Drivers of geophagy by red brocket deer (Mazama americana) at Amazonian interior forest mineral licks.

Mineral licks are key ecological components of the Amazon rainforest, providing critical dietary functions for herbivorous and frugivorous mammals and birds, which help maintain the structure and function of the forest itself through seed and nutrient dispersal. One of the most frequent visitors of interior forest mineral licks in the Amazon is the red brocket deer (Mazama americana), a large-bodied ruminant frugivore and seed predator. While several hypotheses for the drivers of geophagy exist, including mineral supplementation, toxin adsorption, and habitat selection, robust data on geophagy for the red brocket deer for large numbers of mineral licks is nonexistent. We used soil data from 83 mineral licks in conjunction with camera trap data from 52 of those mineral licks and a mixed-effects modeling approach to test the three proposed hypotheses of geophagy for the red brocket deer. We found that consumed soils at mineral licks had elevated concentrations of almost all major and minor biologically active minerals measured, including Ca, Na, Mg, K, Cu, Zn, and Mn. Model results suggest that all three hypotheses hold true to some extent for the red brocket deer, with the greatest support for the mineral supplementation hypothesis, in particular with respect to Mg, Ca, Na, Cu, and Zn. This study provides critical information on the feeding ecology of the red brocket deer in the wild, and the first robust analysis of geophagy of an Amazonian mammal involving a large sample size of interior forest mineral licks.

Physical, landscape, and chemical properties of Amazonian interior forest mineral licks.

Mineral licks, sites where animals go to consume soil, are key resources for herbivorous birds and mammals in the Amazon, providing supplemental dietary nutrients and toxin adsorption functions. However, because they are often difficult to find, the properties of mineral licks are poorly understood. Here, we undertake the largest survey of Amazonian mineral licks to date to determine the landscape, physical, and chemical properties of these critical sites. We used a generalized linear mixed-effects modeling framework to assess how soil samples from 83 mineral licks differ from nearby control soils in a series of physical and chemical characteristics, then used Jaccard's index of similarity and a principal component analysis (PCA) to determine how those samples differed among themselves. We found that mineral licks were generally located in specific ranges of landscape variables. Soils from mineral licks had elevated concentrations of almost all minerals measured. There was very little similarity between consumed and control samples, and within each sample type. We suggest that these mineral licks have the potential to provide multiple services to visiting species, demonstrating their ecological importance. The high levels of dissimilarity between samples indicate that a large sample of mineral licks is needed to draw conclusions in studies pertaining to geophagy. We emphasize that studying mammal and bird visitation at these sites could provide critical conservation and physiological information on cryptic and understudied species of Amazonian herbivores.

The socio-cultural significance of mineral licks to the Maijuna of the Peruvian Amazon: implications for the sustainable management of hunting.

BACKGROUND: The overhunting of wild species is a major threat to biodiversity in the Amazon; yet, managed, sustainable hunting is widely considered part of the solution to conserving wildlife populations. Hunting is both a culturally important activity for Indigenous people and provides an important food source. Mineral licks, a focal point of hunting in Amazonia, are naturally occurring areas in the forest where animals come to obtain essential minerals or clays that are thought to neutralize plant-based alkaloids. We sought to better understand the socio-cultural importance of mineral licks to the Maijuna Indigenous group to inform the sustainable management of this habitat and associated wildlife populations. METHODS: Semi-structured interviews, focus groups, and participatory mapping were carried out with hunters to assess the significance of mineral licks and their associated animal resources as well as to determine how the relationship that the Maijuna have with mineral licks has changed over time. RESULTS: Mineral licks are culturally significant and useful to the Maijuna in a variety of ways. Hunters target these areas year-round both during the day and night, and animals killed are consumed for subsistence and sold to generate income. The spatial use of mineral licks across the landscape is determined on the generational family level, with families maintaining exclusive use of selected mineral licks and excluding access by other hunters. The Maijuna also have traditional beliefs for why animals visit mineral licks, which is linked to the traditional Maijuna story of the creation of the first tapir. The relationship that the Maijuna have with mineral licks has changed considerably over time, which is observed through changes in hunting technologies and methods as well as the loss of traditional knowledge and beliefs. CONCLUSIONS: Traditional and current Maijuna hunting conventions, in which families maintain exclusive use of selected mineral licks, likely reduce the probability of overexploitation of animal populations. Community-based management plans for mineral licks in Maijuna lands and beyond must incorporate and account for the multiple cultural and economic needs of local communities while also striving toward ecological sustainability. Country-wide strategies to conserving forests and using them sustainably should aim to ensure land tenure for rural peoples and encourage management that incorporates traditional sustainable hunting conventions.

Temporal patterns of visitation of birds and mammals at mineral licks in the Peruvian Amazon.

Mineral licks are key ecological resources for many species of birds and mammals in Amazonia, providing essential dietary nutrients and clays, yet little is known about which species visit and their behaviors at the mineral licks. Studying visitation and behavior at mineral licks can provide insight into the lives of otherwise secretive and elusive species. We assessed which species visited mineral licks, when they visited, and whether visits and the probability of recording groups at mineral licks were seasonal or related to the lunar cycle. We camera trapped at 52 mineral licks in the northeastern Peruvian Amazon and detected 20 mammal and 13 bird species over 6,255 camera nights. Generalized linear models assessed visitation patterns and records of groups in association with seasonality and the lunar cycle. We report nocturnal curassows (Nothocrax urumutum) visiting mineral licks for the first time. We found seasonal trends in visitation for the black agouti (Dasyprocta fuliginosa), red howler monkey (Alouatta seniculus), blue-throated piping guan (Pipile cumanensis), red brocket deer (Mazama americana), collared peccary (Pecari tajacu), and tapir (Tapirus terrestris). Lunar trends in visitation occurred for the paca (Cuniculus paca), Brazilian porcupine (Coendou prehensilis), and red brocket deer. The probability of recording groups (>1 individual) at mineral licks was seasonal and related to lunar brightness for tapir. Overall, our results provide important context for how elusive species of birds and mammals interact with these key ecological resources on a landscape scale. The ecological importance of mineral licks for these species can provide context to seasonal changes in species occupancy and movement.