Infanticide in gelada baboons (Theropithecus gelada)

In a captive group of geladas three cases of infanticide have been observed after replacement of the harem-leader. Two of the infants were born before the replacement, the third one 12 weeks afterwards. The possible function of infanticide is discussed. Female counterstrategies other than avoiding contact with the male were not observed.     

The distribution of baboon species and a new population of gelada baboons along the Wabi-Shebeli river,Ethiopia

We conducted an extensive survey in search of hybrid baboons betweenPapio hamadryas andP. anubis along the Wabi-Shebeli river at the border of the Arusi and Bale Regions, Ethiopia. We made inquiries of villagers on the roadsides concerning the existence of baboon species. We also conducted direct observations at several sites. There are three routes which lead to the north bank of the Wabi-Shebeli river (Arusi Region), and we found hybrid baboons on the bank of the Wabi-Shebeli river in two routes among the three. We found hamadryas baboons in all of the three routes at the cliff areas. There are two routes which lead to the south bank of the Wabi-Shebeli river (Bale Region). We conducted a survey on one of the two. We found hamadryas baboons at the cliff areas of the route. We observed a population of gelada baboons along the cliff extending over 20 km along the north bank of the Wabi-Shebeli river (Arusi Region). This area is far to the south of the known distribution range of gelada baboons (Yalden et al., 1977). The gelada baboons of this area appeared to represent a different form (subspecies?) from those at Debre Sina (Showa Region) based on our observations in both areas. We reached the conclusion that the distributions of baboon species along the Wabi-Shebeli river may have been strongly affected by the intensive cultivation on the plateau of the highland. The distribution patterns of the three baboon species,P. anubis, P. hamadryas, andTheropithecus gelada, appeared to be influenced by their individual adaptabilities to the cliff environment. Hamadryas baboons were distributed continuously along the cliff and the narrow lowland of the Wabi-Shebeli river. Anubis baboons were distributed discontinuously on the cliffs, and their populations tended to be small and isolated. These anubis baboons were strongly hybridized with hamadryas baboons.     

Anti-predator behavior of gelada baboons

The anti-predator behavior of gelada baboons has been observed to consist of simple flight (i.e. they flee to cliffs after becoming alarmed by potential predators). However, active antipredator behavior was observed in a recently found gelada population in Arsi, Ethiopia. This population showed frequent active counter-attacks and severe mobbing at predators. Males fought domestic dogs on the plain and exhibited a systematic mobbing behavior towards a leopard on the cliff face to chase it off. These active anti-predator behaviors are the first confirmed reports on gelada baboons and may provide a useful insight for the understanding of the process of evolutionary adaptation to highland habitats by gelada baboons, as well as for the origin of this small southern population.     

The integration of an adult female gelada baboon (Theropithecus gelada)

An adult female gelada baboon has been integrated into an old-established group in the zoo in Rheine, West Germany. The integration took place in three steps: sight-contact, hourly meetings with the group, continuous stay in the group. Both the agonistic and the social-positive behaviour have been observed between the new female and the group-members. The integration was very difficult and lasted more than six months. The female was not really accepted, before she had not presented to the most dominant female of the one-male unit she has joined. This presenting only took place during the last part of the observations. In contrast to the adult female, the integration of juveniles occurred very quickly and nearly without any problems.     

Sociological and demographic characteristics of a recently found arsi gelada population in ethiopia

A new population of gelada baboons isolated from other known gelada populations living on the opposite side of the Rift Valley was found in 1989 in the Arsi region of Ethiopia (Mori &Belay, 1990). Subsequent observations were conducted on the new gelada population in three study periods of 16 to 55 days over three consecutive years, 1994–1996. When we compare this population with other well studied northern populations, densities were lower, band size was smaller and the ratio of juveniles to adult females was lower. Based onOhsawa andDunbar's (1984) criteria these results suggest that this population exploits the harshest environment among known gelada populations. This may be due to the severe effect of the dry season at low altitude in the study site. Band size was small in the study site. Association rates of units were low, and each unit behaved more independently than those of northern populations. Age-sex composition of units changed drastically between consecutive study periods, indicating unstable unit structure. Moreover, there seems to be a tendency in this population whereby several adult males easily invade and are incorporated into a unit but the unit is expected to thereafter divide. The phenomenon can be explained by two factors: (1) Each unit fed rather independently in this area, where units fed intensively on both plateau and the slope of the cliff; and (2) Males may be incorporated in a unit for defense against leopards. As the units were vary small in size and unstable as compared with the Semien gelada units, the traditional concept of a stable gelada unit formed by blood related females, does not seem to fit this population.     

