根田鼠的熟悉性及其自然动情下的配偶选择

报道了在室内雌鼠自然动情条件下根田鼠两性个体配偶选择的3种熟悉性效应的5组实验结果,包括雌性对熟悉和陌生雄鼠、配偶和陌生雄鼠、配偶和熟悉雄鼠的择偶行为实验 , 雄性对熟悉和陌生雌鼠、配偶和陌生雌鼠的择偶行为实验。在实验前, 将1对性成熟的雌雄鼠 (非亲缘关系) 每天关养8 h 共8 d 建立熟悉性; 配对雌雄鼠至少生育1胎则为配偶关系。在 Y 形迷宫内的30 min 实验中, 两个被选择鼠分别以项链拴在横跨选择箱顶端中央的一根铁丝上, 限制它们在各自箱内活动; 而允许异性选择鼠从中立箱自由进入两个选择箱。记录选择鼠对异性被选择鼠的访问、社会探究、攻击、交配和友好行为的频次和时间。经Wilcoxon 关联样本 T 检验发现, 除交配行为不显著外, 雌性根田鼠均选择熟悉性较高的雄鼠; 而雄鼠不具这种选择性。该结果提示雌雄根田鼠的不同择偶行为也许就是反映该种婚配制度特征的直接行为过程。因此, 在择偶行为中, 雌性根田鼠表现的单配性倾向和雄鼠的多配性倾向, 只能以其婚配制度为一雄多雌制的假设来解释。我们的实验还说明在多配制田鼠中, 一雄多雌制与混交制在雌鼠择偶行为上是不同的, 而与单配制的相似或相近, 故简单地比较多配制与单配制则不能反映田鼠亚科动物婚配制度的多样性。     

不同海拔地区高原鼠兔探究性和静止代谢率的差异

环境的差异影响动物种群生活史对策的进化。对地理分布范围广的物种而言,栖息地环境差异大,不同种群的生活史对策亦存在显著差异。个性特征作为生活史的一部分,反映了动物对环境的适应模式。前期研究表明,不同海拔区域的高原鼠兔的生活史对策存在显著差异,然而,其个性特征及与能量代谢的关联性是否也存在差异,目前尚不清楚。2018年9-10月,分别在海拔3268 m的贵南县和3980 m的玛沁县测定当地高原鼠兔的探究性与静止代谢率。结果发现,高海拔雄性高原鼠兔的探究性显著低于低海拔雄性个体;高海拔雌性高原鼠兔体重矫正静止代谢率显著高于低海拔雌性个体。高海拔地区,雌性高原鼠兔的探究性和体重矫正静止代谢率呈显著正相关,雄性高原鼠兔的探究性和体重呈显著负相关;低海拔地区,高原鼠兔的探究性和体重矫正静止代谢率或体重之间均无显著相关性。该结果 表明,调整个性特征和能量代谢及其两者的关联性也是高原鼠兔适应不同海拔栖息地环境差异的生活史对策之一。     

非繁殖期大仓鼠对同种气味的反应和个体间的行为关系

在实验室通过对陌生成年大仓鼠（Ｃｒｉｃｅｔｕｌｕｓｔｒｉｔｏｎ）非繁殖期的气味偏好,性别选择和两鼠间的行为关系的实验研究表明,用Ｙ－型迷宫进行选择测试时,与空白组比较,大仓鼠了同种个体鼠垫的气味,在雌雄巢垫气味之间,雌鼠偏好雄性巢垫的气味,雄鼠不表现性别偏好,与空白组比较,被试鼠选择同种个体;在雌雄个体之间,雄性大仓鼠选择同性个体,雌性不表现性别偏好,在观察箱内,无论同性相遇还是异性相遇,两鼠间攻     

黄腹山鹪莺稳定的配偶关系限制雄性欺骗者

多数鸟类通过性特征限制在同性竞争和配偶选择中的“欺骗者”存在,与此相反,雀形目扇尾莺科部分物种表现出繁殖季节性特征消退的身体特征变化模式.在广州市南沙区通过“目字笼”对黄腹山鹪莺配偶关系稳定性的限制机制进行研究,发现虽然雌性个体到访原配个体和对照个体的次数几乎相同,但是雌性个体对原配雄性的单次选择时间明显长于对照雄性个体,总计选择时间也明显长于对照雄性个体.选择实验过程中,原配雄性的跳动次数明显高于对照个体雄性,以竖尾扑哧和鸣声恐吓等为代表的威慑行为次数也明显高于对照雄性个体.结果说明,雌性更青睐于原配个体,配对时间越长,忠诚度越高,而且原配雄性比入侵雄性个体表现出更高的活跃度和威慑行为.繁殖季节性特征消退的物种可以通过保持稳定的配偶关系以限制“欺骗者”存在.可以推测繁殖的巨大投入和雌性之间的同性竞争可能是产生这种配偶稳定性的主要原因.     

