Eulemur Fulvus Research Articles

Telemetered electromyography of the fast and slow extensors of the leg of the brown lemur (Lemur fulvus).

Quantitative telemetered electromyography from the four heads of the quadriceps femoris (vastus medialis, rectus femoris, vastus intermedius and vastus lateralis) during normal postures and locomotion (quadrupedal resting, walk/run, gallop and leaping) is presented for the brown lemur, Lemur fulvus. The vastus intermedius is the sole contributor to muscle recruitment during quadrupedal resting postures. It exhibits consistently high levels of electrical activity during all locomotory behaviour. The vastus medialis is recruited least among these muscles during walk/run and tends to be 'saved' for galloping and leaping. The rectus femoris and vastus lateralis are recruited at similarly high levels during all phasic activities. The rectus femoris appears to be used eccentrically, storing 'elastic strain energy' during all phasic activities. The vastus lateralis combines exceptionally high potential effective force with relatively high potential velocity and resistance to fatigue and probably develops the majority of force in all phasic activities. These results support previously documented structural and histochemical data that imply a functional division of labour among these muscle synergists.

A safe technique for collecting semen from Lemur fulvus mayottensis.

A safe technique for collecting semen from Lemur fulvus mayottensis.

Successful artificial insemination in Lemur fulvus mayottensis.

A method is reported for collection of sperm by electrostimulation or prostatic massage in order to carry out artificial in utero insemination in Lemur fulvus mayottensis. Using fresh sperm, one success out of 7 attempts was obtained, although it was achieved with a vesiculectomized male.

Soil Consumption of Two Groups of Semi‐free‐ranging Lemurs {Lemur catta and Lemur fulvus)

AbstractSoil consumption of two Malagasy lemurs, Lemur catta and Lemur fulvus was observed in an enclosure simulating a natural habitat at Duke University Primate Center (Durham, USA). Soil eaten by L. catta contained more Na than random soil samples. Concentrations of the four major minerals in soil eaten by L. fulvus did not differ from random samples. L. fulvus stopped soil ingestion in summer when they ate large amounts of foliage rich in K and Mg, also in winters after being fed with MgCl2. It is suggested that, in this study, soil was consumed in relation to its mineral content and not for physical properties related to its structure. Some non physiological factors that might influence food selection are discussed.

A possible role of plantations for primate conservation in Madagascar.

The utilization of eucalyptus plantations by seven sympatric species of prosimians was studied in the eastern rainforest of Madagascar. The species were Avahi laniger, Cheirogaleus major, Hapalemur griseus, Indri indri, Lemur fulvus, Lepilemur mustelinus, and Microcebus rufus. None of the lemurs was ever found in young eucalyptus plantations with little undergrowth. This was mainly due to the lack of travel opportunities within the shrub layer and between the shrubs and the canopy. Food (mainly berries) is seasonally available in the shrub layer but cannot be exploited because frugivorous lemurs cannot reach it. Old eucalyptus plantations with dense undergrowth are used by all prosimian species. They provide food as well as travel and resting facilities. Mixed tree plantations in the western part of Madagascar were used by groups of Lemur fulvus, Lepilemur mustelinus, and Propithecus verreauxi. According to these results, old eucalyptus plantations and mixed tree species plantations could be used to provide firewood and construction wood for the human population. They also might extend the habitat for lemurs and serve as buffers against human disturbance.

Measurement of body segment mass, center of gravity, and determination of moments of inertia by double pendulum in Lemur fulvus.

The collection of data on physical parameters of body segments is a preliminary critical step in studying the biomechanics of locomotion. Little data on nonhuman body segment parameters has been published. The lack of standardization of techniques for data collection and presentation has made the comparative use of these data difficult and at times impossible. This study offers an approach for collecting data on center of gravity and moments of inertia for standardized body segments. The double swing pendulum approach is proposed as a solution for difficulties previously encountered in calculating moments of inertia for body segments. A format for prompting a computer to perform these calculations is offered, and the resulting segment mass data for Lemur fulvus is presented.

