckoo cuculus canorus. | certain kinds of hosts are commonly regarded as being more suitable than other for rearing european cuckoos (cuculus canorus) - insectivores that lay small eggs and have open, shallow nests - although empirical tests of cuckoo host selection are lacking. we analysed host use by the european cuckoo in 72 british passerines that are potential hosts and for which there was information available on life-history variables and variables related to cuckoo-host coevolution, such as rate of parasitism, r ... | 1999 | 28307703 |
| isolation and characterization of microsatellite dna loci for an obligate brood parasitic bird, the common cuckoo (cuculus canorus). | | 1998 | 9787455 |
| analysis of genetic differentiation of host races of the common cuckoo cuculus canorus using mitochondrial and microsatellite dna variation. | it has long been argued that populations of the parasitic common cuckoo cuculus canorus consist of sympatric host-specific female races, each of which lays eggs that match, to varying degrees, those of their chosen hosts. we tested this hypothesis by comparing rapidly evolving dna markers among the cuckoo chicks reared by the three most common hosts in the united kingdom. comparing cuckoos from different hosts, we found no significant differences in the number of repeats in the control region of ... | 1996 | 8587899 |
| [uropygial gland secretion of the cuckoo (cuculus canorus)]. | | 1972 | 4649853 |
| a host-race of the cuckoo cuculus canorus with nestlings attuned to the parental alarm calls of the host species. | the common cuckoo has several host-specific races, each with a distinctive egg that tends to match its host's eggs. here, we show that the host-race specializing on reed warblers also has a host-specific nestling adaptation. in playback experiments, the nestling cuckoos responded specifically to the reed warbler's distinctive 'churr' alarm (given when a predator is near the nest), by reducing begging calls (likely to betray their location) and by displaying their orange-red gape (a preparation f ... | 2006 | 16608688 |
| speciation by host switch in brood parasitic indigobirds. | a growing body of empirical and theoretical work supports the plausibility of sympatric speciation, but there remain few examples in which all the essential components of the process are well understood. the african indigobirds vidua spp. are host-specific brood parasites. indigobird nestlings are reared along with host young, and mimic the mouth markings of their respective hosts. as adults, male indigobirds mimic host song, whereas females use these songs to choose both their mates and the nes ... | 2003 | 12931185 |
| the common cuckoo is an effective indicator of high bird species richness in asia and europe. | common cuckoo cuculus canorus is a charismatic bird species with a dominant presence in human culture: from folklore legends to nowadays there is evidence of cuckoos being a prime candidate as a surrogate of bird diversity. recent studies demonstrated that the cuckoo can predict hotspots of taxonomic diversity and functional diversity of bird communities in european countries. in this study, we demonstrated that the cuckoo is an excellent bioindicator at multi-spatial scale, extending cuckoo sur ... | 2017 | 28663558 |
| asymmetry of eye color in the common cuckoo. | bilateral symmetry is assumed to contribute to the evolution of eye color, with the left and right eye being the same color in most vertebrates; yet, few studies tested this assumption. here, we compared the amount of iris flecking (black spots presented on the iris) between the left and right eye of 76 adult common cuckoos cuculus canorus. we found considerable variation in the total amount of iris flecking among individuals, with variation being associated with body size and sex. we also found ... | 2017 | 28790375 |
| resource tracking within and across continents in long-distance bird migrants. | migratory birds track seasonal resources across and between continents. we propose a general strategy of tracking the broad seasonal abundance of resources throughout the annual cycle in the longest-distance migrating land birds as an alternative to tracking a certain climatic niche or shorter-term resource surplus occurring, for example, during spring foliation. whether and how this is possible for complex annual spatiotemporal schedules is not known. new tracking technology enables unprecedent ... | 2017 | 28070557 |
| population decline is linked to migration route in the common cuckoo. | migratory species are in rapid decline globally. although most mortality in long-distance migrant birds is thought to occur during migration, evidence of conditions on migration affecting breeding population sizes has been completely lacking. we addressed this by tracking 42 male common cuckoos from the rapidly declining uk population during 56 autumn migrations in 2011-14. uniquely, the birds use two distinct routes to reach the same wintering grounds, allowing assessment of survival during mig ... | 2016 | 27433888 |
| cuckoos vs. top predators as prime bioindicators of biodiversity in disturbed environments. | we studied the abundance of the common cuckoo cuculus canorus l. little cuckoo cuculus poliocephalus l. and asian cuckoo cuculus saturatus l. and avian top predators as indicators of bird species richness (surrogate of biodiversity) in disturbed environments caused by radioactive contamination in chernobyl, ukraine and fukushima, japan, comparing their efficiency as indicators of local biodiversity hotspots. bird species richness and birds abundance were quantified in each sample site during the ... | 2017 | 28686944 |
