The responses of wild jacamars (Galbula ruficauda, Galbulidae) to aposematic, aposematic and cryptic, and cryptic butterflies in central Brazil

Abstract

1. This article reports the responses of wild, adult jacamars to butterflies with distinct coloration types in central Brazil. Fully aposematic species, i.e. those exhibiting bright and/or contrasting colours on both wing surfaces (= A/A), were predominantly sight‐rejected by birds and, with one exception, the few butterflies attacked and captured were taste‐rejected afterwards.2. Aposematic and cryptic butterflies, i.e. those exhibiting bright and/or contrasting colours on the upper and cryptic colours on the underwings (= A/C) were sight‐rejected while flying, when they show their conspicuous colours to predators. This suggests that birds associate butterfly colours with their difficulty of capture, as in the case of Morpho and several Coliadinae species. These butterflies, however, were heavily attacked at rest, when they are cryptic.3, Fully cryptic butterflies, i.e. those exhibiting cryptic colours on both wing surfaces (= C/C) did not elicit sight rejections by birds. Comparisons involving the number of attacks and the capture success of flying and resting individuals showed no significant differences in species more frequently observed like some cracker butterflies (Hamadryas feronia and H. februa) and Taygetis laches. Compared with the A/C Coliadinae, these butterflies showed a lesser, although not significantly different, ability to escape while flying, but a greater and significantly different ability to escape while at rest.4, A hunting tactic of jacamars, which consists of following flying A/C and C/C butterflies on sight, and waiting until they perch to locate and attack them, is described for the first time.

Evolutionary and ecological processes influencing chemical defense variation in an aposematic and mimeticHeliconiusbutterfly

“…However, empirical data on Heliconius imply direct benefits (surviving predator attacks) for chemically defended individuals [70][71][72] , and indicate an increase in protection level especially when comparing low to moderate cyanogenic toxicity levels 69 , applicable to observed cyanogen levels of H. erato 3,19 .…”

Variation of chemical compounds in wild Heliconiini reveals ecological factors involved in the evolution of chemical defenses in mimetic butterflies

“…Additionally, CGs release toxic cyanide and chemical by‐products for birds when put in contact with specific degrading enzymes (Cardoso, ; Conn, ). CGs and enzymes or stored in different cell or tissue compartment and are mixed upon tissue disruption under a predator's attack, so that Heliconiini butterflies often survive an attack after being tasted (e.g., by lizard (Boyden, ) or avian predators (Boyden, ; Chai, ; Pinheiro & Campos, )). Therefore, the bitter taste provided by CG and toxic metabolites may act as a chemical defense because of immediate deterrent effect on predator.…”

The effect of insect cyanoglucosides on predation by domestic chicks

“…Muhtasib & Evans (1987), found aversive response in quails offered water with linamarin concentrations that were equal to or higher than the concentration in adult moths, not noticeably higher than that of Heliconius butterflies (Davis & Nahrstedt 1981, Nahrstedt & Davis 1983, which suggests that the intact cyanoglucosides can be detected by a predator. It would be instructive to know the detection thresholds of regular butterfly 10 predators which are probably more fine-tuned, given its regular exposure to cyanogenic prey (Pinheiro & Campos 2019). One important aspect from Muhtasib & Evans (1987) work is that a lower linamarin concentration was effective when combined with additional defensive compounds such as histamine.…”

“…In contrast to the moderate response by the chicks, a specialized predator reacts in a non-hesitant fashion to Heliconius taste. For instance, even when free flying Heliconius is captured by a jacamar, they are soon released without significant harm (Langham 2004, Pinheiro & Campos 2019, which clearly shows that these insects are unpalatable.…”

“…Two of the most studied cyanogenic lepidopterans are the aposematic moth family Zygaenidae (burnet moths) (Zagrobelny et al 2008) and Heliconiinae butterflies (Nahrstedt 1988, Castro et al 2019, many of which have been shown to be unpalatable to birds and other predators (Brower et al 1963, Boyden 1976, Chai 1986, Pinheiro & Campos, 2019. The insectivorous jacamar (Galbula ruficauda) discriminates between palatable (Dryas iulia and Agraulis vanillae) and unpalatable Heliconiinae (Heliconius) butterflies (Chai 1990), which is consistent with differences in cyanoglucoside accumulation patterns in these species (Nahrstedt & Davis 1983, Cardoso & Gilbert 2013.…”