Revising the convergence hypothesis of avian use of honeydew: evidence from Dominican subtropical dry forest

Abstract

Revising the convergence hypothesis of avian use of honeydew: evidence from Dominican subtropical dry forest. -Oikos 93: 250-259.A honeydew-producing scale insect (family Margarodidae, tribe Xylococcini, genus Stigmacoccus) was found associated with the tree Bursera simaruba in subtropical dry forests at elevations of 100 -400 m on the south side of the Sierra de Bahoruco, Pedernales Province, Dominican Republic. At two study sites, 91% of Bursera trees supported locally dense populations of Margarodidae. Fifteen species of birds were observed foraging on the honeydew, but most observations were of the winter resident Cape May warbler (Dendroica tigrina) and black-throated blue warbler (D. caerulescens), and the permanent resident bananaquit (Coereba fla6eola) and blackcrowned palm tanager (Phaenicophilus palmarum). The Cape May warbler actively defended the honeydew resource but frequency of use of honeydew was influenced by the close presence of flowering agave and scale insect density. Data suggest that honeydew may be a critical component of the diet of this species especially during the late winter dry-season. Hymenopteran insects also were observed feeding on honeydew, but rates of consumption did not approach that of avian species. The occurrence of this phenomenon in Dominican dry forest is discussed in light of the convergence hypothesis of bird use and defense of homopteran honeydew in which it is proposed that birds are able to maintain relationships with scale insects in moist, warm temperate forests because it is in these climates where ant abundance is low. We suggest that our observation of a well-developed bird -homopteran system in classic subtropical dry forest supports the proposed mechanism of reduced competition with ants allowing bird use of honeydew, but we suggest that a broader array of especially insular habitats which may be relatively depauperate in terms of ants also can be expected to support bird -homopteran systems.

Honeydew foraging by birds in an Atlantic Forest fragment of Minas Gerais State, Brazil

“…There has been a known interaction between Coereba flaveola and scale insects (Coccoidea) in the subtropical dry forests at Dominican Republic (Latta et al 2001). However, this is the first report recording the use of honeydew by this species in Brazil.…”

“…Honeydew foraging by birds has been extensively documented as a result of an important interaction with scale insects (Hemiptera, Coccoidea) (Gamper & Koptur 2010, Beggs 2001, Gaze & Clout 1983, Greenberg et al 1993, Jirón & Salas 1975, Koster & Stoewesand 1973, Latta et al 2001, Murphy & Kelly 2003, Paton 1980, Woinarski 1984. Scale insects need large amounts of phloem to fulfill their nutrient demands and therefore excrete large amounts of honeydew, which is sugary waste rich in carbohydrates and amino acids.…”

Seasonality in Gum and Honeydew Feeding in Gray Mouse Lemurs

“…In vertebrates, mainly birds and geckos have been observed using honeydew as food resource (birds: see Edwards 1982;Gaze and Clout 1983;Greenberg et al 1993;Latta et al 2001, geckos: Fölling et al 2001). Tending behavior is observed when animals elicit the excretion of droplets by a hemipteran.…”

Invasive wasps, not birds, dominate in a temperate honeydew system

“…Greenberg et al (1993) argued that the cool moist temperate conditions likely to reduce ant activity were also likely to enable honeydew production over much of the year and that honeydew was likely to become a critical resource for birds if it was plentiful at times of the year when nectar was sparse and few insects were available as prey. Latta et al (2001) pointed out that a number of the documented bird-honeydew associations occur on islands where isolation rather than climate has shaped the ant fauna. Our study also suggests that Greenberg et al's emphasis on the wider landscape context was important and should be retained.…”

“…However, birds appear to be the major vertebrate consumers as honeydew feeding has been reported in many bird families and in many locations around the world (refs cited in Appendix S1, Edwards 1982;refs cited in Greenberg et al 1993;Oliver 2000;Murphy & Kelly 2001;Lara et al 2011). However, Latta et al (2001) documented avian-honeydew associations in subtropical dry forests on a Caribbean island, leading them to modify the Avian Convergence Hypothesis: they argued that while low ant activity was a necessary prerequisite for bird-honeydew associations, ant activity was determined by biogeographic factors as well as climate. Paton (1980) explained the Australian avianhoneydew association in evolutionary terms, suggesting that the honeyeaters (Meliphagidae) may have co-radiated in Australia along with eucalypt-eating insects and eucalypts, and that the ability to utilize honeydew along with nectar accounts for the success of the honeyeater family in Australia.…”