Foraging with finesse: A hard‐fruit‐eating primate selects the weakest areas as bite sites

Abstract

This hard-fruit feeding specialist primate is not biting at random on the surface of diet fruits. To access seeds they are focusing on those areas requiring less force to penetrate. This may be to save energy, to minimize the risk of breaking teeth used in food processing, or a combination of both. The study shows, for the first time, the subtlety by which these powerfully-jawed animals process their diet items.

Juggling options: Manipulation ease determines primate optimal fruit‐size choice

“…Accordingly, igapó fruit production peaks between March and June, that of leaves between July and October, at which time tree canopy fruit availability is low, and during November–February neither fruit nor young leaves are available in igapó (Barnett, 2010). The current work is part of a broader study of golden‐backed uacari foraging ecology (Barnett, 2010; Barnett, Almeida, et al, 2012; Barnett et al., 2013, 2016; Barnett & Shaw, 2014; Bezerra et al., 2011) conducted between October 2006 and April 2008 in Jaú National Park.…”

“…However, in the current study, mature A. latifolia fruits collected from water at the same time as those consumed by uacaris, had substantially lower perforation resistance values (max. : 1.46 kg/mm 2 ), similarly to most other immature fruits in the uacari diet (for details of each specie, see Table 5: Barnett et al, 2016). It is likely that these characteristics facilitate access to the seed as well as reducing overall energy expenditure.…”

“…Accordingly, igapó fruit production peaks between March and June, that of leaves between July and October, at which time tree canopy fruit availability is low, and during November-February neither fruit nor young leaves are available in igapó (Barnett, 2010). The current work is part of a broader study of golden-backed uacari foraging ecology (Barnett, 2010;Barnett et al, 2013Barnett et al, , 2016Barnett & Shaw, 2014;Bezerra et al, 2011) (Aguiar, 2015;Ferreira & Parolin, 2007;Montero, Piedade, & Wittmann, 2014;Parolin, Adis, Rodrigues, Amaral, & Piedade, 2004). The fruit is drupaceous, woody and tardily dehiscent (Ramos et al, 2016), with a fibrous endocarp.…”

“…Fruits and seeds vary in size (Michaels et al, 1988) both within and between species. The selection of fruits by primates and other frugivorous involves nutritional and sensory factors such as color (Melin et al, 2019), smell (Nevo et al, 2015), touch (Wrangham, 1975), level of toxins, hardness (Ayres, 1986;Barnett et al, 2016;Norconk & Veres, 2011), nutritional content (Felton et al, 2009;Rothman, Raubenheimer, & Chapman, 2011), and size (Corlett & Lucas, 1990;Flörchinger, Braun, Böhning-Gaese, & Schaefer, 2010;Stevenson, Pineda, & Samper, 2005). The size of the fruit, however, is considered as the primary selection criterion for many frugivorous species (Jordano, 1995a(Jordano, , 1995b(Jordano, , 2014Martin, 1985;Mello, Leiner, Guimarães, & Jordano, 2005).…”

The bitter end: primate avoidance of caterpillar-infested trees in a central Amazon flooded forest

“…As part of a broader study of the foraging ecology (see Bezerra et al 2010;Barnett and Shaw 2014;Barnett et al 2012Barnett et al , 2013Barnett et al , 2016, golden-backed uacaris were followed through their flooded igapó habitat in a wooden canoe, and, following Altmann (1974) For plants species from which uacaris ate leaves, individual plants were always checked for any leaf-damage that indicated recent prior herbivory. Both in and outside the study plots, trees on which uacaris fed were marked with numbered tags.…”