Although eating clay at “licks” (a form of geophagy) has been described, there are few behavioral data on temporal patterns, social interactions, species associations, or reactions to potential predators. We examined the behavior of nine species of macaws, parrots, and parakeets at the Machiguenga Ccolpa, a clay lick on the Rio Manu, Peru in the dry season. Three distinct mixed-species groups used the licks: in the early morning (parrots and small macaws), in mid-morning (large macaws), and in the early afternoon (parakeets), although the latter two groups used the licks at other times of day as well. The first parrots to begin eating at the lick in the early morning were yellow-crowned parrots (Amazona ochrocephala) and dusky-headed parakeets (Aratinga weddellii), followed by blue-headed parrots Pionus sordidus, and then by mealy (Amazona farinosa) and orange-cheeked (Pionopsitta barrabandi) parrots, and chestnut-fronted macaws (Ara severa). Although blue-headed parrots fed in dense groups of over 50, the others rarely exceeded 20 individuals. Scarlet macaws (A. macao) sometimes fed alone or joined the early morning groups, but most associated with a large group of red and green macaws (A. chloroptera) that arrived, often scaring off the smaller birds. On average, about 100 macaws and parrots fed in the early morning, macaw feeding groups averaging just over 40, and the parakeets averaged over 70. Average time at the lick ranged from 28 min for yellow-crowned parrots to 47 min for tui parakeets. Of the early morning group, blue-headed and mealy parrots were the most aggressive and orange-cheeked parrots were the least aggressive. Red and green macaws were more aggressive than scarlet macaws; the parakeets were equally aggressive. All species had more aggressive interactions with conspecifics than with other species. Responses to intruders and predators varied by species of parrot/macaw and type of intruder. In response to intruders or loud calls, responses could be partial (some individuals flew away, circled, and returned), temporary (all individuals flew away but returned within a few minutes), or total (all flew away and abandoned feeding for at least a half hour). The large macaws showed the lowest rate of total abandonment and the parakeets showed the highest. People passing up or down river in boats scared birds from the lick. The local residents (Machiguenga tribespeople in boats) elicited a much greater response than did the researchers. In the recent past, macaws and parrots were hunted for food, feathers, and the pet trade, and the birds’ response, as well as the presence of parrot and macaw feathers in local villages we visited, suggests some continued exploitation, or a long-term memory in the birds.

The authors wish to thank Wilfredo Arizabal Arriaga (Willie) for serving as our guide and field assistant, Faustino Fernandez, Alberto Flores, and Miguel Palacio for field assistance, Kit Herring and the U.S. and Peruvian staffs of Inkanatura for logistical arrangements and provision of a well-trained field staff. We are particularly indebted to C.A. Munn for setting us up in his field station and providing information on the parrots and local people. We thank the Peruvian government and the Manu National Park for permits for work in the restricted area of the park and for providing advice while at the station.

Authors and Affiliations

1. Division of Life Sciences, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854-8082, USA

   Joanna Burger

2. Environmental and Community Medicine, Environmental and Occupational Health Sciences Institute, UMDNJ–Robert Wood Johnson Medical School, Piscataway, NJ, 08854, USA

   Michael Gochfeld

Corresponding author

Correspondence toJoanna Burger.

Communicated by R.F. Oliveira

Reprints and permissions