Analyses of masticatory muscle architecture-specifically fascicle length (FL; a correlate of muscle stretch and contraction speed) and physiological cross-sectional area (PCSA; a correlate of force)-reveal soft-tissue dietary adaptations. For instance, consumers of large, soft foods are expected to have relatively long FL, while consumers of obdurate foods are expected to have relatively high PCSA. Unfortunately, only a few studies have analyzed these variables across large primate samples-an order of particular interest because it is our own. Previous studies found that, in strepsirrhines, force variables (PCSA and muscle masses; MM) scale with isometry or slight positive allometry, while the body size corrected FL residuals correlate with food sizes. However, a study of platyrrhines using different methods (in which the authors physically cut muscles between fascicles) found very different trends: negative allometry for both the stretch and force variables. Here, we apply the methods used in the strepsirrhine study (chemical dissection of fascicles to ensure full length measurements) to reevaluate these trends in platyrrhines and extend this research to include catarrhines. Our results conform to the previous strepsirrhine trends: there is no evidence of negative allometry in platyrrhines. Rather, in primates broadly and catarrhines specifically, MM and PCSA scale with isometry or positive allometry. When examining size-adjusted variables, it is clear that fascicle lengths (especially those of the temporalis muscle) correlate with diet: species that consume soft, larger, foods have longer masticatory fiber lengths which would allow them to open their jaws to wider gape angles. Anat Rec, 301:311-324, 2018. © 2018 Wiley Periodicals, Inc.
By combining muscle architectural data with biomechanical variables relating to the jaw, we produce anatomically derived maximum bite force estimations for 23 species of catarrhine and platyrrhine primates. We investigate how bite force scales across the sample as a whole (and within each parvorder) relative to two size proxies, body mass and cranial geometric mean, and the effect of diet upon bite force. Bite force is estimated at three representative bite points along the dental row: the first maxillary incisor, canine, and third‐most mesial paracone. We modeled bite force by combining calculated physiological cross‐sectional area of the jaw adductors from Hartstone‐Rose et al. [Anat Rec 301 (2018) 311–324] with osteological measurements of lever‐ and load‐arm lengths from the same specimens [Hartstone‐Rose et al., Anat Rec 295 (2012) 1336–1351]. Bite force scales with positive allometry relative to cranial geometric mean across our entire sample and tends toward positive allometry relative to body mass. Bite force tends toward positive allometry within platyrrhines but scales isometrically within catarrhines. There was no statistically significant scaling difference with diet. Our findings imply an absence of a dietary signal in the scaling of bite force, a result that differs from the scaling of physiological cross‐sectional area alone. That is, although previous studies have found a dietary signal in the muscle fiber architecture in these species, when these are combined with their leverages, that signal is undetectable. On the parvorder level, our data also demonstrate that the platyrrhine masticatory system appears more mechanically advantageous than that of catarrhines. Anat Rec, 2019. © 2019 American Association for Anatomy Anat Rec, 303:2026–2035, 2020. © 2019 American Association for Anatomy
Carnivorans represent extreme ecomorphological diversity, encompassing remarkable variation in form, habitat, and diet. The relationship between the masticatory musculature and dietary ecology has been explored in a number of carnivoran lineages, including felids and the superfamily Musteloidea. In this study, we present novel architectural data on two additional carnivoran families—Ursidae and Canidae—and supplement these previous studies with additional felid, musteloid, herpestid, hyaenid, and viverrid taxa (a total of 53 species across 10 families). Gross dissection data were collected following a standardized protocol—sharp dissection followed by chemical digestion. Summed jaw adductor forces were also transformed into bite force estimates (BF) using osteologically calculated leverages. All data were linearized, log‐transformed, and size‐adjusted using two proxies for each taxon—body mass (BM) and cranial geometric mean—to assess relative scaling trends. These architectural data were then analyzed in the context of dietary ecology to examine the impact of dietary size (DS) and dietary mechanical properties (DMP). Muscle mass, physiological cross‐sectional area, and BF scaled with isometry or positive allometry in all cases, whereas fascicle lengths (FLs) scaled with isometry or negative allometry. With respect to diet, BM‐adjusted FLs were strongly correlated with DS in musteloids, but not in any other lineage. The relationship between size‐adjusted BF and DMP was also significant within musteloids, and across the sample as a whole, but not within other individual lineages. This interfamilial trend may reflect the increased morphological and dietary diversity of musteloids relative to other carnivoran groups.
Evolving financial behavior, an unpredictable public policy atmosphere, and an unparalleled global pandemic have collaborated to disrupt nonprofit fundraising. The COVID‐19 pandemic alone exacerbated consumer demands for nonprofit services while curtailing nonprofit organizations' ability to fundraise. Without fundraising, nonprofit organizations cannot achieve their mission or support their causes, leading to a precarious situation for societal well‐being. Meanwhile, consumers are changing their financial behaviors, with younger generations often going cashless. At the same time, governments continue to change policies that affect nonprofit organizations. In keeping with the transformative consumer research movement, the present study provides a conceptual framework for the state of nonprofit fundraising amid the challenges associated with changes in financial behavior and public policy, coupled with the effects of the global pandemic. Marketing strategies for fundraising success are presented to aid nonprofits going forward and serve societal interests.
The infrequency of a total solar eclipse renders the event novel to those animals that experience its effects and, consequently, may induce anomalous behavioral responses. However, historical information on the responses of animals to eclipses is scant and often conflicting. In this study, we qualitatively document the responses of 17 vertebrate taxa (including mammals, birds, and reptiles) to the 2017 total solar eclipse as it passed over Riverbanks Zoo and Garden in Columbia, South Carolina. In the days leading up to the eclipse, several focal teams, each consisting of researchers, animal keepers, and student/zoo volunteers conducted baseline observations using a combination of continuous ad libitum and scan sampling of each animal during closely matched seasonal conditions. These same focal teams used the same protocol to observe the animals in the hours preceding, during, and immediately following the eclipse. Additionally, for one species—siamangs (Symphalangus syndactylus)—live video/audio capture was also employed throughout observations to capture behavior during vocalizations for subsequent quantitative analysis. Behavioral responses were classified into one or more of four overarching behavioral categories: normal (baseline), evening, apparent anxiety, and novel. Thirteen of seventeen observed taxa exhibited behaviors during the eclipse that differed from all other observation times, with the majority (8) of these animals engaging in behaviors associated with their evening or nighttime routines. The second predominant behavior was apparent anxiety, documented in five genera: baboons (Papio hamadryas), gorillas (Gorilla gorilla gorilla), giraffes (Giraffa cf. camelopardalis), flamingos (Phoenicopterus ruber), and lorikeets (Trichoglossus moluccanus and Trichoglossus haematodus). Novel behaviors characterized by an increase in otherwise nearly sedentary activity were observed only in the reptiles, the Galapagos tortoise (Chelonoidis nigra) and the Komodo dragon (Varanus komodoensis). While the anthropogenic influences on animal behaviors—particularly those relating to anxiety—cannot be discounted, these observations provide novel insight into the observed responses of a diverse vertebrate sample during a unique meteorological stimulus, insights that supplement the rare observations of behavior during this phenomenon for contextualizing future studies.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.