Advances in studies of sociality in nocturnal prosimians.
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Animals↗
Biomedical subjects
E J Sterling
Publications and source records attributed to E J Sterling.
Spatial patterning in nocturnal prosimians: a review of methods and relevance to studies of sociality.
Patterns of home range overlap between individuals are key parameters used in discussions of sociality in nocturnal prosimians. Despite the importance of space use variables in defining social structure in nocturnal prosimians, researchers have yet to reach a consensus concerning the most reliable techniques for measuring patterns of home range use. In this paper, we review the methods used in 27 studies of nocturnal prosimian ranging behavior published since 1977. We discuss the usefulness and limitations of the various methods of data collection (radio tracking, trap mark, and identification of sleeping site locations) and data analysis (minimum convex polygon method, minimum concave polygon method, and quadrat analysis) used in these studies. We conclude that the most effective method for gathering data on individual movements and social interactions is direct observation of individual radio tagged animals during all-night follows. In those cases where radio tracking and/or all-night follows are not possible, trap mark techniques can be used, although they tend to greatly underestimate home range size. We recommend that data collected on nocturnal prosimian ranging behavior be analyzed using the minimum convex polygon method, quadrat analysis, and, perhaps, one other of the more mathematically sophisticated techniques popular in studies of non-primate mammals. Finally, we urge researchers to employ standardized methods of data collection and data analysis in future studies of range use in nocturnal prosimians. Without standardization of methods, quantitative comparisons of the findings from different studies are biologically meaningless and prevent cross-species comparisons of space use and its relation to sociality.
Animals↗
High-performance liquid chromatographic assay for Melanotan-1 ([Nle4-DPhe7]alpha-melanocyte-stimulating hormone) in biological matrices.
The overall objective of this research was to develop a sensitive, specific, and stability-indicating HPLC assay for the determination of the [Nle4-DPhe7]alpha-melanocyte-stimulating hormone analog known as Melanotan-1 (MT-1) in biological matrices, i.e., cell culture transport media and human plasma. Separation was accomplished isocratically within 8.0 min using a C8 reversed-phase column. The mobile phase consisted of 0.1 M phosphate buffer-acetonitrile (80:20, v/v) with 18 microliters/l triethylamine at pH 2.50. The flow-rate was 1 ml/min with detection at 214 nm. Standard curves (n = 5) were linear over the concentration range 100-1000 ng/ml. The precision, accuracy, intra- and inter-day variations were good with C.V.s typically within 8.7% for concentrations greater than 100 ng/ml. This method was applied to a study of the transport of MT-1 in the Caco-2 cell monolayer model.
Amino Acid Sequence↗
Aye-ayes: out of the dark and into the light?
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Animals↗
Evidence for nonseasonal reproduction in wild aye-ayes (Daubentonia madagascariensis).
The lemurs of Madagascar typically exhibit a strictly seasonal pattern of breeding, with a limited number of successive estrous cycles occurring at a particular time of the year, which varies from species to species. Previous reports indicated that aye-ayes also exhibit such a strictly seasonal polyestrous pattern. Data from the author's 2-year field study of aye-ayes on the island of Nosy Mangabe, combined with information from recently initiated captive breeding programs, now indicate that this species in fact shows an extended breeding season or even year-round breeding. Actual mating or signs of estrus were observed in the field throughout a 5-month period (October-February). Further, data from captured pregnant females and young offspring indicate that births take place during the period from February to September. Apart from aye-ayes, extended breeding periods have been reported for wild Eulemur coronatus and for captive Eulemur fulvus and Mirza coquereli. Analysis of information on seasonal variation in food availability for aye-ayes and other lemurs provides no clear evidence that the degree of seasonality of breeding is directly dependent on ecological factors.
Animals↗
Dietary intake, food composition and nutrient intake in wild and captive populations of Daubentonia madagascariensis.
Data are presented on dietary and nutrient intake in a wild population of aye-ayes. Study animals ate 4 main food types: seeds, nectar, fungus and insect larvae. Calculated calorie intake was slightly lower during the cold season than during the hot, wet and the hot, dry seasons. Total intakes almost doubled to compensate for the lower energy content of the diet during the cold season. Comparison of natural and captive diets suggests that maintenance and even growth requirements of aye-ayes can be met by relatively low-fat, low-protein diets. Daily energy requirements were estimated to average about 280 kcal metabolizable energy/day. Animals in the wild were estimated to eat between 260 and 342 kcal, while captive animals consumed 260 kcal/day.
Animal Feed↗
Aye-ayes: specialists on structurally defended resources.
During the course of a 2-year field study on aye-ayes (Daubentonia madagascariensis), data were collected on dietary composition, food acquisition and structural properties of food resources. Aye-ayes in this study sampled remarkably few species from a variety of food types. A majority of these resources were heavily structurally defended and therefore difficult of access for other mammals. Aye-ayes used their modified finger and anterior teeth to harvest most of these resources.
Animals↗
Tool use, aye-ayes, and sensorimotor intelligence.
Humans, chimpanzees, capuchins and aye-ayes all display an unusually high degree of encephalization and diverse omnivorous extractive foraging. It has been suggested that the high degree of encephalization in aye-ayes may be the result of their diverse, omnivorous extractive foraging behaviors. In combination with certain forms of tool use, omnivorous extractive foraging has been hypothesized to be linked to higher levels of sensorimotor intelligence (stages 5 or 6). Although free-ranging aye-ayes have not been observed to use tools directly in the context of their extractive foraging activities, they have recently been reported to use lianas as tools in a manner that independently suggests that they may possess stage 5 or 6 sensorimotor intelligence. Although other primate species which display diverse, omnivorous extractive foraging have been tested for sensorimotor intelligence, aye-ayes have not. We report a test of captive aye-ayes' comprehension of tool use in a situation designed to simulate natural conditions. The results support the view that aye-ayes do not achieve stage 6 comprehension of tool use, but rather may use trial-and-error learning to develop tool-use behaviors. Other theories for aye-aye encephalization are considered.
Animals↗