Singing in the rain! Climate constraints on the occurrence of indri's song.

The study of how animals adapt their behaviors depending on weather variables has gained particular significance in the context of climate change. This exploration offers insights into endangered species' potential threats and provides information on the direction to take in conservation activities. In this context, noninvasive, cost-effective, and potentially long-term monitoring systems, such as Passive Acoustic Monitoring (PAM), become particularly appropriate.

Isochrony as ancestral condition to call and song in a primate.

Animal songs differ from calls in function and structure, and have comparative and translational value, showing similarities to human music. Rhythm in music is often distributed in quantized classes of intervals known as rhythmic categories. These classes have been found in the songs of a few nonhuman species but never in their calls.

In "Tone" with dogs: exploring canine musicality.

This study investigates the musical perception skills of dogs through playback experiments. Dogs were trained to distinguish between two different target locations based on a sequence of four ascending or descending notes. A total of 16 dogs of different breeds, age, and sex, but all of them with at least basic training, were recruited for the study.

Who you live with and what you duet for: a review of the function of primate duets in relation to their social organization.

Duets are one of the most fascinating displays in animal vocal communication, where two animals fine-tune the timing of their emissions to create a coordinated signal. Duetting behavior is widespread in the animal kingdom and is present in insects, birds, and mammals. Duets are essential to regulate activities within and between social units.

"The song remains the same": not really! Vocal flexibility in the song of the indris.

In studying communicative signals, we can think of flexibility as a necessary correlate of creativity. Flexibility enables animals to find practical solutions and appropriate behaviors in mutable situations. In this study, we aimed to quantify the degree of flexibility in the songs of indris (Indri indri), the only singing lemur, using three different metrics: Jaro Distance, normalized diversity, and entropy.

Behavioural Correlates of Lemur Scent-Marking in Wild Diademed Sifakas () in the Maromizaha Forest (Madagascar).

Scent-marking through odours from excreta and glandular secretions is widespread in mammals. Among primates, diurnal group-living lemurs show different deployment modalities as part of their strategy to increase signal detection. We studied the diademed sifaka () in the Maromizaha New Protected Area, Eastern Madagascar.

Singing more, singing harsher: occurrence of nonlinear phenomena in a primate' song.

Nonlinear phenomena (NLP) in animal vocalizations arise from irregularities in the oscillation of the vocal folds. Various non-mutually exclusive hypotheses have been put forward to explain the occurrence of NLP, from adaptive to physiological ones. Non-human primates often display NLP in their vocalizations, yet the communicative role of these features, if any, is still unclear.

Evidence for acoustic discrimination in lemurs: A playback study on wild indris .

Indris are group-living lemurs that occupy stable territories over several years and perform remarkable long-distance vocal displays. Vocal exchanges between long-term territory neighbors may contribute to assessing reciprocal resource-holding potentials, thus adaptively reducing the costs of territorial defense by limiting aggressive escalation. Previous work showed that indris' songs show distinctive acoustic features at individual and group level.

There You Are! Automated Detection of Indris' Songs on Features Extracted from Passive Acoustic Recordings.

The growing concern for the ongoing biodiversity loss drives researchers towards practical and large-scale automated systems to monitor wild animal populations. Primates, with most species threatened by extinction, face substantial risks. We focused on the vocal activity of the indri (Indri indri) recorded in Maromizaha Forest (Madagascar) from 2019 to 2021 via passive acoustics, a method increasingly used for monitoring activities in different environments.

Erratum to: Born to sing! Song development in a singing primate.

[This corrects the article DOI: 10.1093/cz/zoab018.].

Fungal Patterns from Soils in Madagascar: an Insight from Maromizaha Forest (Evergreen Humid Forest) to Outside (Deciduous Forest).

Soil fungal diversity was studied by next-generation sequencing and compared in two different Malagasy ecosystems, the first a New Protected Area (Maromizaha NAP) that is a rich humid evergreen forest and the second a degraded and declined deciduous forest (Andaravina) whose area has been also eroded. Both areas, however, have comparable annual rainfalls and soil pH values. So it was of interest to examine the soil fungal diversity in each system and compare them.

Born to sing! Song development in a singing primate.

In animal vocal communication, the development of adult-like vocalization is fundamental to interact appropriately with conspecifics. However, the factors that guide ontogenetic changes in the acoustic features remain poorly understood. In contrast with a historical view of nonhuman primate vocal production as substantially innate, recent research suggests that inheritance and physiological modification can only explain some of the developmental changes in call structure during growth.

Categorical rhythms in a singing primate.

What are the origins of musical rhythm? One approach to the biology and evolution of music consists in finding common musical traits across species. These similarities allow biomusicologists to infer when and how musical traits appeared in our species. A parallel approach to the biology and evolution of music focuses on finding statistical universals in human music.

Disentangling the Possible Drivers of Microbiome: A Threatened Lemur Species of Madagascar.

Research on the gut microbiome may help with increasing our understanding of primate health with species' ecology, evolution, and behavior. In particular, microbiome-related information has the potential to clarify ecology issues, providing knowledge in support of wild primates conservation and their associated habitats. Indri () is the largest extant living lemur of Madagascar.

Dominance style is a key predictor of vocal use and evolution across nonhuman primates.

