积极的互动帮助个人获得和保护资源,但是它们可能很昂贵,导致捕食风险增加,损伤,或死亡。涉及声音和颜色的信号可以使鸟类避免种内侵略性遭遇的成本,但是我们对物种之间的激动信号知之甚少,在那里打架可能很频繁而且成本很高。这里,我们回顾了鸟类之间积极相互作用的照片和视频证据(N=337相互作用记录了来自120属的164种不同鸟类的积极信号,50个家庭,和24条命令)记录个体在物种之间的攻击性遭遇中如何发出信号,并探索这些视觉信号是否类似于在与特定物种的激进遭遇中使用的信号。尽管被检查的鸟类种类繁多,最积极地发出信号的鸟类展示了武器(账单,爪子,机翼)用于战斗,并在发出信号时将这些武器放置在最接近其异质对手的位置。大多数物种都将自己的身体定位并向前看,他们的账单指向异类对手,经常突出他们的脸,喉咙,嘴,和比尔。许多鸟也张开了翅膀和/或尾巴,增加它们在显示器中的表观尺寸,与体型在确定物种间行为优势方面的重要性一致。在物种和分类科中,攻击性姿势通常相似。例外情况包括Acipitridae和Falconidae,经常突出它们在空中的爪子,Columbidae,经常从侧面突出它们的翅膀,和Trochilidae,它经常在空中直立盘旋,并将扇形的尾巴朝下。大多数物种在它们的信号中突出了明亮的类胡萝卜素颜色,但突出显示的颜色因物种而异,并且通常涉及多种颜色的组合(例如,黑色,白色,和基于类胡萝卜素的颜色)。最后,鸟类倾向于在与同种物种的侵略性遭遇中使用相同的视觉信号,这表明,无论竞争对手的身份如何,从积极的相互作用中选择可能会对相同的信号特征起作用。
Aggressive interactions help individuals to gain access to and defend resources, but they can be costly, leading to increased predation risk, injury, or death. Signals involving sounds and color can allow birds to avoid the costs of intraspecific aggressive encounters, but we know less about agonistic signaling between species, where fights can be frequent and just as costly. Here, we review photographic and video evidence of aggressive interactions among species of birds (N = 337 interactions documenting the aggressive signals of 164 different bird species from 120 genera, 50 families, and 24 orders) to document how individuals signal in aggressive encounters among species, and explore whether these visual signals are similar to those used in aggressive encounters with conspecifics. Despite the diversity of birds examined, most aggressively signaling birds displayed weapons (bills, talons, wings) used in fighting and placed these weapons closest to their heterospecific opponent when signaling. Most species oriented their bodies and heads forward with their bills pointing towards their heterospecific opponent, often highlighting their face, throat, mouth, and bill. Many birds also opened their wings and/or tails, increasing their apparent size in displays, consistent with the importance of body size in determining behavioral dominance among species. Aggressive postures were often similar across species and taxonomic families. Exceptions included Accipitridae and Falconidae, which often highlighted their talons in the air, Columbidae, which often highlighted their underwings from the side, and Trochilidae, which often hovered upright in the air and pointed their fanned tail downward. Most species highlighted bright carotenoid-based colors in their signals, but highlighted colors varied across species and often involved multiple colors in combination (e.g., black, white, and carotenoid-based colors). Finally, birds tended to use the same visual signals in aggressive encounters with heterospecifics that they use in aggressive encounters with conspecifics, suggesting that selection from aggressive interactions may act on the same signaling traits regardless of competitor identity.