The Common Diuca-Finch is part of the year-round ground foraging guild (de Casenave et al. 2008, Cueto et al. 2013). They forage by walking on the ground, with a diet consisting of primarily surface seeds (Marone et al. 1997). Grass seeds made up approximately 80% of the stomach contents of samples from Argentina (Jaksic and Lazo 1999). They are not of any agricultural concern because they feed on spilled seeds and don’t disperse seeds (Jaramillo 2011). This species has been shown to change their seed preference in response to short-term fluctuations in seed abundance as well as presence of other seed eating birds (Lopez-Calleja 1995, Jaksic and Lazo 1999). Diuca diuca prefers larger seeds such as E. cicutarium, but will eat smaller ones such as Opuntia sp. in addition to a wider variety of grass seeds in the winter when species density depends on seed availability, which is not the case in the warmer seasons (Lopez-Calleja 1995, Blendinger and Ojeda 2001, Jaramillo 2011, Cueto et al. 2013). In the warmer seasons, more arthropods are found in the diet, and foraging occurs more arboreally on lower shrubs (Blendinger 2005, Jaramillo 2011). Also in the summer, more nocturnal seed foraging occurs (Kelt et al. 2004). They have been observed to commonly eat the seed arils from Capparis atamisquea and the seeds of Prosopis flexuosa (Blendinger 2005). This species obtained their food from the ground in over 90% of foraging observations (Blendinger 2005). The results of 451 (120 individuals) foraging observations in the nonbreeding season, and 247 (70) observations in the breeding season are recorded in Table 2 (de Casenave et al. 2008).
|Table 2. Foraging manuevers and microhabitat|