Claudia M. Campos

Endozoochory by native and exotic herbivores in dry areas: consequences for germination and survival of Prosopis seeds.

Mammalian herbivores can play a role in the endozoochorous dispersal of Prosopis seeds in the arid zones of Argentina, and the introduction of exotic mammals can change relevant parameters of the plants reproductive ecology. Our specific goals were to quantify the seeds of Prosopis flexuosa , P. chilensis and P. torquata contained in the faeces of native [mara ( Dolichotis patagonum ), guanaco ( Lama guanicoe )] and exotic [donkey ( Equus asinus ) and hare ( Lepus europaeus )] mammals, and to determine the mortality, germination percentage and germination speed of seeds borne in faeces, compared with those collected from trees. In 2006, seeds were collected directly from trees or removed from mammal faeces. Seeds were counted and classified as apparently healthy or damaged. P. torquata and P. flexuosa seeds were found in the dung of guanaco, hare and mara, whereas only P. flexuosa seeds appeared in donkey faeces. P. chilensis seeds were only found in guanaco faeces. There was a notable relative abundance of seeds contained in small herbivore faeces in comparison to the large herbivores. The passage through the digestive tract of animals modified seed germination capacity and speed, with great variability between animal species. Guanacos had greater effects than donkeys on mortality, germination percentage and germination speed. Differences between the effects of both smaller-sized herbivores on seeds were much smaller.

Herbivory by tuco-tucos (Ctenomys mendocinus) on shrubs in the upper limit of the Monte desert (Argentina)

Ctenomys (tuco-tuco) is a small fossorial herbivorous rodent of the Monte desert, and is probably the most abundant and widely distributed rodent in these arid lands. The aim of this study is to describe the impact of C. mendocinus herbivory on shrubs in two plant communities (Reserve of Divisadero Largo and Villavicencio) in the upper limit of the Monte desert, and to assess the association between environmental variables and level of damage caused by tuco-tucos. Herbivory by tuco-tucos affected 39% of the total shrubs in Villavicencio, and 9.37% of the total plants sampled in Divisadero Largo. In Villavicencio, the most highly damaged species were Larrea divaricata (65%), Lycium aff. chilensis (41%), Junellia seriphioides (38%) and Menodora decemfida (33%). In Divisadero Largo, damage was lower: J. seriphioides (14%), Lycium chilensis (9%), and M. decemfida (6%). With respect to the association between level of damage caused by tuco-tucos and environmental variables, in Divisadero Largo the level of damage was negatively associated with both maximum and mean soil depth, while in Villavicencio it was negatively associated with plant cover, and positively associated with maximum and mean soil depth. There was no association between level of damage caused by tuco-tucos and mean stone diameter.

Management of Protected Areas and Its Effect on an Ecosystem Function: Removal of Prosopis flexuosa Seeds by Mammals in Argentinian Drylands

The ecological function of animal seed dispersal depends on species interactions and can be affected by drivers such as the management interventions applied to protected areas. This study was conducted in two protected areas in the Monte Desert: a fenced reserve with grazing exclusion and absence of large native mammals (the Man and Biosphere Ñacuñán Reserve; FR) and an unfenced reserve with low densities of large native and domestic animals (Ischigualasto Park; UFR). The study focuses on Prosopis flexuosa seed removal by different functional mammal groups: “seed predators”, “scatter-hoarders”, and “opportunistic frugivores”. Under both interventions, the relative contribution to seed removal by different functional mammal groups was assessed, as well as how these groups respond to habitat heterogeneity (i.e. vegetation structure) at different spatial scales. Camera traps were used to identify mammal species removing P. flexuosa seeds and to quantify seed removal; remote sensing data helped analyze habitat heterogeneity. In the FR, the major fruit removers were a seed predator (Graomys griseoflavus) and a scatter-hoarder (Microcavia asutralis). In the UFR, the main seed removers were the opportunistic frugivores (Lycalopex griseus and Dolichotis patagonum), who removed more seeds than the seed predator in the FR. The FR shows higher habitat homogeneity than the UFR, and functional groups respond differently to habitat heterogeneity at different spatial scales. In the FR, because large herbivores are locally extinct (e.g. Lama guanicoe) and domestic herbivores are excluded, important functions of large herbivores are missing, such as the maintenance of habitat heterogeneity, which provides habitats for medium-sized opportunistic frugivores with consequent improvement of quality and quantity of seed dispersal services. In the UFR, with low densities of large herbivores, probably one important ecosystem function this group performs is to increase habitat heterogeneity, allowing for the activity of medium-sized mammals who, behaving as opportunistic frugivores, did the most significant seed removal.