| the adaptiveness of defence strategies against cuckoo parasitism. | host bird species of the eurasian cuckoo, cuculus canorus, often display egg-discrimination behaviour but chick-rejection behaviour has never been reported. in this paper, we analyse a host-cuckoo association in which both population dynamics and evolutionary dynamics are explored in a discrete-time model. we introduce four host types, each with their own defence behaviour, displaying either egg or chick rejection, neither or both, we also introduce fitness functions for each of these host types ... | 2002 | 12508530 |
| changes in body temperature pattern in vertebrates do not influence the codon usages of alpha-globin genes. | codon usages are known to vary among vertebrates chiefly due to variations in isochore structure. under the assumption that marked differences exist in isochore structure between warm-blooded and cold-blooded animals, the variations among vertebrates were previously attributed to an adaptation to homeothermy. however, based on data from a turtle species and a crocodile (archosauromorpha), it was recently proposed that the common ancestors of mammals, birds and extent reptiles already had the "wa ... | 2002 | 12207041 |
| molecular genetic perspectives on avian brood parasitism. | advances in molecular genetic techniques have provided new approaches for addressing evolutionary questions about brood parasitic birds. we review recent studies that apply genetic data to the systematics, population biology, and social systems of avian brood parasites and suggest directions for future research. recent molecular systematics studies indicate that obligate brood parasitism has evolved independently in seven different avian lineages, a tally that has increased by one in cuckoos (cu ... | 2002 | 21708732 |
| obligate brood parasites as selective agents for evolution of egg appearance in passerine birds. | many passerine host species have counteracted the parasite egg mimicry in their coevolutionary arms race with the common cuckoo (cuculus canorus) by evolving increased interclutch and reduced intraclutch variation in egg appearance. such variations make it easier for hosts to recognize a foreign egg, reduce the possibility of making recognition errors, and reduce the ability of the cuckoo to mimic the eggs of a particular host. here, we investigate if such clutch characteristics have evolved amo ... | 2002 | 11913664 |
| fitting different visual models to behavioral patterns of parasitic egg rejection along a natural egg color gradient in a cavity-nesting host species. | avian brood parasites lay their eggs in other birds' nests, and hosts can mitigate the fitness cost of raising unrelated offspring by rejecting parasitic eggs. a visually-based cognitive mechanism often thought to be used by hosts to discriminate the foreign egg is to compare it against the hosts' own eggshell by size, shape, maculation, and/or ground coloration (i.e., absolute chromatic contrast). however, hosts may instead discriminate eggs based on their colors along a scale of natural avian ... | 2020 | 31958715 |
| heterospecific alarm-call recognition in two warbler hosts of common cuckoos. | species facing similar selection pressures should recognize heterospecific alarm signals. however, no study has so far examined heterospecific alarm-call recognition in response to parasitism by cuckoos. in this study, we tested whether two sympatric host species of the common cuckoo cuculus canorus, oriental reed warbler acrocephalus orientalis (orw, main host), and black-browed reed warbler acrocephalus bistrigiceps (brw, rare host), could recognize each other's alarm calls in response to cuck ... | 2019 | 31506795 |
| why do all host species not show defense against avian brood parasitism: evolutionary lag or equilibrium? | avian brood parasitism reduces the reproductive success of hosts and is therefore expected to select for host defenses against parasitism, such as an ability to reject parasitic eggs. field studies have shown that some hosts recognize and reject parasitism, whereas others do not, and the degree of the defense varies from population to population. one long-standing debate concentrates on the differences in the distribution of host defenses observed in hosts parasitized by the brown-headed cowbird ... | 1998 | 18811417 |
| parasites and supernormal manipulation. | social parasites may exploit their hosts by mimicking other organisms that the hosts normally benefit from investing in or responding to in some other way. some parasites exaggerate key characters of the organisms they mimic, possibly in order to increase the response from the hosts. the huge gape and extreme begging intensity of the parasitic common cuckoo chick (cuculus canorus) may be an example. in this paper, the evolutionary stability of manipulating hosts through exaggerated signals is an ... | 2001 | 11749709 |
| genetic evidence for female host-specific races of the common cuckoo. | the common cuckoo cuculus canorus is divided into host-specific races (gentes). females of each race lay a distinctive egg type that tends to match the host's eggs, for instance, brown and spotted for meadow pipit hosts or plain blue for redstart hosts. the puzzle is how these gentes remain distinct. here, we provide genetic evidence that gentes are restricted to female lineages, with cross mating by males maintaining the common cuckoo genetically as one species. we show that there is differenti ... | 2000 | 11001055 |
