The community of hummingbirds (Aves: Trochilidae) and the assemblage of flowers in a Caatinga vegetation

Abstract

We studied hummingbirds and their food plants in an area of caatinga vegetation. We specifically examined their seasonal use of this habitat, migratory and non-migratory status, their foraging strategies and community roles The study was conducted in an area of arboreal-shrub caatinga, located in the Serra do Pará, municipality of Santa Cruz do Capibaribe, state of Pernambuco in northeastern Brazil. Field work was undertaken during 12 expeditions on a monthly basis between June, 2007 and May, 2008. Five species of hummingbirds were recorded visiting flowers in the community studied. Three were considered residents: Chlorostilbon lucidus (Shaw, 1812), Eupetomena macroura (Gmelin, 1788), and Heliomaster squamosus (Temminck, 1823). Hummingbirds visited 31 species of plants, of which only five presented attributes related to ornithophily. C. lucidus visited 29 plant species, including all ornithophilous species, and it was the most aggressive, defending territories. Among hummingbirds, C. lucidus may be considered the principal pollinator. Hummingbirds may also be acting as pollen vectors for some of the plant species not identified as ornithophilous. The hummingbird guilds varied among the plant species used as floral resources, as well as in their frequency of visits. Differences in plant species abundance, hummingbird preference, competitive exclusion or flowering seasonality are factors likely to influence those variations.

The role of size and dominance in the feeding behaviour of coexisting hummingbirds

“…In a hummingbird community in western Mexico, Des Granges (1979) also proposed that the size of hummingbird species determines their interspecific dominance. Although dominance by larger species appears clearly to occur in many hummingbird communities (Lyon 1976, Des Granges 1979, Las-Casas et al 2012, this could differ for more complex and diverse communities. Martin and Ghalambor (2014), for instance, found that larger bird species were dominant over smaller species during aggressive interactions for shared resources in three guilds (vultures, hummingbirds and antbirds/ woodcreepers), but the advantage of a larger body size declined with increasing evolutionary distance among the species.…”

“…Likewise, some authors have proposed that aggressive dominance in hummingbirds is related to body size (Lyon , Las‐Casas et al . ), higher wing disc loading (Feinsinger & Chaplin , Kodric‐Brown & Brown , Carpenter et al . ) and migratory status (Des Granges , Rodríguez‐Flores & Arizmendi ).…”

“…In general, dominant species are larger than subordinate ones and often access the best food resources (Wolf et al 1976, Morse 1982. Likewise, some authors have proposed that aggressive dominance in hummingbirds is related to body size (Lyon 1976, Las-Casas et al 2012, higher wing disc loading (Feinsinger & Chaplin 1975, Kodric-Brown & Brown 1978, Carpenter et al 1993) and migratory status (Des Granges 1979, Rodr ıguez-Flores & Arizmendi 2016). Des Granges (1979) defined the dominance hierarchy of the hummingbird community as the species at the top of the hierarchy that wins most of their interspecific chases while the species at the bottom lose most chases.…”

Drought leads to reproductive quiescence in smooth‐billed anis: Phenotypic evidence for opportunistic breeding and reproductive readiness

“…A previous study suggested that the smooth‐billed ani ( Crotophaga ani ) breeds opportunistically in drought areas (Hing, ). This joint‐nesting cuckoo is a common residential species in Brazil (Las‐Casas, Azevedo Júnior, & Dias Filho, ; Lucena & Freire, ; Teixeira et al, ); similar to other anis in the Crotophagidae family, it displays communal breeding behavior in which all females from the same group lay eggs in a single communal nest and males are responsible for incubation (Loflin, ; Macedo, Cariello, Pacheco, & Schwabl, ; Robertson et al, ; Vehrencamp, Bowen, & Koford, ). In view of the evidence for opportunistic breeding, we hypothesized that the end of the rainy season in a drought region would induce morphological involution of the reproductive system of free‐living smooth‐billed anis and a significant decline in gametogenesis, providing proof of opportunistic behavior.…”

The importance of winter-flowering Aloe ferox for specialist and generalist nectar-feeding birds

“…For those bird species that feed on nectar, flowering phenology often influences where individuals are found and when, particularly at smaller spatial scales (Craig and Hulley 1994;Malizia 2001;Symes et al 2001;Cotton 2007;Las-Casas et al 2012). The influx of nectar-feeding birds associated with mass flowering events may be particularly pronounced owing to the transient nature of such occurrences (Brown and Hopkins 1996;.…”