Departments of Biology and Environmental Studies, University of Pittsburgh at Johnstown , Johnstown, PA, USA.
Department of Biology, New Mexico State University , Las Cruces, NM, USA.
Proc Biol Sci. 2024 Aug;291(2029):20240659. doi: 10.1098/rspb.2024.0659. Epub 2024 Aug 21.
Species worldwide are experiencing anthropogenic environmental change, and the long-term impacts on animal cultural traditions such as vocal dialects are often unknown. Our prior studies of the yellow-naped amazon () revealed stable vocal dialects over an 11-year period (1994-2005), with modest shifts in geographic boundaries and acoustic structure of contact calls. Here, we examined whether yellow-naped amazons maintained stable dialects over the subsequent 11-year time span from 2005 to 2016, culminating in 22 years of study. Over this same period, this species suffered a dramatic decrease in population size that prompted two successive uplists in IUCN status, from vulnerable to critically endangered. In this most recent 11-year time span, we found evidence of geographic shifts in call types, manifesting in more bilingual sites and introgression across the formerly distinct North-South acoustic boundary. We also found greater evidence of acoustic drift, in the form of new emerging call types and greater acoustic variation overall. These results suggest cultural traditions such as dialects may change in response to demographic and environmental conditions, with broad implications for threatened species.
全世界的物种都在经历人为的环境变化，而这些变化对动物文化传统（如声音方言）的长期影响往往不得而知。我们之前对黄颈亚马逊鹦鹉的研究发现，在 1994 年至 2005 年的 11 年间，其稳定的声音方言发生了适度的变化，包括联络叫声的地理边界和声学结构。在这里，我们研究了黄颈亚马逊鹦鹉在 2005 年至 2016 年的随后 11 年时间跨度内是否保持了稳定的方言，最终研究了 22 年。在同一时期，该物种的数量急剧减少，促使其在 IUCN 地位上连续两次上调，从脆弱物种上升到极危物种。在最近的 11 年时间跨度内，我们发现了叫声类型在地理上发生变化的证据，表现在双语地点更多，以及曾经明显的南北声学边界的基因渗透。我们还发现了更多声学漂移的证据，表现为新出现的叫声类型和更大的整体声学变化。这些结果表明，像方言这样的文化传统可能会因人口和环境条件的变化而发生变化，这对受威胁的物种具有广泛的影响。
