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Wei Liang - One of the best experts on this subject based on the ideXlab platform.
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Cuckoos use host egg number to choose host nests for parasitism
Proceedings of the Royal Society. B Biological Sciences, 2020Co-Authors: Longwu Wang, Canchao Yang, Wei Liang, Anders Pape MøllerAbstract:To maximize their offspring success common Cuckoo (Cuculus canorus) females should lay their eggs into host nests before incubation has begun. This ensures that the parasite chick hatches before all host chicks and can evict its foster siblings to monopolize host parental care. Many studies have demonstrated that most Cuckoo eggs are indeed laid before the onset of host incubation. But cues used by female Cuckoos to choose the right nest at the right time remain unclear. Here, we combine field observations with a field experiment to test whether female Cuckoos use the number of eggs in the nests of their Oriental reed warbler (Acrocephalus orientalis) hosts to direct their choice. Over 8 years of field observations and 5 years of experiments, Cuckoo females placed the majority of their eggs in nests with fewer than three host eggs, i.e. early in the laying sequence. For natural nests, the Cuckoos may use information gleaned from the activity and behaviour of the host parents to make their choice. In our sets of experimental nests containing different numbers of model eggs, the vast majority of parasitism events occurred in nests containing a single egg. To our knowledge, this is the first field experiment showing that Cuckoos choose host nests for parasitism based on the number of host eggs they contain. It appears that Cuckoo females use the egg number to estimate the appropriate host nest stage for timely parasitism.
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Heterospecific alarm-call recognition in two warbler hosts of common Cuckoos
Animal Cognition, 2019Co-Authors: Wei Sun, Haitao Wang, Wei Liang, Anders Pape MøllerAbstract: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 Cuckoos. Dummies of common Cuckoo (parasite) and Eurasian sparrowhawk Accipiter nisus (predator) were used to induce and record alarm calls of the two warbler species, respectively. In the conspecific alarm-call playback experiments, ORW responded more strongly to Cuckoo alarm calls than to sparrowhawk alarm calls, while BRW responded less strongly to Cuckoo alarm calls than to sparrowhawk alarm calls. In the heterospecific alarm-call playback experiments, both ORW and BRW responded less strongly to Cuckoo alarm calls than sparrowhawk alarm calls. BRW seemed to learn the association between parasite-related alarm calls of the ORW and the Cuckoo by observing the process of ORW attacking Cuckoos. In contrast, alarm calls of BRW to Cuckoos were rarely recorded in most cases. BRW with low parasite pressure still developed recognition of heterospecific parasite-related alarm call. Unintended receivers in the same community should recognize heterospecific alarm calls precisely to extract valuable information.
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Differently sized Cuckoos pose different threats to hosts
Current zoology, 2019Co-Authors: Mingju E, Haitao Wang, Wei Liang, Wei Sun, Anders MøllerAbstract: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 different threats to Chinese tits. A green-backed tit Parus monticolus population that is sympatric with Asian emerald Cuckoo Chrysococcyx maculatus (eme-Cuckoo, small-sized parasite) and common Cuckoo Cuculus canorus (com-Cuckoo, large-sized parasite), and a cinereous tit P. cinereus population that is only sympatric with com-Cuckoo were chosen as study organisms. We observed behavioral response and recorded alarm calls of the 2 tit species to eme-Cuckoo, com-Cuckoo, chipmunk Tamias sibiricus (a nest predator) and dove Streptopelia orientalis (a harmless control), and subsequently played back alarm calls to conspecific incubating females. In dummy experiments, both tit species performed intense response behavior to chipmunk, but rarely responded strongly to the 3 avian species. In playback experiments, both tit species responded strongly to conspecific chipmunk alarm calls, but rarely responded to dove alarm calls. The intensity of response of incubating female green-backed tits to eme-Cuckoo and com-Cuckoo alarm calls were similar to that of chipmunk alarm calls, while the intensity to eme-Cuckoo alarm calls was higher than the intensity to dove alarm calls which was similar to that of com-Cuckoo alarm calls. In contrast, few female cinereous tits responded to eme-Cuckoo and com-Cuckoo alarm calls. These findings indicated that the threat level of eme-Cuckoo was slightly greater than that of com-Cuckoo for sympatric green-backed tits, but not for allopatric cinereous tits.
