https://hdl.handle.net/10481/31070 Sun, 26 Apr 2026 10:21:09 GMT 2026-04-26T10:21:09Z https://hdl.handle.net/10481/112966 Genetic Legacy of the Last Ice Age Shapes Shallow Phylogeographic Structure in a Widespread Mediterranean Snake Salvi, Daniele; Machado, Luís; Pleguezuelos Gómez, Juan Manuel; Cheylan, Marc; Carretero, Miguel A.; Harris, David James Aim: Mediterranean peninsulas typically harbour high intraspecific genetic diversity associated with long-term persistence in multiple glacial refugia. However, some widespread taxa show unexpectedly shallow phylogeographic structure. Here, we investigate which historical processes can generate a pattern of strong genetic depletion within a classic southern European refugial region. Location: Iberian Peninsula and southern France. Taxon: A widespread Mediterranean colubrid snake (Zamenis scalaris). Methods: We combined range-wide multilocus genetic data (mitochondrial and nuclear markers) with coalescent-based demographic inference, species distribution modelling under present and Last Glacial Maximum climatic conditions, and Pliocene–Pleistocene fossil evidence. This integrative framework was used to reconstruct refugial history, post-glacial expansion dynamics, and spatial patterns of genetic diversity. Results: Both mitochondrial and nuclear markers indicate very low genetic variation across most of the species' range, with rare, derived haplotypes geographically clustered in southeastern and eastern Iberia. This pattern, combined with demographic reconstructions, indicates persistence through the Late Pleistocene in a single, spatially restricted refugium with reduced effective population size, followed by rapid post-glacial expansion around ~20 ka. Climatic suitability models and fossil records independently support this scenario, showing persistent suitable conditions confined to eastern–southeastern Iberia during glacial phases and a broad east-to-west temporal gradient of fossil occurrences consistent with long-term eastern persistence and subsequent westward expansion. Main Conclusions: Despite its long-term presence in Iberia, Zamenis scalaris lacks the multilayered phylogeographic structure typical of many Mediterranean vertebrates. Its genetic legacy is consistent with strong Late Pleistocene contraction that overrode deeper evolutionary history. This study highlights how glacial dynamics can erode genetic complexity even in widespread taxa within classical refugial regions, with broader implications for comparative phylogeography and the interpretation of genetic diversity patterns in southern Europe. https://hdl.handle.net/10481/112966 https://hdl.handle.net/10481/111988 Factors determining the timing of host response towards parasitic eggs: a meta-analytical approach Huertas Gómez, José Ignacio; Honza, Marcel; Ruiz-Raya, Francisco; Soler Cruz, Manuel; Samas, Peter Egg rejection is the most widespread defence strategy used by hosts of avian brood parasites to mitigate the fitness costs imposed by parasitism. Although the timing of this response (that is the latency between parasitism and egg rejection) is a critical component of host defences, the variation in rejection latency across different brood parasite–host systems remains poorly understood. Here, a meta-analysis of experimental studies on egg rejection was conducted to identify the key predictors of rejection latency. Results showed that hosts from sympatric populations, where parasites are present, tend to reject eggs more rapidly than hosts from allopatric populations. Egg characteristics strongly influenced response timing: mimetic eggs were ejected later; similarly sized eggs showed the longest latencies and smaller eggs were rejected most quickly. In addition, higher rejection rates were associated with shorter latencies. The duration of nest monitoring also showed a significant effect on measured latency, highlighting a major methodological factor that can bias latency estimates. Our findings indicate that the characteristics known to trigger egg rejection also shape its timing and emphasize the need for methodological standardization (particularly in nest monitoring protocols) to accurately assess egg-rejection behaviours. This work provides new insights into the proximate and ultimate factors driving the timing of host responses in avian brood parasite systems. https://hdl.handle.net/10481/111988 https://hdl.handle.net/10481/111403 Interactions between urbanization, malaria infection and avian cloacal microbiome Garrigós, Marta; Jiménez-Peñuela, Jéssica; Saavedra, Irene; Veiga, Jesús; García-López, María José; Garrido Escudero, Mario; Ruiz-López, María José; Figuerola, Jordi; Moreno-Indias, Isabel; Martínez de la Puente, Josué Urbanization, a major component of global