Searching for the Haplorrhine Heterotherm: Field and Laboratory Data of Free-Ranging Tarsiers

The observation of heterothermy in a single suborder (Strepsirrhini) only within the primates is puzzling. Given that the placental-mammal ancestor was likely a heterotherm, we explored the potential for heterothermy in a primate closely related to the Strepsirrhini. Based upon phylogeny, body size...

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Main Authors: Shaun Welman, Andrew A. Tuen, Barry G. Lovegrove
Format: Article
Language:English
Published: Frontiers Media S.A. 2017-09-01
Series:Frontiers in Physiology
Subjects:
Online Access:http://journal.frontiersin.org/article/10.3389/fphys.2017.00745/full
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author Shaun Welman
Andrew A. Tuen
Barry G. Lovegrove
author_facet Shaun Welman
Andrew A. Tuen
Barry G. Lovegrove
author_sort Shaun Welman
collection DOAJ
description The observation of heterothermy in a single suborder (Strepsirrhini) only within the primates is puzzling. Given that the placental-mammal ancestor was likely a heterotherm, we explored the potential for heterothermy in a primate closely related to the Strepsirrhini. Based upon phylogeny, body size and habitat stability since the Late Eocene, we selected western tarsiers (Cephalopachus bancanus) from the island of Borneo. Being the sister clade to Strepsirrhini and basal in Haplorrhini (monkeys and apes), we hypothesized that C. bancanus might have retained the heterothermic capacity observed in several small strepsirrhines. We measured resting metabolic rate, subcutaneous temperature, evaporative water loss and the percentage of heat dissipated through evaporation, at ambient temperatures between 22 and 35°C in fresh-caught wild animals (126.1 ± 2.4 g). We also measured core body temperatures in free-ranging animals. The thermoneutral zone was 25–30°C and the basal metabolic rate was 3.52 ± 0.06 W.kg−1 (0.65 ± 0.01 ml O2.g−1.h−1). There was no evidence of adaptive heterothermy in either the laboratory data or the free-ranging data. Instead, animals appeared to be cold sensitive (Tb ~ 31°C) at the lowest temperatures. We discuss possible reasons for the apparent lack of heterothermy in tarsiers, and identify putative heterotherms within Platyrrhini. We also document our concern for the vulnerability of C. bancanus to future temperature increases associated with global warming.
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spelling doaj.art-c26f5f3488db4d8bb22da6f6eaaeb0992022-12-22T00:32:54ZengFrontiers Media S.A.Frontiers in Physiology1664-042X2017-09-01810.3389/fphys.2017.00745277354Searching for the Haplorrhine Heterotherm: Field and Laboratory Data of Free-Ranging TarsiersShaun Welman0Andrew A. Tuen1Barry G. Lovegrove2School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South AfricaInstitute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak, Kota Samarahan, MalaysiaSchool of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South AfricaThe observation of heterothermy in a single suborder (Strepsirrhini) only within the primates is puzzling. Given that the placental-mammal ancestor was likely a heterotherm, we explored the potential for heterothermy in a primate closely related to the Strepsirrhini. Based upon phylogeny, body size and habitat stability since the Late Eocene, we selected western tarsiers (Cephalopachus bancanus) from the island of Borneo. Being the sister clade to Strepsirrhini and basal in Haplorrhini (monkeys and apes), we hypothesized that C. bancanus might have retained the heterothermic capacity observed in several small strepsirrhines. We measured resting metabolic rate, subcutaneous temperature, evaporative water loss and the percentage of heat dissipated through evaporation, at ambient temperatures between 22 and 35°C in fresh-caught wild animals (126.1 ± 2.4 g). We also measured core body temperatures in free-ranging animals. The thermoneutral zone was 25–30°C and the basal metabolic rate was 3.52 ± 0.06 W.kg−1 (0.65 ± 0.01 ml O2.g−1.h−1). There was no evidence of adaptive heterothermy in either the laboratory data or the free-ranging data. Instead, animals appeared to be cold sensitive (Tb ~ 31°C) at the lowest temperatures. We discuss possible reasons for the apparent lack of heterothermy in tarsiers, and identify putative heterotherms within Platyrrhini. We also document our concern for the vulnerability of C. bancanus to future temperature increases associated with global warming.http://journal.frontiersin.org/article/10.3389/fphys.2017.00745/fullmetabolismprimate thermoregulationtropicsevolutiontarsiers
spellingShingle Shaun Welman
Andrew A. Tuen
Barry G. Lovegrove
Searching for the Haplorrhine Heterotherm: Field and Laboratory Data of Free-Ranging Tarsiers
Frontiers in Physiology
metabolism
primate thermoregulation
tropics
evolution
tarsiers
title Searching for the Haplorrhine Heterotherm: Field and Laboratory Data of Free-Ranging Tarsiers
title_full Searching for the Haplorrhine Heterotherm: Field and Laboratory Data of Free-Ranging Tarsiers
title_fullStr Searching for the Haplorrhine Heterotherm: Field and Laboratory Data of Free-Ranging Tarsiers
title_full_unstemmed Searching for the Haplorrhine Heterotherm: Field and Laboratory Data of Free-Ranging Tarsiers
title_short Searching for the Haplorrhine Heterotherm: Field and Laboratory Data of Free-Ranging Tarsiers
title_sort searching for the haplorrhine heterotherm field and laboratory data of free ranging tarsiers
topic metabolism
primate thermoregulation
tropics
evolution
tarsiers
url http://journal.frontiersin.org/article/10.3389/fphys.2017.00745/full
work_keys_str_mv AT shaunwelman searchingforthehaplorrhineheterothermfieldandlaboratorydataoffreerangingtarsiers
AT andrewatuen searchingforthehaplorrhineheterothermfieldandlaboratorydataoffreerangingtarsiers
AT barryglovegrove searchingforthehaplorrhineheterothermfieldandlaboratorydataoffreerangingtarsiers