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Global congruence between Cuckoo species richness and biodiversity hotspots
Biological Conservation, 2019Co-Authors: Federico Morelli, Piotr Tryjanowski, Wei Liang, Yanina Benedetti, David Moravec, Leszek Jerzak, Anders Pape MøllerAbstract:Abstract Considering loss of biodiversity a global threat, cost-effective tools for monitoring spatial distribution of species are relevant for conservation planning. The aims of this study were (a) to compare the global pattern of species richness in Cuculidae with species richness of birds, amphibians and mammals; (b) whether it is spatially congruent with hotspot areas of biodiversity at a global scale; and (c) whether the distribution of night light intensity reflecting human population density is associated with Cuckoo species richness. We mapped the global distribution of all Cuckoo species, classified as parasitic or non-parasitic species. Species richness was calculated at a fixed spatial scale for: Cuculidae, amphibians, birds and mammals. We applied Generalized Linear Mixed Models in order to explore the associations between species richness of each group of animals, night light intensity and hotspots of biodiversity areas at a global scale. Worldwide patterns of species richness of parasitic and non-parasitic Cuckoos reflected species richness of birds, amphibians and mammals. In addition, and importantly, species richness of Cuckoos was spatially congruent with hotspot areas of biodiversity across the world. Finally, night light intensity was slightly positively associated with species richness of parasitic Cuckoos. Our findings confirmed that Cuckoos constitute an important surrogate of high species richness of different animal taxa at a global scale: It is easy to learn how to identify Cuckoos, whereas other species of birds, mammals or amphibians can only be identified by specialists. Our findings also suggest that other parasitic Cuckoo species can be used as a biodiversity surrogate in a similar way as the common Cuckoo in Eurasia.
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costs of breeding far away from neighbors isolated host nests are more vulnerable to Cuckoo parasitism
Behavioural Processes, 2018Co-Authors: Canchao Yang, Wei Liang, Jianping Liu, Jianwei Zhang, Anders Pape MøllerAbstract:Abstract A series of parasitic and anti-parasitic strategies has evolved during the long-term coevolution between Cuckoos and their hosts. The first stage of the arms race is host nest choice by Cuckoos, followed by nest defense by hosts. This study examined nest defense strategies of the Oriental reed warbler (Acrocephalus orientalis) in relation to parasitism by the common Cuckoo (Cuculus canorus). Attack rate of Oriental reed warblers against common Cuckoo dummies was 100% and neighboring individuals participated in 87.1% of such attacks. Furthermore, the number of hosts attacking Cuckoo dummies was significantly positively correlated with the number of neighbors at a distance from 40 to 70 m, indicating social anti-parasitic behavior. Analysis of nest-site parameters indicated that the distance to the nearest neighboring unparasitized nest was significantly shorter than that of parasitized nests. Our study demonstrated that isolated nests of Oriental reed warblers with distant neighbors were more vulnerable to common Cuckoo parasitism suggesting a cost of breeding far away from neighbors. We hypothesize that cooperative behavior within local populations of Oriental reed warblers can probably be considered as an anti-parasitic strategy developed through long-term coevolution. Choice and parasitism of isolated host nests far away from neighbors may be an adaptive parasitic strategy by common Cuckoos to increase the probability of successful parasitism.
Anders Pape Møller - One of the best experts on this subject based on the ideXlab platform.
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Diet specialization and brood parasitism in Cuckoo species.
Ecology and evolution, 2020Co-Authors: Federico Morelli, Yanina Benedetti, Anders Pape MøllerAbstract:Brood parasitism is a breeding strategy adopted by many species of Cuckoos across the world. This breeding strategy influences the evolution of life histories of brood parasite species.In this study, we tested whether the degree on diet specialization is related to the breeding strategy in Cuckoo species, by comparing brood parasite and nonparasite species. We measured the gradient of diet specialization of Cuckoos, by calculating the Gini coefficient, an index of inequality, on the multiple traits describing the diet of species. The Gini coefficient is a measure of statistical dispersion on a scale between 0 and 1, reflecting a gradient from low to high specialization, respectively. First, we tested the strength of the phylogenetic signal of diet specialization index among Cuckoo species worldwide. Then, we ran phylogenetic generalized least square (PGLS) models to compare diet specialization, distribution range, and body mass of parasitic and nonparasitic Cuckoo species, considering the phylogenetic signal of data.After adjusting for the phylogenetic signal of the data and considering both, species distribution range and species body mass, brood parasitic Cuckoos were characterized by higher diet specialization than nonbrood parasitic species. Brood parasitic species were also characterized by a larger breeding distribution range than nonparasitic species.The findings of this study provide an additional understanding of the Cuckoos' ecology, relating diet and breeding strategies, information that could be important in conservation ecology.
