Wang Q, Buntin J D
Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, USA.
Horm Behav. 1999 Jun;35(3):241-53. doi: 10.1006/hbeh.1999.1517.
In addition to stimulating crop "milk" formation in ring doves, prolactin (PRL) may promote the parental regurgitation behavior that transfers this "milk" to the young at the time of hatching. Although earlier studies suggest that previous breeding experience is an important modulator of PRL-induced parental regurgitation behavior in ring doves, the ways in which experience, hormones, and stimuli from young interact to promote parental behavior have not been well characterized in this species. In the first study, untreated, nonbreeding female doves with and without previous breeding experience were given 10 daily parental behavior tests (2 h/day) with a hungry 5- to 10-day-old foster squab. Experienced females exhibited a higher incidence of regurgitation behavior, defensive behavior, and crouching or sitting in the nest than did inexperienced females. In a second study, nonbreeding females were given 10 daily tests for parental behavior while they received sc injections of ovine PRL or vehicle. Prolactin reduced squab-directed aggression and increased the incidence of regurgitation feeding behavior of foster squabs in both experienced and inexperienced females. However, the average number of regurgitation feeding acts displayed by those PRL-treated females that showed the behavior was over eight times higher in experienced females than in inexperienced females. Previous experience also enhanced the stimulatory effects of PRL on defensive behavior and crouching or sitting in the nest. The parental behavior exhibited by nonbreeding, PRL-treated experienced females was qualitatively and quantitatively similar to that observed in normally breeding females during a single test with their own hungry 5- to 10-day-old squabs. These findings indicate that PRL and previous breeding experience both enhance the parental responsiveness of nonbreeding female doves and that under optimal hormonal, experiential, and squab exposure conditions, nonbreeding doves exhibit levels of parental activity that rival those of normally breeding parents.
除了刺激环鸽嗉囊中“鸽乳”的形成，催乳素（PRL）还可能促进亲代反刍行为，即在孵化时将这种“鸽乳”传递给幼雏。尽管早期研究表明，以往的繁殖经验是环鸽中催乳素诱导亲代反刍行为的重要调节因素，但在该物种中，经验、激素和幼雏刺激相互作用促进亲代行为的方式尚未得到充分描述。在第一项研究中，对有无繁殖经验的未处理非繁殖雌性鸽子，每天与一只5至10日龄饥饿的寄养雏鸽进行10次亲代行为测试（每天2小时）。有经验的雌性比无经验的雌性表现出更高的反刍行为、防御行为以及蹲伏或坐在巢中的发生率。在第二项研究中，非繁殖雌性鸽子在接受皮下注射绵羊催乳素或赋形剂的同时，每天进行10次亲代行为测试。催乳素减少了针对雏鸽的攻击行为，并增加了有经验和无经验雌性中寄养雏鸽的反刍喂食行为发生率。然而，表现出反刍喂食行为的催乳素处理雌性鸽子，其平均反刍喂食行为次数在有经验的雌性中比无经验的雌性高出八倍多。以往经验还增强了催乳素对防御行为以及蹲伏或坐在巢中的刺激作用。非繁殖、接受催乳素处理的有经验雌性所表现出的亲代行为，在质量和数量上与正常繁殖雌性在单独测试中与自己饥饿的5至10日龄雏鸽相处时所观察到的行为相似。这些发现表明，催乳素和以往的繁殖经验都增强了非繁殖雌性鸽子的亲代反应能力，并且在最佳的激素、经验和雏鸽接触条件下，非繁殖鸽子表现出的亲代活动水平可与正常繁殖的亲代相媲美。
