Avian Communication and Behaviour in Dynamic Environments.

动态环境中的鸟类交流和行为。

• 批准号: RGPIN-2014-04300
• 负责人: Otter, Kenneth
• 金额: $ 1.75万
• 依托单位: University of Northern British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=587721
• 关键词: Avian; Communication; Behaviour; Dynamic; Environments.

Behavioural flexibility may enable species to cope with changing or novel environments, which we will investigate among chickadee and sparrow species that have invaded urban areas, expanded their range into novel regions, or come into contact with closely-related (but typically isolated) species. Black-capped, chestnut-backed and mountain chickadees are often attracted to settle in urban greenspace through provision of feeders and nestboxes, but such settlement subjects them to the increased noise levels and altered habitats associated with urbanization. Though these species settle in urban spaces, their capacity to alter vocalizations may affect their ability to compensate for the different environments. Our and other studies show low-frequency urban noise masks lower-pitched vocalizations, which would favour shifts to higher-frequency and louder signals among settling individuals/populations. Black-capped chickadees primarily use long-range songs during spring signalling; mountain chickadees alternate the use of song and shorter-range chick-a-dee calls; and chestnut-backed chickadees lack song and produce only chick-a-dee calls. Using portable speakers broadcasting urban noise, we will test the capacity of males to dynamically adjust their signals to avoid masking, and determine whether the flexibility to adjust differs between species. We will also test the perceptive ability of both females and males to distinguish songs of birds embedded in urban noise, and whether birds that have already settled in urban landscapes produce songs that are less easily masked. Both urban development and forestry practices can also affect likelihood of species interactions. Black-capped and mountain chickadees prefer different habitats and typically do not have overlapping distributions. However, contact sites occur where the lower-altitude deciduous forests (black-capped habitat) abut higher-altitude coniferous forests (mountain habitat), which can arise from land clearing associated with either urbanization or forestry . In one contact population, mountain chickadees (the subordinate species) alter their songs and song/call usage to avoid signal overlap with black-capped chickadees. Despite these adjustments, we found that extra-pair matings between female mountain and male black-capped chickadees resulted in hybrid young appearing in mountain, but not black-capped, nests. We will use genetic analysis to explore the generality of these patterns in new study populations, and determine whether hybrids suffer reduced offspring or adult condition. We will playback mountain chickadee songs to black-capped chickadees to determine whether altering songs is sufficient to reduce aggression from the socially-dominant species. We will also playback black-capped chickadee song bouts within territories of mountain chickadees to determine whether birds dynamically adjust signalling in the presence of a dominant competitor. Logging and dam construction in the northern Rockies have been implicated as the likely source of habitat corridors that have allowed eastern species, like white-throated sparrows, to establish small breeding populations in north central British Columbia. This small western population of sparrows sings a distinctive dialect from the common song heard throughout eastern Canada, and may result from founder effects of this western population coupled with behavioural learning of songs. We will use a combination of genetic analyses, distinctive isotope levels in feathers and light-sensing geolocator backpacks mounted on migrating birds to determine the degree to which populations on either side of the Rockies are isolated, and how this affects the evolution and spread of song dialects in this peripheral population.

行为灵活性可能使物种能够科普不断变化的或新的环境，我们将在入侵城市地区的山雀和麻雀物种中进行调查，将其范围扩展到新的区域，或与密切相关的（但通常是孤立的）物种接触。 黑顶、栗背和山雀经常被吸引到城市绿地定居，通过提供喂食器和巢箱，但这种定居使它们受到城市化带来的噪音水平增加和栖息地改变的影响。 虽然这些物种定居在城市空间，但它们改变发声的能力可能会影响它们对不同环境的补偿能力。 我们和其他研究表明，低频城市噪音掩盖了较低音调的发声，这将有利于在定居的个人/人群中转向更高频率和更大的信号。 黑顶山雀主要使用长距离的歌曲在春天的信号;山雀交替使用歌曲和短距离的鸡一迪呼叫;和栗子支持山雀缺乏歌曲，只产生鸡一迪呼叫。 使用便携式扬声器广播城市噪音，我们将测试男性的能力，以动态地调整他们的信号，以避免掩蔽，并确定是否灵活调整物种之间的差异。 我们还将测试女性和男性的感知能力，以区分嵌入在城市噪音的鸟类的歌曲，以及是否已经定居在城市景观的鸟类产生的歌曲，不太容易掩盖。 城市发展和林业实践也会影响物种相互作用的可能性。 黑顶山雀和山地山雀喜欢不同的栖息地，通常没有重叠的分布。 然而，接触地点发生在低海拔落叶林（黑顶生境）毗邻高海拔针叶林（山地生境）的地方，这可能是由于城市化或林业相关的土地清理造成的。 在一个接触人群，山雀（下属物种）改变他们的歌曲和歌曲/呼叫使用，以避免信号重叠与黑顶山雀。 尽管有这些调整，我们发现，额外的对女性之间的交配山和男性黑顶山雀导致的混合年轻出现在山区，但不是黑顶，巢。 我们将使用遗传分析来探索这些模式在新研究人群中的普遍性，并确定杂交后代或成年人是否会遭受减少。 我们将播放山雀的歌声给黑顶山雀，以确定改变歌声是否足以减少社会优势物种的攻击性。 我们还将播放黑顶山雀的歌曲回合内山雀的领土，以确定鸟类是否动态调整信号的存在下，一个占主导地位的竞争对手。 在北方落基山脉的伐木和水坝建设被认为是栖息地走廊的可能来源，这些栖息地走廊允许东部物种，如白喉麻雀，在不列颠哥伦比亚省中北部建立小规模的繁殖种群。 这一小批西部麻雀唱着一种独特的方言，来自加拿大东部各地听到的常见歌曲，可能是由于这一西部人口的创始人效应加上对歌曲的行为学习。 我们将结合使用遗传分析，羽毛中独特的同位素水平和安装在候鸟身上的光传感地理定位器背包，以确定落基山脉两侧的种群被隔离的程度，以及这如何影响这一周边种群中歌曲方言的进化和传播。