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Heterospecific alarm-call recognition in two warbler hosts of common Cuckoos
Animal Cognition, 2019Co-Authors: Wei Sun, Haitao Wang, Wei Liang, Anders Pape MøllerAbstract: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 Cuckoos. Dummies of common Cuckoo (parasite) and Eurasian sparrowhawk Accipiter nisus (predator) were used to induce and record alarm calls of the two warbler species, respectively. In the conspecific alarm-call playback experiments, ORW responded more strongly to Cuckoo alarm calls than to sparrowhawk alarm calls, while BRW responded less strongly to Cuckoo alarm calls than to sparrowhawk alarm calls. In the heterospecific alarm-call playback experiments, both ORW and BRW responded less strongly to Cuckoo alarm calls than sparrowhawk alarm calls. BRW seemed to learn the association between parasite-related alarm calls of the ORW and the Cuckoo by observing the process of ORW attacking Cuckoos. In contrast, alarm calls of BRW to Cuckoos were rarely recorded in most cases. BRW with low parasite pressure still developed recognition of heterospecific parasite-related alarm call. Unintended receivers in the same community should recognize heterospecific alarm calls precisely to extract valuable information.
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Global congruence between Cuckoo species richness and biodiversity hotspots
Biological Conservation, 2019Co-Authors: Federico Morelli, Piotr Tryjanowski, Wei Liang, Yanina Benedetti, David Moravec, Leszek Jerzak, Anders Pape MøllerAbstract:Abstract Considering loss of biodiversity a global threat, cost-effective tools for monitoring spatial distribution of species are relevant for conservation planning. The aims of this study were (a) to compare the global pattern of species richness in Cuculidae with species richness of birds, amphibians and mammals; (b) whether it is spatially congruent with hotspot areas of biodiversity at a global scale; and (c) whether the distribution of night light intensity reflecting human population density is associated with Cuckoo species richness. We mapped the global distribution of all Cuckoo species, classified as parasitic or non-parasitic species. Species richness was calculated at a fixed spatial scale for: Cuculidae, amphibians, birds and mammals. We applied Generalized Linear Mixed Models in order to explore the associations between species richness of each group of animals, night light intensity and hotspots of biodiversity areas at a global scale. Worldwide patterns of species richness of parasitic and non-parasitic Cuckoos reflected species richness of birds, amphibians and mammals. In addition, and importantly, species richness of Cuckoos was spatially congruent with hotspot areas of biodiversity across the world. Finally, night light intensity was slightly positively associated with species richness of parasitic Cuckoos. Our findings confirmed that Cuckoos constitute an important surrogate of high species richness of different animal taxa at a global scale: It is easy to learn how to identify Cuckoos, whereas other species of birds, mammals or amphibians can only be identified by specialists. Our findings also suggest that other parasitic Cuckoo species can be used as a biodiversity surrogate in a similar way as the common Cuckoo in Eurasia.
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costs of breeding far away from neighbors isolated host nests are more vulnerable to Cuckoo parasitism
Behavioural Processes, 2018Co-Authors: Canchao Yang, Wei Liang, Jianping Liu, Jianwei Zhang, Anders Pape MøllerAbstract:Abstract A series of parasitic and anti-parasitic strategies has evolved during the long-term coevolution between Cuckoos and their hosts. The first stage of the arms race is host nest choice by Cuckoos, followed by nest defense by hosts. This study examined nest defense strategies of the Oriental reed warbler (Acrocephalus orientalis) in relation to parasitism by the common Cuckoo (Cuculus canorus). Attack rate of Oriental reed warblers against common Cuckoo dummies was 100% and neighboring individuals participated in 87.1% of such attacks. Furthermore, the number of hosts attacking Cuckoo dummies was significantly positively correlated with the number of neighbors at a distance from 40 to 70 m, indicating social anti-parasitic behavior. Analysis of nest-site parameters indicated that the distance to the nearest neighboring unparasitized nest was significantly shorter than that of parasitized nests. Our study demonstrated that isolated nests of Oriental reed warblers with distant neighbors were more vulnerable to common Cuckoo parasitism suggesting a cost of breeding far away from neighbors. We hypothesize that cooperative behavior within local populations of Oriental reed warblers can probably be considered as an anti-parasitic strategy developed through long-term coevolution. Choice and parasitism of isolated host nests far away from neighbors may be an adaptive parasitic strategy by common Cuckoos to increase the probability of successful parasitism.
