Premium
Effects of substrate and phylogeny on quadrupedal gait in free‐ranging platyrrhines
Author(s) -
Dunham Noah T.,
McNamara Allison,
Shapiro Liza J.,
Hieronymus Tobin L.,
Phelps Taylor,
Young Jesse W.
Publication year - 2019
Publication title -
american journal of physical anthropology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.146
H-Index - 119
eISSN - 1096-8644
pISSN - 0002-9483
DOI - 10.1002/ajpa.23942
Subject(s) - gait , quadrupedalism , arboreal locomotion , biology , phylogenetic tree , phylogenetics , animal ecology , evolutionary biology , orientation (vector space) , ecology , anatomy , geometry , mathematics , genetics , habitat , physiology , gene
Objectives Primate diagonal sequence (DS) gaits are often argued to be an adaptation for moving and foraging in the fine‐branch niche; however, existing data have come predominantly from laboratory studies that are limited in taxonomic breadth and fail to account for the structural and ecological variation of natural substrates. We test the extent to which substrate diameter and orientation influence gait sequence type and limb phase in free‐ranging primates, as well as how phylogenetic relatedness might condition response patterns. Materials and methods We filmed quadrupedal locomotion in 11 platyrrhine species at field sites in Ecuador and Costa Rica and measured the diameter and orientation of locomotor substrates using remote sensors. We quantified limb phase values and classified strides by gait sequence type ( N = 988 strides). Results Our results show that most of the species in our sample consistently used DS gaits, regardless of substrate diameter or orientation; however, all taxa also used asymmetrical and/or lateral sequence gaits. By incorporating phylogenetic eigenvectors into our models, we found significant differences in gait sequence patterns and limb phase values among the major platyrrhine clades, suggesting that phylogeny may be a better predictor of gait than substrate diameter or orientation. Discussion Our field data generally corroborate locomotor patterns from laboratory studies but capture additional aspects of gait variability and flexibility in response to the complexity of natural environments. Overall, our results suggest that DS gaits are not exclusively tailored to narrow or oblique substrates but are used on arboreal substrates in general.