Pair‐bonded primates have uniquely enduring relationships and partners engage in a suite of behaviors to maintain these close bonds. In titi monkeys, pair bond formation has been extensively studied, but changes across relationship tenure remain unstudied. We evaluated differences in behavioral indicators of pair bonding in newly formed (~6 months paired, n = 9) compared to well‐established pairs (average 3 years paired, n = 8) of titi monkeys (Callicebus cupreus) as well as sex differences within the pairs. We hypothesized that overall males would contribute more to maintenance than females, but that the pattern of maintenance behaviors would differ between newly formed and well‐established pairs. Each titi monkey (N = 34) participated in a partner preference test (PPT), where the subject was placed in a middle test cage with grated windows separating the subject from the partner on one side and an opposite‐sex stranger on the other side. During this 150‐min behavioral test, we quantified four key behaviors: time in proximity to the partner or stranger as well as aggressive displays toward the partner or stranger. Overall, we found different behavioral profiles representing newly formed and well‐established pair‐bond relationships in titi monkeys and male‐biased relationship maintenance. Males spent ∼40% of their time in the PPT maintaining proximity to the female partner, regardless of relationship tenure. Males from well‐established bonds spent less time (14%) near the female stranger compared to males from newly formed bonds (21%) at the trend level. In contrast, females from well‐established bonds spent less (23%) time near the male partner in the PPT compared to females from newly formed bonds (47%). Aggressive displays were more frequent in newly formed bonds compared to well‐established bonds, especially for females. Scan sampling for homecage affiliation showed that newly formed pairs were more likely to be found tail twining than well‐established pairs.

中文翻译：

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关系权属不同地影响公母一夫一妻制的公猴（Callicebus cupreus）的成对键行为。

成对的灵长类动物具有独特的持久关系，伴侣进行一系列行为以维持这些紧密的联系。在titi猴子中，对成对键的形成已进行了广泛的研究，但是跨关系任期的变化仍未研究。我们评估了新形成的配对配对（〜6个月，n  = 9）与成熟的成对配对（平均3年配对，n  = 8）的山地猴（Callicebus cupreus）配对对行为指标的差异以及性别差异对内。我们假设男性总体上对维护的贡献要大于女性，但是新形成的和成熟的夫妇之间的维护行为模式会有所不同。每只titi猴（N = 34）参加了伴侣偏好测试（PPT），其中将受试者放置在中间的测试笼中，该格栅带有磨碎的窗户，使受试者与伴侣的一侧分开，另一侧为异性陌生人。在此150分钟的行为测试中，我们量化了四个关键行为：靠近伴侣或陌生人的时间以及对伴侣或陌生人的攻击性展示。总体而言，我们发现了不同的行为特征，这些行为特征代表了titi猴子中新形成的和建立良好的配对关系以及维持男性偏见的关系。男性在PPT中花费约40％的时间来保持与女性伴侣的亲近感，而不管双方的任期如何。在趋势水平上，来自成熟债券的男性在女性陌生人附近花费的时间更少（14％），而来自新成立债券的男性（21％）花费的时间更少。相比之下，与建立新债券的女性相比（47％），来自建立良好债券的女性在PPT中接近男性伴侣的时间更少（23％）。与已建立的纽带相比，在新成立的纽带中，侵略性展示更为频繁，尤其是女性。扫描笼笼隶属关系的样本显示，新形成的对比成对的更容易发现尾巴缠绕。