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 […]

Guest editorial: Ruminant physiology; digestion, metabolism and effects of nutrition on reproduction and welfare


Metabolomics Has Great Potential for Clinical and Nutritional Care and Research with Exotic Animals

This essay explores the potential of metabolomics for exotic animal research in a zoological setting. Metabolomics is a suite of analytical tools aimed at gaining a holistic understanding of animal metabolism without prior knowledge of the compounds to be measured. These metabolic fingerprints can be used to define normal metabolism for an unstudied species, to […]