African elephant vocal communication I: antiphonal calling behaviour among affiliated females

Background Patterns of vocal communication have implications for species conservation: a change in calling behaviour can, for instance, reflect a disturbed habitat. More importantly, call rate is a parameter that allows conservation planners to convert call density into animal density, when detecting calls with a passive acoustic monitoring system (PAM). Methods We investigated chimpanzee (Pan troglodytes schweinfurthii) call rate during the late dry season in the Issa Valley, western Tanzania by conducting focal follows. We examined the socio-ecological factors that influence call production rate of savanna woodland chimpanzees. Results We found that sex, proportion of time spent in a vegetation type, proportion of time spent travelling, time of the day, party size and swollen parous female presence had a significant effect on the call rate. Call rate differed among the different demographic classes with subadult and adult males vocalising twice as often as the subadult and adult females and three times as often as the juveniles. Applications The use of PAM and recent statistical developments to estimate animal density is promising but relies on our knowing individual call rate, often not available for many species. With the improvement in automatic call detection, we anticipate that PAM will increasingly be broadly applied to primates but also across taxa, for conservation.

Download Full-text

Vocal behaviour of the squirrel glider (Petaurus norfolcensis)

Australian Journal of Zoology ◽

10.1071/zo08075 ◽

2009 ◽

Vol 57 (1) ◽

pp. 55 ◽

Cited By ~ 4

Author(s):

David J. Sharpe ◽

Ross L. Goldingay

Keyword(s):

Vocal Communication ◽

New South ◽

Territorial Defence ◽

North East ◽

Calling Behaviour ◽

Vocal Behaviour ◽

South Wales ◽

Squirrel Glider ◽

Animal Handling ◽

Frequent Call

We describe the vocal behaviour of the squirrel glider (Petaurus norfolcensis) from 465 h of observation across five sites in north-east New South Wales and south-east Queensland. A monosyllabic or polysyllabic nasal grunt was the most frequent call (56% of 208 calls); it ranged from single calls to sequences of up to 20-min duration (mean 2.1 min ± 0.6, s.e.) and was heard on 34% of nights (n = 83) at two sites. The rate of the nasal grunt showed a positive relationship with population density at one site. The nasal grunt was typically made when conspecifics were near the caller, but responses were infrequent (7% of observations). Call playback produced no discernable change in call response. The nasal grunt appears to regulate individual spacing by facilitating mutual avoidance, a function hypothesised to be an evolutionary precursor to the use of calls in territorial defence. Threatening calls were the next most common vocalisation (17% of calls) and were accompanied by scuffles and/or chases. They were also used when gliders were preyed upon and during animal handling. The calling behaviour of the squirrel glider confirms the importance of vocal communication among petaurid gliders.

Download Full-text

Does Social Complexity Drive Vocal Complexity? Insights from the Two African Elephant Species

Animals ◽

10.3390/ani11113071 ◽

2021 ◽

Vol 11 (11) ◽

pp. 3071

Author(s):

Daniela Hedwig ◽

Joyce Poole ◽

Petter Granli

Keyword(s):

Communication Systems ◽

Social Complexity ◽

Vocal Communication ◽

Reproductive Rate ◽

African Elephant ◽

African Elephants ◽

Savanna Elephant ◽

The Social ◽

Forest Elephant ◽

Vocal Complexity

The social complexity hypothesis (SCH) for communication states that the range and frequency of social interactions drive the evolution of complex communication systems. Surprisingly, few studies have empirically tested the SHC for vocal communication systems. Filling this gap is important because a co-evolutionary runaway process between social and vocal complexity may have shaped the most intricate communication system, human language. We here propose the African elephant Loxodonta spec. as an excellent study system to investigate the relationships between social and vocal complexity. We review how the distinct differences in social complexity between the two species of African elephants, the forest elephant L. cyclotis and the savanna elephant L. africana, relate to repertoire size and structure, as well as complex communication skills in the two species, such as call combination or intentional formant modulation including the trunk. Our findings suggest that Loxodonta may contradict the SCH, as well as other factors put forth to explain patterns of vocal complexity across species. We propose that life history traits, a factor that has gained little attention as a driver of vocal complexity, and the extensive parental care associated with a uniquely low and slow reproductive rate, may have led to the emergence of pronounced vocal complexity in the forest elephant despite their less complex social system compared to the savanna elephant. Conclusions must be drawn cautiously, however. A better understanding of vocal complexity in the genus Loxodonta will depend on continuing advancements in remote data collection technologies to overcome the challenges of observing forest elephants in their dense rainforest habitat, as well as the availability of directly comparable data and methods, quantifying both structural and contextual variability in the production of rumbles and other vocalizations in both species of African elephants.

Download Full-text

Close range vocal interaction in the common marmoset (Callithrix Jacchus)

10.1101/2019.12.19.882118 ◽

2019 ◽

Cited By ~ 1

Author(s):

R. Landman ◽

J. Sharma ◽

J.B. Hyman ◽

A. Fanucci-Kiss ◽

O. Meisner ◽

...

Keyword(s):

Social Context ◽

Spectral Properties ◽

Home Cage ◽

Vocal Communication ◽

Common Marmoset ◽

Call Rate ◽

Close Proximity ◽

Antiphonal Calling ◽

Close Range ◽

The Common

AbstractVocal communication in animals often involves taking turns vocalizing. In humans, turn taking is a fundamental rule in conversation. Among non-human primates, the common marmoset is known to engage in antiphonal calling using phee calls and trill calls. Calls of the trill type are the most common, yet difficult to study, because they are not very loud and uttered in conditions when animals are in close proximity to one another. Here we recorded trill calls in captive pair-housed marmosets using wearable microphones, while the animals were together with their partner or separated, but within trill call range. Trills were exchanged mainly with the partner and not with other animals in the room. Animals placed outside the home cage increased their trill call rate and uttered more trills in response more to their partner. The fundamental frequency, F0, of trills increased when animals were placed outside the cage. Our results indicate that trill calls can be monitored using wearable audio equipment. Relatively minor changes in social context affect trill call interactions and spectral properties of trill calls, indicating that marmosets can communicate subtle information to their partner vocally.

Download Full-text

Vocal coordination and vocal imitation: A role for mirror neurons?

Behavioral and Brain Sciences ◽

10.1017/s0140525x13002410 ◽

2014 ◽

Vol 37 (2) ◽

pp. 211-212

Author(s):

John D. Newman

Keyword(s):

Communication Systems ◽

Mirror Neurons ◽

Vocal Communication ◽

Vocal Imitation ◽

Antiphonal Calling

AbstractSome birds and mammals have vocal communication systems in which coordination between individuals is important. Examples would include duetting or antiphonal calling in some birds and mammals, rapid exchanges of the same vocalization, and vocal exchanges between paired individuals and other nearby pairs. Mirror neurons may play a role in such systems but become functional only after experience.

Download Full-text