Grassland ecosystems are evolutionarily linked to disturbances such as grazing and fire. These disturbances define grassland plant communities and habitat heterogeneity, which influence animal communities. We evaluated the influence of fire disturbance on plant and bird communities and on habitat structure by sampling grassland fragments with different time elapsed since the last fire event. Habitat structure was sampled using plant life forms and abiotic variables and birds were sampled through point counts. We recorded 862 bird individuals from 70 species. Intermediately-burnt sites harbor higher habitat heterogeneity and plant species richness in comparison with recently or long-burnt sites. Bird abundance and taxonomic diversity decreased linearly as time since fire increased. Finally, time since fire influenced the relative distribution of plant life forms and bird food guilds. Our results indicate that fire management should be included in the framework for conservation and sustainable use of grasslands, because it promotes habitat heterogeneity and diversity. To maintain habitat heterogeneity and the related habitat-specific bird species and functional groups, conservation efforts should maintain grassland patches under different management intensities and frequencies on a landscape level. However, studies focused on determining the periodicity with which fire management should be used are still lacking.

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Despite the importance and ubiquity of grasslands, the degradation and the loss of these habitats have negatively affected bird populations throughout the world. The use of fire to manage grassland areas in some regions of southern Brazil can help to maintain these areas but can also influence the bird community in different ways. We assessed temporal changes in richness, abundance, and composition of bird communities in areas with different histories of fire disturbance in highland grasslands of southern Brazil, the most extensive remnant of grassland of the Atlantic Forest domain. We censused birds during four breeding seasons (2015–2018), through point counts in areas burned only once in the last ten years (OF, n = 3), areas burned annually (AF, n = 2), and areas without fire in the last ten years (WF, n = 2). In OF the richness, abundance, and species composition changed in the year of the fire, compared to the previous year, and returned to the initial values two years later. In AF and WF we found some differences among the years, but not with an equally clear pattern. Three of the six grassland associated species assessed individually for density responded significantly to temporal habitat modification since the fire. Our results show that two years without fire were enough time for the bird community to recover after a fire, but some responses are species-specific. Therefore, fire can be used as a management tool for grasslands and may help in the conservation of birds of southern Brazil, as long as with a minimum interval between fires in an area is guaranteed.

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Parque Estadual do Tainhas – PET (Tainhas State Park) is a protected area with significant extensions of natural grasslands located in highland grasslands of northeastern Rio Grande do Sul state, Brazil, and recognized as an Important Bird Area. Our aim was to record the bird species richness of PET with a greater sampling effort than previous studies at the site, including unpublished data such as occurrence status of most species and evidence of breeding of some of them in the park. We surveyed birds between 2012 and 2018 performing aleatory trails covering mainly the central portion of PET (1,500 ha). We also added records from published studies. We listed 208 species, of which 203 were recorded during our fieldwork (including 18 species of conservation concern). The estimated richness was 222.22 (SD = 10.91) species, according to Jackknife 1 method. This result represents a 58% increase in the species richness of the park and shows that long-term monitoring of the bird community allows to access more accurate richness and to identify the regular species (core avifauna) of the park. The presence of 55 breeders and threatened species shows the importance of this protected area for breeding and conservation of grassland birds, such as Urubitinga coronata, Cinclodes pabsti, Xolmis dominicanus, Anthus nattereri, Xanthopsar flavus, and Sporophila melanogaster.