Batesian mimicry is the process in which harmless species adopt the appearance of a dangerous, aposematic species.In some prey species,both Batesian mimetic and non-Batesian morphs coexist,presupposing that both morph...Batesian mimicry is the process in which harmless species adopt the appearance of a dangerous, aposematic species.In some prey species,both Batesian mimetic and non-Batesian morphs coexist,presupposing that both morphs have to be evolutionarily advantageous.The viperine snake, Natrix maura,exhibits a zigzag dorsal pattern and antipredatory behavior that mimics European vipers.This snake also has a striped dorsal pattern that coexists with the zigzag pattern.We have examined whether individuals belonging to different geographically structured clades were more likely to exhibit a certain dorsal pattern,and whether the zigzag pattern has a protective function by exposing artificial snakes to predation in natural environments,in addition to comparing antipredatory behavior between zigzag and striped snakes also in natural environments.Our results indicate that the striped pattern was not geographically structured,but habitat-dependent.Aerial predators less frequently attacked zigzag plasticine models than striped or unpatterned models.We detected a shift in antipredator behavior between the 2 morphs,as Batesian mimicking N.maura responded to an approaching potential predator by remaining immobile or fleeing at shorter distances than did striped ones.We conclude that Batesian mimics maintain the cryptic and aposematic value by resembling vipers,whereas in open habitats the non-Batesian mimic has altered its antipredator behavior to maintain its fitness.展开更多
The resemblance of some parasitic cuckoos to Accipiter hawks has been known since ancient times. Recent experiments show that the hawk-like features of Common Cuckoos (Cuculus canorus) facilitate access to Reed Warble...The resemblance of some parasitic cuckoos to Accipiter hawks has been known since ancient 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 information alerts hosts to see through the cuckoo’s mimetic disguise. In turn, this has promoted the evolution 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 mimicry dynamics are particularly likely to promote the evolution of various guises in parasitic cuckoos to beat host defences.展开更多
Mimicry is widely used to exemplify natural selection＇s power in promoting adaptation. Nonetheless, it has become increasingly clear that mimicry is frequently imprecise. Indeed, the phenotypic match is often poor be...Mimicry is widely used to exemplify natural selection＇s power in promoting adaptation. Nonetheless, it has become increasingly clear that mimicry is frequently imprecise. Indeed, the phenotypic match is often poor between mimics and models in many Batesian mimicry complexes and among co-mimics in many Mtillerian mimicry complexes. Here, we consider whether such imperfect mimicry represents an evolutionary compromise between predator-mediated selection favoring mimetic conver- gence on the one hand and competitively mediated selection favoring divergence on the other hand. Specifically, for mimicry to be effective, mimics and their models/co-mimics should occur together. Yet, co-occurring species that are phenotypically similar often compete for resources, successful reproduction, or both. As an adaptive response to minimize such costly interactions, in-teracting species may diverge phenotypically through an evolutionary process known as character displacement. Such divergence between mimics and their models/co-mimics may thereby result in imperfect mimicry. We review the various ways in which character displacement could promote imprecise mimicry, describe the conditions under which this process may be especially likely to produce imperfect mimicry, examine a possible case study, and discuss avenues for future research. Generally, character displacement may play an underappreciated role in fostering inexact mimicry .展开更多
Many animals mimic the behavior or the appearance of venomous snakes.When humans or other potential predators place their hand near the nest of tits belonging to the family Paridae(and a few other species),the incubat...Many animals mimic the behavior or the appearance of venomous snakes.When humans or other potential predators place their hand near the nest of tits belonging to the family Paridae(and a few other species),the incubating female performs a hissing display that mimics the inhalation hiss of a viper or another snake.They hiss vigorously while lunging their head forward and shaking their wings and tail,repeating this behavior several times.The structure of the hiss in tits is similar to that of the inhalation hiss of a snake,providing evidence of significant convergence of the mimic toward the model.The behavior of individual females is repeatable among tri als.Individuals that flew away from their nest box only performed the hissing display on 6%of later trials,when present at their box,whereas individuals that did not fly away hissed on 28% of occasions,consistent with great tits Parus major either cautiously flying away or staying put on their nest while actively defending it.Individuals that flew away produced fewer chicks than individuals that stayed and hissed.The hissing display was more common when snakes were more abundant:1)When breeding late during the season;2)when breeding at sites with more snakes;and 3)when breeding in subtropical and tropical China with a higher abundance of snakes than in Denmark with a lower abundance.The frequency of nest predation was higher in sites with no snakes,and the frequency of predation increased with decreasing frequency of hissing display.These findings are consistent with expectations for frequency-dependent selection acting on snake mimicry.展开更多
Argentine ant invasion changed colour-polymorphic composition of ant-mimetic jumping spider Myrmarachne in southwestern Japan. In Argentine ant-free sites, most of Myrmarachne exhibited all-blackish colouration. In Ar...Argentine ant invasion changed colour-polymorphic composition of ant-mimetic jumping spider Myrmarachne in southwestern Japan. In Argentine ant-free sites, most of Myrmarachne exhibited all-blackish colouration. In Argentine ant-infested sites, on the other hand, blackish morph decreased, and bicoloured (i.e. partly bright-coloured) morphs increased in dominance. Invasive Argentine ant drives away native blackish ants. Disappearance of blackish model ants supposedly led to malfunction of Batesian mimicry of Myrmarachne.展开更多
文摘Batesian mimicry is the process in which harmless species adopt the appearance of a dangerous, aposematic species.In some prey species,both Batesian mimetic and non-Batesian morphs coexist,presupposing that both morphs have to be evolutionarily advantageous.The viperine snake, Natrix maura,exhibits a zigzag dorsal pattern and antipredatory behavior that mimics European vipers.This snake also has a striped dorsal pattern that coexists with the zigzag pattern.We have examined whether individuals belonging to different geographically structured clades were more likely to exhibit a certain dorsal pattern,and whether the zigzag pattern has a protective function by exposing artificial snakes to predation in natural environments,in addition to comparing antipredatory behavior between zigzag and striped snakes also in natural environments.Our results indicate that the striped pattern was not geographically structured,but habitat-dependent.Aerial predators less frequently attacked zigzag plasticine models than striped or unpatterned models.We detected a shift in antipredator behavior between the 2 morphs,as Batesian mimicking N.maura responded to an approaching potential predator by remaining immobile or fleeing at shorter distances than did striped ones.We conclude that Batesian mimics maintain the cryptic and aposematic value by resembling vipers,whereas in open habitats the non-Batesian mimic has altered its antipredator behavior to maintain its fitness.
