The male song of the Javan silvery gibbon (Hylobates moloch)

More documents

Recommendations

Info

14 T. Geissmann et al. – The Male Song of the Javan Silvery Gibbonand 5 correlations, respectively) than in the incompletelyrecorded songs of the Halimun, Jakarta1 and Jakarta 2 males (1 significant correlationeach).As shown in Table 5, no two males haveexactly the same note types among their set ofsignificant correlations. Only five note typesexhibit matching correlations in two males (i.e.A+B1, B3, C2, C combined, E), six note types aresignificant in only one male (C3, C4, C5, C6, C7,D) and three note types (B2, B4, C1) do notexhibit any correlation with song motivation.Phrase compositionTypical excerpts of the main phase of each studyanimal are shown in the sonagrams of Figure 6.The males appear to differ strongly not only in theproportions of the various note types, but also inthe structure of the phrases.In order to understand the sequential structureof note types in male phrases, we compared allphrases from the main song phase among allavailable song bouts as well as among individuals.Only phrases of at least 3 notes were included, andinspiration notes were ignored for this part of thekHz2a10101banalysis. The calculated note sequence probabilitiesfor each gibbon are shown in Figure 7.Data from multiple song bouts of the sameindividual were pooled.The Halimun male (Fig. 7a) begins 52% of hisphrases in the main song phase with a note of thetype B2. This note is followed by a B3 note in42% of the cases, which is followed by two morenotes of the same type in succession. All othernote sequences also occurring in this male’sphrases only play a subordinate role.Male 1 from Howletts (Fig. 7b) begins 83% ofhis phrases with a note of the type B3. This note isfollowed by a B3 note in 63% of the cases, whichis followed, again, by two more notes of the sametype in succession. Male 2 from Howletts (Fig. 7c)exhibits the same preferred phrase structure, butthe relative frequencies for each position in thephrase are less narrowly determined.The tape-recorded song bouts of the Jakarta 1male (Fig. 7d) reveal a much different preferredorder of phrase notes. The first note is of the B2note type in 59% of the cases, similar to theHalimun male. Unlike the phrases of any otherstudy male, the first note is followed by a note oftype B2 in 49% of all phrases (or – in 43% – bynote type C), followed by C and B3 in third andfourth positions, respectively.The Jakarta 2 male (Fig. 7e) starts 78% of allphrases with note type C and preferentially insertstype C in positions 2-5 of his phrases as well. Thisgibbon exhibits the most pronounced preferencefor note type C of all study males. Moreover, thephrase structure of this male appears to be theleast variable of the study males and, therefore,01010101010cd0 2 4 6 8 10 12 14 16 skHz2e1010f1010g1Fig. 6. Representative excerpts from song bouts of silverygibbon males, showing individual differences and low degreeof stereotypy in song structure. All sonagrams stem from themain phase of song bouts. The individual males are: (a)Halimun, (b) Howletts 1, (c) Howletts 2, (d) Jakarta 1, (e)Jakarta 2, (f) Kalejetan, (g) Munich.0100 2 4 6 8 10 12 14 16 sFig. 6. (ctd.)
Contributions to Zoology, 74 (1/2) – 2005 1544%B 2n = 48 %B 2n = 715 %43%B 3n = 36 %B 1n = 918 %B 2n = 2652 %33%35%42%19%B 3n = 36 %B 2n = 918 %B 3n = 1122 %B 4n = 510 %33%44%45%27%B 2n = 66 %B 3n = 48 %B 3n = 510 %B 4n = 36 %80%B 3n = 48 %B 3n = 4083 %15%63%17%B 2n = 613 %B 3n = 2552 %Cn = 715 %12%16%64%43%43%B 1n = 36 %B 2n = 48 %B 3n = 1633 %B 1n = 36 %B 2n = 36 %25%44%B 2n = 48 %B 3n = 715 %(a)B 3n = 1530 %60%40%B 3n = 918 %B 4n = 612 %44%44%50%50%B 3n = 48 %B 4n = 48 %B 3n = 36 %B 4n = 36 %75%B 4n = 36 %1 2 3 4Rank of phrase note1 2 3 4Rank of phrase note(b)Fig. 7. (ctd.)B 3n = 2958 %10%48%38%B 2n = 36 %B 3n = 1428 %B 4n = 1122 %100%64%21%45%45%B 3n = 36 %B 3n = 918 %B 4n = 36 %B 3n = 510 %B 4n = 510 %67%33%100%80%B 3n = 612 %Cn = 36 %B 3n = 510 %B 3n = 48 %Fig. 7. Phrase structure in the male song of Hylobatesmoloch: (a) Halimun, (b) Howletts 1, (c) Howletts 2, (d)Jakarta 1, (e) Jakarta 2, and (f) Munich. Data of several songbouts of the same individual (Munich, Jakarta 1) were pooled.Fifty phrases were analysed of each song (including onlyphrases with at least three notes). The preferred phrasestructure is drawn in bold lines. The letters in the boxesindicate the note type. The numbers in the boxes indicate theabsolute (n) and the relative frequency (%) of a note typeoccurring in this particular position in the phrase, and thenumbers accompanying the arrows represent the relativefrequency of two particular note types following each other inthese particular positions (ranks) within a phrase. In order tokeep the figures simple, we omitted relative frequenciesbelow 5% and absolute frequencies below n=2.Cn = 2142 %1 2 3 4Rank of phrase note(c)Fig. 7. (ctd.)43%57%B 3n = 918 %Cn = 1224 %33%50%33%B 3n = 612 %B 3n = 612 %Cn = 48 %50%50%B 4n = 36 %B 3n = 36 %
Page 1 and 2: Contributions to Zoology, 74 (1/2)
Page 3 and 4: Contributions to Zoology, 74 (1/2)
Page 6 and 7: 6 T. Geissmann et al. - The Male So
Page 8 and 9: 8 T. Geissmann et al. - The Male So
Page 10 and 11: 10 T. Geissmann et al. - The Male S
Page 16 and 17: B 1Cn = 475%n = 38 %6 %CCCCn = 3284

The male song of the Javan silvery gibbon (Hylobates moloch)

Create successful ePaper yourself

Delete template?

Save as template?