Blood protein variation of a new population of gelada baboons (Theoropithecus gelada), in the Southern Rift Valley, Arsi Region, Ethiopia

Blood protein polymorphism of gelada baboon (Theropithecus gelada) to the south of the Rift Valley, Arsi Region, were examined for 36 genetic loci using three electrophoresis techniques for 48 blood samples from three localities, and compared with the northern geladas. New variant alleles and genetic markers of Hb-α, PA-2, and TBPA loci were detected. The distribution patterns of the variant alleles of Hb-α, PA-2, TBPA, Pi, Gc, PGM-II, and TBPA loci were localized in the geographic regions of south and north gelada populations, respectively. Genetic variability of southern geladas was estimated as P_poly=0.083 and , which was comparable to northern geladas. A remarkably high genetic differentiation between the two geographic populations was shown byNei's genetic distance=0.071 and G_ST value=0.420. Our results of genetic analysis suggest that the southern and northern gelada populations have been separated for several hundred thousand years, and gene flow between the two geographic populations is severely restricted. The southern gelada baboon may be regarded as a distinct subspecies.     

Male takeover in Colobus vellerosus at Boabeng-Fiema Monkey Sanctuary, central Ghana

We describe a case of male takeover in the ursine black-and-white colobus (Colobus vellerosus). In April 2001, an all-male group attacked and eventually invaded our uni-male study group. Aggression increased following the takeover and the former resident male, severely wounded, became peripheral. The youngest immature received severe aggression from the new males but survived. The immatures mother intervened in most instances of this aggression. Eventually, the former resident male re-established relationships with some of the females and concurrently intervened to protect the immature. Defeated males that stay in their group can contribute to the protection of infants born during their tenure from infanticidal males. The females mated with the new males. Takeovers may be a means by which males acquire groups of females in C. vellerosus.     

Evidence for sexually selected infanticide in captiveCercopithecus mitis,Cercocebus torquatus,andMandrillus leucophaeus

Adult resident males of one-male-multi-female primate groups housed at the Hannover Zoo exhibited aggression, when confronted with nonadult individuals, which were fathered by other males: (1) a new adult resident male in a group of blue monkeys killed a 5.8-month-old female infant: (2) a new adult resident male in a group of white collared mangabeys injured a 24.0-month-old female and an 18.9-month-old male severely; they would have died without veterinary care; and (3) the resident male of a group of drills threatened an 1.8-month-old foreign female infant seriously; efforts to introduce the infant were discontinued. Pathological explanations are unlikely because the adult males showed no aggression towards own nonadult offspring under the same captive conditions. By and large, the events support the theory that infanticide is the result of sexual selection among males.     

A case study of mother-son transfer in mountain gorillas

In mountain gorillas (Gorilla g. beringei), male immigration in bi-sexual units is rare. This paper presents the case of a nearly weaned male infant gorilla who followed his mother in her transfer. This case was recorded in the study population at the Kariske Research Center in 1988. The data come from observation in Group B (on 12 days just prior to the transfer and on 54 days after the transfer over a period of 6 months). The situation of the infant did match the conditions in which infanticide occurs in gorillas, but he was not killed, despite receiving male aggression and being wounded twice. In fact, both the mother and the infant received male aggression more frequently than the long term residents in the group. The aggression received by the mother decreased after she mated with the males and after she weaned the infant. The aggression received by the infant, however, did not decrease after his mother mated with the males, and increased in intensity. The infant reacted fearfully to male aggression, in marked contrast to his mother, who reacted either with indifference, or by simply avoiding the males. The aggression eventually stopped, and the infant became a blackback in Group B. Evolutionarily, the death of the infant would not have markedly accelerated the mother's return to estrus, but the death of the infant could still have benefitted the males, by decreasing the reproductive output of a competitor. Adult male gorillas are also presumably selected to resist male immigration. Proximately, the aggression directed towards the infant was not related to mating access to the mother. The sex of the infant may contribute to explain the post-transfer male aggression, but data on the integration of old female infants in a new group is needed to test whether the sex of the infant has an effect on their vulnerability to infanticide. Also, the intense fear displayed by the infant may have played a role in prompting male aggression.     