Animal communication has long been thought to be subject to pressures and constraints associated with social relationships. However, our understanding of how the nature and quality of social relationships relates to the use and evolution of communication is limited by a lack of directly comparable methods across multiple levels of analysis. Here, we analysed observational data from 111 wild groups belonging to 26 non-human primate species, to test how vocal communication relates to dominance style (the strictness with which a dominance hierarchy is enforced, ranging from 'despotic' to 'tolerant').

Dolphin whistles can be useful tools in identifying units of conservation.

Background: Prioritizing groupings of organisms or 'units' below the species level is a critical issue for conservation purposes. Several techniques encompassing different time-frames, from genetics to ecological markers, have been considered to evaluate existing biological diversity at a sufficient temporal resolution to define conservation units. Given that acoustic signals are expressions of phenotypic diversity, their analysis may provide crucial information on current differentiation patterns within species.

Linguistic laws of brevity: conformity in Indri indri.

Vocal and gestural sequences of several primates have been found to conform to two general principles of information compression: the compensation between the duration of a construct and that of its components (Menzerath-Altmann law) and an inverse relationship between signal duration and its occurrence (Zipf's law of abbreviation). Even though Zipf's law of brevity has been proposed as a universal in animal communication, evidence on non-human primate vocal behavior conformity to linguistic laws is still debated, and information on strepsirrhine primates is lacking. We analyzed the vocal behavior of the unique singing lemur species (Indri indri) to assess whether the song of the species shows evidence for compression.

Allometric escape and acoustic signal features facilitate high-frequency communication in an endemic Chinese primate.

The principle of acoustic allometry-the larger the animal, the lower its calls' fundamental frequency-is generally observed across terrestrial mammals. Moreover, according to the Acoustic Adaptation Hypothesis, open habitats favor the propagation of high-frequency calls compared to habitats with complex vegetational structures. We carried out playback experiments in which the calls of the Guizhou snub-nosed monkey (Rhinopithecus brelichi) were used as stimuli in sound attenuation and degradation experiments to test the hypothesis that propagation of Guizhou snub-nosed monkey calls is favored above vs through the forest floor vegetation.

I Like the Way You Eat It: Lemur (Indri indri) Gut Mycobiome and Geophagy.

Here, we investigated the possible linkages among geophagy, soil characteristics, and gut mycobiome of indri (Indri indri), an endangered lemur species able to survive only in wild conditions. The soil eaten by indri resulted in enriched secondary oxide-hydroxides and clays, together with a high concentration of specific essential micronutrients. This could partially explain the role of the soil in detoxification and as a nutrient supply.

Biological Sound vs. Anthropogenic Noise: Assessment of Behavioural Changes in Exposed to Boats Noise.

Despite the growing interest in human-made noise effects on marine wildlife, few studies have investigated the potential role of underwater noise on elasmobranch species. In this study, twelve specimens of small-spotted catshark () were exposed to biological and anthropogenic sounds in order to assess their behavioural changes in response to prey acoustic stimuli and to different amplitude levels of shipping noise. The sharks, individually held in aquariums, were exposed to four experimental acoustic conditions characterized by different spectral (Hz) components and amplitude (dB re 1 µPa) levels.

Sexually dimorphic phrase organization in the song of the indris (Indri indri).

Animal acoustic communication often takes the form of complex sequences, composed of multiple distinct acoustic units, which can vary in their degree of stereotypy. Studies of sequence variation may contribute to our understanding of the structural flexibility of primates' songs, which can provide essential ecological and behavioral information about variability at the individual, population, and specific level and provide insights into the mechanisms and drivers responsible for the evolutionary change of communicative traits. Several methods have been used for investigating different levels of structural information and sequence similarity in acoustic displays.

Evidence of genetic monogamy in the lemur Indri (Indri indri).

Monogamy is a rare strategy among mammals but relatively common among primates. The study of the evolution of monogamy in mammals and primates is lacking empirical studies that assess the relationship between a pair-living social organization and genetic monogamy. Sexual or genetic monogamy can only be assessed by performing molecular analyses and investigating rates of extra-pair paternity (EPP).

Finding Meanings in Low Dimensional Structures: Stochastic Neighbor Embedding Applied to the Analysis of Vocal Repertoire.

Although there is a growing number of researches focusing on acoustic communication, the lack of shared analytic approaches leads to inconsistency among studies. Here, we introduced a computational method used to examine 3360 calls recorded from wild indris () from 2005-2018. We split each sound into ten portions of equal length and, from each portion we extracted spectral coefficients, considering frequency values up to 15,000 Hz.

Female indris determine the rhythmic structure of the song and sustain a higher cost when the chorus size increases.

Among the behavioral traits shared by some nonhuman primate species and humans there is singing. Unfortunately, our understanding of animals' rhythmic abilities is still in its infancy. Indris are the only lemurs who sing and live in monogamous pairs, usually forming a group with their offspring.

First ethnobotanical inventory and phytochemical analysis of plant species used by indigenous people living in the Maromizaha forest, Madagascar.

Ethnopharmacological Relevance: Characterized by one of the highest rates of endemism and biodiversity in the world, Madagascar provides a wide variety of medicinal plants, that could represent a potential source of new drugs. The main aim of this study was to investigate the potential medicinal properties of the plant species used by indigenous people in Maromizaha forest and to provide the first ethnobotanical inventory of the area.

Materials And Methods: Data were collected through open semi-structured interviews with local informants, the reported plants were collected and identified to create a specimen herbarium.