ABSTRACT The relationships between locomotor performance and major features of environmental stru... more ABSTRACT The relationships between locomotor performance and major features of environmental structure, such as incline and diameter, have been consistently identified in several vertebrate groups. The effects of variation in characteristics such as texture and structural complexity, in contrast, remain neglected, and associations between sprint speeds achieved during steady-level locomotion and the way an animal grips the surface are particularly obscure. In the present study, we have used the habitat generalist lizard Tropidurus torquatus to test the hypothesis that animals run faster on the substrates where gripping performance is higher. We ran 18 individuals on seven different substrates (wood, thin and coarse sand, coarse gravel, rock, leaf litter and grass) and recorded their maximum speeds using high-speed cameras. Surfaces were characterized for height variation and grip, the last given by average grip performance achieved by lizards of different sizes. Maximum sprint speeds were highest on rock and grass and lowest on thin and coarse sand, and variation in performance among substrates was explained by grip: substrates in which lizards gripped stronger are those that enhanced average maximum sprint speed. This study is the first report providing evidence for variation in maximum sprint speeds achieved by a generalist lizard running on different substrates, and demonstrates how friction resulting from the interaction of the lizard with the sub-strate may be critically important for sprint speed.
The Brazilian Atlantic Forest (BAF) is one of the biodiversity hotspots, but in the last decades,... more The Brazilian Atlantic Forest (BAF) is one of the biodiversity hotspots, but in the last decades, it has been fragmented due to agricultural and urban-industrial expansion, which has a strong impact on forest fragments. The goal of this study was to analyze the Biotic Integrity Index (BII) in fragments of BAF in two medium-sized cities in Southeastern Brazil and to analyze the relation between BII and landscape metrics (size and shape). The method (BII) has eleven indicators (litter, grass, dead trees, exotic species, vines, gaps, epiphytes, orchids, palms, later species in canopy and understory). The survey was carried out in nine forest fragments in Ribeirão Preto (SP) and 23 in Sorocaba (SP), with a size variation between 0.33 and 185 ha, all of them in urban influence. The relation between BII and landscape metrics were analyzed by the Pearson regression. BII value was registered from 28.7 to 40.0 to Ribeirão Preto and from 22.34 to 35.34 to Sorocaba. Pearson regression was stro...
The relationships between locomotor performance and major features of environmental structure, su... more The relationships between locomotor performance and major features of environmental structure, such as incline and diameter, have been consistently identified in several vertebrate groups. The effects of variation in characteristics such as texture and structural complexity, in contrast, remain neglected, and associations between sprint speeds achieved during steady-level locomotion and the way an animal grips the surface are particularly obscure. In the present study, we have used the habitat generalist lizard Tropidurus torquatus to test the hypothesis that animals run faster on the substrates where gripping performance is higher. We ran 18 individuals on seven different substrates (wood, thin and coarse sand, coarse gravel, rock, leaf litter and grass) and recorded their maximum speeds using high-speed cameras. Surfaces were characterized for height variation and grip, the last given by average grip performance achieved by lizards of different sizes. Maximum sprint speeds were highest on rock and grass and lowest on thin and coarse sand, and variation in performance among substrates was explained by grip: substrates in which lizards gripped stronger are those that enhanced average maximum sprint speed. This study is the first report providing evidence for variation in maximum sprint speeds achieved by a generalist lizard running on different substrates, and demonstrates how friction resulting from the interaction of the lizard with the substrate may be critically important for sprint speed.
ABSTRACT The relationships between locomotor performance and major features of environmental stru... more ABSTRACT The relationships between locomotor performance and major features of environmental structure, such as incline and diameter, have been consistently identified in several vertebrate groups. The effects of variation in characteristics such as texture and structural complexity, in contrast, remain neglected, and associations between sprint speeds achieved during steady-level locomotion and the way an animal grips the surface are particularly obscure. In the present study, we have used the habitat generalist lizard Tropidurus torquatus to test the hypothesis that animals run faster on the substrates where gripping performance is higher. We ran 18 individuals on seven different substrates (wood, thin and coarse sand, coarse gravel, rock, leaf litter and grass) and recorded their maximum speeds using high-speed cameras. Surfaces were characterized for height variation and grip, the last given by average grip performance achieved by lizards of different sizes. Maximum sprint speeds were highest on rock and grass and lowest on thin and coarse sand, and variation in performance among substrates was explained by grip: substrates in which lizards gripped stronger are those that enhanced average maximum sprint speed. This study is the first report providing evidence for variation in maximum sprint speeds achieved by a generalist lizard running on different substrates, and demonstrates how friction resulting from the interaction of the lizard with the sub-strate may be critically important for sprint speed.
