Mammal Conservation Program

Micromammals Project

Patricia Mancilla
© Patricia Mancilla
Damián Ganime
© Damián Ganime

Context and objectives

Changes in altitude often have a direct impact on species diversity. Throughout the mountains and plateaus, various factors such as climate, vegetation, and resource availability shape which species are present and how they interact. However, in regions like Patagonia, much remains to be learned about these dynamics, especially in groups like micromammals. In the province of Santa Cruz, bats, rodents, and marsupials form a key but understudied group. The diversity of bats in Patagonia is low compared to other regions of the country, but includes unique species that only inhabit Argentina and Chile. For their part, sigmodontine rodents represent one of the most diverse subfamilies and have several endemic species that exclusively inhabit the Patagonian steppe. The impact of human activities, such as overgrazing, has degraded the environments where many of these species live, altering their habitats and affecting their survival. This is especially serious in the Patagonian steppe, considered one of the most vulnerable ecoregions of the continent. Our work seeks to understand in detail the diversity and distribution of micromammals on the Lago Buenos Aires plateau and its surroundings, and to understand how factors such as altitude, climate, and human impact influence these communities. The information generated will be fundamental to developing conservation strategies adapted to this unique region of southern Patagonia.

Scope of the project

Our actions

  • We record which species inhabit different environments, from the highest areas to the valleys, crossing different latitudes and longitudes of the plateau.
  • We study how diversity varies, analyzing how many species there are, how abundant they are, and how they are grouped in different sectors of the landscape.
  • We investigate which environmental factors—such as the type of vegetation, proximity to water, topography, or climate—influence the presence and abundance of each species.
  • We evaluate human impact to understand if the presence of ranches, posts, or other constructions affects the composition and diversity of these wild communities.
© Gonzalo Ossa

Protagonists

© Damián Ganime | Illustration: Pollo Pazo
©Damián Ganime
Bunny Rat
Reithrodon auritus​
© Damián Ganime | Illustration: Pollo Pazo
©Damián Ganime
Patagonian Leaf-eared Mouse
Phyllotis xanthopygus
© Simón García Pla | Illustration: Pollo Pazo
©Simón García Pla
Andean long-clawed mouse
Paynomys macronyx
© Florencia Mottola | Illustration: Pollo Pazo
©Florencia Mottola
Long-tailed Pygmy Rice Rat
Oligoryzomys longicaudatus
© Sabrina Villalba | Illustration: Pollo Pazo
©Sabrina Villalba
Edwards’s Long-clawed Mouse
Notiomys edwardsii
© Sabrina Villalba | Illustration: Pollo Pazo
©Sabrina Villalba
Southern Big-eared Mouse
Loxodontomys micropus
© Walter Prado | Illustration: Pollo Pazo
©Walter Prado
Gray Leaf-eared Mouse
Graomys griseoflavus
© Pollo Pazo | Illustration: Pollo Pazo
©Pollo Pazo
Long-clawed Mole Mouse
Geoxus michaelseni
© Damián Ganime | Illustration: Pollo Pazo
©Damián Ganime
Patagonian Chinchilla Mouse
Euneomys chinchilloides
© Darío Podestá | Illustration: Pollo Pazo
©Darío Podestá
Lowland Gerbil Mouse
Eligmodontia typus
© Darío Podestá | Illustration: Pollo Pazo
©Darío Podestá
Western Patagonian Laucha
Eligmodontia morgani
© Vanessa Ramos | Illustration: Pollo Pazo
©Vanessa Ramos
Drylands Vesper Mouse
Calomys musculinus
© Darío Podestá | Illustration: Pollo Pazo
©Darío Podestá
Intelligent Grass Mouse
Akodon iniscatus
© Ezequiel Racker | Illustration: Pollo Pazo
©Ezequiel Racker
Olive grass mouse
Abrothrix olivacea
© d-catulus | Illustration: Pollo Pazo
©d-catulus
Woolly Grass Mouse
Abrothrix lanosa
© Ezequiel Racker | Illustration: Pollo Pazo
©Ezequiel Racker
Long-haired Grass Mouse
Abrothrix hirta
© Darío Podestá | Illustration: Pollo Pazo
©Darío Podestá
Patagonian opossum
Lestodelphys halli
© Bat Conservation International and Minden Pictures | Illustration: Pollo Pazo
©Bat Conservation International and Minden Pictures
Brazilian Free-tailed Bat
Tadarida brasiliensis
© Gonzalo Ossa | Illustration: Pollo Pazo
©Gonzalo Ossa
Chilean Myotis
Myotis chiloensis
© Gonzalo Ossa | Illustration: Pollo Pazo
©Gonzalo Ossa
Cinnamon Red Bat
Lasiurus varius
© Wilfredo Koehler | Illustration: Pollo Pazo
©Wilfredo Koehler
Small Big-eared Brown Bat
Histiotus montanus
© Mónica Díaz | Illustration: Pollo Pazo
©Mónica Díaz
Southern Big-eared Brown Bat
Histiotus magellanicus

Habitat and behavior

Both rodents and marsupials are terrestrial, occupying a wide variety of environments, ranging from vegetation, rocky areas, sandy areas, etc. Bats, on the other hand, use all types of environments, since they depend on the availability of shelter and food.

Feeding

Rodents and marsupials are very diverse with respect to their diet (herbivores, carnivores, omnivores, etc.). Bats, on the other hand, have an exclusively insectivorous diet.

Reproduction

Rodents can have more than one reproductive event during a year, and gestation times are short. Bats have a single offspring during the favorable time of year (abundance of food and warm temperatures). Little is yet known about the reproductive aspects of the marsupial species present in Santa Cruz.

Curiosity

The role or importance of these species is varied. They control populations on which they feed, for example, bats control those insects that can be considered pests and that cause damage to the human population in some aspect. Rodents and marsupials are an important part of the diet of other species, for example birds of prey and medium and large carnivorous mammals.

Threats

The main threats to this group of mammals are ignorance and bad press, especially in bats. The myths that have been created around them for years make their important role in nature to be ignored.

© Eliseo Misciu
Micromammals Project

Lines of work

Influence of environmental gradients on the structure of micromammal communities on the Buenos Aires Lake plateau

© Damián Ganime