Estimating Population Density of the San Martin Titi Monkey (Callicebus oenanthe) in Peru Using Vocalisations

Kuijk, Silvy M. van; García-Suikkanen, Carolina; Tello-Alvarado, Julio C.; Vermeer, Jan; Hill, Catherine M.

doi:10.1159/000442974

Cited by 13 publications

(4 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The necessary long-term fieldwork costs make these values difficult to assess, but clearly this correction factor varies between long-term assessments and approximate estimations [Aldrich et al, 2008;López-Strauss and Wallace, 2015;Van Kuijk et al, 2015]. We provide territorial call rates for the Bolivian endemic titi monkeys from a year-round observation period for each species, values that could be used in further density assessments.…”

Section: Discussionmentioning

confidence: 99%

Ecological and Behavioural Factors Influencing Territorial Call Rates for the Bolivian Titi Monkeys, Plecturocebus modestus and Plecturocebus olallae

Martínez¹,

Wallace²

2016

IJFP

View full text Add to dashboard Cite

Primate territorial calls have been used to locate groups in censuses. Daily variations in call rates are a potential source of error in these studies. To obtain more accurate estimations of population density it is necessary to determine how much variation there is in group call rates and to identify the factors that influence them. We present data on the emission of territorial calls by two threatened and endemic titi monkeys in Bolivia: Plecturocebus olallae and P. modestus. We found interspecific differences in daily call rates (52% P. modestus and 33% P. olallae). Groups inhabiting more continuous forests vocalized more frequently than groups in fragmented forests, which might be linked to the higher abundance of groups in less fragmented forests. We found seasonal differences in call rates between species, with more frequent calling in P. modestus during the dry season, while P. olallae called more frequently in the rainy season. The study groups emitted territorial calls mostly from the central zones of their territories, suggesting they do not face intense spatial competition with neighbouring groups. Our results improve the general ecological knowledge on P. olallae and P. modestus, and can also be used to improve population abundance studies and ongoing conservation efforts.

show abstract

Section: Discussionmentioning

confidence: 99%

Ecological and Behavioural Factors Influencing Territorial Call Rates for the Bolivian Titi Monkeys, Plecturocebus modestus and Plecturocebus olallae

Martínez¹,

Wallace²

2016

IJFP

View full text Add to dashboard Cite

show abstract

“…Our recording from P. oenanthe northern population was made at an altitude of 850 m. The mountains of the San Martin Department provide a physical barrier for this critically endangered titi monkey. Given its restricted distribution range, we may expect very little gene flow between the northern and southern populations, a situation exacerbated by heavy deforestation [ 110 , 111 , 112 ]. Over time, genetic drift might lead to vocal divergence between these two isolated populations of P. oenanthe .…”

Section: Discussionmentioning

confidence: 99%

Duetting Patterns of Titi Monkeys (Primates, Pitheciidae: Callicebinae) and Relationships with Phylogeny

Adret

Dingess

Caselli

et al. 2018

Animals

Self Cite

View full text Add to dashboard Cite

Simple SummaryTiti monkeys—a diversified group of pair-bonded, territorial neotropical primates exhibiting biparental care—produce elaborate, powerful vocal duets used for long-range communication. While the callicebine taxonomy has been centered mainly on the biogeography, morphology, anatomy, and genetics of titi populations, vocal attributes have received little attention as potentially informative markers of phylogenetic relationships. We conducted acoustic analysis of callicebine loud calls recorded from ten species of titis at sites in Bolivia, Peru, and Ecuador and found four distinct patterns of duetting that only partially match three major clades identified in recent molecular genetic studies. In particular, we found that the loud calls of the San Martin titi monkey, P. oenanthe, and the Urubamba brown titi, P. urubambensis, strikingly differ from putative relatives within the donacophilus lineage. Our findings highlight interplay between genes and environment on the expression of vocal behavior and suggest that closer interaction between taxonomists, ethologists, and molecular biologists should be rewarding in resolving the callicebine phylogeny. Such concerted efforts, in turn, will most likely generate valuable recommendations for the conservation of some endangered populations of titi monkeys, such as the vocally distinctive San Martin titi.AbstractLong-range vocal communication in socially monogamous titi monkeys is mediated by the production of loud, advertising calls in the form of solos, duets, and choruses. We conducted a power spectral analysis of duets and choruses (simply “duets” hereafter) followed by linear discriminant analysis using three acoustic parameters—dominant frequency of the combined signal, duet sequence duration, and pant call rate—comparing the coordinated vocalizations recorded from 36 family groups at 18 sites in Bolivia, Peru and Ecuador. Our analysis identified four distinct duetting patterns: (1) a donacophilus pattern, sensu stricto, characteristic of P. donacophilus, P. pallescens, P. olallae, and P. modestus; (2) a moloch pattern comprising P. discolor, P. toppini, P. aureipalatii, and P. urubambensis; (3) a torquatus pattern exemplified by the duet of Cheracebus lucifer; and (4) the distinctive duet of P. oenanthe, a putative member of the donacophilus group, which is characterized by a mix of broadband and narrowband syllables, many of which are unique to this species. We also document a sex-related difference in the bellow-pant phrase combination among the three taxa sampled from the moloch lineage. Our data reveal a presumptive taxonomic incoherence illustrated by the distinctive loud calls of both P. urubambensis and P. oenanthe within the donacophilus lineage, sensu largo. The results are discussed in light of recent reassessments of the callicebine phylogeny, based on a suite of genetic studies, and the potential contribution of environmental influences, including habitat acoustics and social learning. A better knowledge of callicebine loud calls may also impac...