Prosimian hemoglobins. III. The primary structures of the duplicated α-globin chains of Lemur variegatus

The amino acid sequences of the α chains of hemoglobins purified from Lemur variegatus erythrocytes have been determined. The sequences were determined primarily from peptides generated from treatment of the isolated α chains with cyanogen bromide or warm formic acid. The ordering of the peptides from both α globins was based on the homology between lemur hemoglobins and those of other primates. The genetic difference at position 15 (Asn vs. Lys) explains the phenotypic characteristic of two hemoglobin species during alkaline electrophoresis. The function of certain residues is discussed in the context of other known sequences. The dispersion of the amino acid changes noted in lemur species falls mostly within the first 75 residues of the α chain (exons 1 and 2). The extent of divergence of the L. variegatus α-globin chains from the Lemur fulvus α globin is similar to that seen for the β-globin chains of these species. This degree of separation (11–16 residues) is consistent with an extended period of independent evolution by these congeneric species after their divergence.

Architectural and histochemical diversity within the quadriceps femoris of the brown lemur (Lemur fulvus).

Physiologically related features of muscle morphology are considered with regard to functional adaptation for locomotor and postural behavior in the brown lemur (Lemur fulvus). Reduced physiological cross-sectional area, estimated maximum excursion of the tendon of insertion, length of tendon per muscle fasciculus, and areal fiber type composition were examined in the quadriceps femoris in order to assess the extent of a "division of labor" among four apparent synergists. Each of these four muscles in this prosimian primate displays a distinguishing constellation of morphological features that implies functional specialization during posture and normal locomotion (walk/run, galloping, leaping). Vastus medialis is best suited for rapid whole muscle recruitment and may be reserved for relatively vigorous activities such as galloping and leaping (e.g., small cross-sectional area per mass, long excursion, predominance of fast-low oxidative fibers, relatively little tendon per fasciculus). In theory, rectus femoris could be employed isometrically in order to store elastic strain energy during all phasic activities (e.g., large cross-sectional area per mass, short excursion, predominance of fast-high oxidative fibers, large amount of tendon per fasciculus). Vastus intermedius exhibits an overall morphology indicative of a typical postural muscle (e.g., substantial cross-sectional area, short excursion, predominance of slow-high oxidative fibers, large amount of tendon per fasciculus). The construction of vastus lateralis reflects an adaptation for high force, relatively high velocity, and resistance to fatigue (e.g., large cross-sectional area, long excursion, most heterogeneous distribution of fiber types, large amount of tendon per fasciculus); this muscle is probably the primary contributor to a wide range of locomotor behaviors in lemurs. Marked dramatic architectural disparity among the four bellies, coupled with relative overall fiber type heterogeneity, suggests the potential for exceptional flexibility in muscle recruitment within this mass. One interpretation of this relatively complex neuromuscular organization in the brown lemur is that it represents an adaptation for the exploitation of a three-dimensional arboreal environment by rapid quadrupedalism and leaping among irregular and spatially disordered substrates.

Feeding behavior ofLemur catta andLemur fulvus

The feeding behavior of two sympatric species of lemurs, Lemur cattaand Lemur fulvus,was studied in an enclosure simulating a natural habitat at the Duke University Primate Center. L. fulvusspent less time feeding during the day than L. catta.But the former species ate more fruit and had longer feeding bouts on preferred food items than L. catta.They also had a shorter food passage time than L. cattaand their choice of resting places was more influenced by food distribution. Furthermore, the two lemur species ate parts of different plant species and showed different reactions to chemical plant components. According to these results, L. fulvusis a more conservative feeder than L. catta.These interspecific differences in feeding behavior may be one of a number of differences that allow the two species to coexist. In allopatry, however, L. fulvusmay also adopt feeding patterns similar to those of L. catta.But L. cattawas never found to change its feeding strategies in different areas. It may be this option of L. fulvusto adopt different feeding strategies in different situations that allows this species to have the widest range of all Malagasy lemurs.

Arboviruses and lemurs in Madagascar: experimental infection of Lemur fulvus with yellow fever and West Nile viruses.

In previous serological surveys of lemurs in Madagascar, antibodies against flaviviruses were frequently detected. To examine the epidemiological role of Lemur fulvus, experimental infections with yellow fever (YF) virus and West Nile (WN) virus were performed. YF and WN infections were clinically unapparent. A 3 to 4-day-long viremia, with moderate levels was observed with YF virus. WN virus, especially the strain isolated in Madagascar, provoked a 4 to 6-day-long viremia sufficient to infect Aedes aegypti. In all experiments, the antibody response was studied during the following weeks by 3 methods. The results led to the conclusion that Malagasy lemurs could act as amplifying hosts for WN virus present in Madagascar, and as hosts for YF virus if it were introduced on the island. The epidemiological role of these primates is discussed according to their ecology and their contact with potential mosquito vectors in forest areas of Madagascar.

