Parasitic birds and their hosts
01 Jan 1998-
About: The article was published on 1998-01-01 and is currently open access. It has received 191 citations till now. The article focuses on the topics: Obligate parasite & Ecology (disciplines).
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TL;DR: It is shown that the breach of host egg defences by cuckoos creates a new stage in the coevolutionary cycle and is suggested that it has selected for the evolution of nestling mimicry in bronze-cuckoos.
Abstract: Cuckoo nestlings that evict all other young from the nest soon after hatching impose a high reproductive cost on their hosts1. In defence, hosts have coevolved strategies to prevent brood parasitism. Puzzlingly, they do not extend beyond the egg stage2,3,4,5. Thus, hosts adept at recognizing foreign eggs remain vulnerable to exploitation by cuckoo nestlings6,7. Here we show that the breach of host egg defences by cuckoos creates a new stage in the coevolutionary cycle. We found that defences used during the egg-laying period by host superb fairy-wrens (Malurus cyaneus) are easily evaded by the Horsfield's bronze-cuckoo (Chrysococcyx basalis), a specialist fairy-wren brood parasite. However, although hosts never deserted their own broods, they later abandoned 40% of nests containing a lone Horsfield's bronze-cuckoo nestling, and 100% of nests with a lone shining bronze-cuckoo nestling (Chrysococcyx lucidus), an occasional fairy-wren brood parasite. Our experiments demonstrate that host discrimination against evictor-cuckoo nestlings is possible, and suggest that it has selected for the evolution of nestling mimicry in bronze-cuckoos.
294 citations
TL;DR: Clutch size comparisons revealed that females combine egg recognition and counting to make clutch size decisions—by counting their own eggs, while ignoring distinctive parasitic eggs, females avoid a maladaptive clutch size reduction.
Abstract: Birds parasitized by interspecific brood parasites often adopt defences based on egg recognition but such behaviours are puzzlingly rare in species parasitized by members of the same species. Here I show that conspecific egg recognition is frequent, accurate and used in three defences that reduce the high costs of conspecific brood parasitism in American coots. Hosts recognized and rejected many parasitic eggs, reducing the fitness costs of parasitism by half. Recognition without rejection also occurred and some hosts banished parasitic eggs to inferior outer incubation positions. Clutch size comparisons revealed that females combine egg recognition and counting to make clutch size decisions—by counting their own eggs, while ignoring distinctive parasitic eggs, females avoid a maladaptive clutch size reduction. This is clear evidence that female birds use visual rather than tactile cues to regulate their clutch sizes, and provides a rare example of the ecological and evolutionary context of counting in animals.
261 citations
TL;DR: It is shown that declines and increases can be deduced from current species distributions alone, using spatial patterns of occupancy combined with distribution size, and this link between current distribution patterns and processes of distribution change could be used to assess relative levels of threat facing different species.
Abstract: Interpretation of global biodiversity change is hampered by a lack of information on the historical status of most species in most parts of the world1, 2, 3, 4, 5. Here we show that declines and increases can be deduced from current species distributions alone, using spatial patterns of occupancy combined with distribution size. Declining species show sparse, fragmented distributions for their distribution size, reflecting the extinction process; expanding species show denser, more aggregated distributions, reflecting colonization. Past distribution size changes for British butterflies were deduced successfully from current distributions, and former distributions had some power to predict future change. What is more, the relationship between distribution pattern and change in British butterflies independently predicted distribution change for butterfly species in Flanders, Belgium, and distribution change in British rare plant species is similarly related to spatial distribution pattern. This link between current distribution patterns and processes of distribution change could be used to assess relative levels of threat facing different species, even for regions and taxa lacking detailed historical and ecological information.
235 citations
TL;DR: Genetic evidence that gentes are restricted to female lineages is provided, with cross mating by males maintaining the common cuckoo genetically as one species, and there is differentiation between gentes in maternally inherited mitochondrial DNA, but not in microsatellite loci of nuclear DNA is shown.
Abstract: 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 differentiation between gentes in maternally inherited mitochondrial DNA, but not in microsatellite loci of nuclear DNA. This supports recent behavioural evidence that female, but not male, common cuckoos specialize on a particular host, and is consistent with the possibility that genes affecting cuckoo egg type are located on the female-specific W sex chromosome. Our results also support the ideas that common cuckoos often switched hosts during evolution, and that some gentes may have multiple, independent origins, due to colonization by separate ancestral lineages.
223 citations
TL;DR: The intersection of life-history evolution, conflicts of interest, and frequency-dependent fitness provides much scope for theoretical exploration, and recent models indicate a complex range of evolutionary dynamics is possible, including consequences of CBP for population dynamics and conservation.
Abstract: Conspecific brood parasitism (CBP), whereby females lay eggs in the nests of other conspecifics, occurs in over 200 species of birds. As an alternative tactic to typical nesting, CBP expands and enriches the classic avian clutch size problem. It is an integral component of a flexible life-history strategy and, consequently, many intriguing aspects of this behavior—adaptive benefits to parasites, host-parasite interactions, population and evolutionary dynamics—can be understood best from a life-history perspective. Because parasite fitness depends on hosts, yet parasitism potentially reduces host fitness, CBP offers a novel opportunity to explore conflicts of interest within species. The intersection of life-history evolution, conflicts of interest, and frequency-dependent fitness provides much scope for theoretical exploration, and recent models indicate a complex range of evolutionary dynamics is possible, including consequences of CBP for population dynamics and conservation. CBP may also be a macroevolutionary stepping stone to diverse breeding systems.
185 citations
Cites background from "Parasitic birds and their hosts"
...See Rothstein & Robinson 1998, pp. 376–406 Power HW, Kennedy ED, Romagnano LC, Lombardo MP, Hoffenberg AS, et al. 1989....
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...See Rothstein & Robinson 1998, pp. 407–18 Jamieson IG, McRae SB, Simmons RE, Trewby M. 2000....
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