Conservatism and divergence in communication systems: sound signals of shorebirds and woodpeckers

动物的声音是多种多样的，具有多种功能和用途。声音被广泛用于保护和管理，以探测或监测不同的物种，包括稀有和濒危物种。例如，啄木鸟用它们的喙击打树木来吸引配偶或宣布领土要求（击鼓）。生物学家可以利用这些响亮的鼓声来确定不同啄木鸟物种的存在和数量。不同物种的声音具有独特性的常见原因是：(1)需要有效地识别同一物种的成员；(2)当种群在地理上被某些障碍（如山脉）分隔开时，它们之间的差异进化很快。最近的研究令人惊讶地表明，许多动物的声音进化得非常缓慢。一个例子是滨鸟，这是一个在恐龙时代出现的群体，但即使在远亲物种之间，声音也有许多相似之处。拟议中的研究项目将调查不同种类的滨鸟和啄木鸟的声音表现有何不同，以及这些差异如何与数百万年来进化保守主义的更大图景相适应。这些声音进化缓慢是因为声音器官（“鸣管”）非常简单吗？在表演曲目中，不同的叫声是否因为都是由一个发声器官产生而一起进化成一个集合？如果是这样的话，每个物种都应该有自己的特点。或者，它们是否可以彼此独立进化，因为它们各自的产生方式不同？如果一个物种的不同叫声或多或少可以独立进化，那么有些叫声可能进化得很快（例如性叫声），而另一些则可能进化得很慢（例如一般用途的警报叫声），这种模式将通过在该物种的系统发育（“家谱”）的背景下检查发声来证明。这个谜题的最后一部分是发声器官（鸣管），它将从博物馆的标本中被解剖出来，并与声学展示一起观看，从而对鸟类本能的声音和声音产生是如何进化的有一个广泛的了解。

Animal sounds are diverse and have diverse functions and applications. Sounds are widely used in conservation and management to detect or monitor different species, including rare and endangered species. Woodpeckers for example, strike trees with their bills to attract mates or announce territorial claims (drumming"). Biologists can use these loud drumming sounds to determine presence and abundance of different woodpecker species. Common reasons for sounds of different species to be unique are (1) requirements to efficiently identify members of the same species, and (2) rapid divergent evolution between populations when they are separated geographically by some barrier, such as a mountain range. Recent research has surprisingly shown that many animal sounds have evolved extremely slowly. An example is shorebirds, a group that arose in the time of dinosaurs, but that shows many similarities in voice even between distantly related species. The proposed program of research will investigate how sound displays differ among different species of shorebirds and woodpeckers, and how these differences fit into the bigger picture of evolutionary conservatism over millions of years. Do these sounds evolve slowly because the organ of voice ("syrinx") is very simple? Do different calls in the display repertoire evolve together as a set, because all are produced by a single vocal organ? If so, particular qualities should pervade each species' repertoire. Or can they evolve independently of one another, because each is produced in a different way? If different calls of a species can evolve more-or-less independently, then some kinds probably evolve quickly (e.g. sexual calls), and others slowly (e.g. general-purpose alarm calls), a pattern that will be evident by examining vocalizations in the context of the group's phylogeny ("family tree"). The last part of the puzzle is the vocal organ (syrinx), which will be dissected from museum specimens, and viewed alongside acoustic displays, to give a broad picture of how instinctive sounds and sound production evolve in birds.