Hradec Michal, Bolechová Petra, Vostrá-Vydrová Hana
Department of Ethology and Companion Animal Science, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Prague, Czechia.
Front Vet Sci. 2025 Apr 7;12:1574926. doi: 10.3389/fvets.2025.1574926. eCollection 2025.
The effects of hormonal contraception in non-human primates have been studied predominantly in relation to reproductive physiology. To date, no study has investigated how hormonal contraception affects vocal patterns in non-human primates. As part of our long-term research into the vocal behavior of southern yellow-cheeked gibbons () in zoos, we have managed to obtain vocal datasets from four adult contracepted (Nexplanon and Depo-Provera) females of this species. In addition, we also recorded coda vocalizations (i.e., male calls added after the completion of the great call) from three paired males who are partners of three of the four females studied. We quantified 11 acoustic features in the female great calls and five acoustic features in the male coda vocalizations, for which we applied a Principal Component Analysis (PCA) and subsequently components were tested using multivariate Generalized Linear Mixed Models (GLMM). Our study revealed that hormonal contraception did indeed affect the vocal structure of great call in southern yellow-cheeked gibbon females. In contrast, our study did not reveal any flexible adjustment of the structure of the coda vocalization in direct response to changes in the females' song. In female great call, we found that the Group 1 call component and Group 2 call component were not affected by the hormonal contraceptive (Depo-Provera) in the during-application period. However, it was noteworthy that once the effects of contraception had worn off (post-application period), the values of components did not return to pre-application periods but continued to change. Conversely, although the values of the Group 1 call component and Group 2 call component were most greatly affected by the contraceptive Nexplanon (during-application period). The values of both components tended to return to pre-treatment levels once the effects had waned. There was a change in the values of the Group 3 call component only after application of the contraceptive Nexplanon. These values remained significantly higher than the values at the pre-application level once the effects waned. This study provides the first evidence of changes in the stable vocal patterns of female southern yellow-cheeked gibbons as a consequence of the application of hormonal contraception.
激素避孕对非人灵长类动物的影响主要是在生殖生理学方面进行研究的。迄今为止，尚无研究调查激素避孕如何影响非人灵长类动物的发声模式。作为我们对动物园中南颊黄长臂猿发声行为长期研究的一部分，我们成功获取了该物种4只接受避孕措施（使用依伴侬和醋酸甲羟孕酮注射液）的成年雌性的发声数据集。此外，我们还记录了3对雄性的结尾发声（即在大叫声结束后添加的雄性叫声），这3对雄性是所研究的4只雌性中3只的配偶。我们对雌性大叫声中的11个声学特征和雄性结尾发声中的5个声学特征进行了量化，为此我们应用了主成分分析（PCA），随后使用多元广义线性混合模型（GLMM）对各成分进行了测试。我们的研究表明，激素避孕确实影响了南颊黄长臂猿雌性大叫声的发声结构。相比之下，我们的研究并未发现结尾发声结构因雌性歌声变化而有任何灵活调整。在雌性大叫声中，我们发现第1组叫声成分和第2组叫声成分在应用激素避孕药（醋酸甲羟孕酮注射液）期间不受影响。然而，值得注意的是，一旦避孕效果消失（应用后阶段），各成分的值并未恢复到应用前阶段，而是继续变化。相反，虽然第1组叫声成分和第2组叫声成分的值在应用依伴侬期间受影响最大。但一旦效果减弱，两组成分的值都倾向于恢复到治疗前水平。仅在应用依伴侬避孕药后，第3组叫声成分的值发生了变化。一旦效果减弱，这些值仍显著高于应用前水平。这项研究首次证明了激素避孕的应用导致南颊黄长臂猿雌性稳定发声模式发生变化。