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Multiple species of Cuckoos are superior predictors of bird species richness in Asia
Ecosphere, 2017Co-Authors: Anders Pape Møller, Federico Morelli, Piotr Tryjanowski, Yanina Benedetti, Timothy A. Mousseau, Bo Zhou, Wei LiangAbstract:The abundance and the presence of common Cuckoos Cuculus canorus have been shown to predict species richness of birds across Europe, while there are no such analyses available for other continents where species richness of parasitic Cuckoos is larger. Here, we tested whether species richness of birds increased with the number of Cuckoo species in two study areas in China and one in Japan. We also tested whether species richness of birds can be predicted by the number of Cuckoo individuals. Furthermore, we compared the strength of association between overall bird species richness and species richness of Cuckoos, Paridae, Corvidae, and birds of prey. This is the first study demonstrating that Cuckoo species richness is more strongly associated with overall bird species richness than richness of species belonging to other families, and rather than occurrence of a single Cuckoo species, as already demonstrated for the common Cuckoo in Europe. The number of Cuckoo species was positively associated with both non-host and host species richness. We found evidence of the number of Cuckoo species being associated with species richness of birds independently of country and year, while abundance of individual Cuckoos was not a statistically significant predictor. Furthermore, we showed that richness of host species is strongly positively correlated with overall bird species richness in both countries. This implies that the high species richness of Cuckoos in South-East Asia is a reliable predictor of overall bird species richness.
N B Davies - One of the best experts on this subject based on the ideXlab platform.
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female Cuckoo calls misdirect host defences towards the wrong enemy
Nature Ecology and Evolution, 2017Co-Authors: Jennifer Elaine York, N B DaviesAbstract:Prey are sensitive to even subtle cues of predation risk, which provides the evolutionary potential for parasites to exploit host risk perception. Brood parasitic common Cuckoos (Cuculus canorus) lay their eggs in the nests of host species and their secretive laying behaviour enables them to evade host defences. Therefore, it seems paradoxical that female Cuckoos often give a conspicuous ‘chuckle’ call after parasitizing a host’s clutch. Here, we show that this hawk-like chuckle call increases the success of parasitism by diverting host parents’ attention away from the clutch and towards their own safety. In our field experiments, reed warbler (Acrocephalus scirpaceus) hosts paid no more attention to the ‘cuck-oo’ call of the male common Cuckoo than the call of a harmless dove. However, the chuckle call of the female Cuckoo had the same effect as the call of a predatory hawk in distracting the warblers’ attention and reducing rejection of a foreign egg. Our results show that the female Cuckoo enhances her success by manipulating a fundamental trade-off in host defences between clutch and self-protection. Female common Cuckoos often make a hawk-like call after parasitizing a host’s clutch. Here, field experiments show that this call increases the chances of parasitic success by diverting host parents’ attention.
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direct and indirect assessment of parasitism risk by a Cuckoo host
Behavioral Ecology, 2012Co-Authors: Justin A. Welbergen, N B DaviesAbstract:When the risk of encountering enemies varies in space or in time, this may select for plasticity of costly defenses. Hosts are known to vary both mobbing of adult Cuckoos and egg rejection with spatiotemporal variation in brood parasitism, but it is unclear what parasitism cues they use to guide their defense plasticity. There is evidence that hosts use Cuckoo activity near their nests as a direct cue, but Cuckoos are secretive and resemble dangerous birds of prey so hosts may use indirect environmental predictors of parasitism too, such as their nest’s proximity to potential Cuckoo lookout perches. Here, we compared reed warbler Acrocephalus scirpaceus nest defense responses with models of various enemies at a parasitized site and at a site where no common Cuckoos Cuculus canorus were present. Reed warblers approached model Cuckoos less closely and mobbed them less at the unparasitized site. However, at both sites, the warblers reduced their mobbing in a similar manner with increasing distance to the nearest potential Cuckoo perch. The variation in response was specific to Cuckoos and was not shown to harmless controls. Thus, hosts use both direct (Cuckoo presence) and indirect cues (perch distance) of parasitism risk for modulating their costly defenses against their secretive parasite. We suggest that reciprocal selection for detection and suppression of direct and indirect cues provides a unifying feature of Cuckoo–host arms races.
