Naturalist guide Lizardo Proaño observed daddy longlegs capturing and eating live frogs in the cloud forests of Ecuador [1, 2].
This discovery is significant because it suggests these arachnids may be predators of vertebrates. Traditionally, daddy longlegs, known as harvestmen, are not viewed as hunters of animals with backbones, meaning this behavior expands their known diet beyond invertebrates [3, 4, 5].
The observation occurred in February 2020 [2]. Proaño documented the arachnids devouring prey that was approximately the same size as the daddy longlegs themselves [1]. This size parity highlights the ability of the arachnid to overpower and consume a vertebrate of comparable mass.
Harvestmen differ from true spiders in several biological ways, yet this behavior positions them as more aggressive predators than previously understood. The sightings took place within the tropical forests of South America, where the unique ecosystem of the cloud forest provides a diverse range of prey [1, 2].
While harvestmen are often seen as scavengers or hunters of small insects, the evidence from Ecuador indicates a more opportunistic approach to hunting. The capture of live frogs suggests that these arachnids can successfully engage and kill vertebrates in their natural habitat [3, 5].
“Daddy longlegs may be predators of vertebrates.”
The observation of harvestmen hunting vertebrates challenges existing biological assumptions about the dietary limitations of daddy longlegs. If these arachnids regularly prey on small vertebrates like frogs, it suggests a more complex role in the food web of South American cloud forests and may prompt further research into the hunting mechanisms of non-spider arachnids.
