upon leaves and seeds for food, and also that these large-bodied specialists would be most vulnerable to habitat disturbance and fragmentation due to their low reproductive resilience and their need for large, undisturbed habitats. Still, much of the island remained covered in forest, even into the 20th century. Linking human colonization to a specific cause for extinction has been difficult since human activities have varied from region to region. No single human activity can account for the extinction of the giant subfossil lemurs, but humans are still regarded as being primarily responsible. Each of the contributing human-caused factors played a role (having a synergistic effect) in varying degrees. The most widespread and adaptable species, such as Archaeolemur, were able to survive despite hunting pressure and human-caused habitat change until human population growth and other factors reached a tipping point, cumulatively resulting in their extinction. Extinction timeline and the primary trigger While it is generally agreed that both human and natural factors contributed to the subfossil lemur extinction, studies of sediment cores have helped to clarify the general timeline and initial sequence of events. Spores of the coprophilous fungus, Sporormiella, found in sediment cores experienced a dramatic decline shortly after the arrival of humans. Since this fungus cannot complete its life cycle without dung from large animals, its decline also indicates a sharp decline in giant subfossil lemur populations, as well as other large herbivores, starting around 230–410 cal yr CE. Following the decline of megafauna, the presence of charcoal particles increased significantly, starting in the southwest corner of the island, gradually spreading to the other coasts and the island's interior over the next 1,000 years. The first evidence for the introduction of cattle to the island dates to 1,000 years after the initial decline of coprophilous fungal spores. The loss of grazers and browsers might have resulted in the accumulation of excessive plant material and litter, promoting more frequent and destructive wildfires, which would explain the rise in charcoal particles following the decline in coprophilous fungus spores. This in turn resulted in ecological restructuring through the elimination of the wooded savannas and preferred arboreal habitats on which the giant subfossil lemurs depended. This left their populations at unsustainably low levels, and factors such as their slow reproduction, continued habitat degradation, increased competition with introduced species, and continued hunting (at lower levels, depending on the region) prevented them from recovering and