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a parasite in wolf s clothing hawk mimicry reduces mobbing of Cuckoos by hosts
Behavioral Ecology, 2011Co-Authors: Justin A. Welbergen, N B DaviesAbstract:The reciprocal interactions between brood parasites and their hosts provide models for studying coevolution. For example, where hosts have evolved egg or chick discrimination, brood parasites have evolved mimicry of host eggs or chicks. Here, we suggest that there is another form of mimicry by Cuckoos. A previous study has shown that naive small birds, with no evolutionary history of brood parasitism, are as afraid of adult common Cuckoos Cuculus canorus as of sparrowhawks Accipiter nisus because of their physical resemblance. However, it has yet to be shown whether host species regard Cuckoos as hawk like, or how hawk resemblance might benefit the Cuckoo. We provide the first evidence that hawk resemblance involving barred underparts is an adaptive brood parasitic trait. We show by plumage manipulations of taxidermic models that reed warbler (Acrocephalus scirpaceus) hosts are more reluctant to approach and mob common Cuckoos with barred rather than unbarred underparts. Our results indicate that reed warblers are more aggressive toward Cuckoos that appear less hawk like and that hence, hawk resemblance facilitates access to host nests. Therefore, we suggest that Cuckoos employ 2 forms of mimicry: To enhance parasitic laying, Cuckoo adults are Batesian mimics of hawks, appearing dangerous to adult host survival, when in fact they could be safely attacked. At later stages, Cuckoo eggs and chicks are aggressive mimics, appearing harmless but in fact dangerous to host reproduction. These strategies are each countered by host discrimination, providing the means for distinct coevolutionary arms races at successive stages of the host nesting cycle. Key words: brood parasitism, coevolution, Cuckoo, dove, mimicry, sparrowhawk. [Behav Ecol]
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a failure to demonstrate host imprinting in the Cuckoo cuculus canorus and alternative hypotheses for the maintenance of egg mimicry
Ethology, 2010Co-Authors: M. L. Brooke, N B DaviesAbstract:The Cuckoo Cuculus canorus is divided into various gentes, each laying a distinctive egg and favouring a different species as host. It has long been assumed that the gentes remain distinct because female Cuckoos lay the same egg-type as their mother and prefer the same host, developing this preference by imprinting on their foster parents. We tested whether imprinting occurred by laboratory experiments with 7 Cuckoos originating from reed warbler Acrocephalus scirpaceus nests. Two were transferred soon after hatching to robin Erithacus rubecula nests and were raised by robins, while the other five were raised by reed warblers. When about 12 d old, the nestling Cuckoos and their foster parents were transferred from the wild to aviaries, where the fosterers continued to raise the Cuckoos to independence. The fosterers were then released and the Cuckoos retained and presented, at one and two years of age, with a behavioural choice between robins and reed warblers. None of the Cuckoos (five females and two males) displayed a consistent preference for the host that reared them even, in the case of females, after oestradiol implantation. We discuss the inadequacies of our experiment and present data on Cuckoo egg types to test whether natal philopatry might be sufficient to maintain the gentes. We suggest that mitochondrial DNA studies, now underway, will help to resolve the issue.
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a host race difference in begging calls of nestling Cuckoos cuculus canorus develops through experience and increases host provisioning
Proceedings of The Royal Society B: Biological Sciences, 2006Co-Authors: Joah R Madden, N B DaviesAbstract: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 dunnock-Cuckoos, whereas controls transferred to the nests of robins or left to be raised by reed warblers developed calls more typical of reed warbler-Cuckoos. We tested the effectiveness of these different calls in stimulating host provisioning by placing in host nests a single blackbird or song thrush nestling (of similar size to a young Cuckoo, but lacking its exuberant begging calls); when it begged we broadcast, from a small loudspeaker on the nest rim, recordings of either dunnock-Cuckoo or reed warbler-Cuckoo begging calls. Playback of dunnock-Cuckoo begging calls induced higher levels of provisioning by dunnocks, whereas playback of reed warbler-Cuckoo begging calls did so for both reed warblers and robins. We suggest that the young Cuckoo (which ejects the host's eggs/chicks and so is raised alone) learns by experience which calls best stimulate host provisioning.
Federico Morelli - One of the best experts on this subject based on the ideXlab platform.
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Diet specialization and brood parasitism in Cuckoo species.
