Palatablility and escaping ability in Neotropical butterflies: tests with wild kingbirds (Tyrannus melancholicus, Tyrannidae)

Abstract

The palatability and the ability of neotropical butterflies to escape after being detected, attacked and captured by wild kingbirds (Tyrannus melancholicus Vieillot), was investigated by the release of 668 individuals of 98 butterfly species close to the birds, during their usual feeding activities. Most of the butterflies were attacked and eaten. Only the troidine swallowtails (Parides and Battus; Papilionidae) were consistently rejected on taste and elicited aversive behaviours in birds. Most other aposematic and/or mimetic species in the genera Danaus and Lycorea (Danainae), Dione, Eueides and Heliconius (Heliconiinae), Hypothyris, Mechanitis and Melinaea (Ithomiinae), Biblis, Callicore and Diaethria (Limenitidinae) were generally eaten. Cryptic and non-mimetic species were always attacked and, if captured, they were also eaten. All Apaturinae, Charaxinae, Nymphalinae, Hesperidae, most Limenitidinae, Heliconiinae (Agraulis, Dryas, Dryadula and Philaethria) and Papilionidae (Eurytides, Heraclides and Protesilaus) were in this group. Results indicate that the learning process in kingbirds may demand a large mortality in prey populations, even among species generally accepted as unpalatable and aposematic. They also support the assertion that escaping ability and unpalatability evolved in butterflies as alternative strategies to avoid predation by birds. Mimetic relationships among several species are discussed. Evidence for the evolution of aposematism not related to unpalatability, but to escaping ability, was found for two hardto-catch Morpho species.

The evolution of locomotory behavior in profitable and unprofitable simulated prey

“…In a general sense, our work supports the view that escape and unpalatability are alternative ways of avoiding attack (Pinheiro 1996). Thus, when unprofitable (unpalatable) prey were readily recognized, there was no selection on these individuals to evolve the rapid movement that necessarily evolved in profitable prey.…”

“…However, it is less well appreciated that such species also tend to exhibit slow and predictable movement (Pasteels et al 1983;Whitman et al 1985;Chai and Srygley 1990;Srygley and Chai 1990;Marden and Chai 1991;Pinheiro 1996;Hatle and Faragher 1998;Hatle et al 2002). The slow movement reported in conspicuous unprofitable species is qualitatively different from the near motionlessness exhibited by many cryptic but otherwise profitable species (those lacking significant noxious qualities once attacked).…”

“…The two prey species were very different, very similar, or identical in morphological appearance (no mimicry, imperfect mimicry, and perfect mimicry). Unprofitable prey items survived attack with a fixed probability (see Järvi et al 1981;Wiklund and Järvi 1982;Pinheiro 1996), whereas profitable prey items were always "killed" when attacked. By preventing those prey individuals that were killed by foragers from contributing to the next generation, we have, for the first time, simulated the evolution of movement characteristics in unprofitable and profitable species as a consequence of selective predation.…”

Sequestration of aristolochic acids by the pipevine swallowtail, Battus philenor (L.): evidence and ecological implications

“…However, knowledge of the defensive roles of AAs lags behind the chemical investigations; unpalatablity is more often assumed than documented. Among the species in Table 1, only for P. aristolochiae (Uesugi 1996), Troides aeacus (C. & R. Felder) (Rothschild et al 1970), Battus polydamas (L.) (Chai 1986;Pinheiro 1996), and B. philenor (L.) does some experimental evidence for unpalatability complement the chemical data.…”

Effects of pyrrolizidine alkaloids through different trophic levels

“…Field observations and cage experiments have shown that adults of conspicuous ithomiines and danaines were taste-rejected by the rufous-tailed jacamars Galbula ruficauda (Galbulidae), the kingbirds Tyrannus melacholicus (Tyrannidae) and the golden lion-tamarin Leontopithecus rosalia (Callitrichidae). In contrast, cryptic butterflies, supposed to be palatable, were eaten (Brown 1985 and references therein;Chai 1986;Pinheiro 1996). The red-winged blackbird Agelaius phoeniceus (Icteridae) rejected adults of the leaf beetle O. cacaliae, which contain PAs in a secretion produced in the elytra glands, as well as in the entire body (Rowell-Rahier et al 1995).…”