'BABBLING' IN PYGMY MARMOSETS: DEVELOPMENT AFTER INFANCY

Behaviour ◽  
2001 ◽  
Vol 138 (10) ◽  
pp. 1235-1248 ◽  
Author(s):  
Charles Snowdon ◽  
A. Margaret Elowson

AbstractInfant pygmy marmosets (Cebuella pygmaea) are extremely vocal with much of their calling occurring in long sequences of mixed call-types that appears to have several parallels to the babbling of human infants (Elowson et al., 1998b). We refer to this vocal behaviour as Pygmy Marmoset Babbling (PMB) (Elowson et al., 1998a). We followed several of our original subjects beyond infancy to adulthood. Babbling bouts continued to appear through the age of puberty though at a reduced rate from that seen in infancy, but babbling was rarely observed in adults. With increasing age the vocal bouts contained a greater diversity of call types per bout and a decrease in call series duration. In addition, with increasing age there were decreasing proportions of calls that were Adult Variant and Infant calls and an increase in Adult calls. Structural analyses of trills, the most common call type found in vocal bouts, showed increased proportions of well-formed trills and decreased proportions of poorly formed trills with increased age, with different features reaching adult form at different ages. Babbling by juvenile marmosets was associated with increased social interactions with other group members as we had observed with infants. 'Babbling' in both infant and juvenile marmosets might provide vocal practice as well as attract attention from other group members.

2021 ◽  
pp. 030098582110526
Author(s):  
Avery James Cooley ◽  
Anne Savage ◽  
Charles T. Snowdon

In a retrospective study of a western pygmy marmoset ( Cebuella pygmaea) colony, postmortem examination of 1/8 juvenile and 29/47 adult animals identified vascular, cardiac, and renal lesions consistent with systemic hypertension. This included frequent renal arteriolar hypertrophy, hyaline and proliferative arteriolosclerosis, fibrinoid necrosis of arterioles, glomerulosclerosis, and nephrosclerosis. Affected animals ranged from 0.6 to 12 years of age (mean 6 years) and had an observed male predominance. Genealogical relatedness was evident in several breeding pairs and spanned multiple generations. Concurrent cardiac and renal disease was commonly identified, although frequently subclinical, and both were important causes of morbidity and mortality in affected animals. Cardiomegaly and hypertrophy were typical features and were accompanied by left atrial thrombosis in 10 animals. Signs of heart failure included chronic pulmonary edema in 20 cases and body cavity effusions in 17. In the kidneys, 19 cases had glomerular disease and hypertensive vasculopathy, and 26 cases had nephrosclerosis or glomerulosclerosis. Common extrarenal secondary causes of hypertension were excluded by necropsy examination. The pathogenesis is suggested to involve primary hypertension leading to renal and cardiac disease. Elevated sympathetic activity might be an underlying factor in the frequent development of primary systemic hypertension in the pygmy marmoset, as for the owl monkey.


2020 ◽  
Vol 287 (1941) ◽  
pp. 20202531
Author(s):  
Julia Fischer ◽  
Franziska Wegdell ◽  
Franziska Trede ◽  
Federica Dal Pesco ◽  
Kurt Hammerschmidt

The extent to which nonhuman primate vocalizations are amenable to modification through experience is relevant for understanding the substrate from which human speech evolved. We examined the vocal behaviour of Guinea baboons, Papio papio , ranging in the Niokolo Koba National Park in Senegal. Guinea baboons live in a multi-level society, with units nested within parties nested within gangs. We investigated whether the acoustic structure of grunts of 27 male baboons of two gangs varied with party/gang membership and genetic relatedness. Males in this species are philopatric, resulting in increased male relatedness within gangs and parties. Grunts of males that were members of the same social levels were more similar than those of males in different social levels ( N = 351 dyads for comparison within and between gangs, and N = 169 dyads within and between parties), but the effect sizes were small. Yet, acoustic similarity did not correlate with genetic relatedness, suggesting that higher amounts of social interactions rather than genetic relatedness promote the observed vocal convergence. We consider this convergence a result of sensory–motor integration and suggest this to be an implicit form of vocal learning shared with humans, in contrast to the goal-directed and intentional explicit form of vocal learning unique to human speech acquisition.


2018 ◽  
Vol 285 (1872) ◽  
pp. 20172645 ◽  
Author(s):  
Elizabeth A. Tibbetts ◽  
Michelle L. Fearon ◽  
Ellery Wong ◽  
Zachary Y. Huang ◽  
Robin M. Tinghitella

In many cooperatively breeding animals, subordinate group members have lower reproductive capacity than dominant group members. Theory suggests subordinates may downregulate their reproductive capacity because dominants punish subordinates who maintain high fertility. However, there is little direct experimental evidence that dominants cause physiological suppression in subordinates. Here, we experimentally test how social interactions influence subordinate reproductive hormones in Polistes dominula paper wasps. Polistes dominula queens commonly found nests in cooperative groups where the dominant queen is more fertile than the subordinate queen. In this study, we randomly assigned wasps to cooperative groups, assessed dominance behaviour during group formation, then measured levels of juvenile hormone (JH), a hormone that mediates Polistes fertility. Within three hours, lowest ranking subordinates had less JH than dominants or solitary controls, indicating that group formation caused rapid JH reduction in low-ranking subordinates. In a second experiment, we measured the behavioural consequences of experimentally increasing subordinate JH. Subordinates with high JH-titres received significantly more aggression than control subordinates or subordinates from groups where the dominant's JH was increased. These results suggest that dominants aggressively punished subordinates who attempted to maintain high fertility. Low-ranked subordinates may rapidly downregulate reproductive capacity to reduce costly social interactions with dominants. Rapid modulation of subordinate reproductive physiology may be an important adaptation to facilitate the formation of stable, cooperative groups.


Sociology ◽  
2018 ◽  
Vol 53 (1) ◽  
pp. 139-155 ◽  
Author(s):  
Yuval Feinstein ◽  
Maha Shehade Switat

This study examines how emotion management is linked to subjective identity among members of ethnic minority groups in ethnically mixed workplaces. Data were drawn from interviews with Arab/Palestinian citizen residents of Israel. The results reveal three distinct strategies of emotion management: (1) Arab/Palestinians, regardless of their subjective identity, tend to conceal emotions during interactions with majority group members; (2) individuals who identify as ‘Arab’ also tend to regulate social interactions to avoid the emotional risks that accompany interactions with majority group members; (3) those who choose a ‘Palestinian’ label are more likely to actively express their ethnic identities despite the emotional risks associated with this type of identification. The findings suggest that emotion management is influenced not only by a person’s assignment to a social minority category (the emphasis of previous research), but also by a person’s subjectively defined identity.


Behaviour ◽  
1996 ◽  
Vol 133 (11-12) ◽  
pp. 827-845 ◽  
Author(s):  
A.H. Harcourt ◽  
K.J. Stewart

We investigate the social significance of the within group ('close') calls of gorillas by examining correlates of calling with dominance rank and with relatedness of adults, and by examining whether the outcomes of interactions between adults differ depending on the calls given during the interactions. In two wild gorilla groups, the majority of adults give most of their calls when near another adult and fully in sight of them. Thus gorillas' use 'close' calls as more than mere contact calls. An adult gorilla's use of 'close' calls correlates with its own and with its partner's dominance rank, with effects being most obvious for the most dominant animals, the fully adult males. Thus the proportion of 'double grunts', the most common 'close' call, in an individual's repertoire correlated consistently with dominance rank; all non-silverback adults gave a higher percent of double grunts in the presence of subordinates than they did near dominant animals; individuals were most likely to give 'non-syllabled' grunts in the adult male's presence; and they consistently exchanged calls at a higher rate with the adult males than with other group members. An adult's type of calls did not obviously differ depending on whether their neighbour was kin or non-kin, but kin were overall more likely to give calls in the presence of kin, and to exchange calls with kin than with non-kin, although the association was not consistent throughout the two years of the study. With regard to the consequences of calling, subordinates were less likely to be feeding one minute after an approach by a fully adult male during which calls were exchanged than during silent approaches. In contrast to findings from studies of some other species, calling did not correlate with duration of grooming. We suggest that, among other functions, gorillas' 'close' calls mediate social interactions. One form of calls, 'non-syllabled' calls, are interpretable as appeasement signals. The broadest interpretation of the 'double grunt' is that it is an exaggerated announcement of presence, whose function is to attract attention to the caller, and to signal conditional future activity.


2017 ◽  
Vol 284 (1863) ◽  
pp. 20171682 ◽  
Author(s):  
Jennifer Susan McClung ◽  
Sarah Placì ◽  
Adrian Bangerter ◽  
Fabrice Clément ◽  
Redouan Bshary

While we know that the degree to which humans are able to cooperate is unrivalled by other species, the variation humans actually display in their cooperative behaviour has yet to be fully explained. This may be because research based on experimental game-theoretical studies neglects fundamental aspects of human sociality and psychology, namely social interaction and language. Using a new optimal foraging game loosely modelled on the prisoner's dilemma, the egg hunt, we categorized players as either in-group or out-group to each other and studied their spontaneous language usage while they made interactive, potentially cooperative decisions. Both shared group membership and the possibility to talk led to increased cooperation and overall success in the hunt. Notably, analysis of players' conversations showed that in-group members engaged more in shared intentionality, the human ability to both mentally represent and then adopt another's goal, whereas out-group members discussed individual goals more. Females also helped more and displayed more shared intentionality in discussions than males. Crucially, we show that shared intentionality was the mechanism driving the increase in helping between in-group players over out-group players at a cost to themselves. By studying spontaneous language during social interactions and isolating shared intentionality as the mechanism underlying successful cooperation, the current results point to a probable psychological source of the variation in cooperation humans display.


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