The role of the environment in the spatial dynamics of an extensive hybrid zone between two neotropical cats

Abstract

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 analysed 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 favouring hybrids over parental species.

Non-invasive genetic sampling reveals a habitat use extension of Chrysocyon brachyurus and Leopardus guttulus inside a protected area of Southeastern Brazil

“…Our findings suggest a habitat use extension of C. brachyurus inhabiting grassland and forest in the studied area. In contrast, L. guttulus was mostly found in the forest formation (67%) as expected, corroborating its habitat use already reported (Oliveira and Cassaro, 1999;Gourlart et al 2009;Sartor et al 2021), although scats of this species were also obtained in grassland formation (31%), suggesting an important association with this habitat in PNI. It is well known that C. brachyurus is affected throughout its original range by habitat loss and modification due to urbanization, agricultural and livestock raising (Paula et al 2013;Queirolo et al 2011Queirolo et al , 2014Vynne, 2014).…”

“…Regarding habitat use, we expected that C. brachyurus would be associated with grassland and L. guttulus with forest formations. In addition, C. brachyurus inhabits the Brazilian savannas in altitudes up to 2000 m (Queirolo et al 2011;Paula & DeMatteo, 2015;Bereta et al 2017) and L. guttulus appears in areas of dense vegetation, such as Atlantic Forest from the coastal plain to fields with altitudes no higher than 1300 m (Oliveira and Cassaro 1999;Goulart et al 2009), although it can reach up to 2000 m of altitude (Oliveira et al 2016;Sartor et al 2021). Hence, we also expected to find both species up to a maximum altitude of 2000 meters.…”

Relictual Hybridization and Biogeography of Massasauga Rattlesnakes (Sistrurusspp.)

“…Given the weak fossil record for S. tergeminus (Holman, 2000; Parmley and Holman, 2007), we cannot confirm if it was present in the southwest at the Pliocene-Pleistocene transition, or if it gradually encroached post-transition. Nevertheless, our observed diversification patterns, coupled with a recently formed but highly labile habitat, highlight the strong ecological component to its divergence, as noted in other taxa as well (Sartor et al, 2021).…”

A holocenic and dynamic hybrid zone between two cactophilicDrosophilaspecies in a coastal lowland plain of the Brazilian Atlantic Forest

“…Moreover, we generated graphical representations using Clumpak v1.1 (Kopelman et al, 2015). We used a conservative threshold to estimate potential introgressed individuals (Burgarella et al, 2009;Rohde et al, 2015;Sartor et al, 2021;Vähä & Primmer, 2006), with a membership probability of 0.3 < mp or Q < 0.7, and as putatively pure individuals those with mp or Q = 0.7 to their group of origin. Finally, we also performed an analysis of molecular variance (AMOVA) in Arlequin v2.5.2.2 (Excoffier & Lischer, 2010) with 1000 permutations.…”

“…Hybridization is indicated as a possible cause of the taxonomic problem for leaf frogs of the Rhinella crucifer species complex and toads of the Phyllomedusa burmeisteri species group (Brunes et al, 2014;Thomé et al, 2012) in the AF. Otherwise, for two Neotropical cats, Leopardus guttulus and Leopardus geoffroyi were described a contact zone with the co-occurrence of two species and hybrids with their distribution influenced by human-induced habitat alteration (Sartor et al, 2021).…”