show abstract

“…Red titis are small-bodied, pair-living primates found in Colombia, Ecuador, and Perú (Vermeer and Tell-Alvarado, 2015). Though mostly cryptic, titi individuals produce loud calls of various types (e.g., solo calls, duets, and choruses) often in the early morning (Robinson, 1981;Kinzey and Becker, 1983;Aldrich, 2006;Van Kuijk, 2013;Dolotovskaya and Heymann, 2022). In the field, the duet of one pair is often followed by response duets from neighboring pairs (Caselli et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Automated detection and detection range of primate duets: a case study of the red titi monkey (Plecturocebus discolor) using passive acoustic monitoring

van Kuijk,

O’Brien,

Clink

et al. 2023

Front. Ecol. Evol.

View full text Add to dashboard Cite

Passive acoustic monitoring (PAM) – an approach that uses autonomous acoustic recording units (ARUs) – can provide insights into the behavior of cryptic or endangered species that produce loud calls. However, extracting useful information from PAM data often requires substantial human effort, along with effective estimates of the detection range of the acoustic units, which can be challenging to obtain. We studied the duetting behavior of pair-living red titi monkeys (Plecturocebus discolor) using PAM coupled with an open-source automated detection tool. Using data on spontaneous duetting by one titi pair, combined with recordings from two Song Meter SM2 ARUs placed within their home range, we estimated that the average source level of titi duets was ~105 dB re 20 μPa at 1 m with an attenuation rate of 8 dB per doubling of distance, and we determined that the detection radius for manual annotation of duets in audio recordings was at least 125 to 200 m, depending on the approach used. We also used a supervised template-based detection algorithm (binary point matching) to evaluate the efficacy of automated detection for titi duets in audio recordings using linear arrays of ARUs within a ~2 km2 area. We used seven titi duet templates and a set of “off-target” howler monkey (Alouatta seniculus) templates to reduce false positive results. For duets with a signal-to-noise (SNR) ratio > 10 dB (corresponding to a detection radius of ~125 m) our detection approach had a recall (the number of all duets that are correctly detected) of 1.0. Performance decreased when including duets with a lower SNR (recall = 0.71, precision = 0.75). The fact that multiple lines of evidence suggest an effective detection radius of 125 to 200 m for titi duets across upland terra firme and seasonally flooded forest lends support to our findings. We suggest that PAM studies of other cryptic but vocally active species would benefit from following similar experimental and analytic procedures to determine an ARU’s effective detection radius and to improve the performance of automated detection algorithms.

show abstract

Estimating Population Density of the San Martin Titi Monkey (Callicebus oenanthe) in Peru Using Vocalisations

Cited by 13 publications

References 21 publications

Ecological and Behavioural Factors Influencing Territorial Call Rates for the Bolivian Titi Monkeys, Plecturocebus modestus and Plecturocebus olallae

Ecological and Behavioural Factors Influencing Territorial Call Rates for the Bolivian Titi Monkeys, Plecturocebus modestus and Plecturocebus olallae

Duetting Patterns of Titi Monkeys (Primates, Pitheciidae: Callicebinae) and Relationships with Phylogeny

Automated detection and detection range of primate duets: a case study of the red titi monkey (Plecturocebus discolor) using passive acoustic monitoring

Contact Info

Product

Resources

About