A case of non-scaling in mammalian physiology? Body size, digestive capacity, food intake, and ingesta passage in mammalian herbivores☆
As gut capacity is assumed to scale linearly to body mass (BM), and dry matter intake (DMI) to metabolic body weight (BM0.75), it has been proposed that ingesta mean retention time (MRT) should scale to BM0.25 in herbivorous mammals. We test these assumptions with the most comprehensive literature data collations (n=74 species for gut capacity, […]
Estrogenic plant consumption predicts red colobus monkey (Procolobus rufomitratus) hormonal state and behavior
Numerous studies have examined the effects of anthropogenic endocrine disrupting compounds; however, very little is known about the effects of naturally occurring plant-produced estrogenic compounds (i.e., phytoestrogens) on vertebrates. To examine the seasonal pattern of phytoestrogen consumption and its relationship to hormone levels (407 fecal samples analyzed for estradiol and cortisol) and social behavior (aggression, […]
Variation in Growth and Potentially Associated Health Status in Hermann’s and Spur-Thighed Tortoise (Testudo hermanni and Testudo graeca)
Captive reptiles often show higher growth rates than in the wild, possibly due to higher feeding intensity. Although health problems are usually linked to inappropriate diets, fast growth itself, such as triggered by appropriate diets fed in high amounts, has traditionally also been considered unfavorable for tortoises. We document growth rates (based on age and […]
Digestive physiology of the plains viscacha (Lagostomus maximus): A large herbivorous hystricomorph rodent
Plains viscachas (Lagostomus maximus) are large South American, fossorial rodents susceptible to diabetic cataracts. Various aspects of their digestive physiology were studied in three different experiments with nine male and seven female adult animals and six different diets (total n of feeding trials = 35). Viscachas achieved mean retention times of 23–31 hr, which is of a magnitude […]