PSGB Winter Meeting 1997

3 DECEMBER, 1997

To be held in the Meeting Rooms of the Zoological Society of London, Regent's Park, London NW1 4RY. Organised by Dr Paul E. Honess

NEW PERSPECTIVES ON NOCTURNAL PRIMATES

9:15-9:45 Registration

9:45-10:00 Organiser's introduction

Chair: Paul Honess

10:00-10:25 Simon Bearder (Oxford Brookes University)

Redefining nocturnal diversity: Prosimian primates and other mammals

10:25-10:50 Caroline Harcourt

The conservation of nocturnal primates

10:50-11:20 COFFEE

Chair: Hilary Box

11:20-11:45 Deborah Curtis (Universitat Zurich-Irchel, Switzerland)

A third activity pattern in primates: cathemerality in lemurs

11:45-12:10 Elke Zimmermann (Tieraerztliche Hochschule Hannover, Germany)

Diversity and speciation in nocturnal Malagasy lemurs: an

integrative approach

12:10-12:35 Laura Harste (University of Liverpool)

Social cohesion in mixed-sex and all-male groups of mouse lemurs

(Microcebus murinus): evidence from observations on tactile

communication in captivity

12:35-12:50 Award of the Napier Medal by Alan Dixson

12:50-14:00 LUNCH

Chair: Simon Bearder

14:00-14:25 Robin Crompton (University of Liverpool)

Anomalous saltatory locomotor adaptation in two small-bodied,

folivorous, nocturnal lemurs

14:25-14:50 Lon Alterman (Clarke College, Iowa, USA)

Description and survey of three Nycticebus species in Bolikhamxay

Province, Laos

14:50-15:15 Paul Honess (Oxford Brookes University)

Taxonomic revision of the galagos: academic indulgence or

practical necessity?

15:15-15:45 TEA

Chair: Alan Dixson

15:45-16:10 Caroline Ross (Roehampton Institute London)

Strepsirhine infant care and life history evolution

16:10-16:35 Michelle Bayes (Institute of Zoology, London)

Phylogenetic relationships among the prosimians: understanding

primate origins and evaluating cryptic species

16:35-18:00 POSTER SESSION & WINE RECEPTION

ABSTRACTS FOR ORAL PAPERS:

DESCRIPTION AND SURVEY OF THREE NYCTICEBUS SPECIES IN BOLIKHAMXAY PROVINCE, LAOS

Lon Alterman (1) and Benjamin Z. Freed (2)

(1) Clarke College, Dubuque Iowa, USA. E-mail: lalterma@keller.clarke.edu

(2) Washington University, St. Louis, Missouri, USA. E-mail: bfreed@artsci.wustl.edu

The genus Nycticebus (slow loris) is generally thought to contain only two species, Nycticebus coucang and N. pygmaeus. Researchers from China and Viet Nam, however, have suggested that other slow loris species or subspecies exist. Schwartz and Beutel (1995) presented evidence of unidentified members of the genus in osteological collections. We describe the pelage, weight, dental morphology, and local geographic distribution of what we suggest is a third distinct slow loris species. Morphological descriptions of this species are derived from ten captive and six wild individuals from Bolikhamxay Province, in central Laos. Descriptions of local slow loris distribution are derived from initial surveys that we conducted during 1996-1997.

From our initial analyses, we suggest the third slow loris species: 1) differs from the others in pelage, body size, and anterior dentition; 2) does not co-occur with N. pygmaeus; 3) may or may not co-occur with N. coucang; and 4) may correspond to that species identified by Dao (1960).

REDEFINING NOCTURNAL DIVERSITY: PROSIMIAN PRIMATES AND OTHER MAMMALS

Simon K. Bearder

Nocturnal Primate Research Group, Anthropology Department, Oxford Brookes University, Oxford OX3 0BP. E-mail: skbearder@brookes.ac.uk

At a time when new species of dayliving primates are still being found on a regular basis, it is reasonable to suppose that even more nocturnal species remain to be discovered. They are easily overlooked for 3 main reasons: they are hard to see; their appearence can be deceptive and relatively few populations have been studied in any depth. Nevertheless, the view that prosimian primates are a conservative group of primitive survivors can be challenged by work which shows that they are an ecologically and socially diverse radiation, comparable to that of the monkeys and apes, but founded on specialisations for a nocturnal lifestyle.

