摘要:

Wild rufous‐tailed jacamars (Galbula ruficauda) were shown to prey frequently, but selectively, upon butterflies in a Costa Rican rainforest. Two individually caged birds (a male and a female) were further tested with over 1000 butterflies of 114 morphs. Both wild jacamars and the two captive individuals were able to capture and handle all kinds and sizes of local butterflies. These butterflies (and other winged insects) were recognized by the jacamars as prey only through their movement. The captive birds discriminated between an unacceptable group of butterflies, which generally fly slowly or regularly, are warningly coloured and mimetic, with transparent, or white, orange, red, and/or black coloration, and an acceptable group that generally fly fast or erratically, are cryptic (on one or both sides), and have yellow, orange, green, blue, and/or brown coloration. These different morphological and behavioural characteristics of butterflies presumably helped the jacamars to assess their palatability.Most individuals of unacceptable butterflies (e.g.BattusandParides(Papilionidae), some Pieridae,DiaethriaandCallicore(Nymphalinae), Heliconiinae, Acraeinae, Ithomiidae, and Danaidae) were sight‐rejected by the male jacamar (Jacamar 2), and many of the same were also sight‐rejected by the female (Jacamar 1). In cases when the above butterflies were attacked, they were quickly released and usually unharmed. The captive female bird, after long periods without food, consumed many pierid and heliconiine butterflies that were consistently rejected by the male for their distasteful and dangerous qualities. In contrast, palatable butterflies (e.g.Papilio, Charaxinae, most Nymphalinae,Morpho, Brassolinae, and Satyrinae) were usually quickly attacked and consumed. The captive jacamars were able to discriminate between the very similar colour patterns of some Batesian mimics and their models, and could memorize the palatability of a large variety of butterflies. The discriminatory abilities of specialized insectivorous birds such as jacamars are likely to play a major role in the evolution of neotropical butterfly mi

ISSN:0024-4066    

DOI:10.1111/j.1095-8312.1986.tb01772.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

The treatment advocated requires coding of every multistate character in additive binary form and accepts, but does not require, assignment of direction to the transformations. For each binary character is computed the ratio of the number of incompatibilities observed to the number of incompatibilities expected on the null hypothesis of the random distribution of its states. At this stage the ‘noisy’ characters are identified by their high ratios. These ratios are used as the basis for selecting a set of core characters common to several large compatible sets (cliques), plus the several characters particular to each large clique, followed by those characters which add further resolution or corroboration with low levels of homoplasy. The ‘labelling’ procedure of Guise, Peacock&Cleaves (1982) is adapted to identify ‘noisy’ taxa and individual character scores which are likely to be homoplastic. The procedure facilitates recognition of the robust portions of a dendrogram, alternative further resolutions, and remaining areas of uncertainty.For the purposes of illustration, data for African toads of theNectophrynoideslineage are analysed and the resulting dendrogram is plotted on the map of Africa. Some observations are also made on data for lizards of the family Pygopodidae and on birds of the fam

ISSN:0024-4066    

DOI:10.1111/j.1095-8312.1986.tb01773.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Geographic variation was investigated in populations of the day gecko Phelsuma sundbergi from 22 islands in the Seychelles, using multivariate ordination procedures. Multiple group principal components analysis was used to negate ontogenetic variation. Seventy‐eight characters from three character systems (body proportions, scalation and colour pattern) were analysed from 349 specimens. Three phenetic aggregations of granitic island populations were detected from the northwestern, northeastern and southern island groups. A comparison of the results from the three character systems analysed separately suggests that the separation of the southern form preceded that of the northern forms. Colour pattern characters reflect this closely, while body proportions and scalation characters follow evolution of body size. The populations ofPhelsuma sundbergion the coralline islands are not well differentiated from the races on the granitic islands, and probably represent recent colonizations or introductions by ma

ISSN:0024-4066    

DOI:10.1111/j.1095-8312.1986.tb01774.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY