Spatial variability in the social organisation of the yellow-bellied glider (Petaurus australis) near Ravenshoe, north Queensland

2001 ◽  
Vol 49 (4) ◽  
pp. 397 ◽  
Author(s):  
Ross L. Goldingay ◽  
Darren G. Quin ◽  
Sue Churchill

A detailed study was conducted over a 12-month period of 10 yellow-bellied glider groups at Nitchaga Creek in north Queensland. Adult gliders were sexually dimorphic in body size and were characterised by yellow ventral fur, which is consistent with southern populations. Gliders lived in groups of 3–6 individuals that occupied exclusive areas of about 50 ha. The structure of glider groups varied enormously: five contained one adult pair, three contained one adult male and 2–3 adult females, and two initially contained 2–3 adult males and one adult female but then persisted as bachelor groups after the death or disappearance of the adult female. Group size changed during the year as offspring matured and as individuals died. One male glider dispersed about 1 km from its natal home-range and became the dominant male in a nearby group. Young were born throughout the year, with a peak in the number of pouch-young in June. This study has confirmed the highly variable social system of the yellow-bellied glider, which appears to be mediated by local resource abundance.

Author(s):  
Kara Walker ◽  
Brian Hare

The dominance style of bonobos presents an evolutionary puzzle. Bonobos are not male dominant but female bonobos do not show traits typical of female-dominant species. This chapter proposes the offspring dominance hypothesis (ODH) as a potential solution. ODH suggests the social system of bonobos evolved as a defence against infanticide and is not due to pressure to monopolize resources. Females that prevented aggression towards offspring and preferred mating with less aggressive males were most successful. Supporting ODH, during observations at Lola ya Bonobo Sanctuary it was found that: 1) adult male bonobos are rarely aggressive towards offspring with mothers, 2) some mother-reared juvenile bonobos attain rank higher than adult males and 3) mother-reared offspring often socially interact with adult males without their mothers nearby. These preliminary findings provide initial support that the bonobo social system evolved due to fitness advantages of effectively protecting offspring against consequences of male aggression. Le style de dominance des bonobos présente un puzzle évolutionnaire. Les bonobos ne sont pas dominés par les mâles mais les bonobos femelles ne montrent pas les traits caractéristiques d’une espèce dominée par femelles. On propose l’hypothèse de dominance de progéniture (ODH) comme une solution potentielle. La ODH suggère que le système social des bonobos a évolué en défense contre l’infanticide et pas sous pression pour la monopolisation des ressources. Les femelles qui préviennent l’agression vers leur progéniture et leur préférence d’accouplement avec des mâles moins agressives étaient très efficaces. À l’appui de la ODH on a trouvé pendant nos observations à Lola ya Bonobo Sanctuary que: 1) les mâles adultes bonobos agressent rarement vers les bébés avec mères, 2) quelques adolescents bonobos qui furent élevés par leurs mères atteignent un rang plus haut que les mâles adultes et 3) la progéniture élevée par la mère interagissent avec avec d’adultes mâles sans la présence de leur mère. Ces trouvailles préliminaires donnent appuie à l’hypothèse que le système social des bonobos a évolué par les avantages corporelles de la protection de la progéniture contre les conséquences de l’agression mâle.


2003 ◽  
Vol 30 (3) ◽  
pp. 281 ◽  
Author(s):  
David S. Dique ◽  
Jim Thompson ◽  
Harriet J. Preece ◽  
Deidré L. de Villiers ◽  
Frank N. Carrick

Koala dispersal was investigated as part of a detailed ecological study of a nationally significant koala population located 20 km south-east of Brisbane, Queensland. From 1996 to 2000, 195 koalas from three sites were captured and fitted with radio-collars. A total of 40 koalas (23 males and 17 females) dispersed from these sites. Most (93%) dispersing individuals were 20–36 months of age. Three adult females (more than 36 months old) dispersed and no adult males dispersed during the study. A significantly higher proportion of young males dispersed than females. Dispersal occurred between June and December, with most dispersal of males commencing in July and August and that of females commencing between September and November prior to, and early in, the annual breeding season. The mean straight-line distance between the natal and breeding home ranges for males and females was similar and was measured at 3.5 km (range 1.1–9.7 km) and 3.4 km (range 0.3–10.6 km) respectively. Dispersing males and females tended to successfully disperse south and west of their natal home ranges and were generally unable to successfully disperse to urban areas within the study area, as a high proportion of the mortality of dispersing koalas was associated with attacks by domestic dogs and with collisions with vehicles on roads. Information from other studies indicates that most young koalas disperse from their natal areas. It is likely that the social behaviour and mating systems of koala populations provide mechanisms for young koalas to disperse. The potential role of dispersal in the dynamics of regional koala populations is discussed.


Behaviour ◽  
1980 ◽  
Vol 72 (1-2) ◽  
pp. 26-48 ◽  
Author(s):  
Patrick Duncan

AbstractTime-budgets of adult and weaned sub-adult horses were studied in a small population of Camargue horses living in semi-liberty. The categories of activities used were: Standing resting, Lying flat, Lying up, Standing alert, Walking, Trotting, Galloping, Rolling and Foraging. The main differences in time-budgets were related to age and to sex : young horses spent more time lying (sleeping), males spent more time standing alert and in rapid movements (trot, gallop), while usually foraging less than did the adult females. During the three years of the study the population increased from 20 to 54 horses and there were considerable changes in social structure as the number of adult males increased. Associated with these developments there were some changes between years in the time-budgets: the most striking of which was a general trend for all horses to spend less time lying. Nonetheless the time-budgets showed a considerable constancy across years and age/sex-classes, especially with regard to time spent foraging. This conclusion may provide a clue as to why horses have an unusual social system based on long term relationships between a male and the females of his harem.


1994 ◽  
Vol 45 (2) ◽  
pp. 169 ◽  
Author(s):  
WD Sumpton ◽  
MA Potter ◽  
GS Smith

In Moreton Bay, Queensland, externae of Sacculina granifera Boschma were found in 7.0% of adult males and 123% of adult females of Portunus pelagicus. Infection rates were seasonal for both sexes and higher in the adult female population, with more than 20% of adult females carrying externae during some summer months. Infection rates were less than 3% in areas outside the bay and generally highest in the southern and central bay. Nineteen males and 15 females had abdominal scars where externae had become dislodged. The gonads of most parasitized crabs were underdeveloped, but 5.6% of externa-bearing females and 10% of externa-bearing males also had well developed gonads. Two female sand crabs were found with both a small egg mass and a mature externa (a condition not previously reported). Size distributions of infected and uninfected adult crabs were similar, suggesting that large crabs as well as juvenile crabs were likely to be infected.


Zootaxa ◽  
2010 ◽  
Vol 2459 (1) ◽  
pp. 1 ◽  
Author(s):  
CHRIS HODGSON ◽  
DUG MILLER

This paper reviews the present status of all genera of Eriococcidae (Hemiptera: Sternorrhyncha: Coccoidea) known from South America and provides generic diagnoses based on the adult females of all available species for each genus. Redescriptions and illustrations are provided for the adult females of Aculeococcus morrisoni Lepage, Apiococcus gregarius Hempel, Capulinia sallei Signoret, Carpochloroides viridis Cockerell, Macracanthopyga verganiana Lizer y Trelles, Pseudocapulinia lanosa Hempel and Tectococcus ovatus Hempel, which are all type species of their respective genera. In addition, modified reproductions of original illustrations are provided for the adult females of the following species as representatives or type species of South American genera: Acanthococcus aceris Signoret, Chilechiton lynnae Hodgson & Miller, Chilecoccus browni Miller & González, Coxicoccus foldi Kozár & Konczné Benedicty, Eriobalachowskya valenzualae (Balachowsky), Exallococcus laureliae Miller & González, Hempelicoccus paranaensis (Foldi & Kozár), Icelococcus nothofagi Miller & González, Intecticoccus viridis Kondo, Melzeria horni Green, Orafortis luma Hardy, Oregmopyga neglecta (Cockerell), Poliloculus stipae González, Pseudotectococcus anonae Hempel and Stibococcus cerinus Miller & González. Descriptions and illustrations are also provided of the first-instar nymphs of: Acanthococcus aceris Signoret, Aculeococcus morrisoni, Apiococcus gregarius, A. singularis Hempel (which appears to be sexually dimorphic), Capulinia sallei, Carpochloroides viridis, Chilechiton lynnae, Exallococcus laureliae, Hempelicoccus tucumanensis (González & Granara de Willink), Icelococcus lithrae Miller & González, Melzeria horni, Oregmopyga peruviana Granara de Willink & Diaz, Pseudocapulinia lanosa, Pseudotectococcus anonae and Tectococcus ovatus. In addition, illustrated descriptions of the adult males of Capulinia sallei, Carpochloroides viridis, and Tectococcus ovatus are included. The first-instar nymphs and adult males of the other genera, where they are known, are also diagnosed and discussed. Based on the molecular studies of Cook & Gullan (2004), most species currently included in Eriococcus Targioni Tozzetti known from South America are considered to belong to the genus Acanthococcus Signoret, resulting in the following new combinations: A. clapsae (González) n. comb., A. cuneifoliae (González) n. comb., A. divaricatae (González) n. comb., A. pituilensis (González) n. comb. and A. lahillei (Leonardi) n. comb. In additon, Eriococcus pumuliae González, E. santiaguensis González & Granara de Willink and E. tucumanensis González & Granara de Willink are transferred to Hempelicoccus, as H. pumuliae (González) n. comb., H. santiaguensis (González & Granara de Willink) n. comb. and H. tucumanensis n. comb. (González & Granara de Willink). The status of Opisthoscelis prosopidis Kieffer & Jorgensen, the only species from the Neotropics currently included in Opisthoscelis Schrader, is discussed, and it is concluded that this species is unlikely to belong to this genus but is currently unrecognizable. Keys are provided for the identification of the 24 genera now known from South America based on the morphology of: (i) the adult females; (ii) the first-instar nymphs; and (iii) adult males, as far as these are known. In addition, Appendix 1 lists all Eriococcidae known from South America with their current generic placement, along with a brief summary of their host plants.


Behaviour ◽  
1968 ◽  
Vol 32 (1-3) ◽  
pp. 49-68 ◽  
Author(s):  
Stuart A. Altmann

AbstractDuring a two-year field study of rhesus monkeys, data were obtained that are relevant to a hypothesis, proposed by MASON, GREEN & POSEPANKO (1960), that adult females will show a higher incidence of affective reactions than adult males, including threat behavior and aggressive posturing, and will probably more often be involved in episodes of minor aggression. This hypothesis is here restated in probabilistic terms, and a method is described for quantitative testing of the hypothesis under field conditions. Relevant data from a two-year field study of rhesus monkeys are presented and analyzed. These data gave no indication that females showed a higher incidence of affective responses as a whole, nor that they were more inclined to exhibit the milder forms of agonistic behavior. There was an indication that the affective social behavior of adult males is somewhat more likely to be aggressive than is that of adult females, while the behavior of the adult females is more likely to be submissive. Adult females were more likely to ignore the social partner than were adult males, and were perhaps less likely to lip-smack in affective situations. Among juveniles, the females displayed relatively more affective behavior than did males, as predicted. There was no indication that juvenile females were more likely to ignore their social partner than were males of the same age class. With juveniles, too, there was no indication that the females were more prone to display mild forms of agonism in their affective interactions. While the available data do not confirm the hypothesis of MASON et al., they do support an alternative hypothesis, namely, that in affective behavior, adult males tend, more often than adult females, to lunge, screech, approach, chase, or screech while grimacing, and that females tend, more often than males, to hit, avoid, flee from, or ignore their social partner. Some possible sources of error in this kind of research are discussed; at present the accuracy of generalizations that are made about primate behavior on the basis of field observations is greatly restricted by errors of sampling.


2008 ◽  
Vol 4 (3) ◽  
pp. 243-245 ◽  
Author(s):  
A.R Martin ◽  
V.M.F da Silva ◽  
P Rothery

Amazon river dolphins or botos ( Inia geoffrensis Blainville) were observed carrying objects in 221 social groups over a 3-year study period. Sticks, branches and clumps of grass were taken from the water surface and often repeatedly thrashed or thrown. Lumps of hard clay were collected from the river bed and held in the mouth while the carrier rose slowly above the surface and submerged again. Carriers were predominantly adult males and less often subadult males. Adult females and young dolphins rarely carried objects. Groups of dolphins in which object carrying occurred were differentially large and comprised a greater proportion of adult males and adult females. Aggression, mostly between adult males, was significantly associated with object carrying. The behaviour occurred year-round, with peaks in March and July. A plausible explanation of the results is that object carrying by adult males is aimed at females and is stimulated by the number of females in the group, while aggression is targeted at adult males and is stimulated by object carrying in the group. We infer that object carrying in this sexually dimorphic species is socio-sexual display. It is either of ancient origin or has evolved independently in several geographically isolated populations.


1977 ◽  
Vol 55 (7) ◽  
pp. 1151-1157 ◽  
Author(s):  
M. B. Fenton

The social calls of 14 Myotis lucifugus (5 adult males; 5 adult females; 2 subadult males; 2 subadult females) produced under controlled conditions were more variable than echolocation calls made by hunting individuals in the wild. The social calls contained lower frequencies and in some cases were of longer duration than the echolocation calls. Careful examination of sound spectrographs of the calls indicated tremendous variability in details of frequency and time. Although several types of calls can be recognized, a discrete classification is not feasible because of the variability. The possible significance of the variation in the calls of these bats is discussed in the context of recognition of individuals by their vocalizations.


Behaviour ◽  
2003 ◽  
Vol 140 (10) ◽  
pp. 1235-1246 ◽  
Author(s):  
◽  

AbstractLemur social systems have the striking social feature, that adult females consistently evoke submissive behaviour of adult males. In the Alaotran gentle lemur, Hapalemur griseus alaotrensis, however, female dominance has not been studied yet. Here we confirm female dominance over males on the basis of a 5-month field study of the social behaviour of four groups, in the Lake Alaotra marshland of eastern Madagascar. Further, we found that dominant individuals initiated aggressive interactions significantly more often than lowerranking ones, they initiated group movements more often and higher-ranking individuals were groomed more often. The spatial configuration was remarkable, since individuals were closer in space to those more distant in rank.


1993 ◽  
Vol 71 (1) ◽  
pp. 204-218 ◽  
Author(s):  
Darwin R. Wiggett ◽  
David A. Boag

The results of this study support the hypothesis that male-biased emigration of yearling male Columbian ground squirrels (Spermophilus columbianus) is socially induced. The likelihood of emigration from both the natal site and the natal colony was correlated with parameters of social structure and behavior. Agonism by the mother and (or) neighboring adult females, in association with parturition and lactation, apparently caused the initial shifts of yearling males away from their natal home ranges. After these shifts, yearling males that lived in areas where the number of neighboring males (both adult and yearling) was high relative to the number of females emigrated to areas within the natal colony that were more female-biased (intracolony emigration), or emigrated from the natal colony (intercolony emigration). Reduced numbers of adult males apparently resulted in lower rates of emigration by yearling males. Among the latter, emigrants appeared to be subordinate to non-emigrants. We discuss these findings in light of current hypotheses concerning the proximate and ultimate causes of emigration in ground-dwelling sciurids.


Sign in / Sign up

Export Citation Format

Share Document