change, has drastically modified the landscape, and is generally associated with biodiversity loss. Pollutants and low-quality food resources, among other urban stressors, can alter the physiology of urban-dwelling birds, ultimately affecting their interactions with other organisms, including pathogens and symbiotic microorganisms. The house sparrow (Passer domesticus) is one of the most common passerine species closely associated with anthropized environments. Here, we explored the association between the level of habitat urbanization, avian malaria infection (Plasmodium and Haemoproteus are grouped together in this study) and their combined effects on the composition of the cloacal microbiome of wild house sparrows. Urban birds showed a lower parasite prevalence than those from natural and rural habitats. In addition, the association between avian malaria infection and avian cloacal bacterial-microbiome composition depended on the habitat type. In natural habitats, infected birds showed a nearly significant increase in bacterial richness and significant differences in the relative abundance of various taxa, compared to uninfected individuals. In contrast, infection status was not associated with any microbiome parameter in birds from rural and urban habitats. In conclusion, habitat type is associated with avian malaria prevalence in house sparrows and may modulate the relationship between parasite infection and the bacterial composition of avian cloacal microbiome. https://hdl.handle.net/10481/111403 https://hdl.handle.net/10481/111399 A riddle wrapped in an enigma: parasitic lice as clues to the evolutionary puzzle of Sapayoa (Aves) Soto-Patiño, Juliana; Doña Reguera, Jorge; Johnson, Kevin P. Parasites can provide powerful insights into host evolution and biogeography. The bird Sapayoa aenigma, the only Neotropical member of the otherwise Old World clade Eurylaimides, has long puzzled ornithologists due to its phylogenetic placement and uncertain biogeographic origin. We investigated the evolutionary origin of a chewing louse in the genus Myrsidea found on Sapayoa. Using genome-wide data from 91 Myrsidea specimens from oscine, suboscine and non-passerine hosts, we reconstructed a global phylogeny to evaluate hypotheses about the origin of Sapayoa and its parasite. Phylogenomic, molecular dating and cophylogenetic analyses support a scenario in which the Myrsidea lineage on Sapayoa originated outside the Neotropics and was acquired via host-switching from an Old World oscine. The parasite’s divergence time (24.4–17.9 Ma) postdates the split between Sapayoa and other Eurylaimides, ruling out strict codivergence. Ancestral host reconstruction supports an oscine origin and Old World acquisition, and biogeographic analysis also indicates Old World origins, though with uncertainty in the exact region. These findings support a co-dispersal scenario in which Sapayoa acquired its parasite in the Old World and brought it to the Neotropics. Our study highlights the value of parasites as complementary tools for disentangling complex evolutionary and biogeographic histories. A Spanish translation is available in the electronic supplementary material. https://hdl.handle.net/10481/111399 https://hdl.handle.net/10481/111296 Condition- and parasite- dependent expression of a male-like trait in a female bird Martínez Padilla, Jesús; Vergara, Pablo; Pérez-Rodríguez, Lorenzo; Casas Arenas, Fabián; Ludwig, Sonja; Haines, Jessica; Zeineddine, M.; Redpath, Steve In many species, females display brightly coloured and elaborate traits similar to those that males use in intra- and inter-sexual selection processes. These female characters are sometimes related to fitness, and might function as secondary sexual characteristics that have evolved through sexual selection. Here, we used descriptive data from 674 females in 10 populations and an experimental removal of Trichostrongylus tenuis parasites in four populations, to examine the effects of season, age, condition, and parasites on the size of supraorbital combs displayed by female red grouse Lagopus lagopus scoticus. We found that comb size (i) was greater during the breeding than the non-breeding season, (ii) was greater in adult than in young females, (iii) was positively correlated with body condition, and (iv) negatively correlated with parasite abundance. Experimentally, we showed that comb size increased proportionally to the number of worms removed after parasite dosing. Our findings provide a better understanding of proximate mechanisms behind the expression of a male-like trait in females, and we discuss its possible function as a female ornament. This study was funded by a Natural Environment Research Council grant (NE/D014352/1). https://hdl.handle.net/10481/111296