Interlimb coordination and gait in the brown lemur (Lemur fulvus) and the talapoin monkey (Miopithecus talapoin)

AbstractPatterns of interlimb coordination based on telemetered electromyography of extensor muscles are described for the brown lemur (Lemur fulvus) and the talapoin monkey (Miopithecus talapoin) in order to address the issue of possible motor programs for quadrupedal stepping in primates. Differences in modal patterns of ipsilateral limb coupling (phase intervals) between walking and galloping indicate that gait‐specific programs do exist in primates, especially for symmetrical gaits. These preferred patterns distinguish primates from most other mammals (e.g., the domestic cat), but do not rule out the possibility of subtle differences among primates in species‐specific mechanisms of neural control. Variability about the preferred modes is better interpreted as an expression of the flexibility or facultative capabilities of the neural mechanisms controlling locomotion than as “errors” in the motor program.

Meat eating and predation in captive‐born semi‐free‐ranging Lemur fulvus and caged Lemur macaco

AbstractA group of brown lemurs, Lemur fulvus, and a group of black lemurs, Lemur macaco, at the Duke University Center for the Study of Primate Biology and History have been observed to capture and eat birds and lizards. Although vertebrate prey are not unusual for many carnivorous prosimians, folivorous prosimians never have been observed to take vertebrates in the wild and rarely even insects.

Oxygen Consumption in Lemur fulvus: Deviation from the Ideal Model

The pattern of oxygen consumption (![Graphic][1] ) for Lemur fulvus deviated from the Scholander-Irving model of energetics. Minimal rate of metabolism was 0.139 cm2 O2 g−1 h−1, which is 28% of the basal value expected from the Kleiber relationship for a mammal of 2.33 kg. This minimal rate occurred at ambient temperatures ( Ta ) from 30–40°C; thermal conductance (C) at Ta of 22–30°C was 0.235 cm2 O2 g−1 h−1 °C−1. Deviation from the standard model occurred most notably at Ta < 22°C as rate of metabolism and thermal conductance decreased. At Ta = 0–7°C, #### was 0.152 cm3 O2 g−1 h−1, and C was 0.0037 cm3 O2 g−1 h−1 °C−1, which are 31% and 18% of the expected values, respectively. Below 0°C, #### increased. A high body temperature, 38.2°C, was maintained at Ta from −2 to 40°C. The low minimal rate of metabolism of L. fulvus may be partially explained by its folivorous diet. It is also possible the minimal rate was a depressed rate, below that referred to as basal in the standard model. Low #### and C at cold Ta 's probably resulted from decreased peripheral circulation and a heat conserving posture at abnormally cold environmental temperatures. [1]: /embed/inline-graphic-1.gif

A DNA fragment from the human X chromosome short arm which detects a partially homologous sequence on the Y chromosomes long arm.

An X linked human DNA fragment (named DXS31 ) which detects partially homologous sequences on the Y chromosome has been isolated. Regional localisation of the two sex linked sequences was determined using a panel of rodent-human somatic cell hybrids. The X specific sequence is located at the tip of the short arm ( Xp22 .3-pter), i.e. within or close to the region which pairs with the Y chromosome short arm at meiosis. However the Y specific sequence is located in the heterochromatic region of the long arm ( Yq11 -qter) and lies outside from the pairing region. DNAs from several XX male subjects were probed with DXS31 and in all cases a double dose of the X linked fragment was found, and the Y specific fragment was absent. DXS31 detects in chimpanzee a male-female differential pattern identical to that found in man. However results obtained in a more distantly related species, the brown lemur, suggest that the sequences detected by DXS31 in this species might be autosomally coded. The features observed with these X-Y related sequences do not fit with that expected from current hypotheses of homology between the pairing regions of the two sex chromosomes, nor with the pattern observed with other X-Y homologous sequences recently characterized. Our results suggest also that the rule of conservation of X linkage in mammals might not apply to sequences present on the tip of the X chromosome short arm, in bearing with the controversial issue of steroid sulfatase localisation in mouse.

The banded chromosomes of coquerel’s sifaka,Propithecus verreauxi coquereli (Primates, Indriidae)

The karyotype of Propithecus verreauxi coquereli isdescribed in this report using G-, Q-, and C-banding and silver staining for nucleolus organizer regions. The banded chromosomes of P. v. coquereli(family Indriidae) are compared with those of Lemur fulvus fulvus(family Lemuridae), revealing few karyotypic similarities between the two groups and suggesting a wellestablished phylogenetic divergence between these families.