雌性布氏田鼠对雄鼠气味的辨别

通过雌性布氏田导其配偶和陌生雄鼠气味的辨别实验,以及无交配经历的成年雌鼠对社会等级不同的陌生雄鼠气的辨别实验发现,有生育经历的雌鼠对陌生雄鼠气味的探究行为明显多于对配偶气味的控究,但雌鼠在配偶雄鼠气味周围的停留时间、自身修饰行为和何处行为的发生频次和持续地陌生雄鼠,没有交配经历的雌鼠对处于从鼠地位的雄性个体气味探究行为多于对优势雄性的控究,而其他行为表现没有明显差异。表明,雌性布氏田鼠可以利用气味     

雄性根田鼠的同胞竞争及其对同性个体的气味识别

采用两两互作实验并以尿标记来确定共居至成年的2雄性根田鼠同胞在行为竞争上的差异,之后在行为选择箱中分别观察它们对来自熟悉和陌生同性个体的新鲜尿气味的行为反应,以确定气味识别差异。结果表明：①雄性根田鼠两两互作时,尿标记的多少可以作为判断其社会等级的标准;②从属鼠对熟悉气味存在明显偏好,其对熟悉气味的访问时间、接近频次和自我修饰频次都显著高于陌生气味;③优势鼠则优先访问陌生气味,其对陌生气味的访问时间、嗅舔频次、嗅舔时间、自我修饰及反标记均显著高于熟悉气味;④对于陌生气味,优势鼠和从属鼠之间存在明显不同的行为反应模式。本实验结果提示,雄性根田鼠对同性尿气味识别的差异以及对陌生气味的行为反应,可能暗含着其领域防卫的信息。     

熟悉性对棕色田鼠和根田鼠择偶行为的影响

以两性配对共居至交配或生仔作不同熟悉处理,在Y字型选择箱中分别观察棕色田鼠,根田鼠的择偶行为和配偶识别。结果如下：（1）棕色田鼠雌雄两性均表现出对熟悉异性或配偶的喜好倾向;（2）在根 中,只有雌性表现出对熟悉雄鼠或配偶的选择倾向,雄鼠无明显的选择取向;（3）每种雌性田鼠对2种熟悉性不同的同种雄性的嗅舔时间均有显著差异性,而每种雄性田鼠对2种熟悉性不同的同种雌性的嗅舔时间均无显著差异性。这些结果表明：（1）熟悉性对棕色田鼠择偶行为的影响大于对根田鼠的影响;（2）嗅舔时间差别可反映不同田鼠的配偶识别能力,熟悉性对棕色田鼠配偶识别能力的影响大于对根田鼠的影响;（3）2种田鼠配偶识别的性别差异的一致性,提示这2种田鼠的雌性配偶识别能力均强于雄性田鼠,而雌鼠的配偶识别能力可能取决于雌鼠受酱或分娩刺激的生理状态;（4）棕色田鼠室内所表现的择偶行为的两性熟悉性特征与其单配制有关,根田鼠所表现的择偶行为的雌性熟悉性特征与其一雄多雌制有关。     