The Brazilian Atlantic Forest (BAF) is one of the biodiversity hotspots, but in the last decades,... more The Brazilian Atlantic Forest (BAF) is one of the biodiversity hotspots, but in the last decades, it has been fragmented due to agricultural and urban-industrial expansion, which has a strong impact on forest fragments. The goal of this study was to analyze the Biotic Integrity Index (BII) in fragments of BAF in two medium-sized cities in Southeastern Brazil and to analyze the relation between BII and landscape metrics (size and shape). The method (BII) has eleven indicators (litter, grass, dead trees, exotic species, vines, gaps, epiphytes, orchids, palms, later species in canopy and understory). The survey was carried out in nine forest fragments in Ribeirão Preto (SP) and 23 in Sorocaba (SP), with a size variation between 0.33 and 185 ha, all of them in urban influence. The relation between BII and landscape metrics were analyzed by the Pearson regression. BII value was registered from 28.7 to 40.0 to Ribeirão Preto and from 22.34 to 35.34 to Sorocaba. Pearson regression was stro...
The relationships between locomotor performance and major features of environmental structure, su... more The relationships between locomotor performance and major features of environmental structure, such as incline and diameter, have been consistently identified in several vertebrate groups. The effects of variation in characteristics such as texture and structural complexity, in contrast, remain neglected, and associations between sprint speeds achieved during steady-level locomotion and the way an animal grips the surface are particularly obscure. In the present study, we have used the habitat generalist lizard Tropidurus torquatus to test the hypothesis that animals run faster on the substrates where gripping performance is higher. We ran 18 individuals on seven different substrates (wood, thin and coarse sand, coarse gravel, rock, leaf litter and grass) and recorded their maximum speeds using high-speed cameras. Surfaces were characterized for height variation and grip, the last given by average grip performance achieved by lizards of different sizes. Maximum sprint speeds were highest on rock and grass and lowest on thin and coarse sand, and variation in performance among substrates was explained by grip: substrates in which lizards gripped stronger are those that enhanced average maximum sprint speed. This study is the first report providing evidence for variation in maximum sprint speeds achieved by a generalist lizard running on different substrates, and demonstrates how friction resulting from the interaction of the lizard with the substrate may be critically important for sprint speed.
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the surface are particularly obscure. In the present study, we have used the habitat generalist lizard Tropidurus torquatus to test the hypothesis that animals run faster on the substrates where gripping performance is higher. We ran 18 individuals on
seven different substrates (wood, thin and coarse sand, coarse gravel, rock, leaf litter and grass) and recorded their maximum speeds using high-speed cameras.
Surfaces were characterized for height variation and grip, the last given by average grip performance achieved by lizards of different sizes. Maximum sprint speeds were highest on rock and grass and lowest on thin and coarse sand, and variation
in performance among substrates was explained by grip: substrates in which lizards gripped stronger are those that enhanced average maximum sprint speed.
This study is the first report providing evidence for variation in maximum sprint speeds achieved by a generalist lizard running on different substrates, and demonstrates how friction resulting from the interaction of the lizard with the substrate may be critically important for sprint speed.
the surface are particularly obscure. In the present study, we have used the habitat generalist lizard Tropidurus torquatus to test the hypothesis that animals run faster on the substrates where gripping performance is higher. We ran 18 individuals on
seven different substrates (wood, thin and coarse sand, coarse gravel, rock, leaf litter and grass) and recorded their maximum speeds using high-speed cameras.
Surfaces were characterized for height variation and grip, the last given by average grip performance achieved by lizards of different sizes. Maximum sprint speeds were highest on rock and grass and lowest on thin and coarse sand, and variation
in performance among substrates was explained by grip: substrates in which lizards gripped stronger are those that enhanced average maximum sprint speed.
This study is the first report providing evidence for variation in maximum sprint speeds achieved by a generalist lizard running on different substrates, and demonstrates how friction resulting from the interaction of the lizard with the substrate may be critically important for sprint speed.