Just as monkeys and apes have a long history of adaptation to diurnal niches, with some recent reversions to nocturnality, the lemurs, lorises and tarsiers can be characterised by their long history of specialisation to nocturnal niches, with some secondary shifts to more diurnal habits. This paper explores the apparent paucity of species among nocturnal primates compared to their diurnal counterparts and predicts substantial changes in the future taxonomy and phylogenetic arrangement of both prosimian primates and nocturnal forest mammals in general.

PHYLOGENETIC RELATIONSHIPS AMONG THE PROSIMIANS: UNDERSTANDING PRIMATE ORIGINS AND EVALUATING CRYPTIC SPECIES.

Michelle K. Bayes (1), Simon K. Bearder (2) and Mike W. Bruford (1)

(1) Conservation Genetics Unit, Institute of Zoology, Regents Park, London. NW1 4RW. E-mail: suaamkb@ucl.ac.uk

(2) Nocturnal Primate Research Group, Anthropology Department, Oxford Brookes University, Oxford. OX3 0BP.

Over the last ten years, molecular data has increasingly contributed to the understanding of the evolutionary history of many groups (Avise, 1994). One application of such phylogenies has been the study of cryptic species, where genetic differentiation is not reflected in phenotypic diversity (Avise, 1994), and where reproductively isolated groups have speciated

(Daugherty, et al., 1990). This is especially the case in nocturnal mammals (Barratt et al., 1997; Bearder et al. 1995) where aspects of life history may constrain character evolution or lead to convergence. These factors may be compounded by visual cues being less important in species recognition (Littlejohn, 1989; Jones et al., 1993). The phylogenetic relationships among the lorisoid prosimians and particularly within the galagos, are largely unresolved, and this group is believed to contain cryptic species (de Boer, 1973; Bearder et al., 1995; Honess, 1996). This study uses sequence data from two mitochondrial genes, approximately 500 bp of the cytochrome b gene and the entire 12s rRNA gene to a) reconstruct a detailed phylogeny within the galagos, b) address the relationship between the galagos and African and Asian lorises, and c) attempt clarify the origins of the lemuroid prosimians.

ANOMALOUS SALTATORY LOCOMOTOR ADAPTATION IN TWO SMALL-BODIED, FOLIVOROUS, NOCTURNAL LEMURS

Warren, R.D., Li, Y. and Crompton, R.H.

The University of Liverpool, Merseyside, UK. E-mail: rhcromp@liverpool.ac.uk

Avahi occidentalis (Primates, Indriidae) and Lepilemur edwardsi (Primates, Lepilemuridae) utilize leaping as their main locomotor mode, but subsist on a low quality foodstuff, when its quality is particularly low. This appears anomalous. Leaping locomotion is acyclic, hence expensive. Energy cannot be conserved between leaps, without a mechanism for elastic (or other) storage. No such mechanism has yet been demonstrated for small-bodied prosimians. Further, Alexander demonstrated that mammals that have elongated femora, but lack extended tarsi, will not be as effective leapers as those which do. Neither species shows the degree of tarsal elongation present in other small-bodied, behaviourally specialized primate leapers, such as Tarsius bancanus (Primates, Tarsiidae) and Galago moholi (Primates, Lorisidae). Kinematic analysis of leaping shows that Lepilemur, which has a small degree of tarsal elongation, leaps in a manner similar to the tarsifulcrumating Galago moholi and Tarsius bancanus, but attains relatively shorter distances; it compensates for the energetic 'anomaly' by reducing activity levels. Avahi, however, leaps in the same manner as other, much larger members of its family, and covers large nightly distances. Body size and phylogenetic inertia both channel leaping adaptation; however, which is more significant depends on the locomotor ecology of the species under consideration.