Reproductive skew and individual strategies: infanticide or cooperation?

Infanticide in species with shared reproduction may indicate attempts to control the degree of skew within groups. Alternatively, individuals that have done poorly in reproduction could use infanticide for hastening the next breeding attempt. Many factors influence the individual’s decision over whether it is best to cooperate or engage in destruction. We present a qualitative model incorporating kinship among adults and progeny, social status, group size and seasonality to predict behavioural options for individuals of diverse backgrounds. The social system used for the model was that of the guira cuckoo (Guira guira), a Neotropical bird that breeds communally. We suggest communal breeders utilise the best available predictors for enhancing seasonal reproductive success, with favourable consequences for lifetime inclusive fitness. Predictors rely upon parameters that change over time, including the individual’s assessment of present and future possibilities. The model produces predictions that may be tested through field observations and molecular analyses for species with similar social dynamics.     

Group takeover by a natal male howling monkey (Alouatta palliata) and associated disappearance and injuries of immatures

As part of a long-term study on howling monkey behavior and social dynamics, a known natal male was observed taking over his group from his putative sire. Due to the accidental death of one of the adult males, this natal male had matured in a one-male group and had never observed juvenile male emigration nor adult male immigration and associated behaviors. Nevertheless, the behaviors associated with the takeover were indistinguishable from those of an immigrant male, including disappearance of immatures, one of whom was found with extensive injuries. While it cannot be said that the natal male inherited these behaviors from his presumed father, it can be said that he exhibited species-typical behaviors associated with male takeover in the absence of observational learning.     

Synchronous spawning in a recently established population of the zebra mussel,Dreissena polymorpha,in western Lake Erie,USA

Seasonal patterns of reproduction in a newly established population of Dreissena polymorpha are described for a site in the western basin of Lake Erie. Reproduction was monitored by histological examination of gonads, analysis of shell length-dry weight relationships, and following abundance of planktonic and settling larvae. Patterns of planktonic larval abundance and settling showed a distinct bimodal pattern in July and August, but conflicted with histological and length-dry weight data that showed spawning was a brief, highly synchronous event occurring in late August. Differences between histological data and abundance of larvae in the plankton can be explained as resulting from drift of larvae from disjunct populations of D. polymorpha which spawned earlier, into the study area. Veliger larvae were present in the plankton at low densities throughout the warm months before and after periods of peak abundances. The presence of these larvae can be explained by a combination of asynchronous spawning among local populations and postponed settlement by planktonic larvae.     

Inbreeding in a french peasant population

Genealogical pedigrees were collected from 976 farming couples who lived in a canton of central France in the XIXth and XXth century. Several methods (genealogical, isonymic and probability of origin of genes) were used to appraise the evolution of the biological structure of this population, which has gone through two phases. The first phase from 1800 to the World War I, shows gene flows between the farming population of the canton and those of neighbouring rural districts which are linked to an increase in consanguineous marriages. The second phase, from 1920 onwards, shows important gene flow from distant areas. This trend implies a decrease in consanguineous marriages.     

Simultaneous determination of thioTEPA, TEPA and a novel, recently identified thioTEPA metabolite, monochloroTEPA, in urine using capillary gas chromatography

An assay for the simultaneous quantitative determination of thioTEPA, TEPA and the recently identified metabolite N,N′-diethylene-N″-2-chloroethylphosphoramide (monochloroTEPA) in human urine has been developed. MonochloroTEPA was synthesized by incubation of TEPA with sodium chloride at pH 8. Thus, with this assay monochloroTEPA is quantified as TEPA equivalents. Analysis of the three analytes in urine was performed using gas chromatography with selective nitrogen–phosphorous detection after extraction with a mixture of 1-propanol and chloroform from urine samples. Diphenylamine was used as internal standard. Recoveries ranged between 70 and 100% and both accuracy and precision were less than 15%. Linearity was accomplished in the range of 25–2500 ng/ml for monochloroTEPA and 25–5000 ng/ml for thioTEPA and TEPA. MonochloroTEPA proved to be stable in urine for at least 4 weeks at −80°C. ThioTEPA, TEPA and monochloroTEPA cummulative urinary excretion from two patients treated with thioTEPA are presented demonstrating the applicability of the assay for clinical samples and that the excreted amount of monochloroTEPA exceeded that of thioTEPA on day 2 to 5 of urine collection.     

