Showing papers by "Sarah A. Boyle published in 2015"
TL;DR: It is found that ant presence significantly reduced both rates of visitation and of fruit removal by C. ouakary, and appears to be only the second-known demonstration of the repellent effect of ants on primates and, indeed, the first for squirrels and psittacine birds.
Abstract: Although plant-inhabiting ants are known to act as effective deterrents to a variety of vertebrate and invertebrate herbivores, this has been reported only once before for primates, a group better known for their predation of ants. In the present study, we investigated the effects that colonies of Pseudomyrmex viduus ants living in individual Macrolobium acaciifolium (Fabaceae) trees have on the rates of visitation and fruit removal by four taxa of seed-predating vertebrates: the primate Cacajao melanocephalus ouakary; macaws (Ara spp.); large parrots (Amazona spp.); and the Northern Amazonian red squirrel (Sciurus igniventris). We found that ant presence significantly reduced both rates of visitation and of fruit removal by C. m. ouakary. The same pattern of reduced fruit removal was also observed for other seed predators (parrots, macaws, and squirrels) but not for visitation rates (although this may be a result of the small sample size). This appears to be only the second-known demonstration of the repellent effect of ants on primates and, indeed, the first for squirrels and psittacine birds. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114, 260–273.
51 citations
TL;DR: Given that the elephants walked more during the day, two of the three elephants had an increase in rest behavior during the night, and there were minimal changes in cortisol response after theflooring renovations, it is concluded that the flooring renovations overall had a positive impact on animal welfare.
Abstract: Captive African (Loxodonta africana) and Asian (Elephas maximus) elephants can experience foot pathologies and arthritis. As a preventative measure against these pathologies and to alleviate the potential discomfort due to concrete substrates, some zoological institutions have renovated elephant housing to increase the amount of natural or shock-absorbent substrates. The objective of this study was to compare behavioral (diurnal and nocturnal) and glucorticoid (e.g., serum cortisol) responses of three female African elephants before, during, and after renovation to their indoor housing floor to assess whether renovations had short-term effects on the elephants' behavior and stress physiology. Behavioral data were collected using scan-sampling methods, and activity budgets were constructed for each of the three elephants. In addition, the duration of all lying rest activities were recorded. Weekly serum cortisol concentrations were determined with enzyme immunoassay (EIA). Overall, eating was the most prevalent behavior exhibited outdoors during the day, while resting (either in a lying or standing position) were most common during the indoor, nocturnal periods. Although variation existed among the three elephants, all three females spent significantly more time walking and less time eating during the day after the completion of the renovations. The extent to which the three elephants exhibited nocturnal lying rest behavior varied among the elephants, with the oldest elephant exhibiting the least amount (an average of 13.2 ± 2.8% of the nightly behavioral scans) compared to the two younger elephants (an average of 34.5 ± 2.1% and 56.6 ± 2.8% of the nightly behavioral scans). There was a significant increase in lying rest behavior for one elephant and standing rest for a second elephant following renovations. Baseline cortisol concentrations prior to renovations were 3.0 ± 0.4 ng/ml, 4.5 ± 0.5 ng/ml, and 4.9 ± 0.5 ng/ml for the three elephants. Cortisol concentrations remained baseline for two of the elephants throughout and after the renovation period, while one elephant that was pregnant had elevated cortisol during construction. Cortisol concentrations for the pregnant elephant remained higher than baseline once she was introduced to the new flooring and allowed back into the building, but these values were closer to the cortisol concentrations before renovations than during construction. Our findings demonstrate that individual elephants can vary in their behavioral and physiological responses to exhibit modifications. Given that the elephants walked more during the day, two of the three elephants had an increase in rest behavior during the night, and there were minimal changes in cortisol response after the flooring renovations, we conclude that the flooring renovations overall had a positive impact on animal welfare.
19 citations
TL;DR: This work replaces a fruit penetrometer's standard plunger with a Cacajao calvus canine prosthesis and believes this new approach using dental prostheses has potential in the analysis of primate foraging mechanisms, especially for pitheciines for which canines are of paramount importance in accessing food.