A THIRD ACTIVITY PATTERN IN PRIMATES: CATHEMERALITY IN LEMURS

Deborah J. Curtis

Anthropological Institute, University of Zurich-Irchel, Winterthurerstrasse 190, 8057 Zurich, Switzerland. E-mail: djc@aim.unizh.ch

Over the past few decades, it has become clear that activity patterns in the Malagasy lemurs can no longer be classified simply as diurnal or nocturnal, as several species exhibit both diurnal and nocturnal behaviour. The term now generally employed to describe the exploitation of both the diurnal and nocturnal phases in lemurs is "cathemeral". During a 10-month study carried out on the mongoose lemur, Eulemur mongoz, in the seasonally dry forests of North-West Madagascar, a detailed investigation of the activity pattern was conducted in the attempt to assess (1) the proximate role of environmental cues, (2) its functional relevance and evolution and (3) seasonal shifts in the activity cycle. E. mongoz was cathemeral throughout the entire year, but exhibited a shift towards more diurnal behaviour during the wet season and towards more nocturnal behaviour during the dry season. This activity pattern appears to be coordinated with sunrise, sunset and daylength and modulated by low nocturnal light intensity in the forest during the wet season. Few advantages to food-related behaviour appear to be derived from this activity pattern. However, nocturnal behaviour during the dry season, when minimal protection is afforded by the vegetation, may allow avoidance of predation by raptors, and also represent a behavioural thermoregulatory mechanism which allows the conservation of energy by being active during the cool nights. Cathemerality should be regarded as a stable evolutionary strategy, and the ancestral activity pattern for the genus Eulemur.

THE CONSERVATION OF NOCTURNAL PRIMATES

Caroline Harcourt

Bramley Lane Farm, Higher Kinnerton, Chester. CH4 9AX.

E-mail: CHARCOURT@Compuserve.com

This talk is a general introduction to the nocturnal primates and their conservation problems. It is probably fortunate for these species that they are mostly small creatures, none much heavier than a large cat and that 'they quietly live their obscure lives in obscure places' (Harrison-Matthews, 1971). This means that few are threatened directly by humans, but, sadly, the obscure places are becoming less obscure and the nocturnal species are threatened by habitat destruction as much as the diurnal ones are. Even those very small species, eating insects and running around in secondary vegetation, often need large trees for breeding and sleeping sites. As most people are well aware, the prognosis for the long-term survival of the unique fauna and flora of Madagascar, home to many of the nocturnal prosimians is not good. The problems in this country and in other countries of Africa and Asia will be briefly outlined.

SOCIAL COHESION IN MIXED-SEX AND ALL-MALE GROUPS OF MOUSE LEMURS (Microcebus murinus): EVIDENCE FROM OBSERVATIONS ON TACTILE COMMUNICATION IN CAPTIVITY

Laura V. Harste

Population Biology Research Group, School of Biological Sciences, University of Liverpool, Nicholson Building, Bedford Street, South Liverpool, L69 3BX. E-mail: lvharste@liverpool.ac.uk

A colony of 17 mouse lemurs was observed to determine the uses of tactile communication, both active and passive, in this species. The individuals were housed in various groupings, primarily mixed-sex and all-male groups. Percentages of allogrooming and mutual grooming were recorded with one minute scan samples to determine the levels of these behaviours for both group types (all-male and mixed sex). Passive tactile behaviours were also recorded at one minute intervals, these included: looking, resting, and feeding while in zero proximity to another group member. Data collected display differences in the behavioural patterns between group types. Mixed-sex groups spent more time together during the breeding season than the rest of the year. All-male groups maintained consistently high levels of tactile contact year-round with only a slight decrease during the breeding season, in comparison to mixed-sex groups. Tactile behaviours were observed for a maximum of approximately 80% of the total waking period in both all-male and mixed-sex groups during the study. Although time spent in passive tactile behaviours was lower than observed in many higher primates, the levels observed in this species are higher than would be expected from their supposed solitary nature. These behaviours between males are also significant in light of previously suspected male intolerance to one another in this species. These findings show that mouse lemurs are not as solitary as previously suggested and that this species may elucidate primate patterns in the evolution from a solitary to a social species.