Liriomyza huidobrensis in Yunnan, China: current distribution and genetic structure of a recently established population

Liriomyza huidobrensis Blanchard (Diptera: Agromyzidae) is a very serious and economically important pest around the world. Liriomyza huidobrensis in China was first reported from Kunming of Yunnan province in 1993. We report here that this pest has recently expanded its distribution, along with a host plant range extension and population explosion. The mitochondrial cytochrome oxidase II gene was sequenced for eight populations from Yunnan. All individuals were identical: no genetic variation was observed between populations either from different geographical localities or from different host plants. The phylogenetic analysis shows that the Yunnan population is grouped into the South American clade, which also includes other recently introduced Asian populations. Together with ecological data and colonization history of this pest, our results suggest that Yunnan population might have an ultimate, albeit not immediate, origin from South American populations.     

Infanticide in a chacma baboon troop

This report describes an infanticide and two attacks of an infant and a juvenile by a natal adult male in a troop of chacma baboons (Papio ursinus). The infanticidal male had become the dominant male in his troop five months before the infanticide suggesting that a trigger for infanticidal behavior is a rise in rank to dominant status.     

Chromosomes of Temnocephala minor,an ectosymbiotic turbellarian on Australian crayfish found in Kagoshima Prefecture,with karyological notes on exotic turbellarians found in Japan

Records of exotic turbellarian species found in Japan are reviewed from taxonomic and karyological viewpoints. Temnocephala minor Haswell, 1888, an ectocommensal on a freshwater crayfish of Australia, was found from culture ponds of Cherax tenuimanus (introduced from W. Australia) in Kagoshima Prefecture. T. minor had the chromosome number of 2x = 18 (2sm + 2m + 2m + 2sm + 2m + 2m + 2m + 2sm + 2m). The following 3 species of exotic freshwater triclads were recorded from tanks and ponds used for tropical fish culture: Dugesia austroasiatica Kawakatsu, 1985 (2x = 16), Dugesia tigrina (Girard, 1850) (2x = 16) and Rhodax? sp. (3x = 24; 3x = 24 &; 3x + 1LB + 1SB = 25 + 1SB). The following 3 species of exotic terrestrial triclads were recorded: Bipalium nobile Kawakatsu et Makino, 1982 (2x = 10), Bipalium kewense Moseley, 1878 (2x = 18), and Platydemus manokwari de Beauchamp, 1962 (n = 6, 2x = 12). An extensive occurrence of P. manokwari in the Southwest Islands of Japan may be due to an unexpected introduction of the animal in very recent years.     

A time series and geographical analysis of population dynamics of the red-backed vole in Hokkaido,Japan

Summary A time series and geographical analysis of the long term (25-years and 16-years) census data of the red-backed vole, Clethrionomys rufocanus bedfordiae, populations in Hokkaido, Japan was carried out. Eighty seven populations from all over Hokkaido were grouped into the following 4 types according to their flucturation patterns: type A: low density-constant type; type B: medium density-gradual increase type; type C: medium density-wavy change type; type D: high density-large amplitude type. The border between type B and type C was not clear. Although the distribution of the fluctuation types did not show any geographical cline, the high density type (type D) occurred in limited areas where the winter was severe and spring came later and almost all the populations in the Oshima peninsula were the low density type (type A). The most common type of population in Hokkaido, type C, greatly fluctuated from year to year with the maximum density level/the minimum one being over 10. The periodicity of the peak years was not statistically significant, although peaks often occurred at 3 or 4 year intervals. The population grew from spring to autumn in almost all years so that the pattern of the seasonal change was qualitatively constant. The population density levels in spring were not significantly different between peak years and others, while those in autumn were greatly different between them, so that the population growth rates from spring to autumn were variable from year to year. This differential pattern was also found between high and low density areas.     

