Species differences in substrate use and diet between sympatric galagos in two Kenyan coastal forests

Two sympatric species of galago,Galago zanzibaricus andG. garnettii, differed significantly in diet (judged mainly by fecal analysis) and substrate use at each of two coastal forest sites in Kenya. The larger-bodiedG. garnettii tended to use branches of a bigger diameter and to be found higher in the canopy than the smallerG. zanzibaricus. The latter species spent most of its time in the thick undergrowth. The larger species ate more fruit than the smaller. There were differences between the species in the type of invertebrate prey remains found in the feces. It is suggested that the differences in habitat use were influenced by the different body sizes of the two galagos, which so enabled these closely related species to coexist. Order of authorship is alphabetical.     

Reproductive patterns in galagos (Galago zanzibaricus and Galago garnettii) in relation to climatic variability

The reproductive patterns (birth seasonality, litter size, litters per year) of two sympatric species of galago (Galago zanzibaricus and G. garnettii) were studied in a coastal forest in Kenya for a two-year period. Trap-retrap and radio tracking methods were employed. G. zanzibaricus has one infant twice per year; G. garnettii has one infant once per year. Both species are seasonal breeders. These East African galagos are intermediate in reproductive patterns when compared with galagos from South African woodland (G. senegalensis moholi and G. crassicaudatus umbrosis) and West African rainforest (G. alleni and G. demidovii). Climatic patterns (total annual rainfall, seasonal variability of rainfall, variability in total annual rainfall, and annual temperature variability) are also compared for the three regions. Climatically, East Africa is intermediate between West and South Africa in total annual rainfall and in seasonality of rainfall, but not in year-to-year variability in rainfall. East Africa shows the highest variability in annual rainfall. South Africa has the coldest dry seasons and highest variability in temperatures. The results of this study suggest that “r-selection” and “K-selection” do not provide adequate explanations of galago reproductive patterns.     

Mitochondrial Sequences as Indicators of Genetic Classification in Bush Babies

Systematic relationships among the African bush babies are not well understood. Various generic designations are currently in use. Some authors refer all species to a single genus (Galago), while others recognize 4 genera. Phylogenetic reconstructions based on morphology, karyology, allozymes and vocal repertoires have generated inconsistent hypotheses of relationship. We analyzed partial sequences of three mitochondrial genes (270 bp from cytochrome b, 387 bp from 12S rRNA, and 241 bp from 16S rRNA, total 898 bp) to resolve some uncertainties. We sampled taxa from each of three genera: Galagoides alleni, G. demidoff and G. zanzibaricus; Galago senegalensis, G. gallarum and G. moholi; and Otolemur crassicaudatus and O. garnettii. Outgroup taxa were Asian lorises: Nycticebus coucang and Loris tardigradus. We analyzed sequences separately and in combination, and modeled phylogenies using maximum parsimony, weighted parsimony, neighbor-joining and maximum-likelihood. We obtained some variation in phylogenetic inference depending on sequence and analytical method, but the results also gave strong phylogenetic signals. The lesser bush babies invariably formed a clade, showing evidence of very recent radiation. The greater bush babies also formed a clade, marked by somewhat greater interspecific genetic distances, which was allied with Galagoides alleni in most instances. Galagoides demidoff and G. zanzibaricus are not closely related, though both diverged early in the history of the group. A genus comprising Galagoides alleni, G. demidoff and G. zanzibaricus is not supported by our data. The most likely alliance for Galagoides alleni is within the genus Otolemur. Of the three partial sequences employed in the study, 16S rRNA gave the most consistent results, while cytochrome b was least informative.     

Social organization of Galagos in Kenyan coastal forests: I. Galago zanzibaricus

The social organization of Galago zanzibaricus was studied for the first time and the study included data from two different sites in the coastal forests of Kenya. A combination of mark-recapture and radio-tracking techniques was used to investigate patterns of inter- and intrasexual home range overlap. Associations in sleeping groups indicated social ties between individuals. Patterns of range use were established by radio-tracking focal individuals. Adult males generally had nonoverlapping ranges, shared with one or two females and their offspring with which the male regularly slept. Young females remained longer in their natal ranges than males and reproduced within their natal ranges. Range size and distance traveled per night were similar between the sexes; both sexes probably defended territories. None of the other galago (bushbaby) species studied to date show the degree of close male-female association found in G. zanzibaricus. This study thus extends the variety of social organization documented in nocturnal prosimians.     