熟悉性对棕色田鼠和根田鼠择偶行为的影响

以两性配对共居至交配或生仔作不同熟悉处理,在Y字型选择箱中分别观察棕色田鼠、根田鼠的择偶行为和配偶识别.结果如下:(1)棕色田鼠雌雄两性均表现出对熟悉异性或配偶的喜好倾向;(2)在根田鼠中,只有雌性表现出对熟悉雄鼠或配偶的选择倾向,雄鼠无明确的选择取向;(3)每种雌性田鼠对2种熟悉性不同的同种雄性的嗅舔时间均有显著差异性,而每种雄性田鼠对2种熟悉性不同的同种雌性的嗅舔时间均无显著差异性.这些结果表明:(1)熟悉性对棕色田鼠择偶行为的影响大于对根田鼠的影响;(2)嗅舔时间差异可反映不同田鼠的配偶识别能力,熟悉性对棕色田鼠配偶识别能力的影响大于对根田鼠的影响;(3)2种田鼠配偶识别的性别差异的一致性,提示这2种田鼠的雌性配偶识别能力均强于雄性田鼠,而雌鼠的配偶识别能力可能取决于雌鼠受交配或分娩刺激的生理状态; (4)棕色田鼠室内所表现的择偶行为的两性熟悉性特征与其单配制有关,根田鼠所表现的择偶行为的雌性熟悉性特征与其一雄多雌制有关.     

鳄蜥对熟悉和陌生个体气味的辨别

个体辨别对于减少同种争斗以及配偶选择具有重要意义。我们用棉棒粘取鳄蜥(Shinisaurus crocodilurus)尿液作为气味源,以香水作为对照,测定鳄蜥对熟悉个体气味、陌生个体气味以及香水的舔舌次数和舔舌潜伏期,来探讨鳄蜥通过化学信息辨别熟悉和陌生个体的能力。结果显示,不论是雌性还是雄性,对不同个体尿液的舔舌次数均显著高于对香水的,舔舌潜伏期显著短于香水的;尽管雄性对陌生同性个体气味与熟悉同性个体气味的舔舌次数无显著差异,但对前者的舔舌潜伏期显著短于后者;雄性对陌生雌性气味的舔舌次数显著多于熟悉雌性气味的,对前者的舔舌潜伏期显著短于后者;雌性对陌生雄性气味的舔舌潜伏期显著短于对熟悉雄性气味的;雄鳄蜥对陌生雌性气味的舔舌次数显著多于雌鳄蜥对陌生雄性的。结果表明,鳄蜥能辨别同种个体的化学信息,并能通过化学信息来辨别熟悉和陌生个体,推测鳄蜥的这种辨别能力对其领域分配以及繁殖交配有重要作用。     

不育雄性对布氏田鼠气味选择和个体选择的影响

在Y型迷宫中进行了动情雌性布氏田鼠对结扎不育雄鼠及正常雄鼠气味和个体的选择实验。气味选择实验以动物的巢垫物为气味源,个体选择直接采用结扎雄性和正常雄性作为被选择个体。记录雌性布氏田鼠对选择源的选择频次以及停留时间。结果表明,无论在气味选择或是个体选择中,动情雌性布氏田鼠在选择频次和停留时间上都具有显的正相关性,而且都没有明显表现出对某—气味或个体选择上的偏好。激素测定结扎不育后雄鼠血清中的睾酮和皮质醇含量有听升高．但这种变化没有对雌性布氏田鼠的选择产生影响。     

Comparison of sociability,parental care and central estrogen receptor alpha expression between two populations of mandarin voles (<Emphasis Type="Italic">Microtus mandarinus</Emphasis>)

The socially monogamous mandarin vole (Microtus mandarinus) shows significant behavioral plasticity. We examined whether levels of sociability, parental care and central expression of estrogen receptor alpha differed between two populations with different ecologies. Our results show that males from the Chengcun population display significantly more amicable and less aggressive behaviors towards novel same-sex individuals compared to males from the second population of Xinzheng. Chengcun voles directed more licking behavior towards neonatal pups than did Xinzheng voles. Differences were also found in the number of estrogen receptor alpha-immunoreactive neurons. For example, Xinzheng males displayed significantly higher immunoreactivity than Chengcun males in the medial amygdala, medial preoptic area and ventromedial nucleus of the hypothalamus. Xinzheng females expressed higher levels of estrogen receptor alpha-immunoreactivity than Chengcun females in the medial preoptic area. Chengcun females exhibited significantly more estrogen receptor alpha expression than Xinzheng females in the bed nucleus of the stria terminalis. Our results indicate that mandarin voles from the Chengcun site possess monogamous traits, and animals from Xinzheng possess polygamous traits. It also appears that different social behavior and levels of parental care in these two populations may be associated with differences in estrogen receptor alpha-immunoreactive neurons.     

