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Substrate type is a key-factor in nest-site selection and nest architecture of burrowing birds. However, little is known about which factors drive nest-site selection for these species, especially in the tropics. We studied the influence of soil attributes on nest-site selection by the campo miner Geositta poeciloptera, an open grassland bird that builds its nests within soil cavities. For all nests found, we measured the depth of the nest cavity and the resistance of the soil to penetration, and identified the soil horizon in which the nest was located. In soil banks with nests, we collected soil samples for granulometric analysis around each nest cavity, while in soil banks without nests we collected these samples at random points. From 43 nests found, 86% were located in the deeper soil horizons (C-horizon), and only 14% in the shallower horizons (B-horizon). Granulometric analysis showed that the C-horizons possessed a high similar granulometric composition, with high silt and low clay contents. These characteristics are associated with a low degree of structural development of the soil, which makes it easier to excavate. Contrarily, soil resistance to penetration does not seem to be an important criterion for nest site selection, although nests in more resistant the soils tend to have shallower nest cavities. Among the soil banks analyzed, 40% of those without cavities possessed a larger proportion of B-horizon relative to the C-horizon, and their texture was more clayey. On the other hand, almost all soil banks containing nest cavities had a larger C-horizon and a silty texture, indicating that soil attributes drive nest-site selection by G. poeciloptera. Thus, we conclude that the patchy distribution of G. poeciloptera can attributed to the infrequent natural exposure of the C-horizon in the tropical region, where well developed, deep and permeable soils are more common.

Summary Understanding the types of movements exhibited by a threatened species is paramount for creating conservation and management strategies. The Campo Miner (Geositta poeciloptera) is a threatened obligate grassland bird endemic to the South American Cerrado. Literature disagrees about its movement ecology, with authors suggesting strategies as contradictory as residency and nomadism. The species requires short and sparse grass cover to breed and seems to be associated with fires, tracking recently burned grassland patches. We studied the movement ecology of marked Campo Miners for seven years, integrating our results with information from citizen science data, museum specimens, and the literature. After investigating every main movement strategy exhibited by bird populations, we found no evidence of regular migration in the species (e.g. altitudinal, short- or long-distance). The Campo Miner is a resident species with territorial behaviour restricted to the breeding season, which apparently results in seasonal variation in its detectability, biasing our perception about its seasonal abundance and distribution. We propose a theoretical framework for understanding local movements in the species, which predicts that Campo Miners: (1) establish their territories at the beginning of the breeding season in patches of suitable habitat; (2) stop defending their territories after the breeding season; (3) stay during the non-breeding season in their home ranges, also wandering across neighbouring home ranges; (4) abandon their home ranges if the grass cover becomes high and dense or when a better quality habitat patch becomes available, using fires as a cue for locating recently burned patches that will soon

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Reproductive seasonality in Neotropical bats has been assessed to the better understand their reproductive behavior. This knowledge is especially important for the control of Desmodus rotundus population as it is a transmitter of rabies virus. Therefore, we aimed to evaluate the functional activity of testis and epididymis of D. rotundus in dry and rainy seasons under a morphological approach. We observed an increase in tubular diameter and epithelial height of the seminiferous tubules during the rainy season. In the latter, additionally, stereological analysis of the testis showed increased proportion of seminiferous epithelium and reduced percentage of lumen. The sperm number in caput/corpus epididymis increased in rainy season, whereas sperm count and transit time were reduced in cauda region. These alterations were probably related to the recovery of epithelium activities after mating season in dry season. Despite altered nuclear and cytoplasm parameters of Leydig cells between seasons, the volume and number of these cells were constant. Moreover, no change in serum testosterone levels, daily sperm production, and apoptotic index were observed, which indicates that the reproductive pattern in D. rotundus does not change between seasons. Our study offers a baseline for the management of vampire bat population as an attempt to control rabies disease.