Increased physical activity is not related to markers of cardiometabolic health in two lemur species
Insufficient physical activity is a major risk factor for cardiometabolic disease (i.e., unhealthy weight gain, heart disease, and diabetes) in humans and may also negatively affect health of primates in human care. Effects of physical activity on energy expenditure and cardiometabolic health are virtually unstudied in nonhuman primates. We investigated physical activity and metabolic markers […]
Evaluation of plasma corticosteroids associated with performance-based activity in bottlenose dolphins (Tursiops truncatus)
This study was designed to evaluate metabolic-related changes in circulating concentrations of cortisol and aldosterone in bottlenose dolphins before vs. after performance-based physical activities associated with dolphin–human swim interactions. Secondarily, samples collected before the swim interactions were used to evaluate the effect of gender, age and aquarium location on corticosteroid concentrations. A total of 31 […]
Behavioral and Physiological Significance of Minimum Resting Metabolic Rate in King Penguins
Because fasting king penguins (Aptenodytes patagonicus) need to conserve energy, it is possible that they exhibit particularly low metabolic rates during periods of rest. We investigated the behavioral and physiological aspects of periods of minimum metabolic rate in king penguins under different circumstances. Heart rate (f(H)) measurements were recorded to estimate rate of oxygen consumption […]
The energetic savings of sleep versus temperature in the Desert Iguana (Dipsosaurus dorsalis) at three ecologically relevant temperatures
One of the proposed ecological functions of sleep is to conserve energy. The majority of studies that support this theory have been done on endothermic animals whose body temperatures drop during sleep due to the reduced neurological control of thermoregulation. In the present study, we examined typical temperatures to which the Desert Iguana, Dipsosaurus dorsalis, […]
The link between metabolic rate and body temperature in galliform birds in thermoneutral and heat exposure conditions: The classical and phylogenetically corrected approach
Three galliform species (grey partridges, ring-necked pheasants, and king quail) were involved in body temperature and resting metabolic rate measurements over a broad range of ambient temperatures (20-45 degrees C). At thermoneutrality, inter-species differences in colonic temperature, as well as in metabolic rate, were observed. During heat exposure, all species reacted by elevating their body […]
Tooth loss rate from two captive sandtiger sharks (Carcharias taurus)
Abstract 10.1002/(SICI)1098-2361(1999)18:43.3.CO;2-4 For 6 months, two sandtiger sharks (Carcharias taurus) were held captive together in a small enclosure at the Lisbon Zoo. During that period, the gravel was monitored daily for teeth shed by the animals. At the end of their stay, the number of teeth divided by the number of days yielded a tooth […]
Bioenergetics of the bull shark, Carcharhinus leucas, maintained in captivity
Abstract 10.1002/zoo.1430130209.abs Understanding the energy requirements for captive sharks is important for their successful long-term maintenance. This information is critical in assessing the health of the animals and the suitability of their environment. We studied five bull sharks (Carcharhinus leucas) for up to 7 years in a 2.5 × 106 liter oceanarium. Individual animal feedings […]
Estimating metabolic heat loss in birds and mammals by combining infrared thermography with biophysical modelling☆
Infrared thermography (IRT) is a technique that determines surface temperature based on physical laws of radiative transfer. Thermal imaging cameras have been used since the 1960s to determine the surface temperature patterns of a wide range of birds and mammals and how species regulate their surface temperature in response to different environmental conditions. As a […]
Stress revisited: A critical evaluation of the stress concept
With the steadily increasing number of publications in the field of stress research it has become evident that the conventional usage of the stress concept bears considerable problems. The use of the term ‘stress’ to conditions ranging from even the mildest challenging stimulation to severely aversive conditions, is in our view inappropriate. Review of the […]
Metabolism and thermoregulation during fasting in king penguins, Aptenodytes patagonicus, in air and water
We measured oxygen consumption rate (O2) and body temperatures in 10 king penguins in air and water. O2 was measured during rest and at submaximal and maximal exercise before (fed) and after (fasted) an average fasting duration of 14.4 ± 2.3 days (mean ± 1 SD, range 10–19 days) in air and water. Concurrently, we […]