Familiarity and partner preferences in female common voles, <Emphasis Type="Italic">Microtus arvalis</Emphasis>

Captive female common voles (Microtus arvalis) had a clear social preference for familiar males in a standard preference test. Cohabitation for a short period resulted in preferences for familiar partners, and females spent eight times more time in body contact with a familiar male than with an unfamiliar male. Females also displayed stranger-directed aggression. Our results suggest that the common vole is a species with selective partner preferences and a tendency to form tight social relationships and stable male–female associations.     

基于交叉抚育的雄性根田鼠对异性同胞尿气味的识别

通过交叉抚育建立室内繁殖种群,在断奶后（80日龄）分别取这些供体的新鲜尿气味作刺激物,在行为观察箱中观察和记录雄性根田鼠对雌鼠气味的行为反应,以研究根田鼠同胞识别的化学通讯机制。结果表明：①在不同的发育时期（2～70日龄）,雄性同巢同胞与异巢同胞的体重没有显著差异。②雄性根田鼠对雌性同巢非同胞气味的接近潜伏期显著长于对异巢非同胞的接近潜伏期（P〈0．05）,其对异巢非同胞气味的访问时间和嗅舔时间都显著高于同巢非同胞气味（P〈0．05）。③雄性根田鼠对雌性异巢同胞和异巢非同胞气味的不存在明显偏好。其对两者的接近潜伏期、访问频次、访问时间、嗅舔频次和嗅舔时间等行为响应均无显著差异（P〈0．05）。这些结果表明,80日龄时,雄性根田鼠能够识别熟悉和陌生的无亲属关系雌性尿气味,但不能区分陌生的亲属和非亲属,因此,其异性同胞识别的机制为共生熟悉模式。     

Behavioural development of conspecific odour preferences in bank voles,Clethrionomys glareolus

Biological odours of conspecifics are known to have strong influences on behavioural interaction in bank voles Clethrionomys glareolus. This experiment tested two hypotheses. (1) Olfactory cues from familiar and unfamiliar mature opposite-sex conspecifics differ in their attractiveness to males and females, and their behavioural reactions change with age. (2) A genetically based mechanism is involved in female recognition of kin.In a two-choice preference test, prepubertal males and females were more attracted to familiar than to unfamiliar odours of opposite-sex conspecifics, as manifested by more time spent sniffing familiar voles. As the young reached sexual maturity they shifted their odour preferences. Mature males and females preferred the novel odour of unrelated opposite-sex conspecifics to that of relatives. The results of experiments testing the second hypothesis indicate that females use a genetically based mechanism to recognise their kin. Young and mature females were able to recognise the odour of their biological but socially unknown fathers, and showed the same pattern of behaviour as females in previous experiments.The possible biological functions of kin recognition in bank voles are discussed.     

Sex differences in olfactory social recognition memory in meadow voles,Microtus pennsylvanicus

Terrestrial mammals, like rodents, use odors, and scent marks to indicate their presence in an area to conspecifics. These odors convey information about the scent donor's genotype, sex, condition, and age. The ability to discriminate among the scent marks of conspecifics and later recollect the identity of the donor is essential for choosing between familiar and unfamiliar mates. We tested the hypothesis that the promiscuous meadow vole (Microtus pennsylvanicus) can recollect the odor of a familiar, opposite-sex conspecific and distinguish it from that of an unfamiliar, opposite-sex conspecific. We also hypothesized that because reproductive success is highly skewed among male meadow voles and competition for mates is intense, males will be more likely than females to recollect the odor of a familiar, opposite-sex conspecific and distinguish it from that of an unfamiliar, opposite-sex conspecific, for a longer period of time. Using a habituation task, we first exposed the voles, 4 times successively, to the anogenital area scent of an opposite-sex conspecific. Then, 1 hr, 24 hrs, 72 hrs, or 96 hrs after the fourth exposure, voles were presented with the odor of the donor from the exposure phase (familiar donor) and that of an unfamiliar, opposite-sex conspecific. Female meadow voles spent similar amounts of time investigating the scent of the familiar male donor and that of an unfamiliar male donor after the 1-hr and 24-hr intervals. Male meadow voles, however, spent more time with the scent of an unfamiliar female donor than that of the familiar female donor after the 1-hr, 24-hr, and 72-hr intervals, suggesting that male voles could recollect the scent mark of a familiar female for at least three days. The implications of these sex differences in social memory may reflect the different strategies male and female meadow voles use in the recognition of previous and potential mates. Recognition of an individual's scents may enhance fitness by allowing animals to direct appropriate behaviors toward those individuals.     