Morphological Correlates of Speciation in Bush Babies

Morphology is not a reliable specific indicator in nocturnal animals. Nevertheless, because species are genetically independent, appropriate analytic methods should reveal subtle and consistent morphological differences among them. Until recently, the diversity of living bush babies was underrated, and new species have been recognized on the basis of genetic, behavioral and soft tissue data. This has placed museum curators in a quandary as to how to sort their skin and skull collections according to the new specific designations.We conducted multivariate analyses of 6 morphologically similar pairs of bush baby taxa: Otolemur crassicaudatus and O. garnettii; Galagoides demidoffand G. thomasi; Galago gallarumand G. senegalensis; G. moholi and G. senegalensis; Euoticus elegantulus and E. pallidus, and Galagoides zanzibaricus and G. granti. We also compared subspecies within the taxa Otolemur crassicaudatus, O. garnettii, Galagoides demidoff, and Galago senegalensis. Five out of six species pairs were discriminated with a high level of reliability (88.5–99%) on the basis of 2–5 morphological variables. Only Euoticus elegantulus and E. pallidus did not show this pattern. All strongly supported specific discriminations share two features: (a) ear length is a highly significant factor, while the involvement of other characters is variable; (b) the greater the reliability of the discrimination, the fewer variables necessary to effect it. Euoticus elegantulus and E. pallidus behaved more like subspecies in the discrimination, while Galago senegalensis sspp. showed a pattern of variation similar to that in the specific analyses.     

Social organization of Galagos in Kenyan coastal forests: II. Galago garnettii

The social organization of Galago garnettii was studied for the first time and the study included data from two different sites in the coastal forests of Kenya. A combination of mark-recapture and radio-tracking techniques was used to investigate patterns of inter- and intrasexual home range overlap. Patterns of range use were established by radio tracking focal individuals. Adult females of different ages shared highly overlapping ranges, while like-aged females showed little range overlap. Females matured and had their first infants in their natal ranges. Adult males' ranges were larger than those of females and overlapped them extensively. Resident adult males showed little range overlap with each other, unless they were of different ages. Turnover of males was frequent in both populations. Males probably dispersed from their natal ranges. Adults rarely slept together. The social organization of G. garnettii is relatively similar to that of the closely related G. crassicaudatus of southern Africa but contrasts with that of its sympatric congener, G. zanzibaricus. The differences and similarities between these three species are discussed in relation to diet and body size.     

Ecological attributes recorded in stable isotope ratios of arboreal prosimian hair

Carbon and nitrogen stable isotope ratios were measured in hair samples from two species of Galago from Gedi Ruins National Monument in eastern Kenya and from Lepilemur leucopus from Beza Mahafaly Special Reserve in southern Madagascar. Forest structure was generally similar in the two areas but average rainfall was lower in Madagascar. Species average ¹³C values varied with feeding height in the forest canopy and with average rainfall level as expected from reported variation in plant ¹³C values. G. garnettii, which feeds higher in the forest canopy, had less negative ¹³C values than G. zanzibaricus, which spends more time below 5 m. L. leucopus, from a drought-afflicted forest, had less negative hair ¹³C values than the two galago species. The values within the Lepilemur sample showed a positive linear relation with percent dependence on a CAM tree species and with xeric conditions within the species reserve. Nitrogen stable isotope ratios varied with trophic level of feeding and with time spent feeding on leguminous plants. The insectivorous galagos had significantly more positive ¹⁵N values than the folivorous L. leucopus. Within the Lepilemur sample, ¹⁵N values varied inversely with the percent of feeding time spent on leguminous plants. The range of ¹⁵N and ¹³C values in each of the prosimian species is larger than reported for animals fed monotonous diets and for New World monkey species. The monkey species feed as groups of individuals whereas the prosimians have solitary feeding habits. The ranges in the prosimian species apparently reflect the greater variation in diet among individual prosimians compared to individual monkeys. The isotope data reported here are equivalent, on average, to those reported for other arboreal species from similar forest habitats and with similar dietary habits. This supports the use of such data for paleoecological reconstruction of forest and woodland systems and diet reconstruction of extinct primate populations and species. Received: 18 April 1997 / Accepted: 11 August 1997     

A comparison ofGalago moholi in South Africa withGalago zanzibaricus in Kenya

Two populations of small bushbabies that frequently have been regarded as subspecies of Galago senegalensisare compared and contrasted. The animals in South Africa differ from those in coastal forests of Kenya in aspects of their morphology, locomotion, calls, reproduction, diet, social organization, and karyotype. The two forms are clearly separate species, namely G. moholiand G. zanzibaricus.     