TAXONOMIC REVISION OF THE GALAGOS: ACADEMIC INDULGENCE OR PRACTICAL NECESSITY?

Paul E. Honess

Nocturnal Primate Research Group, Anthropology Department, Oxford Brookes University, Oxford OX3 0BP. Also at WildCRU, Department of Zoology, Oxford University, Oxford OX1 3PS. E-mail: phoness@brookes.ac.uk

The galagos or bushbabies (galagidae) like many other vertebrate groups have been the subject of a number of taxonomic revisions from Elliot in 1913 to Bearder et al in 1995. Since the 1930s the number of galago species recognised has increased by over 100%, from 6 to possibly over 17. Recent discoveries, including two new species from Tanzania (Honess, 1996), have continued this trend. This process has been driven by the need to produce taxonomies that reflect the diversity encountered in the field. This has been facilitated by developments in how a species is defined. Much of the recent taxonomic work on galagos has been based on comparative behaviour, ecology and morphology. This paper will show, using the galagos as an example, that these types of revision are much more than an exercise in 'splitting' and that the production of an accurate classification is essential for communication. In addition, as has been highlighted recently, accurate taxonomic work is an important element of conservation programmes. Its importance arises from the need to identify species accurately in the field and thereby determine their geographical distribution and threat status.

STREPSIRHINE INFANT CARE AND LIFE HISTORY EVOLUTION

Caroline Ross and Ann Maclarnon

School of Life Sciences, Roehampton Institute, Whitelands College, West Hill, London. SW15 3SN. E-mail: c.ross@roehampton.ac.uk

This study investigates variation in infant care behaviour in the prosimians and possible correlates with the evolution of infant carrying behaviour. The evolution of infant carrying rather than 'parking' has probably occurred several times in primate evolution and, although baby parking is thought to be ancestral to the strepsirhine group, it is likely that at least one genus (Varecia) has reverted to infant parking from a carrying ancestor. The different types of primate infant care are correlated with a number of other aspects of their reproductive and social lives. For example, 'parkers' have more concentrated milk than 'carriers', they feed their young less frequently and are more likely to be solitary. In many ways, carrying might be though to be disadvantageous to the mother as carrying is energetically costly and may impose other costs such as increased predation risk. Despite this, there is little evidence to suggest that the energetic costs of infant carrying result in either lower rates of postnatal infant growth or slower birth rates. Although infant postnatal growth rates are not significantly different, infant parkers have higher foetal growth rates than do carriers suggesting that their pre-natal maternal investment is higher. Parkers may be able to support high levels of pre-natal maternal investment because they do not have the high costs of infant carrying postnatally. We use data on ecology, activity period and life history parameters to investigate the reasons for the evolution of infant carrying in the prosimian primates

DIVERSITY AND SPECIATION IN NOCTURNAL MALAGASY LEMURS: AN INTEGRATIVE APPROACH

Elke Zimmermann

Institut fur Zoologie, Tieraerztliche Hochschule Hannover, Germany. E-mail: ezimmer@Zoologie.tiho-hannover.de

The extant lemur fauna of Madagascar represents the most spectacular example of adaptive radiation among primates. Nowadays, however, almost all lemur species face a severe threat of extinction because of the continued destruction and fragmentation of their habitats and their unusually small geographical ranges. Unfortunately, our knowledge of the taxonomic status, geographical distribution and biology of all nocturnal, cryptically-living lemurs is highly restricted. Thus, it was not until recently, that the smallest known extant primate (Microcebus myoxinus) was rediscovered in the dry deciduous forest of Kirindy in western Madagascar and that a new species of mouse lemur (Microcebus ravelobensis) was discovered in the

northwestern, dry, deciduous forest in the area of Ampijoroa. Also, the almost extinct hairy-eared dwarf lemur (Allocebus trichotis) was discovered in a previously unknown distribution range in the highland rain forest area near Andasibe. However, detailed information on species diversity, distribution and population ecology is lacking on almost all Malagasy nocturnal lemurs although species recognition and discrimination is an urgent and essential requirement for any conservation programme. I will report on an on-going, long-term field project in Madagascar focussing on the illumination of species diversity and speciation patterns of Malagasy nocturnal lemurs by applying morphological, bioacoustical, ecoethological and genetical techniques.

