Data from: Differing patterns of plant spinescence affect blue duiker (Bovidae: Philantomba monticola) browsing behavior and intake rates

The ways in which spines and thorns on plants affect browsing behavior and
instantaneous intake rate (IIR) have been investigated for several medium
and large ungulates, with most authors concluding that spines either
affect the ability to obtain a full bite, or prevent the removal of twig
material. We investigated how a very small ruminant, the blue duiker
(Philantomba monticola; mass 5 kg), altered its feeding strategy when
confronted with intact or despined branches of three species of woody
plant that differed in leaf and spine size, density, and arrangement, viz.
Dichrostachys cinerea africana, Vachellia (Acacia) karroo and Ziziphus
mucronata. Increasing spine length and density reduced IIR (g/min), while
bite size was directly related to leaf area. Bite rate and the lag time to
taking the first bite did not differ among treatments. In all treatments,
blue duikers cropped leaves in preference to pruning shoots. High spine
density forced duikers to crop leaves at the ends of branches where spines
were softer. At low spine density and on despined treatments, leaves
midway along branches were preferred. Single bites (using incisors) were
used preferentially in the presence of spines, with a shift to cheek bites
on despined branches. We conclude that, as found with larger browsers,
spines coupled with small leaf size provide the best defense against
defoliation.