Identifying factors that create and maintain a hybrid zone is of great interest to ecology, evolution and, more recently, conservation biology. Here, we investigated the role of environmental features in shaping the spatial dynamics of a hybrid zone between the southern tigrina, Leopardus guttulus, and Geoffroy's cat, L. geoffroyi, testing for exogenous selection as the main force acting on its maintenance. These Neotropical felid species are mainly allopatric, with a restricted area of sympatry in the ecotone between the Atlantic Forest and Pampa biomes. As both biomes have experienced high rates of anthropogenic habitat alteration, we also analyzed the influence of habitat conversion on the hybrid zone structure. To do this, we used 13 microsatellite loci to identify potential hybrids and generated ecological niche models for them and their parental species. We compared the influence of variables on parental species and hybrid occurrence and calculated the amount of niche overlap among them. Parental species showed different habitat requirements and predicted co-occurrence was restricted to the forest-grassland mosaic of the ecotone. However, hybrids were found beyond this area, mainly in the range of L. geoffroyi. Hybrids demonstrated higher tolerance to habitat alteration than parental types, with a probability of occurrence that was positively related with mosaics of cropland areas and remnants of natural vegetation. These results indicate that exogenous selection alone does not drive the dynamics of the hybrid zone, and that habitat conversion influences its structure, potentially favoring hybrids over parental species.

中文翻译：

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环境在两只新热带猫之间广泛混合区的空间动态中的作用

识别创建和维持混合区的因素对生态学、进化以及最近的保护生物学非常感兴趣。在这里，我们研究了环境特征在塑造南虎豹、Leopardus guttulus 和 Geoffroy 的猫 L. geoffroyi 之间的混合区空间动态中的作用，测试外源选择作为其维持的主要力量。这些新热带猫科动物主要是异域的，在大西洋森林和潘帕生物群落之间的交错带中具有有限的交感区域。由于这两个生物群落都经历了人为栖息地的高速率改变，我们还分析了栖息地转换对混合区结构的影响。去做这个，我们使用 13 个微卫星位点来识别潜在的杂种，并为它们及其亲本物种生成生态位模型。我们比较了变量对亲本物种和杂种发生的影响，并计算了它们之间的生态位重叠量。亲本物种表现出不同的栖息地要求，预测的共生仅限于交错带的森林 - 草地镶嵌。然而，在该区域之外发现了杂种，主要是在 L. geoffroyi 的范围内。杂种表现出比亲本类型对栖息地改变的更高耐受性，其发生概率与农田区域的镶嵌和自然植被残余呈正相关。这些结果表明，单独的外源选择并不能驱动混合区的动态，