Medicinal use of wild fauna by mestizo communities living near San Guillermo Biosphere Reserve (San Juan, Argentina)

BackgroundWild and domestic animals and their by-products are important ingredients in the preparation of curative, protective and preventive medicines. Despite the medicinal use of animals worldwide, this topic has received less attention than the use of medicinal plants. This study assessed the medicinal use of animals by mestizo communities living near San Guillermo MaB Reserve by addressing the following questions: What animal species and body parts are used? What ailments or diseases are treated with remedies from these species? To what extent do mestizo people use animals as a source of medicine? Is the use related to people’s age?MethodsWe conducted semi-structured interviews with 171 inhabitants (15–93 years old) of four villages close to the Reserve: Tudcúm, Angualasto, Malimán and Colangüil. We calculated the informant consensus factor and fidelity level to test homogeneity of knowledge and to know the importance of different medicinal uses for a given species.ResultsThe medicinal use of animals was reported by 57% of the surveyed people. Seven species were mentioned: Rhea pennata, Lama guanicoe, Puma concolor, Pseudalopex sp., Lama vicugna, Lepus europaeus and Conepatus chinga. Several body parts were used: fat, leg, bezoar-stone, stomach, feather, meat, blood, feces, wool, and liver. The fat of R. pennata was the most frequently used animal part, followed by the bezoar stone and the leg of L. guanicoe. Animals were used to treat 22 ailments, with respiratory and nervous system disorders being the most frequently treated diseases with a high degree of consensus. Old people used animals as remedies more frequently than young residents, showing some differences among villages.ConclusionsA low number of animal species was mentioned as used for medicinal purposes, which could be explained by the perception of strong control related the legislation that bans hunting and the erosion of traditional knowledge produced by mestizaje. However, the presence of a traditional medicine is deeply rooted in the community culture. Management strategy for protected areas should focus not only on the conservation and sustainability of biological resources, but also on the ancestral knowledge of local communities, such as the medicinal use of animals.

Seed removal by different functional mammal groups in a protected and grazed landscape of the Monte, Argentina

Fil: Miguel, Maria Florencia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Aridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Aridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Aridas; Argentina

Studying the quantity component of seed dispersal effectiveness from exclosure treatments and camera trapping

Abstract The quantity component of effectiveness of seed dispersal by animals is determined by two events: fruit removal (intensity of the interaction) and animal visitation to the plant (frequency of interactions). Considering dispersal of Prosopis flexuosa seeds as case study, this work aimed at investigating the strengths and weaknesses of the two methods for assessing the quantity component of seed dispersal effectiveness: exclosures and camera traps. Prosopis fruits were offered for 48 hr. Exclosure treatments were performed using two types of wire‐screen cages, allowing access to ants (“closed exclosure”) and to small mammals up to 100 g (“open to small mammals”), and a treatment without exclosure (“open to all removers”). The camera trapping experiment was carried out using vertically oriented cameras placed at approximately 1.80 m height and focused on the fruits. The cameras were set in “motion detect mode,” taking series of three consecutive photographs. The exclosures largely allowed estimation of fruit removal by size‐based groups of animals, but did not provide information on species identity. In contrast, camera traps were able to identify all visitors to species level and could not only determine the number of visits by each species but also the proportion of visits, which resulted in removal of fruits. Camera trapping allowed discriminating among small mammals playing different roles, without underestimating fruit removal by scatter‐hoarding species. The quality of estimation of the quantity component of seed dispersal is remarkably better when the camera trapping method is applied. Additional information obtained, such as activity patterns of visitors, can contribute to a better understanding of the seed dispersal process.