Measuring Microhabitat Temperature in Arboreal Primates: A Comparison of On-Animal and Stationary Approaches
Behavioral thermoregulation; Behavioral thermoregulation; body-temperature; Climate; costa-rica; environment; japanese macaques; measurement; Microclimate; national-park; neotropical primate; pan-troglodytes-verus; temperature; thermal; Thermal environment; thermoregulation; tropical forest; vervet monkeys; Zoology
Arboreal primates actively navigate a complex thermal environment that exhibits spatial, daily, and seasonal temperature changes. Thus, temperature measurements from stationary recording devices in or near a forest likely do not reflect the thermal microenvironments that primates actually experience. To better understand the thermal variation primates encounter, we attached automated temperature loggers to anklets worn by free-ranging mantled howling monkeys (Alouatta palliata) to record near-animal ambient temperatures. We compared these measures to conventional, stationary temperature measurements taken from within the forest, in nearby open fields, and at a remote weather station 38.6 km from the field site. We also measured temperatures across vertical forest heights and assessed the effects of wind speed, solar radiation, rain, and vapor pressure on primate subcutaneous temperatures (collected via implanted loggers). Ambient temperatures at measurement sites commonly used by researchers differed from those experienced by animals. Moreover, these differences changed between seasons, indicating dynamic shifts in thermal environment occur through space and time. Temperatures increased with height in the forest, with statistically significant, albeit low magnitude, differences between vertical distances of one meter. Near-animal temperatures showed that monkeys selected relatively warmer microhabitats during nighttime temperature lows and relatively cooler microhabitats during the day. Lastly, the thermal variables wind speed, solar radiation, vapor pressure, and rain were statistically associated with primate subcutaneous temperatures. Our data indicate that the temperatures arboreal primates experience are not well reflected by stationary devices. Attaching automated temperature loggers to animals provides a useful tool for more directly assessing primate microhabitat use.
Thompson C L; Williams S H; Glander K E; Vinyard C J
International Journal of Primatology
2016
2016-10
Journal Article
<a href="http://doi.org/10.1007/s10764-016-9917-x" target="_blank" rel="noreferrer noopener">10.1007/s10764-016-9917-x</a>
The Influence of Experimental Manipulations on Chewing Speed During In Vivo Laboratory Research in Tufted Capuchins (Cebus apella)
anthropoid primates; Anthropology; bone strain; elastic model foods; Evolutionary Biology; experimental conditions; human mastication; jaw-muscle electromyography; lemurs lemur-catta; macaca-fascicularis; mandibular corpus; mastication; national-park; platyrrhine; symphyseal fusion
Even though in vivo studies of mastication in living primates are often used to test functional and adaptive hypotheses explaining primate masticatory behavior, we currently have little data addressing how experimental procedures performed in the laboratory influence mastication. The obvious logistical issue in assessing how animal manipulation impacts feeding physiology reflects the difficulty in quantifying mechanical parameters without handling the animal. In this study, we measured chewing cycle duration as a mechanical variable that can be collected remotely to: 1) assess how experimental manipulations affect chewing speed in Cebus apella, 2) compare captive chewing cycle durations to that of wild conspecifics, and 3) document sources of variation (beyond experimental manipulation) impacting captive chewing cycle durations. We find that experimental manipulations do increase chewing cycle durations in C. apella by as much as 152 milliseconds (ms) on average. These slower chewing speeds are mainly an effect of anesthesia (and/or restraint), rather than electrode implantation or more invasive surgical procedures. Comparison of captive and wild C. apella suggest there is no novel effect of captivity on chewing speed, although this cannot unequivocally demonstrate that masticatory mechanics are similar in captive and wild individuals. Furthermore, we document significant differences in cycle durations due to inter-individual variation and food type, although duration did not always significantly correlate with mechanical properties of foods. We advocate that the significant reduction in chewing speed be considered as an appropriate qualification when applying the results of laboratory-based feeding studies to adaptive explanations of primate feeding behaviors. Am J Phys Anthropol 145: 402-414, 2011. (C) 2011 Wiley-Liss, Inc.
Thompson C L; Donley E M; Stimpson C D; Horne W I; Vinyard C J
American Journal of Physical Anthropology
2011
2011-07
Journal Article
<a href="http://doi.org/10.1002/ajpa.21514" target="_blank" rel="noreferrer noopener">10.1002/ajpa.21514</a>