| functional significance of cuckoo cuculus canorus calls: responses of conspecifics, hosts and non-hosts. | male cuckoos cuculus canorus produce calls that differ in number of syllables depending on environmental conditions and presence of male and female conspecifics. why different males produce so repeatable calls that vary greatly in duration among males remains an open question. we used playback of cuckoo calls with few or many syllables (hereafter short and long calls), and woodpigeon calls (a control that also produces few or many syllables), predicting that playback of longer cuckoo calls shoul ... | 2018 | 30245923 |
| gut microbiota in a host-brood parasite system: insights from common cuckoos raised by two warbler species. | an animal's gut microbiota (gm) is shaped by a range of environmental factors affecting the bacterial sources invading the host. at the same time, animal hosts are equipped with intrinsic mechanisms enabling regulation of gm. however, there is limited knowledge on the relative importance of these forces. to assess the significance of host-intrinsic vs environmental factors, we studied gm in nestlings of an obligate brood parasite, the common cuckoo (cuculus canorus), raised by two foster species ... | 2020 | 32672792 |
| host alarm calls attract the unwanted attention of the brood parasitic common cuckoo. | it is well known that avian brood parasites lay their eggs in the nests of other bird species, called hosts. it remains less clear, however, just how parasites are able to recognize their hosts and identify the exact location of the appropriate nests to lay their eggs in. while previous studies attributed high importance to visual signals in finding the hosts' nests (e.g. nest building activity or the distance and direct sight of the nest from vantage points used by the brood parasites), the rol ... | 2019 | 31811179 |
| a recognition-free mechanism for reliable rejection of brood parasites. | hosts often discard eggs of avian brood parasites, whereas parasitic chicks are typically accepted. this can be explained theoretically by fitness losses associated with adults learning to recognize parasitic young and mistakenly rejecting their own young. a new experimental study confirms that rejection of parasitic chicks, without relying on memory to discriminate between foreign and own young, is a feasible and potentially cost-free mechanism used by reed warblers to reject common cuckoo chic ... | 2007 | 17412449 |
| combining personal with social information facilitates host defences and explains why cuckoos should be secretive. | individuals often vary defences in response to local predation or parasitism risk. but how should they assess threat levels when it pays their enemies to hide? for common cuckoo hosts, assessing parasitism risk is challenging: cuckoo eggs are mimetic and adult cuckoos are secretive and resemble hawks. here, we show that egg rejection by reed warblers depends on combining personal and social information of local risk. we presented model cuckoos or controls at a pair's own nest (personal informati ... | 2016 | 26794435 |
| host-race formation in the common cuckoo | the exploitation of a new host by a parasite may result in host-race formation or speciation. a brood parasitic bird, the common cuckoo, is divided into host races, each characterized by egg mimicry of different host species. microsatellite dna markers were used to examine cuckoo mating patterns and host usage in an area where a new host has been recently colonized. female cuckoos show strong host preferences, but individual males mate with females that lay in the nests of different hosts. femal ... | 1998 | 9774273 |
| a game-theoretic model of interspecific brood parasitism with sequential decisions. | the interaction between hosts and parasites in bird populations has been studied extensively. this paper uses game-theoretic methods to model this interaction. this has been done in previous papers but has not been studied taking into account the detailed sequential nature of this game. we introduce a model allowing the host and parasite to make a number of decisions which will depend on various natural factors. the sequence of events begins with the host forming a nest and laying a number of eg ... | 2009 | 18977367 |
| differently sized cuckoos pose different threats to hosts. | hole-nesting tits parus spp. have been classified as "unsuitable" hosts for cuckoo parasitism because cuckoos cannot enter a cavity if the entrance is too small. however, chinese tits could reject alien eggs and egg ejection rate increased with the local diversity of parasitic cuckoo species. antiparasitic behavior among chinese tits may have evolved due to greater size variation among sympatric cuckoo species. this raises the question of whether differently sized parasitic cuckoos pose differen ... | 2020 | 32440285 |
| common cuckoos (cuculus canorus) affect the bacterial diversity of the eggshells of their great reed warbler (acrocephalus arundinaceus) hosts. | the common cuckoo (cuculus canorus) is an avian brood parasite, laying its eggs in the nests of other bird species, where these hosts incubate the parasitic eggs, feed and rear the nestlings. the appearance of a cuckoo egg in a host nest may change the bacterial community in the nest. this may have consequences on the hatchability of host eggs, even when hosts reject the parasitic egg, typically within six days after parasitism. the present study revealed the bacterial community of cuckoo eggshe ... | 2018 | 29351548 |