Ecology and evolution, 2020Co-Authors: Federico Morelli, Yanina Benedetti, Anders Pape MøllerAbstract:Brood parasitism is a breeding strategy adopted by many species of Cuckoos across the world. This breeding strategy influences the evolution of life histories of brood parasite species.In this study, we tested whether the degree on diet specialization is related to the breeding strategy in Cuckoo species, by comparing brood parasite and nonparasite species. We measured the gradient of diet specialization of Cuckoos, by calculating the Gini coefficient, an index of inequality, on the multiple traits describing the diet of species. The Gini coefficient is a measure of statistical dispersion on a scale between 0 and 1, reflecting a gradient from low to high specialization, respectively. First, we tested the strength of the phylogenetic signal of diet specialization index among Cuckoo species worldwide. Then, we ran phylogenetic generalized least square (PGLS) models to compare diet specialization, distribution range, and body mass of parasitic and nonparasitic Cuckoo species, considering the phylogenetic signal of data.After adjusting for the phylogenetic signal of the data and considering both, species distribution range and species body mass, brood parasitic Cuckoos were characterized by higher diet specialization than nonbrood parasitic species. Brood parasitic species were also characterized by a larger breeding distribution range than nonparasitic species.The findings of this study provide an additional understanding of the Cuckoos' ecology, relating diet and breeding strategies, information that could be important in conservation ecology.
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Global congruence between Cuckoo species richness and biodiversity hotspots
Biological Conservation, 2019Co-Authors: Federico Morelli, Piotr Tryjanowski, Wei Liang, Yanina Benedetti, David Moravec, Leszek Jerzak, Anders Pape MøllerAbstract:Abstract Considering loss of biodiversity a global threat, cost-effective tools for monitoring spatial distribution of species are relevant for conservation planning. The aims of this study were (a) to compare the global pattern of species richness in Cuculidae with species richness of birds, amphibians and mammals; (b) whether it is spatially congruent with hotspot areas of biodiversity at a global scale; and (c) whether the distribution of night light intensity reflecting human population density is associated with Cuckoo species richness. We mapped the global distribution of all Cuckoo species, classified as parasitic or non-parasitic species. Species richness was calculated at a fixed spatial scale for: Cuculidae, amphibians, birds and mammals. We applied Generalized Linear Mixed Models in order to explore the associations between species richness of each group of animals, night light intensity and hotspots of biodiversity areas at a global scale. Worldwide patterns of species richness of parasitic and non-parasitic Cuckoos reflected species richness of birds, amphibians and mammals. In addition, and importantly, species richness of Cuckoos was spatially congruent with hotspot areas of biodiversity across the world. Finally, night light intensity was slightly positively associated with species richness of parasitic Cuckoos. Our findings confirmed that Cuckoos constitute an important surrogate of high species richness of different animal taxa at a global scale: It is easy to learn how to identify Cuckoos, whereas other species of birds, mammals or amphibians can only be identified by specialists. Our findings also suggest that other parasitic Cuckoo species can be used as a biodiversity surrogate in a similar way as the common Cuckoo in Eurasia.
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functional significance of Cuckoo cuculus canorus calls responses of conspecifics hosts and non hosts
PeerJ, 2018Co-Authors: Piotr Tryjanowski, Federico Morelli, Tomasz S OsiejukAbstract: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 should attract more male Cuckoos (if males with such calls are dominant and successfully out-compete other males due to intraspecific competition), and attract more hosts mobbing male Cuckoos (Cuckoos with such calls and their females attract more hosts because of an increased risk of parasitism). Because Cuckoos differentially parasitize hosts away from human habitation, we also tested whether the number of syllables in Cuckoo calls differed with distance from buildings. Playback showed significant effects of number of syllables in Cuckoo calls, but not woodpigeon Columba palumbus calls, with an additional effect of distance from human habitation decreasing the response to playback. These findings are consistent with the hypothesis that longer Cuckoo calls, especially played back near human habitation, attract more conspecifics and hosts than shorter calls. To the best of knowledge this is the first study showing that Cuckoo call response modified both other Cuckoo individuals, as well as hosts response.
