Microhabitat Use by the Whip Spider Heterophrynus Longicornis (Amblypygi, Phrynidae) in Central Amazon

Abstract

We investigated microhabitat selection in the Amazonian whip spider Heterophrynus longicornis (Butler 1973). The probability of finding individuals of this species increased according to the diameter of the trees. Moreover, there was a positive correlation between the size of adult individuals and the diameter of the trees on which they were found. Our results also provide quantitative support for a previous suggestion that H. longicornis prefers large trees bearing buttresses and burrows at the base where the individuals hide during daytime. Since whip spiders prefer large trees, the anthropogenic disturbance promoted by selective logging or the degeneration of the forest structure due to fragmentation and edge effect may have a negative effect on the spatial distribution and, consequently, on the density and population ecology of H. longicornis.

The behavioral ecology of amblypygids

“…In common across studied Amblypygi is the occupation and defense of small areas around a single refuge. Refuges typically follow a shape suitable to accommodate the dorso-ventrally flattened amblypygid body form such as in cracks and crevices in cave walls (Chapin 2015) or in tropical tree buttresses (Hebets 2002;Dias & Machado 2006;Carvalho et al 2012;Chapin 2014), under debris like rocks and logs (Fowler-Finn & Hebets 2006), in appropriated abandoned burrows (Weygoldt 2000), in bracts of bromeliads (Jocque & Giupponi 2012), or even in termite mounds (Carvalho et al 2011). Refuges house individuals during daylight hours and provide shelter from predators.…”

“…These species show preferences for large, buttressing trees with refuges in abandoned burrows under bark, under leaf litter piles, or in crevices created by decay or buttressing (Hebets 2002;Dias & Machado 2006;Carvalho et al 2012;Chapin 2014Chapin , 2015. Thus, tree-dwelling species appear to rely on large, old growth trees for territory formation (Chapin 2014).…”

“…3.2 Navigation.-Given that studied amblypygid species tend to reside in refuges that they reliably occupy over various time frames (Hebets 2002;Dias & Machado 2006;Carvalho et al 2012;Porto & Peixoto 2013;Chapin 2014Chapin , 2015Curtis & Bloch 2014;Chapin & Hill-Lindsay 2015), it may not be surprising that residents are capable of finding their way back to these refuges-a phenomenon known as homing. The distances over which amblypygids have been shown to home, in combination with the complex habitats through which they travel (e.g., lowland tropical rainforests), make these feats quite impressive.…”

“…Adults of this species were almost never found singly or in larger groups, but it remains unclear whether or not groups were of related animals (Weygoldt 1977a). Later research on H. longicornis found that multiple individuals are sometimes found in association, but the benefits that group living might afford remain unknown (Dias & Machado 2006;Carvalho et al 2012). Similarly, laboratory observations found that immature Phrynus marginemaculatus from Florida and Damon diadema (Simon, 1876) from Kenya and Tanzania associated with each other and their mothers for as long as a year in captivity (Rayor & Taylor 2006), but field observations of these phenomena remain undocumented.…”

Occurrence of Whip Spiders (Arachnida:Amblypygi) in Isolated Fragments of Atlantic Forest in a Northeastern Brazilian Metropolis: Perspective for New Studies

“…Dias and Machado (2006) have found that amblypygids have a preference for large trees and suggest that human disturbance promoted by selective logging or forest degradation due to habitat fragmentation and edge effect may have a negative effect on the spatial distribution and therefore on the density of these animals. Therefore, considering the great effort in time and space and the variety of methods used, it is inferred that the intense human pressure on the urban systems of Atlantic Rains Forest, causes a significant reduction in abundance and richness of the order Amblypygi.…”