POSTER PRESENTATIONS - ABSTRACTS:

POSTER 1

ACOUSTIC, MORPHOLOGIC AND GENETIC DIVERSITY OF MOUSE LEMUR (Microcebus murinus) POPULATIONS

T. Hafen (1), H. Neveu (2), Y. Rumpler (2), I. Wilden (3), E. Zimmermann (1)

(1) Deutsches Primatenzentrum, Goettingen and Tieraerztliche Hochschule Hannover

(2) Institut d'Embryologie, Faculte de Medecine, Universite Louis Pasteur, Strasbourg

(3) FB Biologie, Math.-Nat. I, Humboldt Universitaet, Berlin

Intraspecific variations in primate vocalizations are often regarded as inherited traits, but the genetic basis of acoustic diversity and the influence of cultural transmission is largely unknown. In order to analyze whether acoustic diversity is correlated to morphologic and genetic differences, we compared two wild populations of the grey mouse lemur (Microcebus murinus) in a dry forest region of western Madagascar. Our major findings were: Acoustical divergence: 85 trill advertisement calls of male mouse lemurs, emitted in the same behavioral situation, were recorded, spectrographically analyzed, and compared using multivariate statistics. A stepwise discriminant analysis identified a set of 3 variables, on which 90% of the calls could be correctly assigned to the population that produced them. Morphological similarity: For morphological comparison, body mass and body proportions of 51 animals were measured. The populations did not differ significantly (Mann-Whitney-U-Test, p < 0.05) in any of these measures. Genetic similarity: Genetic diversity was tested using RAPD-technique. This PCR-based method amplifies DNA-fragments from genomic DNA using arbitrarily chosen 10mer primers. Band patterns revealed can be monomorphic or polymorphic depending on primers. We used six primers that produced polymorphic patterns. Each band for each individual was scored as absent or present leading to a data matrix of 158 different bands that was analyzed by cluster analysis. This analysis showed no population specific clustering. We, therefore, conclude, that populations of the grey mouse lemur can differ in the acoustical design of the advertisement call without genetic isolation. Supported by the DFG.

POSTER 2

MALE-MALE COMPETITION IN FREE-LIVING MICROCEBUS MURINUS IN NORTHWESTERN MADAGASCAR

Ute Radespiel, Elke Zimmermann (Institute of Zoology, Tieraerztliche Hochschule Hannover, Buenteweg 17, D- 30559 Hannover, Germany)

The reproductive success of male mammals is generally limited by the access to oestrus females. If the monopoly of females is possible, intrasexual competition should lead to the evolution of polygynous mating systems and therefore, at any time, to the exclusion of the

majority of males from active reproduction. The mating system of the small-sized, strictly nocturnal grey mouse lemurs is still poorly understood, due to observational difficulties under natural conditions. The aim of this study was to investigate the social organization of this 'solitary' lemur within a natural population living in the Forest Reserve Ampijoroa, Northwestern Madagascar. Methods included capture-recapturing and telemetric analysis of home ranges. Home range sizes and core areas were calculated within and outside the major mating period with particular interest in the overlapping areas of home ranges belonging to neighbouring individuals. The potential access to females was analysed by the degree of overlap between individual male and female home ranges and by the number of females captured in proximity to individual males. Furthermore the relationships between a) home-range size and access to females, b) body weight and home-range size and c) testis size and home-range size were investigated in order to identify the mechanisms of intrasexual competition in male mouse lemurs. Home range analysis showed no exclusion of males from the potential access to females. During the whole study period several males lived in proximity to several cycling females, indicating that a complete monopolization of females is unlikely. The analysis revealed a relationship betwen male home-range size and the number of accessable females. No consistant relationship was found between testis size, body weight and home range size. Data indicate that grey mouse lemurs exhibit a promiscuous mating system, in which the determinants of male reproductive success, i.e. the role and degree of intrasexual competition and other selective mechanisms like female mate choice, remain to be clarified.