Rival recognition in the territorial tawny dragon (Ctenophorus decresii)

The ability to discriminate between familiar and unfamiliar conspecifics is important in territorial animals as it allows animals to distinguish neighbours from non-neighbours. This prevents wasting time and energy in unnecessary aggressive interactions. I investigated the ability of adult males of a territorial lizard, the tawny dragon (Ctenophorus decresii), to distinguish familiar from unfamiliar rivals in a laboratory setting. Males significantly reduced their aggression levels in repeat interactions with familiar rivals and increased their aggression levels towards unfamiliar males. The time taken for interactions to be settled was also significantly lower towards familiar than unfamiliar males. The results of this study suggest that adult male tawny dragons can discriminate familiar from unfamiliar conspecifics. Furthermore, animals were presented with three new rivals in succession and showed a robust ability to discriminate between familiar and unfamiliar males.     

Domestication‐related variation in social preferences in chickens is affected by genotype on a growth QTL

A growth‐related QTL on chicken chromosome 1 has previously been shown to influence domestication behaviour in chickens. In this study, we used Red Junglefowl (RJF) and White Leghorn (WL) as well as the intercross between them to investigate whether stress affects the way birds allocate their time between familiar and unfamiliar conspecifics in a social preference test (‘social support seeking’), and how this is related to genotype at specific loci within the growth QTL. Red Junglefowl males spent more time with unfamiliar chickens before the stressful event compared to the other birds, whereas all birds except WL males tended to spend less time with unfamiliar ones after stress. A significant QTL locus was found to influence both social preference under undisturbed circumstances and social support seeking. The WL allele at this QTL was associated not only with a preference for unfamiliar individuals but also with a shift towards familiar ones in response to stress (social support seeking). A second, suggestive QTL also affected social support seeking, but in the opposite direction; the WL allele was associated with increased time spent with unfamiliar individuals. The region contains several possible candidate genes, and gene expression analysis of a number of them showed differential expression between RJF and WL of AVPR2 (receptor for vasotocin), and possibly AVPR1a (another vasotocin receptor) and NRCAM (involved in neural development) in the lower frontal lobes of the brains of RJF and WL animals. These three genes continue to be interesting candidates for the observed behavioural effects .     

Friend or foe: behavioral responses to conspecifics in the northern scorpion, <Emphasis Type="Italic">Paruroctonus boreus</Emphasis> (Scorpionida: Vaejovidae)

We investigated the behavioral response of male Paruroctonus boreus to male and female pheromones of conspecifics. Adult male scorpions actively search for females during the mating season, but lack visual cues to direct their movement. Chemical cues (pheromones) are thought to be responsible for directing movement. In a series of laboratory experiments, in Y-mazes, males were exposed to areas that had contained males and females from the same population and areas that had contained conspecifics from different populations. Males spent significantly more time in areas that had contained females from the same population but did not show a preference for areas exposed to females from different populations. Males also significantly avoided areas exposed to males from the same population. Our results suggest that P. boreus has a sex-specific response to pheromones and that this response may be population-specific.     

Olfactory Communication and Neighbor Recognition in Giant Kangaroo Rats

We hypothesized that olfactory communication facilitates neighbor recognition in the giant kangaroo rat, Dipodomys ingens , and is therefore influential in coordinating social interactions in this solitary, desert rodent. We tested whether (i) D. ingens can discriminate between odors of same- and opposite-sex conspecifics; and (ii) the kangaroo rats exhibit scent preferences based on familiarity. In habituation-discrimination tests, we found that both genders distinguish differences between the scent of individuals of the same- and opposite-sex. In olfactory preference tests, both males and females spent significantly more time investigating the scent of their familiar cagemate than the scent of an unfamiliar conspecific. Giant kangaroo rats may be able to recognize familiar neighbors from olfactory cues, thus supporting a hypothesis of neighbor recognition. Neighbor recognition may be an important mechanism of social interactions in this endangered species.