Skip to main content

High in the Andes, Peru’s puna grasslands offer a vital lifeline for Andean bears, commonly known as spectacled bears, named for the distinctive markings around their eyes.

These vulnerable creatures, endemic to South America, rely heavily on the grasslands for nourishment, specifically the bromeliad plants that form a staple of their diet. However, their ability to thrive depends on the careful balance of this delicate ecosystem, which is increasingly threatened by human activity and climate change.

A new study published in PLOS ONE by Nicholas Pilfold of the San Diego Zoo Wildlife Alliance and colleagues sheds light on the precise foraging habits of Andean bears (Tremarctos ornatus) and highlights the importance of conserving these high-altitude habitats.

Examples of foraging sign left by Andean bears on terrestrial bromeliads in Peru
Clockwise from the top right: (a) juvenile Andean bear consuming a bromeliad at a camera station inside MNP; (b) characteristic observation of a vegetative P. leptostachya foraged by Andean bear; (c) a close up of the basal meristematic tissue that Andean bears feed on. Credit: Pilfold et al. (2024) | DOI: 10.1371/journal.pone.0314547 | PLOS ONE

Researchers conducted extensive surveys in the puna grasslands of Peru’s Manu National Park, focusing on two species of bromeliads: Puya leptostachya and Puya membranacea. Using field observations and trail cameras, they discovered that Andean bears target specific patches of bromeliads, especially during the dry season when young, tender plants are abundant. These younger plants, found on steep, east-facing slopes at the edges of cloud forests, provide the bears with optimal nutrition and are easier to digest.

Despite their dependence on the grasslands, Andean bears foraged in just 16.7% of the surveyed bromeliad patches, avoiding areas with livestock. Interestingly, they were observed in regions where livestock grazing had ceased decades earlier, suggesting their adaptability to recovering ecosystems.

The study’s findings show the impact of human activity on bear behavior. Livestock grazing not only depletes bromeliads but also disrupts the bears’ foraging patterns. While Andean bears avoid areas with active livestock, their willingness to return to restored grasslands shows promise for conservation efforts. Protecting these habitats and reducing livestock impacts could help the bears reclaim lost territories and ensure their survival in the wild.

“Using the largest collection ever of field data on the feeding behavior of Andean bears in high elevation grasslands, we found that the bears actively selected for specific food resources within the grasslands, indicating that these areas are of nutritional importance to the bears,” the authors noted. “We also found Andean bears strongly avoided areas with livestock impacts to the grasslands, but that the cessation of livestock keeping restored the grasslands into areas Andean bears prefer within a short timeframe.”

High-altitude grasslands serve as a critical buffer between cloud forests and human settlements, offering a space for Andean bears to forage safely. To safeguard these vulnerable creatures, conservation managers must prioritize the protection of puna ecosystems, addressing livestock encroachment and supporting habitat restoration.

Journal Reference:
Pilfold NW, Mateo-Chero D, Farfan-Rios W, Watsa M, Owen MA, Van Horn RC, ‘Andean bears (Tremarctos ornatus) display selective behaviors while foraging bromeliads (Puya spp.) in high elevation puna grasslands’, PLoS ONE 19 (12): e0314547 (2024). DOI: 10.1371/journal.pone.0314547

Article Source:
Press Release/Material by PLOS
Featured image credit: vladimircech | Freepik

Icebergs in the Ilulissat Icefjord, Greenland (s. climate, science, study)
Warming has more impact than cooling on Greenland’s “firn”ClimateScience

Warming has more impact than cooling on Greenland’s “firn”

By University of Colorado at Boulder Scientists have known from ice core research that it's easier to melt an ice sheet than to freeze it…
SourceSourceJuly 25, 2024 Full article
Image: Assorted Vegetable Lot
Improved refrigeration could save nearly half of the 1.3* billion tons of food wasted each year globallyClimate

Improved refrigeration could save nearly half of the 1.3* billion tons of food wasted each year globally

By University of Michigan About a third of the food produced globally each year goes to waste, while approximately 800 million people suffer from hunger,…
SourceSourceMay 29, 2024 Full article
Hourglass with Earth inside with an glacier melting above - global warming concept
Global Billionaires Unite in Efforts to Combat Climate ChangeClimateNews

Global Billionaires Unite in Efforts to Combat Climate Change

In the wake of a tumultuous year of unprecedented climate disasters in 2023, the world's wealthiest individuals are stepping up their efforts to combat climate…
Adrian AlexandreAdrian AlexandreFebruary 5, 2024 Full article