Premise
Closely related species occurring in sympatry may experience the negative consequences of interspecific pollen transfer if reproductive isolation (RI) barriers are not in place. We evaluated the importance of pre‐ and post‐pollination RI barriers in three sympatric species of Achimenes (Gesneriaceae), including ecogeographic, phenological, floral isolation, self‐pollination, and hybrid viability (fruit and seed set).
Methods
We recorded geographic distribution throughout species ranges and assessed flowering phenology and pollinator visitation at one site in central Mexico. In the greenhouse, we measured floral traits involved in RI and quantified fruit and seed set for from self, intraspecific, and interspecific crosses.
Results
Ecogeographic barriers were important in RI, but under sympatry, phenological and floral barriers contributed more to total RI. Phenological RI varied between species and years, while floral RI was 100% effective at preventing interspecific visitation. Species showed differences in floral morphology, color, and scents associated with specialized pollination systems (A. antirrhina–hummingbirds, A. flava–bees, A. patens–butterflies); heterospecific visitation events were restricted to rare secondary pollinators. Hybrid crosses consistently yielded progeny in lower numbers than intraspecific crosses.
Conclusions
This study indicated that neither autogamy nor early post‐pollination barriers prevent interspecific pollen flow between Achimenes species. However, floral isolation, acting through a combination of attraction and reward traits, consistently ensures specificity of the pollination system. These results suggest that selection on floral traits to reduce the costs of hybrid progeny production may have played a role in evolution or maintenance of specialized pollination systems in Achimenes.
Throughout the Anthropocene, urbanization has changed the environment for birds, modifying the types and abundance of available materials to build their nests. Discarded plastics and other anthropogenic materials are very abundant in urbanized and agricultural areas and are being used by birds to build nests, constituting a potential threat to them. Objective: To evaluate the materials used for several species of birds living in an urbanized environment. Methods: We evaluated the composition of 20 nests of several species of birds found in the campus of Universidad Nacional. Results: 52.6% of nests contained some sort of waste classified in 13 types of anthropogenic materials, where the most common were wool, strings and thread. The species with the highest percentage of nest weight comprised by anthropogenic material was Campylorhynchus rufinucha Conclusions: Our results demonstrates the widespread use of anthropogenic waste as nesting material.
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