Callithrix aurita: Occurrence, allochthonous species and landscape attributes

The buffy-tufted-ear marmoset (Callithrix aurita) is a small primate endemic to the Brazilian Atlantic Forest biome, and one of the 25 most endangered primates in the world, due to fragmentation, loss of habitat and invasion by allochthonous Callithrix species. Using occurrence data for C. aurita from published data papers, we employed model selection using Akaike Information Criterion corrected for small samples and cumulative AICc weight (w+) to evaluate whether fragment size, distance to fragments with allochthonous species, altitude, connectivity, and surrounding matrices influence the occurrence of C. aurita within its distributional range. Distance to fragments with C. jacchus (w+ = 0.94) and non-vegetated areas (w+ = 0.59) correlated negatively with C. aurita occurrence. Conversely, the percentage of agriculture and pasture mosaic (w+ = 0.61) and the percentage of savanna formation (w+ = 0.59) in the surrounding matrix correlated positively with C. aurita occurrence. The findings indicate that C. aurita is isolated in forest fragments surrounded by potentially inhospitable matrices, along with proximity of a more generalist and invasive species, thereby increasing the possibility of introgressive hybridization. The findings also highlighted the importance of landscape elements and allochthonous congeneric species for C. aurita conservation, besides indicating urgency for allochthonous species management. Finally, the approach used here can be applied to improve conservation studies of other endangered species, such as C. flaviceps, which is also endemic to the Brazilian Atlantic Forest and faces the same challenges.耳簇绒猴（Callithrix aurita）为小型灵长类动物，是巴西大西洋森林生物群落的特有种，同时位列全球25种最濒危灵长类动物名录，其受胁因素涵盖栖息地破碎化、生境丧失以及外来绒猴属物种的入侵。本研究依托已发表文献中的耳簇绒猴出现记录数据，采用针对小样本校正的赤池信息准则（Akaike Information Criterion, AICc）及累积AICc权重（w+）开展模型选择，旨在评估片段面积、与外来物种栖息片段的距离、海拔、景观连通性及周边基质是否对该物种分布区内的出现概率存在影响。研究结果显示：与普通狨（Callithrix jacchus）栖息片段的距离（w+=0.94）以及无植被区域占比（w+=0.59）均与耳簇绒猴的出现概率呈负相关；与之相反，周边基质中农业与牧场镶嵌景观占比（w+=0.61）与稀树草原植被类型占比（w+=0.59）则与该物种的出现概率呈正相关。本研究表明，耳簇绒猴被隔离在周边基质环境不适宜的森林片段中，且邻近泛化性更强的入侵物种，这一状况提升了其与入侵物种发生渐渗杂交的风险。本研究同时强调了景观要素与外来同属物种在耳簇绒猴保护工作中的重要性，并指出对外来物种实施管控的紧迫性。最后，本研究所采用的研究方法可推广应用于其他濒危物种的保护研究，例如同样为巴西大西洋森林特有、且面临相同生存挑战的黄头狨（Callithrix flaviceps）。