Effect of vesicular-arbuscular mycorrhizae on the growth and yield of rice-stubble cultured soybeans

Summary Inoculation with vesicular-arbuscular (VA) mycorrhizal fungiGlomus fasciculatus, G. mosseae, G. etunicatus orAcaulospora scrobiculatus, increased plant dry weight and seed yields of pot-grown soybean plants in sterilized soil. Inoculation with a mixture ofG. fasciculatus, G. mosseae andG. etunicatus, orG. fasciculatus alone, increased seed yields and other agronomic traits of soybean plants grown in a no-tillage, rice-stubble field.     

Differentiation of vocalizations in bushbabies (Galaginae, Prosimiae, Primates) and the significance for assessing phylogenetic relationships

A comparative bioacustic analysis of vocalizations of the prosimian subfamily Galaginae revealed that morphologically similar sibling taxa within the main groups of the lesser galagos and the greater galagos can be reliably identified phenotypically on the basis of the acoustic structure of their loud call or advertisement call. Results confirm the separation of two distinct species of greater galagos, Galago crassicaudatus and Galago garnettii, and strongly suggest the discrimination of three distinct species from the senegalensis lesser bushbaby group, Galago senegalensis, Galago moholi and Galao zanzibaricus. An investigation of the ontogenetic development of the loud call indicated that it is derived from the infant's isolation call, displaying in all studied bushbaby taxa a fairly similar acoustic pattern. Shared acoustic characters of the loud call among the different taxa as well as the infant's isolation call were used to propose a hypothesis about the phylogenetic affinities in bushbabies. The results seem to be supported by recent fossil records.     

Species differences of male loud calls and their perception in sulawesi macaques

Playback experiments were conducted to investigate interspecific discrimination of male loud calls in Sulawesi macaques. Loud calls of four macaque species living in Sulawesi (Macaca tonkeana, M. maurus, M. hecki, andM. nigrescens) and a control stimulus (an 8-sec frequency modulated sound) were played back to semi-free-ranging Tonkean macaques (M. tonkeana). A preliminary acoustic analysis indicated that the calls of these four species differ in some spectral and temporal features. In the playback experiments, Tonkean macaques responded in a similar manner to conspecific calls and calls of two other species,M. maurus andM. hecki. In contrast, animals responded more weakly to the call ofM. nigrescens and the control stimulus. Males responded more strongly than females to all stimuli, while females appeared to be more discriminating for species differences than males. Analyses on the acoustic features of loud calls suggested that high frequency, wide frequency range, and repetition of sound units at a high rate elicit quick responses from animals.     

Troop-specific responses to long calls of isolated tamarins (Saguinus mystax)

Recently captured moustached tamarins (Saguinus mystax) were briefly separated from other members of their troop. Most separated animals emitted long calls that were, in general, similar in acoustic structure to those of sympatric tamarin species while retaining species distinctiveness. Individual differences also appeared in call structure. The long calls of a separated animal were responded to almost entirely by members of the animal's own troop rather than by other troops, and reciprocal calling occurred among troop members significantly more often than expected by chance. Although there was no evidence of troop-specific call structure or dialect, there were troop-specific responses to the calls of separated tamarins. This response implies the existence of a stable and integrated troop structure that allows troop members to learn and to respond to the individual specific features of each troop member's calls.     

Determination of the G + C content of twoSyntrophus buswellii strains by ultracentrifugation techniques

An anaerobic syntrophic bacterial culture degrading benzoate was isolated from a river sediment. The syntrophic organism was grown in coculture in the presence of a hydrogenotrophic strain,Desulfovibrio fructosovorans orMethanospirillum hungatei. The G+C content of the syntrophic benzoate degrader determined by density gradient ultracentrifugation was similar to that ofSyntrophus buswellii (54.3%). A method ensuring the G+C% determination of syntrophic bacteria is presented.     

Ultrasonic Vocalizations of Six Taxa of Southern African Gerbils (Rodentia: Gerbillinae)