Pegasus, a small terminal inverted repeat transposable element found in the white gene of Anopheles gambiae

Pegasus, a novel transposable element, was discovered as a length polymorphism in the white gene of Anopheles gambiae. Sequence analysis revealed that this 535 bp element was flanked by 8 bp target site duplications and 8 bp perfect terminal inverted repeats similar to those found in many members of the Tcl family. Its small size and lack of long open reading frames preclude protein coding capacity. Southern analysis and in situ hybridization to polytene chromosomes demonstrated that Pegasus occurs in approximately 30 copies in the genomes of An. gambiae and its sibling species and is homogenous in structure but polymorphic in chromosomal location. Characterization of five additional elements by sequencing revealed nucleotide identities of 95% to 99%. Of 30 Pegasus-containing phage clones examined by PCR, only one contained an element exceeding 535 bp in length, due to the insertion of another transposable element-like sequence. Thus, the majority, if not all, extant Pegasus elements may be defective copies of a complete element whose contemporary existence in An. gambiae is uncertain. No Pegasus-hybridizing sequences were detected in nine other anophelines and three culicines examined, suggesting a very limited taxonomic distribution.     

Experiments with trap crops against African bollowrm, Heliothis armigera, in Ethiopia

In a 1 ha haricot bean (HB) (Phaseolus vulgaris L.) field strip-cropped with 2 rows of maize (MZ) (Zea mays L.) on either side and then at 25 m intervals, the number of African bollworm (ABW) (Heliothis armigera (Hubner) (Lepidoptera: Noctuidae)) eggs + larvae on MZ was higher than that on HB by a factor of nearly 18. In a replicated experiment where five trap crops were compared with HB, as a check, all of them contained significantly greater numbers of ABW eggs + larvae than the check. Among the crops tested, lupin (LP) (Lupinus termis Forsk.) and pigeon pea (Cajanus cajan (L.) Millsp.) followed by hyacinth bean (Dolichos lalab L.) contained the highest ABW egg + larval population while sunflower (Helianthus annuus L.) contained the lowest; MZ was intermediate. On the other hand, HB plots bordered with MZ suffered significantly lower percent pod damage by ABW than did the check. Although grain yield differences among treatments were not significant, MZ-bordered plots gave nearly 22% higher yield than the check during the heavy ABW infestation in 1982. These differences were less obvious during the 1983 season because of low ABW infestation. In hot pepper (Capsicum spp.) strip-cropped with lupin, egg + larval counts on the latter were greater by a factor of nearly four in 1981 and 18 in 1982. It is concluded that trap-cropping has a great potential in the integrated management of ABW.

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Résumé En 1981, dans un champ de haricot (Phaseolus vulgaris), des cultures pièges de maïs (Zea mays) ont été semées en rangs doubles tous les 25 m et de chaque côté du champ, soit un total de 5 rangs doubles. Le nombre d'H. armigera (oeufs + chenilles) a été près de 18 fois plus élevé sur maïs que sur haricot.En 1982 et 1983, l'attractivité de 5 cultures pièges: Dolichos lablab, Lupinus termis, Z. mays, Cajanus cajan et Helianthus annuus, a été comparée à celle du haricot. Toutes ces plantes portaient un nombre d'oeufs et de chenilles supérieur au témoin (P. vulgaris). L'ordre décroissant des contaminations était: L. termis, C. cajan, D. lablab, Z. mays et H. annuus. Les rangs de P. vulgaris bordés par des rangs de Z. mays étaient moins contaminés que les témoins. Bien que les différences de rendements en graines suivant les expériences n'aient pas été significatives, les parcelles bordées de maïs ont fourni une récolte supérieure de 22%, pendant l'année 1982, où la contamination par H. armigera a été forte. En 1983, où l'infestation a été faible, les différences étaient moins claires.En 1981 et 1982, 5 rangs de L. tremis à 25 m d'intervalle ont été utilisés comme pièges pour protéger le piment fort (Capsicum spp.). Les décomptes d'oeufs et de chenilles ont été respectivement près de 4 et 18 fois plus élevés.La conclusion est que les cultures pièges ont un grand avenir dans la lutte intégrée contre H. armigera.