As happens with other groups, the functional diversity of the nectarivore
guild can be reduced by urbanization (Pauw and Louw 2012).
Such research has been done for several specialist avian nectarivores
, and for a few passerine occasional nectarivores
, but not, apparently, for any nonpasserine occasional nectarivore
Rio Grande Amazonian * (%) ns (%) * (%) ns (%) Total 2 (100) - 4 (57) 3 (43) Primary Diet Vertebrates - - - 1 (14) Insectivore 2 (100) - 2 (28) - Omnivore - - 1 (14) - Granivore - - - - Frugivore - - 1 (14) 2 (28) Nectarivore
- - - - Primary Macrohabitat Aquatic - - 3 (43) 1 (14) Open - - - - Transitional Forest 1 (50) - - - Closed Forest 1 (50) - 1 (14) 2 (28) Chacoan * (%) ns (%) Total 9 (69) 4 (31) Primary Diet Vertebrates 1 (8) 2 (15) Insectivore 5 (38) - Omnivore 1 (8) - Granivore 2 (15) 1 (8) Frugivore - - Nectarivore
- 1 (8) Primary Macrohabitat Aquatic 1 (8) 1 (8) Open 3 (23) 1 (8) Transitional Forest 2 (16) 2 (16) Closed Forest 3 (23) - Only species grous that could be analyzed (significant or non-significant) are included in this table.
2, 3) with those of a typical nectarivore
, the Apapane, and the Poo-uli, which, although not typical of the truly finch-like drepanidines such as Telespiza, is a basal taxon within the radiation (Lerner et al.
Flowering patterns of long-lived Heliconia inflorescences: implications for visiting and resident nectarivores
such as hummingbirds (Trochilidae) and flowerpiercers (Diglossa spp.
The presence of frugivores and nectarivores
, in particular, may be influenced by drought and other factors that affect flowering and fruiting of plants (Ewert and Askins 1991).
and insectivores had high survival (72%) and low clutch size whereas granivores had low annual survival (54%) and large clutch sizes.
, frugivores, and granivores use food resources that are often dispersed in space and time (Karr 1976, Stiles 1985, Levey 1988a, Stiles and Skutch 1989, Blake and Loiselle 1991), making mobility and use of environments with varying conditions more likely than for many insectivores.
Thus, Asteraceae is an important resource for folivores, florivores, nectarivores
, and pollinivores (Cano-Santana, 1994).
The feeding habits were defined through field observations and literature data (SICK, 1997; KRUGEL, 1998), considering the predominant food item: carnivores (CAR), necrophages (NEP), frugivores (FRU), granivores (GRA), insectivores (INS), nectarivores
(NEC) and omnivores (ONI).
Correspondence of the three main feeding strategies proposed in this paper to the mammalian feeding categories described by Eisenberg (1981) This paper Eisenberg, 1981 Animalivores Piscivores and Squid-Eaters, Carnivores, Crustacivores and Clam-Eaters, Myrmecophages, Insectivores, Planktonivores, Sanguivores Frugivores Frugivores/Omnivores, Frugivores/Granivores, Frugivores/Herbivores, Nectarivores
, Gumivores Herbivores Herbivores/Browsers, Herbivores/Grazers Table 5.