36 research outputs found

    Male spotted bowerbirds propagate fruit for use in their sexual display

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    Cultivation may be described as a process of co-evolution and niche construction, with two species developing a mutualistic relationship through association, leading to coordinated change [1]. Cultivation is rare but taxonomically widespread, benefiting the cultivator, usually through increased access to food, and the cultivar, by improved growth and protection, driving co-evolutionary changes (Supplemental information). Humans cultivate more than food, producing clothing, construction materials, fuel, drugs, and ornaments. A population of male spotted bowerbirds Ptilonorhynchus (Chlamydera) maculata uses fruits of Solanum ellipticum (Figure 1A), not as food but as important components of their sexual display [2,3]. Here, we show that males indirectly cultivate plants bearing these fruit - the first example of cultivation of a non-food item by a species other than humans. Plants appear at bowers following male occupation (Figure 1B). Males benefit, exhibiting more fruit at their bowers. Plants benefit because fruit are deposited in better germination sites. Fruits from plants near bowers differ visually from those far from bowers, and look more similar to fruits that are preferred by males in choice tests

    Genetic, phenotypic and ecological differentiation suggests incipient speciation in two Charadrius plovers along the Chinese coast

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    BackgroundSpeciation with gene flow is an alternative to the nascence of new taxa in strict allopatric separation. Indeed, many taxa have parapatric distributions at present. It is often unclear if these are secondary contacts, e.g. caused by past glaciation cycles or the manifestation of speciation with gene flow, which hampers our understanding of how different forces drive diversification. Here we studied genetic, phenotypic and ecological aspects of divergence in a pair of incipient shorebird species, the Kentish (Charadrius alexandrinus) and the White-faced Plovers (C. dealbatus), shorebirds with parapatric breeding ranges along the Chinese coast. We assessed divergence based on molecular markers with different modes of inheritance and quantified phenotypic and ecological divergence in aspects of morphometric, dietary and climatic niches.ResultsOur integrative analyses revealed small to moderate levels of genetic and phenotypic distinctiveness with symmetric gene flow across the contact area at the Chinese coast. The two species diverged approximately half a million years ago in dynamic isolation with secondary contact occurring due to cycling sea level changes between the Eastern and Southern China Sea in the mid-late Pleistocene. We found evidence of character displacement and ecological niche differentiation between the two species, invoking the role of selection in facilitating divergence despite gene flow.ConclusionThese findings imply that ecology can indeed counter gene flow through divergent selection and thus contributes to incipient speciation in these plovers. Furthermore, our study highlights the importance of using integrative datasets to reveal the evolutionary history and assist the inference of mechanisms of speciation

    Nesting of the Tropical Parula Parula pitiayumi in eastern Ecuador

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    Fat Affects Predator-Avoidance Behavior in Gray Catbirds (\u3ci\u3eDumetella carolinensis\u3c/i\u3e) During Migratory Stopover

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    During migration, birds may store large quantities of fat to fuel long-distance flight. Because mass affects flight performance, fat migrants should behave with greater caution toward aerial predators than lean migrants. We tested a prediction of this hypothesis, namely, that fat birds will remain motionless longer than lean birds after a simulated encounter with a raptor. We captured Gray Catbirds (Dumetella carolinensis) during fall migration, classified their subcutaneous fat, exposed them to a model hawk, and then recorded the time until their first perch change. To determine whether the birds treated the simulated predator as a threat, we also tested them with a hexagon-shaped model and with no model. The birds remained motionless longer with the hawk model than either of the two other treatments. Fat birds remained motionless longer than lean birds when exposed to the hawk model, but we detected no difference with the other two treatments. These results provide evidence that fat affects the predator-avoidance behavior of Gray Catbirds during migratory stopover. That a difference between fat and lean groups was only apparent with the hawk model treatment suggests that the result is attributable to differences in the flight performance of the two groups rather than simply a difference in motivation to begin foraging. We suggest that fat should influence the behavior of a wide variety of migrant birds, particularly those species that typically carry greater fat reserves or that forage in more exposed situations than the Gray Catbirds we tested

    Taxonomic status of the Degodi Lark Mirafra degodiensis, with notes on the voice of Gillett's Lark M. gilletti

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    When first described, from two specimens taken at Bogol Manyo (='Bogol Mayo') in south-east Ethiopia in 1971, the Degodi Lark Mirafra degodiensis was considered a sibling species of the Horn of Africa's Gillett's Lark M. gilletti. However, subsequent field reports have failed to clarify how the two taxa can be separated. In order to evaluate the differences between Degodi Lark and Gillett's Lark we measured the two Degodi specimens (plus one we caught ourselves) and 43 Gillett's, reviewed the literature on the subject to assemble all the published diagnostic characters, and visited Bogol Manyo and adjacent areas to photograph, observe and sound-record both taxa. We find that there is no morphometric disjunction between the taxa, no evidence of vocal separation, no consistent plumage difference, and no molecular distinction. We therefore regard M. degodiensis as most probably a synonym of M. gilletti; if it is retained as a subspecies of gilletti it must be chiefly on account of its smaller mean size. © British Ornithologists' Club 2009.link_to_subscribed_fulltex
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