Food choice from endemic North Carolina tree species by captive prosimians (Lemur fulvus).

Seven captive-born lemurs (Lemur fulvus) at the Duke University Primate Center were presented with leaves of different maturity from five species of North Carolina trees. The animals demonstrated three distinct behaviors toward the novel plant material. They sniffed, tasted, and/or ingested it. New leaves were sniffed, but little tasting and ingestion was observed. Intermediate pine needles were sniffed and ingested but little tasted. Mature leaves were sniffed equally, but the mature leaves of tulip trees and honeysuckle were tasted significantly more than pine, sweetgum, and red maple. Pine, sweetgum, and red maple were ingested significantly more than tulip trees and honeysuckle. Male lemurs ate significantly more mature pine needles and new sweetgum leaves than did the females. Chemical analysis of these plant materials indicated that the new and mature leaves of tulip tree and honeysuckle contained alkaloids. Captive-born lemurs apparently use their sense of smell and taste in choosing what to eat and seem just as capable as free-ranging animals in finding food when faced with the chemical defenses that protect trees from insect predation.

Freeze‐mark techniques applied to mammals at the Santa Barbara Zoo

AbstractDichlorodifluoromethane (CCl2F2) was evaluated as a means of freeze‐marketing ring‐tailed lemurs (Lemur catta), brown lemurs (L. fulvus), and Parma wallabys (Wallabia parma). Application times of 3–6 sec on unshaven lemurs resulted in successful markings, but the wallabys failed to respond with growth of white hair to application times of 3–10 sec. The freeze‐marking process caused little physical discomfort when applied to fleshy regions, and the marks appear to be permanent.

Effects of inbreeding on infant mortality in captive primates

Breeding records for 16 primate colonies representing six families and both suborders were obtained from 10 institutions breeding primates in captivity and from the international studbook on one endangered species. Inbreeding coefficients relative to the founding population were calculated for each individual born. Individuals with an inbreeding coefficient of zero were classified as “noninbred” those with inbreeding coefficients greater than zero, as “inbred.” Infant mortality was defined as all deaths prior to the age of 6 months. Infant mortality of inbred young was higher than that of noninbred young in 15 of the 16 colonies surveyed (P =0.0003, one-tailed sign test). The higher mortality rate of the inbred young was significant by a Fisher’s exact test with a probability less than or equal to 0.05 in five of the individual colonies: Lemur fulvus, Saguinus fuscicollis illigeri, Saguinus fuscicollis, Leontopithecus rosalia,and Mandrillus sphinx.

Isolation and sequence analysis of a hybrid δ-globin pseudogene from the brown lemur

The β-globin gene cluster of the brown lemur, a prosimian, is very short and contains a single ϵ-, γ- and β-globin gene, with an additional β-related gene sequence between the γ- and β-globin genes. Brown lemur DNA was cloned into the bacteriophage vector λL47.1 and a recombinant was isolated which contained an 11 × 10 3 base insert including the β-globin gene and the additional putative β-globin pseudogene. The nucleotide sequence of this β-related gene was completely determined. A complete gene sequence was found, containing four frameshift mutations sufficient to establish its pseudogene status. The gene was interrupted by two intervening sequences with sizes and locations typical of mammalian β-related globin genes. The pseudogene sequence was compared in detail with human ϵ-, γ-, δ- and β-globin genes. The beginning of the pseudogene, from the 5′ flanking region to the second exon, was homologous to the corresponding regions of the human ϵ- and γ-globin genes. In contrast, the second intron, third exon and 3′ flanking region showed a remarkably close homology to the δ-globin, but not β-globin, gene of man. This suggests that the δ-globin gene is not the product of a recent gene duplication, but instead is present in most or all primates. This gene has been silenced on at least two separate occasions in primate evolution (in lemurs and in old world monkeys). In addition, the 5′ end of the lemur ψδ gene appears to have exchanged sequences with an ϵ- or γ-globin gene, and an analogous exchange with the β-globin gene seems to have occurred recently in the human δ-globin gene. The evolution and function of the δ-globin gene are discussed.

Energy Maximizers and Time Minimizers: Theory and Reality

Energy Maximizers and Time Minimizers: Theory and Reality