1. Loud calls as species markers in fork-marked dwarf lemurs (Phaner)
10th Inkaba yeAfrica/!Khure Africa (AEON) Conference/Workshop
Lord Milner Hotel, Matjiesfontein - Karoo
29 September – 3 October 2014
Loud calls as species markers in fork-marked dwarf lemurs (Phaner)
D. Forbanka1, J. Masters 1
1. Department of Zoology & Entomology, University of Fort Hare.
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2. Introduction

3. Introduction
These lemurs are nocturnal and according to Recognition Concept of Species, mate recognition cannot be by visual characteristics alone.
Recognition Concept of Species is means by which organisms attract and recognize each other (SMRS).
One SMRS widely followed and proven fruitful in nocturnal primates is vocalization.
Each species has particular loud call common to both sexes and used to advertise their presence to companions/rivals.
Loud calls are species specific, constant across geographic ranges - provide a diagnostic tool for the identification of new species.
However, loud call species-specificity has never been tested in fork-marked dwarf lemurs

4. Aim
Investigate species specificity in loud calls of fork-marked dwarf lemurs.

5. Methods
Study sites
Data were collected by following animals at night with the aid of a head lamp along existing trails.
Calls were recorded with Digital Professional Recorder (Roland R-26) and a directional microphone (Sennheiser MKE600).
Calls were analyzed using SAP2011.

6. Results Modes of uttering Loud calls in Phaner spp “Kiu” call Duet
Male call

7. Call Parameters measured:
Amplitude (dB); absolute deviation from zero.
Pitch; perceived tone of sound (measure of period of oscillation)
Mean frequency; assesses the center of the distribution of power across frequencies.
Peak frequency; frequency of maximum power.
Goodness of pitch; estimate of harmonic pitch periodicity
Wiener entropy; measure of width and uniformity of power spectrum
Frequency Modulation (FM); estimated based on time and frequency derivatives across frequencies e.g. if freq derivatives are higher than time derivatives FM is low.
Amplitude Modulation (AM); overall time derivative power across all frequencies within a range. Captures changes in amplitude envelope of sound.

8. Number of individuals and syllables measured per site
Species
Local Name
No. of individuals
No. of syllables measured
Montagne d’Ambre National Park (MANP)
Phaner electromontis - 5
921
Analamerana Special Reserve (ASR)
P. electromontis 8
2686
Zombitse National Park (ZNP)
P. pallescence
“kitata” 9
2524
Zahamena National Park (ZaNP)
p. furcifer
“tantana” 6
3025
Manongarivo Special Reserve
P. pariente
“valovy” 7
2217
Total 35
11373

9. Dendrogram showing four clusters of fork-marked dwarf lemurs

10. PCA ordination of fork-marked dwarf lemurs call parameters

11. Eigenvalues and Eigenvectors in relation to PC1 and PC2 of PCA
Variables
PC1
PC2
EIGENVALUES
Eigenvalues
0,695
0,218
% Variation
53,8
16,9
Cumulative % Variation
70,8
EIGENVECTORS
Amplitude
-0,554
-0,177
Pitch
-0,450
0,085
Mean Frequency
0,047
0,046
Peak Frequency
-0,035
0,125
Goodness of Pitch
-0,298
0,121 FM
0,600
-0,025 AM
-0,197
0,213
Entropy
0,003
0,936

12. Acoustic variation supports pelage coloration findings and reflect species specificity.
Differences of loud call in four species of Phaner are consistent with species status of other animal groups (other primates, birds and frogs).
Given that the species live in different habitats, acoustic adaptation hypothesis may explain the evolution of differences in loud calls.
Differences in acoustic components may be caused by genetic divergence which may lead to changes in vocal production and perception system.

13. Divergence in size and mass of laryngeal structure, rate at which vocal cords open and close as well as in control of muscles for breathing and vocal production may explain acoustic differences according to Source Filter Theory of Speech Production.
Revealed specific differences of loud calls of Phaner are linked to differences in vocalization-related neural network as found in squirrel monkeys.
Specific acoustic adaptation to the environment, genetic drift, founder effects and selection factors may have played a role in the evolution of species-specificity in loud calls of Phaner.

14. Conclusion
Cryptic species of Phaner show specific and conspicuous acoustic differences in loud call.
Acoustic fingerprinting may:
be used as a noninvasive tool for species diagnosis and discrimination in Phaner.
offer an easy and inexpensive way to determine species in the field and laboratory.
provide practical means of monitoring biodiversity of animal group in nature.

15. Thank you for your attention
Acknowledgements
African Earth Observatory Network (AEON).
Primate Conservation, Incorporation (PCI).
MEF, Madagascar.
Field assistants.
Thank you for your attention