基金funded by the Natural Environment Research Council
文摘The resemblance of some parasitic cuckoos to Accipiter hawks has been known since ancient 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 information alerts hosts to see through the cuckoo’s mimetic disguise. In turn, this has promoted the evolution 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 mimicry dynamics are particularly likely to promote the evolution of various guises in parasitic cuckoos to beat host defences.
基金We thank Karin Pfennig, the members of the Pfennig lab, and two anonymous referees for helpful comments. We also thank Zhi-Yun Jia for inviting us to submit this paper and the U.S. National Science Foundation for fund-ing our research on mimicry and character displacement.
文摘Mimicry is widely used to exemplify natural selection＇s power in promoting adaptation. Nonetheless, it has become increasingly clear that mimicry is frequently imprecise. Indeed, the phenotypic match is often poor between mimics and models in many Batesian mimicry complexes and among co-mimics in many Mtillerian mimicry complexes. Here, we consider whether such imperfect mimicry represents an evolutionary compromise between predator-mediated selection favoring mimetic conver- gence on the one hand and competitively mediated selection favoring divergence on the other hand. Specifically, for mimicry to be effective, mimics and their models/co-mimics should occur together. Yet, co-occurring species that are phenotypically similar often compete for resources, successful reproduction, or both. As an adaptive response to minimize such costly interactions, in-teracting species may diverge phenotypically through an evolutionary process known as character displacement. Such divergence between mimics and their models/co-mimics may thereby result in imperfect mimicry. We review the various ways in which character displacement could promote imprecise mimicry, describe the conditions under which this process may be especially likely to produce imperfect mimicry, examine a possible case study, and discuss avenues for future research. Generally, character displacement may play an underappreciated role in fostering inexact mimicry .
基金This study was supported by the National Natural Science Foundation of China(Nos.31772453 and 31970427 to W.L.)。
文摘Many animals mimic the behavior or the appearance of venomous snakes.When humans or other potential predators place their hand near the nest of tits belonging to the family Paridae(and a few other species),the incubating female performs a hissing display that mimics the inhalation hiss of a viper or another snake.They hiss vigorously while lunging their head forward and shaking their wings and tail,repeating this behavior several times.The structure of the hiss in tits is similar to that of the inhalation hiss of a snake,providing evidence of significant convergence of the mimic toward the model.The behavior of individual females is repeatable among tri als.Individuals that flew away from their nest box only performed the hissing display on 6%of later trials,when present at their box,whereas individuals that did not fly away hissed on 28% of occasions,consistent with great tits Parus major either cautiously flying away or staying put on their nest while actively defending it.Individuals that flew away produced fewer chicks than individuals that stayed and hissed.The hissing display was more common when snakes were more abundant:1)When breeding late during the season;2)when breeding at sites with more snakes;and 3)when breeding in subtropical and tropical China with a higher abundance of snakes than in Denmark with a lower abundance.The frequency of nest predation was higher in sites with no snakes,and the frequency of predation increased with decreasing frequency of hissing display.These findings are consistent with expectations for frequency-dependent selection acting on snake mimicry.
文摘Argentine ant invasion changed colour-polymorphic composition of ant-mimetic jumping spider Myrmarachne in southwestern Japan. In Argentine ant-free sites, most of Myrmarachne exhibited all-blackish colouration. In Argentine ant-infested sites, on the other hand, blackish morph decreased, and bicoloured (i.e. partly bright-coloured) morphs increased in dominance. Invasive Argentine ant drives away native blackish ants. Disappearance of blackish model ants supposedly led to malfunction of Batesian mimicry of Myrmarachne.