POSTER 3

THE FIRST DISCOVERY OF THE HAIRY-EARED DWARF LEMUR (Allocebus trichotis) IN A HIGHLAND RAINFOREST OF EASTERN MADAGASCAR

Nasolo Rakotoarison (1), Helmut Zimmermann (2) and Elke Zimmermann (3)

(1) Parc Botanique et Zoologique de Tsimbazaza, Department Faune, Antananarivo, Madagascar

(2) AK Natur- und Artenschutz in den Tropen, Stuttgart, Germany

(3) Institut fuer Zoologie, Tieraerztliche Hochschule Hannover, Buenteweg 17, 30559 Hannover, Germany

Original data is presented on the discovery of an almost extinct lemur species (Allocebus trichotis) from a previously unknown distribution range in a highland rain forest of Eastern Madagascar. The biogeographic and conservational consequences and interests are also discussed.

POSTER 4

DOES MALE DOMINANCE REALLY REGULATE ACCESS TO FERTILE FEMALES IN THE LESSER MOUSE LEMUR? MALE MATING BEHAVIOUR IN A BREEDING COLONY OF GREY MOUSE LEMURS

Dorothea Wrogemann, Antje Lindemann, Ute Radespiel and Elke Zimmermann (Institut fuer Zoologie, Tieraerztliche Hochschule Hannover, Buenteweg 17, D- 30559 Hannover, Germany)

The social organization of the lesser mouse lemur is still controversially debated. Observations in captivity suggested a polygynous mating system, with a dominant male inhibited the sexual function in other males. The highest ranking male mated with several females, but females copulated only with the dominant male. Low ranking males differed from dominant males by smaller body weight and testis size. Surprisingly, our colony differed from these usual findings. No correlation was found between dominance status and body weight or testis size. In the presence of females the dominance relations in male pairs changed during the time of female fertility. Females mated both with dominant and subdominant males and subdominant males were not inhibited in their reproductive function. Although males competed for access to fertile females, females could not be monopolized by a single male. Results indicate a promiscuous mating system. Further observations on male-male and male-female bonding patterns, male reproductive success and the role of female mate choice are necessary for a better understanding of the social system of the grey mouse lemur.

POSTER 5

A NEW PRIMATE SPECIES IN NORTHWESTERN MADAGASCAR: THE GOLDEN-BROWN MOUSE LEMUR (Microcebus ravelobensis)

E. Zimmermann (1), P. Ehresmann (1), V. Zietemann (1), U. Radespiel (1),

B. Randrianambinina (2) and N. Rakotoarison (2)

(1) Institut fuer Zoologie, Tieraerztliche Hochschule Hannover, Buenteweg 17, 30559 Hannover, Germany

(2) Parc Botanique et Zoologique de Tsimbazaza, Department Faune, Antananarivo 101, Madagascar

Mouse lemurs (Microcebus spp.) are the smallest nocturnal primates and live in a wide range of forest types in Madagascar. Up to now three different mouse lemur species have been recognized: the long-eared grey mouse lemur (M. murinus), inhabiting dry forests in western and southwestern Madagascar; the short-eared rufous mouse lemur (M. rufus), inhabiting rain forest areas in eastern Madagascar; and the pygmy mouse lemur (M. myoxinus), inhabiting dry forests in western Madagascar. During ecoethological studies on lemurs in a deciduous, dry forest in northwestern Madagascar (Reserve forestiere d'Ampijoroa, 16 deg S, 46 deg E), we found a previously undescribed gracile mouse lemur form with a golden-brown pelage, living in sympatry with the grey form (M. murinus). Individuals of both forms were captured, sexed, individually marked and ten morphological characters measured. 57 mouse lemurs of the grey form and 27 of the golden-brown forms, as well as 15 eastern rufous mouse lemurs were compared using Kruskal-Wallis ANOVA and Mann-Whitney-U tests. Besides the difference in pelage colouration, significant differences (p < 0.005) between the two sympatric forms were found in three out of ten measured morphometric characters. Significant differences between the golden-brown form and the eastern rufous mouse lemur were revealed in nine of the ten measured characters. Characters differing significantly in the Kruskal-Wallis test were included in further multivariate analysis. Three population-specific clusters emerged through cluster analysis. Discriminant function analysis revealed that a combination of three characters (tail length, tail width and hindfoot length) was sufficient to assign 97.5% of the individuals to their respective population. Our results suggest that the northwestern golden-brown mouse lemurs are distinct from each the sympatric grey mouse lemurs in Ampijoroa (M. murinus), the rufous mouse lemurs of eastern (M. rufus) and western Madagascar (M. myoxinus) and therefore form a distinct new species, Microcebus ravelobensis.

