According to a recent study by the University of Exeter, fungal spores found in dung have provided insights into the extinction of large animals in the Colombian Andes. These spores of coprophilous fungi pass through the digestive tracts of megafauna, serving as evidence of the presence of these animals in a particular place and time.
The study analyzed sediment samples from a peat bog in Pantano de Monquentiva, which is situated approximately 60 km from Bogota in the eastern cordillera. This research, the first of its kind conducted in Colombia, revealed that large animals became locally extinct at this location approximately 23,000 and 11,000 years ago, respectively. Such extinctions had significant impacts on the surrounding ecosystems.
The disappearance of large animals, such as elephants, has a vital impact on regulating ecosystems by consuming and trampling vegetation. Through the analysis of fungal spores, along with pollen and charcoal, the study was able to trace the extinction of large animals and the consequences for plant growth and fire activity.
These findings carry particular significance, given the current state of biodiversity crisis, as they highlight how the extinction of large animals can potentially alter ecosystems that sustain both wildlife and humans.
The disappearance of large animals from the Monquentiva ecosystem had a profound impact, as highlighted by the recent study. The analysis of fungal spores, pollen, and charcoal revealed that different plant species thrived and wildfires increased after the megafauna vanished.
Although the fungal spores do not indicate the specific types of megafauna present, giant armadillos and six-meter-tall giant ground sloths were known to roam Colombia during this period. The study found that megafauna had existed in the area for thousands of years before disappearing entirely approximately 23,000 years ago.
Megafauna began to inhabit the area again around 5,000 years later, but at lower numbers. Another wave of extinction about 11,000 years ago reduced their numbers almost to zero. The reason behind these local extinctions is uncertain, with potential factors including climate changes, hunting by humans, or even a meteorite strike.
The loss of megafauna had a significant impact on the ecosystem, causing a shift in plant species towards more woody and palatable plants, which grazing animals prefer. Furthermore, the absence of megafauna meant that plants that depend on animal seed dispersal disappeared. Wildfires became more common due to the increased presence of flammable plants that were no longer being eaten or trampled upon.
The study concludes that conservation efforts need to account for the effects of local herbivore declines on plant species dispersal, fire activity, and the potential loss of ecosystem services, especially given the current biodiversity crisis. The paper, titled “The timing and ecological consequences of Pleistocene megafaunal decline in the eastern Andes of Colombia,” was published in the journal Quaternary Research.
Source: University of Exeter