Rainfall is one of the most predominant geophonic sources in nature, and the major climatic phenomenon influencing species biology in tropical ecosystems. Although its effects on acoustic indices have been studied, rainfall is recognized as a nuisance factor affecting their estimation. Consequently, files with rainfall sounds are typically removed from ecoacoustic analyses. In tropical rainforests, where rainfall is a common and unpredictable event, its influence on acoustic indices needs to be explicitly examined before implementing acoustic passive monitoring. Using mixed‐effects models we assessed the effect of different rainfall conditions on the direction and magnitude of the values of eight commonly used acoustic indices. We obtained 18336 1‐min recordings from 28 sampling sites in a montane forest on the northern Andes of Colombia between May‐July 2018. We identified 2867 1‐min recordings containing light to heavy rainfall. We found that both rainfall occurrence and its variation in intensity were associated with increases in ACI, ADI, H, and M index values, and decreases in AEI, BI, NDSI, and NP values. The estimated indices exhibited differential sensitivity to rainfall, with M, NDSI, and NP showing higher differences associated with increasing frequency and intensity of rainfall. Regardless the direction of change in index values caused by rainfall, we found that the magnitude of variation depended on the index. For instance, ACI and BI indices showed low sensitivity and can be considered as reliable acoustic metrics, even during heavy intensity rainfall. In contrast, M, NDSI, and NP might lead to misleading inferences, if rainfall events are not considered during calculation. We stress the importance of careful interpretation of biological inferences based on these sensitive indices and encourage an explicit assessment of rainfall, particularly in short‐term acoustic surveys in highly pluvious regions where rainfall is a conspicuous component of the soundscape.
On the basis of our recent fieldwork and historical records, we document the diversity of small non-volant mammals in the northern end of Cordillera Central of Colombia, an important region in the context of vertebrate biodiversity. From February 2004 to February 2006, we completed mammal surveys in three localities at the department of Antioquia, with elevations ranging from 1650 to 2000 m. We recorded a total of 14 species: three marsupials, one shrew, one heteromyid, and nine sigmodontinae rodents, including three species endemic in Cordillera Central. The rodents Heteromys australis , Nephelomys pectoralis , and Rhipidomys latimanus were recorded in all localities. Nephelomys pectoralis was captured in all surveys and was the most abundant species. Nearby historical records exist for 16 species, seven of which were not captured during our surveys. The community of small mammals in the northern Cordillera Central has species richness similar or higher than that in other Andean localities with a broader elevational range. We show that small mammal communities from middle elevations are a mixture of middle elevation endemics and highland species, but with little contribution from the lowlands. Finally, the occurrence of endemic and threatened species in this region suggests its importance from a conservational and biogeographical standpoint for small terrestrial mammals.
Fauna in Tropical Dry Forest (TDF) is highly dependent on water availability due to a marked seasonality in precipitation. There are few studies addressing carnivore’s ecology and the role of seasonality of TDF in Neotropics. We used scent-station and camera trapping to assess seasonal changes in occurrence and habitat use probability with seasonality. We also described activity patterns and collected fresh scats to describe diet for small sized carnivore species in a TDF fragment in the Colombian Caribbean region. We present information regarding: Cerdocyon thous, Leopardus pardalis, and Procyon spp. The analysis showed a significantly higher occurrence probability during the dry season for the three species, and no differences in the detection probability between seasons. The diet of C. thous included 24 different food items; for L. pardalis it was composed of seven items, and finally, 25 food items were identified in the diet of Procyon spp. We found that the three species presented activity patterns corresponding with previous studies. Finally, our results reflect that these species are probably making more/larger habitat use during the dry season than in the wet season, because the area has permanent water ponds by which limited resources (such as water and food) are available almost constantly in this natural reserve.
Abstractis an elusive rodent with the smallest known range among ichthyomyines, limited to only three localities in the Andes of Ecuador. Its last known record dates from 1980, and currently it is represented by a low number of specimens and localities, hampering knowledge about its geographic range. We provide the first Colombian record of
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