Ultrasonic calling during male-female encounters between individuals of the same species was investigated in six taxa of southern African gerbils, namely Tatera brantsii, Gerbillurus paeba paeba, G. p. cxilis, G. tytonis, G. setzeri, and G. vallinus. Vocalizations were detected by means of a bat detector utilizing a superheterodyne signal converter and a countdown circuit. Signals were recorded at audible frequencies and analysed with a sonograph. All taxa vocalized at ultrasonic frequencies by means of strongly modulated frequency “sweep” calls, which differed among taxa in duration, maximum and minimum frequency. “Clicks” were emitted by G. p. paeba and G. p. exilis, and G. tytonis emitted a “stutter” vocalization which consisted of a series of clicks. Long modulated “whistles” were identified from G. vallinus and T. brantsii at lower frequencies than “sweep” calls. Only one call type, a “sweep” call which differed in duration and frequency from all other taxa, was identified in G. setzeri. Cluster analysis was applied to the data using 7 acoustic characters. G. p. paeba and G. p. exilis displayed the highest similarity level between taxa and differed only in frequency of “sweep” vocalizations. G. paeba, G. tytonis and G. setzeri formed one cluster, while G. vallinus and T. brantsii formed a separate cluster. Numbers of calls in interspecific encounters were non-significantly less than in intraspecific encounters in all taxa except G. p. paeba, in which more vocalizations were recorded in inter- than intraspecific encounters. It is not clear whether species discrimination, measured by numbers of vocalizations in interspecific encounters, occurs.     

ALARM CALLS OF THE EUROPEAN GROUND SQUIRREL SPERMOPHILUS CITELLUS AND THE TAURUS GROUND SQUIRREL S. TAURENSIS ENCODE INFORMATION ABOUT CALLER IDENTITY

ABSTRACT

Vocalizations of many mammalian species have been reported to encode information about caller identity. In this study, we analyzed 300 alarm calls from 10 free-living European Ground Squirrels Spermophilus citellus (30 per individual) and 300 alarm calls from 10 free-living Taurus Ground Squirrels S. taurensis (30 per individual), and tested the potential of these calls to encode information about the callers' identities. Discriminant analysis including all 10 European Ground Squirrel individuals correctly classified 98% of calls, and cross-validation reached a classification success of 97%. Correct classification of 98% and cross-validation of 98% was assigned when the analysis included only those individuals producing calls consisting of both elements (eight individuals). For the Taurus Ground Squirrel, correct classification was 95% and cross-validation 94% for all 10 animals. When only those individuals producing calls consisting of both elements were included (eight individuals), discriminant analysis led to 94% correct classification and cross-validation produced a classification success of 93%. These analyses demonstrate that the structure of alarm calls in these two closely related species is highly variable and that it has significant potential to encode information about caller identity.     

Activity of a gene in transplanted oocytes in the annelid,Platynereis

Summary Pteridine eye pigment, indicative of the activity of theor ⁺-allele, was observed inor/or larvae ofPlatynereis, derived from transplantedor ⁺/or oocytes. These heterozygous oocytes had grown up inor/or hosts, themselves deficient in pteridine pigment synthesis. It is therefore concluded that theor ⁺ gene product, responsible for pteridine pigment synthesis in theor/or larvae, had been synthesized by the oocyte genomes.Supported by the Deutsche Forschungsgemeinschaft.     

Responses to natural and synthetic phee calls by common marmosets (Callithrix jacchus)

Captive adult common marmosets (Callithrix jacchus) produce whistlelike “phee” calls in two contexts: in the home cage, where phee calls may function as part of territorial marking behavior, and when separated from social companions, where phee calls may function to reunite conspecifics. Natural and synthesized calls representing the acoustic structure of male and female calls in each context were presented to adult marmosets in a playback paradigm. Marmosets demonstrated discriminative abilities according to the context of the call and the caller's sex. Vocal and behavioral responses indicated increased vigilance and territorial behavior, following playbacks of naturally produced calls as well as synthetic calls. All animals scanned more frequently following produced calls as well as synthetic calls. All animals scanned more frequently following natural home cage as well as isolation calls, but only increased contact behavior (trills) in response to home cage calls. The responses were dimorphic according to the sex of the caller, where adult males scanned more following male calls, and adult females were more aggressive following male and female calls. The differential behavioral responses to playbacks of marmoset phee calls suggest a biological relevance to subtle differences found in the acoustic parameters of the phee call. © 1994 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, in the public domain in the United States of America.

     

Genetic and morphological studies of Nothobranchius (Cyprinodontiformes) from Malawi with description of Nothobranchius wattersi sp. nov.

