Diet of Neotropical parrots is independent of phylogeny but correlates with body size and geographical range

Abstract

Body mass and geographical range are two main drivers of diet in animals, yet how these factors influence diet in the morphologically and ecologically diverse avian group of Psittaciformes is little known. We reviewed current knowledge of the diet of Neotropical parrots and assessed the relation between diet (breadth and composition), phylogeny, body mass and geographical range. Diet has been documented for 98 of 165 species, but information is available only for 34 of 59 threatened species, and countries with high species diversity (> 20 species) had few studies (one to seven). Neotropical parrot species consumed 1293 plant species of 125 families. When assessing the relative frequency of different food items in the diet (seed, fruits, flowers, leaves, nectar, bark and stems), we found that parrots mostly exploited seeds (41.9%) and fruits (38.3%) of native species. Diet overlap was very low among genera (0.006-0.321). At the species level, geographical range and body size explained the variation in diet composition. In particular, small parrots of restricted distribution had a distinct diet composition relative to either large or widely distributed species. Although body size and geographical range showed phylogenetic inertia, diet was independent of phylogenetic history. Our review not only reveals ecological factors explaining diet in a generalist group but also exposes information gaps across the Neotropical region.

Feeding ecology of the Green-cheeked Parakeet, Pyrrhura molinae (Psittaciformes, Psittacidae), in a subtropical forest of Argentina

“…In this study, fleshy fruit is the most consumed item and this fact was not unexpected given its high presence in the diet of Pyrrhura and other species of small and medium-size psittacids (Renton et al 2015;Botero-Delgadillo et al 2013;Benavídez et al 2018). The high percentage of fruit in the diet of small parrots has been attributed to body size (Matuzak et al 2008;Renton et al 2015;Benavídez et al 2018) and it is linked to energy requirements, due to the fact that small birds need more carbohydrates, because they display higher mass-specific metabolic rates (Suarez and Gass 2002). Furthermore, the high consumption of fruits, especially fruits with small seeds (e.g.…”

“…Food resource availability for the Green-cheeked Parakeet did not demonstrate significant differences in this study, possibly due to the lack of food resource species in tree phenology samplings. In the study area, Benavídez (2018) found that the Piedmont forest has a marked seasonality with two different seasons, the dry (May-October) and the wet (November-April) seasons, where the plant community shows phenological behaviour, distinguishing flowering peaks in the dry season and two fruiting peaks, one in wet (fleshy fruit) and another in the middle of the dry season. Annual flowering and fruiting likely result from an influence of environmental factors.…”

“…Food resource availability regulates population levels and reproductive success in several parrot species (Rivera et al 2020). Psittacids are primary consumers and feed mainly on seeds and fruit pulp, but they also consume flowers, nectar and leaves of a wide variety of plant species (Renton et al 2015;Benavídez et al 2018). However, the availability of these resources can vary significantly in space and time (Renton 2001), especially in tropical and subtropical forests, where plant community provides alternative periods of food resource abundance and shortage for animals over the annual cycle (Lee et al 2014).…”

“…In addition, dietary information is important to understand the role of parrots in the functioning of ecosystems (Blanco et al 2018). Although the number of ecological studies on this group of birds has increased in recent decades, there are still some information gaps for several species (Renton et al 2015;Benavídez et al 2018), where feeding ecology and resource requirements are two of the least known aspects of psittacine ecology, particularly the relationship of parrots to food resources (Renton et al 2015).…”

When does agriculture enter into conflict with wildlife? A global assessment of parrot–agriculture conflicts and their conservation effects

“…That is, the higher the number of habitats originally used by a species the higher is the likelihood of this species to forage on agricultural lands. Parrots show a great dietary plasticity, which can determine their diversification on habitat use (Renton et al., 2015), and variability among species in dietary plasticity (Benavidez et al., 2018; Blanco et al., 2015) could contribute to explain this result. On the other hand, the relative brain size of birds has been shown to reflect behavioural flexibility (Sol et al., 2005) and inter‐individual variability to colonize anthropogenic habitats like cities (Carrete & Tella, 2011).…”