POSTER 6:

THE RELATIONSHIP BETWEEN BODY WEIGHT, BREATHING RATE AND SPEED OF SEQUENCE PRODUCTION IN NOCTURNAL PRIMATES

Gwen Hewitt (1) and Paul Honess (2)

(1) School of Life Sciences, Roehampton Institute, Whitelands College, West Hill, London. SW15 3SN. E-mail: Ghewitt@Compuserve.com

(2) Nocturnal Primate Research Group, Anthropology Department, Oxford Brookes University, Oxford. OX3 0BP. E-mail: phoness@brookes.ac.uk

A relationship between body weight and the pitch and loudness of calls produced by non- human primates has been proposed previously, for example, larger primates tend to produce lower frequency calls than smaller ones. However, the relationship between body weight, breathing rate and the temporal patterning of sequences of calls has not been studied in non-human primates. Breathing patterns during non-human primates vocalisations have only been reported in a minority of studies. These indicate that most non-human primates produce series of notes (other than quavers and trills) on sequences of inspirations and expirations, sometimes as fast as six times resting breathing rate. Therefore, speed of sequence production could be limited by a tendency to hyperventilate, but smaller primates with faster resting breathing rates, should be less constrained than larger primates. Humans are an exception, giving long sequences of varied phonemes and syllables on extended exhalations (rather than on in/out cycles) fast enough to overcome the limitations of short term memory. Sequences of notes produced by non-human primates may convey more information than each note on its own (Marler's phonological syntax) and production may also need to be fast enough for the relationship between units in a sequence to be perceived. This poster examines the hypothesis that rate of sequence production and resting breathing rates will be related and proposes that nocturnal social primates, for whom vocalisations are the most important form of communication, may be restricted in size by physiological limitations on the rate of sequence production.

POSTER 7:

THE USE OF HAND MORPHOLOGY IN THE TAXONOMY OF GALAGOS

Mat Anderson

Sub-dept of Animal Behaviour, University of Cambridge, Madingley, Cambridge. E-mail mja33@cam.ac.uk

The hands of primates vary enormously in their functional morphology. Functional specialisations range from the utilisation of 'power grips' for locomotion and climbing, to less forceful 'precision' movements for feeding, grooming and (in certain species) 'urine washing' displays. The bushbabies or galagos, (subamily Galaginae), provide ideal subjects for study, as the various species occupy highly specialised niches and exhibit diverse patterns of hand use. Measurements were made of volar hand pad number, shape and area, as well as digit lengths in specimens representing 17 galago populations. Closely related, sympatric species, such as the thick-tailed greater bushbaby (Otolemur crassicaudatus) and Garnett's bushbaby (O. garnettii) exhibited significant differences in volar pad morphology in all characters measured. Two closely related species of lesser galagos (Galago senegalensis and G. moholi)were also found to differ in various features of hand morphology, whereas intraspecific variations in these same features were minor. The comparative morphology of the hands of galagos may therefore provide an additional useful tool for taxonomic studies, particularly because increasing numbers of hitherto unknown species of galagos are currently under review. Data will be presented on several of these (Otolemur argentatus, Euoticus pallidus and Galagoides granti) as well as on well-characterised species (Euoticus elegantulus, Galago gallarum , Galagoides demidoff and Galagoides thomasi). Results obtained to-date confirm that galago hand characteristics provide a useful guide to species type in this family.