Molecular and morphological data were used to explore evolutionary differentiation among populations of Nothobranchius in the Lake Malawi–upper Shire River and the Lakes Chilwa–Chiuta drainage systems in Malawi. The aim of the study was to test the hypothesis that Nothobranchius of the Malawi–Shire system constitute a separate evolutionary group from Nothobranchius kirki. Mitochondrial and nuclear sequence data show a strongly supported phylogenetic split into two monophyletic groups separating the Lake Malawi basin fish from N. kirki. Unlike N. kirki, Lake Malawi–Shire fish do not deviate from neutrality and express an excess of rare haplotypes and mutations in terminal branches, characteristic of recently expanded populations. Further, the two groups significantly differ in morphology. Two body characters (dorsal‐fin base length and pre‐pelvic–pre‐anal distance) are significantly different between the two species in both sexes. Several other characters are significantly different in either male or female comparisons with respect to both standard and head lengths, and robust morphological differentiation is detected by multivariate analysis. The two groups are readily distinguished on the basis of male colouration, especially in scale centres and the caudal fin. On the basis of this differentiation at the molecular and morphological levels, in addition to colouration, the Lake Malawi–Shire fish are hereby formally recognized as constituting a new species, Nothobranchius wattersi. This distinction is in agreement with the geomorphologic and recent climatic history in the region.     

Migratory behaviour shapes spatial genetic structure of cyprinid fishes within the Lake Malawi catchment

• Genetic differences among freshwater fish populations are dependent on life‐history characteristics of the species, including the range of adult dispersal and the extent of homing to natal breeding grounds. However, the effects of variation in such characteristics on population genetic connectivity are rarely studied comparatively among closely related species.
• We studied population genetic structure within three congeneric cyprinid species from the Lake Malawi catchment that differ substantially in life‐history traits and conservation status, using a combination of microsatellite and mitochondrial DNA markers. Mpasa (Opsaridium microlepis) is a large (70 cm total length) migratory species that spawns in rivers, but as an adult is exclusively known from the main lake body. Sanjika (Opsaridium microcephalum), is a medium size (30 cm total length) species that exists in lake breeding, river‐lake migratory and apparently landlocked populations. Dwarf sanjika (Opsaridium tweddleorum) is a small non‐migratory species (15 cm total length) that persists in small tributaries surrounding the main lake and adjoining rivers.
• The results revealed striking differences among the three species in spatial genetic structuring. The river‐lake migratory mpasa showed only weak yet significant population genetic structure within the main Lake Malawi catchment, suggesting that there is no strong natal homing. The habitat‐generalist sanjika showed only weak spatial genetic differentiation at microsatellite loci within the Lake Malawi catchment, but moderate structure in mitochondrial DNA, potentially reflecting male‐biased dispersal. The river‐restricted dwarf sanjika showed strong genetic structure in both microsatellite and mitochondrial DNA, suggesting strictly limited dispersal at both adult and juvenile stages.
• We conclude that contrasting migration life histories have resulted in dramatically different patterns of population genetic structure among these congeneric species. The observed patterns demonstrate how divergent life‐history evolution may strongly influence broader patterns of population genetic connectivity in freshwater fish, with consequences for management and conservation. Specifically the results suggesting gene flow among Lake Malawi populations of mpasa, an IUCN red‐listed ‘Endangered’ species endemic to the lake catchment, imply that conservation initiatives operating at both local and catchment scales are needed to reverse local population decline.

     

Effects of laryngeal nerve transection on squirrel monkey calls

Summary Six squirrel monkeys (Saimiri sciureus) were implanted with intracerebral electrodes yielding specific call types when electrically stimulated. Two animals then received bilateral transection of the recurrent nerve; in another two animals the external branch of the superior laryngeal nerve was cut bilaterally; two further animals received unilateral transection of either the recurrent or the external laryngeal nerve. In one animal with both recurrent nerves cut, the external laryngeal nerves were cut in addition 3 months later. The vocal changes caused by these transections were observed and can be summarized as follows:Unilateral interruption of the recurrent nerve causes only minor disturbances which are limited to low-pitched sounds. Bilateral interruption of the same nerve leads to a reduction of maximal intensities and durations in general. Whereas the frequency-time structure is severely disorganized in all harmonic calls with a fundamental below 1 kHz and all non-harmonic, noise-like calls, it remains unaffected in harmonic calls with a fundamental above 1 kHz. Unilateral transection of the external laryngeal nerve causes a drop of fundamental frequency in high-pitched calls to almost half. Bilateral transection of the same nerve abolishes all calls with a fundamental above 1 kHz. In wide-band frequency calls it is followed by a shift of main energy towards lower frequencies. Low-pitched harmonic as well as noise-like calls remain normal. Cutting both external laryngeal nerves in addition to recurrent nerves is followed by loss of all sounds except one coughing-like, abnormal call. All animals with transection of the external laryngeal nerve show recovery of the high-pitched calls which seems to be due to new innervation of the cricothyroid muscle from the pharyngeal plexus.