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Birds respond similarly to taxidermic models and live Cuckoos Cuculus canorus
Journal of Ethology, 2018Co-Authors: Piotr Tryjanowski, Zbigniew Kwieciński, Federico Morelli, Piotr IndykiewiczAbstract:Stuffed birds are widely used in research for identifying effects of predators and nest parasites on bird behaviour, studying levels of aggression and the size of territories. However, the fact that these models do not move or vocalize may question the results of such studies and open them to criticism. One solution would be to determine how the results of research using stuffed dummies correlate with the response of wild animals to enemies under the same environmental conditions. In a first attempt, we examined the correlation between the intensity of mobbing of a dummy Cuckoo Cuculus canorus and interactions with live Cuckoos in the field during the breeding season in western Poland. A total of 39 bird species mobbed Cuckoo dummies; all 39 were found to attack live Cuckoos, while 24 species (61.5%) did so during experiments using a dummy. The number of individual birds involved in mobbing a dummy was positively correlated with the number of individuals attacking real Cuckoos in the same areas, even when the most commonly mobbing species, the barn swallow Hirundo rustica , was excluded from the analyses. However, we did not find significant differences in frequency of mobbing behaviour depending on Cuckoo behaviour described as flight or sitting, or calling rather than remaining quiet. Therefore, we conclude that the use of a dummy for studying mobbing of hosts and non-hosts of the Cuckoo provide results that are similar to those made in response to the behaviour of live hosts.
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Multiple species of Cuckoos are superior predictors of bird species richness in Asia
Ecosphere, 2017Co-Authors: Anders Pape Møller, Federico Morelli, Piotr Tryjanowski, Yanina Benedetti, Timothy A. Mousseau, Bo Zhou, Wei LiangAbstract:The abundance and the presence of common Cuckoos Cuculus canorus have been shown to predict species richness of birds across Europe, while there are no such analyses available for other continents where species richness of parasitic Cuckoos is larger. Here, we tested whether species richness of birds increased with the number of Cuckoo species in two study areas in China and one in Japan. We also tested whether species richness of birds can be predicted by the number of Cuckoo individuals. Furthermore, we compared the strength of association between overall bird species richness and species richness of Cuckoos, Paridae, Corvidae, and birds of prey. This is the first study demonstrating that Cuckoo species richness is more strongly associated with overall bird species richness than richness of species belonging to other families, and rather than occurrence of a single Cuckoo species, as already demonstrated for the common Cuckoo in Europe. The number of Cuckoo species was positively associated with both non-host and host species richness. We found evidence of the number of Cuckoo species being associated with species richness of birds independently of country and year, while abundance of individual Cuckoos was not a statistically significant predictor. Furthermore, we showed that richness of host species is strongly positively correlated with overall bird species richness in both countries. This implies that the high species richness of Cuckoos in South-East Asia is a reliable predictor of overall bird species richness.
Nicholas B. Davies - One of the best experts on this subject based on the ideXlab platform.
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Hawk mimicry and the evolution of polymorphic Cuckoos
Chinese Birds, 2013Co-Authors: Rose Thorogood, Nicholas B. DaviesAbstract:The resemblance of some parasitic Cuckoos to Accipiter hawks has been known since an- cient times. Recent experiments show that the hawk-like features of Common Cuckoos (Cuculus canorus) facilitate access to Reed Warbler (Acrocephalus scirpaceus) host nests. However, social infor- mation alerts hosts to see through the Cuckoo's mimetic disguise. In turn, this has promoted the evo- lution of a Cuckoo polymorphism to thwart host recognition. Here we show by comparative analyses that parasitic Cuckoos with hawk-like features (yellow eyes, barred underparts, yellow legs) are more likely to be polymorphic (29% of species) than those without (8% of species). Phylogenetic analyses confirm correlated evolution of hawk-like features and Cuckoo polymorphism. We suggest that mim- icry dynamics are particularly likely to promote the evolution of various guises in parasitic Cuckoos to beat host defences.