Abstract: Tooth morphology is an important determinant of primate diet, setting potential limits on processable item size and material properties. Plunger-based commercial fruit firmness testers (penetrometers) have been used to estimate primate diet item hardness and, by proxy, bite force required for penetration. However, geometric forms and surface areas of penetrometer plungers and primate teeth differ considerably. Accurate bite force estimation is especially important with pitheciine primates as these penetrate fruit pericarps with their canines. To achieve more realistic bite force measures, we replaced a fruit penetrometer's standard plunger with a Cacajao calvus canine prosthesis. We compared indentation and penetration values for Hevea spruceana (Euphorbiaceae; hard-pericarp) and Mauritia flexuosa (Arecaceae; soft-pericarp) fruits (both natural Cacajao foods), and standard penetrometer head and canine prosthesis values for penetrating H. spruceana sulci. Compared to the canine prosthesis, a standard head overestimated the force needed to indent and penetrate H. spruceana fruit by more than twofold and, due to greater width, could not effectively penetrate a sulcus: sulcal penetrability data were easily retrieved with the canine prosthesis. We believe this new approach using dental prostheses has potential in the analysis of primate foraging mechanisms, especially for pitheciines for which canines are of paramount importance in accessing food.
6 citations
2 citations
01 Jan 2015
TL;DR: It is suggested cuxius form mixed-species associations at some sites as an adaptive strategy to decrease predation risk and/or increase foraging efficiency and alarm called signi-cantly less frequently during associations.
Abstract: Polyspecificormixed-speciesassociations,wheretwoormorespeciescometogethertoforageandtravelas a unit, have been reported in many primate species. These associations appear to offer a number ofbenefits to the species involved including increased foraging efficiency and decreased risk of predation.While several researchers have suggested that cuxius (genus Chiropotes) form mixed-speciesassociations, previous studies have not identified the circumstances under which cuxius formassociations or whether they form associations more often than would be expected by chance. Here wepresent data on the formation of mixed-species associations by four species of cuxius at eight differentsites in Brazil, Suriname, and Guyana. We analyzed data from two of the study sites, (BiologicalDynamics of Forest Fragments Project (BDFFP), Brazil and the Upper Essequibo ConservationConcession (UECC), Guyana, to assess whether associations occurred more than would be expected bychance encounters and identify the factors influencing their formation. Cuxius showeda high degree ofinter-site variation in the frequency of time spent in association (ranging from 2 to 26% of observationtime) and duration of associations (mean duration from 22min to 2.5hr). Sapajus apella was the mostcommon association partner at most sites. At BDFFP, cuxius formed associations more frequently butnot for longer duration than expected by chance. For much of the year at UECC, associations were notmore frequent or longer than chance. However, during the dry season, cuxius formed associations withS. apella significantly more often and for longer duration than predicted by chance. Cuxius at UECCformed associations significantly more often when in smaller subgroups and when foraging for insects,and alarm called significantly less frequently during associations. We suggest cuxius form mixed-species associations at some sites as an adaptive strategy to decrease predation risk and/or increaseforaging efficiency. Am. J. Primatol. © 2015 Wiley Periodicals, Inc.Key words: polyspecific association; bearded sakis; Guyana; Brazil; SurinameINTRODUCTIONPolyspecific or mixed-species associations in-volve two or more species coming together to forageand travel as a unit [Cords, 1990a]. These associa-tions occurinadiverserange oftaxa,including birds[Munn & Terborgh, 1979; Powell, 1985], ungulates[Sinclair,1985],andfish[Wolf,1985],aswellasNewWorld monkeys [Hardie & Buchanan-Smith, 1997;Norconk, 1990; Porter, 2001; Rehg, 2006; Terborgh,1983], Old World monkeys [Chapman & Chapman,2000; Cords, 1990a; N€oe & Bshary, 1997; Oates WWolters&Zuberbuhler,2003],and€lemurs [Sauther, 2002], leading researchers to