By studying how captive animals use outdoor space, we can determine which areas fulfill their biological and behavioral needs to improve enclosure design for animal welfare and visitor experience. The aim of the study was to determine the differential use of outdoor space in a mixed exhibit of captive ring-tailed lemurs (Lemur catta) and red ruffed lemurs (Varecia rubra), and to assess both the effect of adding environmental enrichment and possible visitor and meteorological effects on the lemurs’ use of space and behavior. For one month, five-minute interval scan sampling was used to record lemur location and behavior, as well as the meteorological conditions and presence of zoo visitors in the lemurs’ outdoor enclosure. That baseline was followed by four alternating two-week periods of food or structural enrichment, both with and without visitors. Enrichment increased the lemurs’ use of the enriched sectors, decreased resting, and increased locomotion. Structural enrichment increased their exploratory behaviors and stimulated arboreal locomotion. Both species preferred sunny and warm conditions for sunbathing and resting, while moving more around the enclosure in cooler and cloudier weather. The visitor effect on the lemurs’ use of space was weaker than the effects of enrichment and meteorological conditions. The availability of areas to hide and possible habituation to humans may have played a role in the reduced visitor effect. The results of the study showed inter-specific differences in the lemurs’ use of space and behavior and a complex combined effect of enrichment, visitor presence and meteorological conditions.

Indiana University-Purdue University Indianapolis (IUPUI) / Seven human alcohol dehydrogenase genes (which encode the primary enzymes involved in alcohol metabolism) are grouped into classes based on function and sequence identity. While the Class I ADH isoenzymes contribute significantly to ethanol metabolism in the liver, Class IV ADH isoenzymes are involved in the first-pass metabolism of ethanol. It has been suggested that the ability to efficiently oxidize ethanol occurred late in primate evolution. Kinetic data obtained from the Class I ADH isoenzymes of marmoset and brown lemur, in addition to data from resurrected ancestral human Class IV ADH isoenzymes, supports this proposal--suggesting that two major events which occurred during primate evolution resulted in major adaptations toward ethanol metabolism. First, while human Class IV ADH first appeared 520 million years ago, a major adaptation to ethanol occurred very recently (approximately 15 million years ago); which was caused by a single amino acid change (A294V). This change increases the catalytic efficiency of the human Class IV enzymes toward ethanol by over 79-fold. Secondly, the Class I ADH form developed 80 million years ago--when angiosperms first began to produce fleshy fruits whose sugars are fermented to ethanol by yeasts. This was followed by the duplication and divergence of distinct Class I ADH isoforms--which occurred during mammalian radiation. This duplication event was followed by a second duplication/divergence event which occurred around or just before the emergence of prosimians (some 40 million years ago). We examined the multiple Class I isoforms from species with distinct dietary preferences (lemur and marmoset) in an effort to correlate diets rich in fermentable fruits with increased catalytic capacity toward ethanol oxidation. Our kinetic data support this hypothesis in that the species with a high content of fermentable fruit in its diet possess greater catalytic capacity toward ethanol.