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Direct and indirect assessment of parasitism risk by a Cuckoo host
Behavioral Ecology, 2012Co-Authors: Justin A. Welbergen, Nicholas B. DaviesAbstract:When the risk of encountering enemies varies in space or in time, this may select for plasticity of costly defenses. Hosts are known to vary both mobbing of adult Cuckoos and egg rejection with spatiotemporal variation in brood parasitism, but it is unclear what parasitism cues they use to guide their defense plasticity. There is evidence that hosts use Cuckoo activity near their nests as a direct cue, but Cuckoos are secretive and resemble dangerous birds of prey so hosts may use indirect environmental predictors of parasitism too, such as their nest’s proximity to potential Cuckoo lookout perches. Here, we compared reed warbler Acrocephalus scirpaceus nest defense responses with models of various enemies at a parasitized site and at a site where no common Cuckoos Cuculus canorus were present. Reed warblers approached model Cuckoos less closely and mobbed them less at the unparasitized site. However, at both sites, the warblers reduced their mobbing in a similar manner with increasing distance to the nearest potential Cuckoo perch. The variation in response was specific to Cuckoos and was not shown to harmless controls. Thus, hosts use both direct (Cuckoo presence) and indirect cues (perch distance) of parasitism risk for modulating their costly defenses against their secretive parasite. We suggest that reciprocal selection for detection and suppression of direct and indirect cues provides a unifying feature of Cuckoo–host arms races. Key words: brood parasites, coevolution, direct cues, host defense, indirect cues, phenotypic plasticity. [Behav Ecol]
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Does coevolution promote species richness in parasitic Cuckoos
Proceedings. Biological sciences, 2009Co-Authors: Oliver Kruger, Michael D. Sorenson, Nicholas B. DaviesAbstract:Why some lineages have diversified into larger numbers of species than others is a fundamental but still relatively poorly understood aspect of the evolutionary process. Coevolution has been recognized as a potentially important engine of speciation, but has rarely been tested in a comparative framework. We use a comparative approach based on a complete phylogeny of all living Cuckoos to test whether parasite–host coevolution is associated with patterns of Cuckoo species richness. There are no clear differences between parental and parasitic Cuckoos in the number of species per genus. However, a cladogenesis test shows that brood parasitism is associated with both significantly higher speciation and extinction rates. Furthermore, subspecies diversification rate estimates were over twice as high in parasitic Cuckoos as in parental Cuckoos. Among parasitic Cuckoos, there is marked variation in the severity of the detrimental effects on host fitness; chicks of some Cuckoo species are raised alongside the young of the host and others are more virulent, with the Cuckoo chick ejecting or killing the eggs/young of the host. We show that Cuckoos with a more virulent parasitic strategy have more recognized subspecies. In addition, Cuckoo species with more recognized subspecies have more hosts. These results hold after controlling for confounding geographical effects such as range size and isolation in archipelagos. Although the power of our analyses is limited by the fact that brood parasitism evolved independently only three times in Cuckoos, our results suggest that coevolutionary arms races with hosts have contributed to higher speciation and extinction rates in parasitic Cuckoos.
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Cuckoo hawk mimicry an experimental test
Proceedings of The Royal Society B: Biological Sciences, 2008Co-Authors: Nicholas B. Davies, Justin A. WelbergenAbstract: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 parasitism by influencing host behaviour. Here, we provide the first evidence that some small birds respond to common Cuckoos Cuculus canorus as if they were sparrowhawks Accipiter nisus. Great tits and blue tits were equally alarmed and reduced attendance at feeders during and after the presentation of mounted specimens of common Cuckoos and sparrowhawks, but not in response to control presentations of collared doves or teal. Plumage manipulations revealed that the strong alarm response to Cuckoos depended on their resemblance to hawks; Cuckoos with barred underparts were treated like hawks, while those with unbarred underparts were treated like doves. However, barring was not the only feature inducing alarm because tits showed similarly strong alarm to barred and unbarred hawks, and little alarm to barred doves. These responses of tits, unsuitable as hosts and hence with no history of Cuckoo parasitism, suggest that naive small birds can mistake Cuckoos for hawks. Thus, any Cuckoo–hawk discrimination by host species is likely to be an evolved response to brood parasitism.
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Cuckoo–hawk mimicry? An experimental test
Proceedings. Biological sciences, 2008Co-Authors: Nicholas B. Davies, Justin A. WelbergenAbstract: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 parasitism by influencing host behaviour. Here, we provide the first evidence that some small birds respond to common Cuckoos Cuculus canorus as if they were sparrowhawks Accipiter nisus. Great tits and blue tits were equally alarmed and reduced attendance at feeders during and after the presentation of mounted specimens of common Cuckoos and sparrowhawks, but not in response to control presentations of collared doves or teal. Plumage manipulations revealed that the strong alarm response to Cuckoos depended on their resemblance to hawks; Cuckoos with barred underparts were treated like hawks, while those with unbarred underparts were treated like doves. However, barring was not the only feature inducing alarm because tits showed similarly strong alarm to barred and unbarred hawks, and little alarm to barred doves. These responses of tits, unsuitable as hosts and hence with no history of Cuckoo parasitism, suggest that naive small birds can mistake Cuckoos for hawks. Thus, any Cuckoo–hawk discrimination by host species is likely to be an evolved response to brood parasitism.