Se comparó la calidad ecológica del río Tota durante agosto 2007 y febrero 2008, y el curso alto del río Bogotá entre los meses de octubre 2013 y enero 2014, aplicando los índices BMWP/Col y ABI. Los puntos de muestreo corresponden a la parte alta, media y baja del gradiente longitudinal. En el río Tota se determinaron 27 familias correspondientes a 11 órdenes, donde las más abundantes fueron Baetidae (25,43 %), Leptohyphidae (16,43 %), Naididae (13,76 %), Chironomidae (11,42 %) y Hyalellidae (10,30 %).  En el curso alto del río Bogotá se determinaron 32 familias correspondientes a 13 órdenes, y las más abundantes fueron Chironomidae (28,94 %), Leptoceridae (25,20 %), Naididae (18,34 %) y Simuliidae (8,63 %). En el río Tota, El BMWP/Col. presentó una calidad de agua buena, mientras que el ABI presentó una calidad aceptable.  Por otra parte, en la parte alta del Río Bogotá, tanto el BMWP/Col. como el ABI presentaron variaciones en la calidad del agua entre aceptable y muy crítica. El ACC para el río Tota mostró correlaciones entre la temperatura y conductividad con las familias Hyalellidae y Leptohyphidae mientras que el caudal se relaciona Sphaeriidae. Mientras que el curso alto del río Bogotá se correlacionó el caudal, conductividad y temperatura con la familia Veliidae. A manera de conclusión, los resultados obtenidos denotan que el índice ABI, que es un índice creado para sistemas andinos de montaña, es más sensible a los impactos que el índice BMWP/Col.

La gestión adecuada de la biodiversidad y los servicios que brinda en áreas urbanas y periurbanas requiere de información como insumo para la planeación. El monitoreo de poblaciones de especies realizado de forma periódica y a largo plazo no solo ofrece información sobre la presencia de especies en un lugar y momento, también revela tendencias poblacionales, lo que permite evidenciar distintos factores que están afectando dichas áreas.

The upper altitude ecosystems of the Andes are among the most threatened by climate change. Computer models suggest that a large percentage of species in these ecosystems will be at risk of extinction and that avian communities will suffer disruption and impoverishment. Studies in other Andean countries lend some support to these predictions, but there are no quantitative data from Colombia appropriate to test these models. In 1991–1992, we conducted a bird survey in a high Andean cloud forest to gather information about the species present and their abundance. We attempted to replicate this earlier study 24 yr later to detect any changes in the avifauna and determine possible causes for those changes. From June 2015 to May 2016, we made bimonthly trips to the study site and identified all birds detected either visually or by voice along a number of trails. We supplemented our observational data by also capturing birds in mist-nets. Community species richness and composition as well as the overall abundance of birds changed little from 1991–1992 to 2015–2016, but nearly 30% of bird species changed in abundance. Changes in the presence or abundance of nine or 10 species reflected upward shifts in elevational limits potentially due to climate change. However, most changes in abundance appeared to reflect changes in the vegetation of the study area due to successional changes in forest and subparamo habitats and a large number of relatively recent treefalls of old canopy trees with heavy epiphyte loads and subsequent changes in the understory vegetation. Our results suggest that the effects of climate change on the avifauna in our study area at a high-altitude site in Colombia are apparently occurring more slowly than predicted by recent computer models, although we conclude that the possible effects of climate change should definitely be considered in future studies. However, single-site studies such as ours have limitations in documenting elevation shifts; the most conclusive and quantitative evidence for elevational shifts comes from long-term studies conducted over a wide range of elevations. As such, we recommend establishment of such a monitoring program in Colombia because data obtained from such a program might be important in designing measures to mitigate the effects of climate change and conserve biodiversity. © 2017 Association of Field Ornithologists

High Neotropical mountains are among the most threatened ecosystems by climate change and this problem could be accentuated in cities where temperatures are higher. However, there are few data of long-term avifaunal changes in Neotropical cities, and the potential impact of climate change has yet to be addressed. Using data from 26 years of Audubon’s Christmas Bird Counts (CBCs) in the Bogotá area (ca. 2,600-3,100 m in Colombia’s eastern Andes), we analyze long-term changes of the avifauna using linear regressions corrected for species’ habitat preferences and compared urban and rural sites. For the CBC we followed the National Audubon Society’s methodology in which birds are counted over a 24-h period within a fixed circle 24 km in diameter. We recorded 235 species in the Bogotá circle with an average of 122 spp/year, including 46 boreal migrants, three endemic species, and four endemic subspecies, two globally and four locally threatened species. Species richness was higher in rural than in urban areas and most species were associated with native forest and scrub and wetlands. Among the species that were analyzed for changes in time 31% increased, 20% decreased, and 49% did not change. Strong fluctuations or changes in abundance were more frequent in urban than rural environments. Many of the species that increased or became established during the CBC interval came from lower elevations or the warmer, drier parts of the region beyond the count circle. By contrast, the lower elevational limits moved to higher elevations in several species that decreased. Climate change with its related effects represented the factor associated with the most changes in abundance. Other potential causes were direct human actions, mostly associated with urbanization, and «natural» successional changes in vegetation; predation by feral dogs and cowbird parasitism also affected several species negatively. Observations indicate that these factors will continue into the future, and the effects of climate change and urbanization in particular will probably intensify. The Bogotá CBC has provided much valuable information for Neotropical urban ornithology and its practice should be encouraged in other Latin American cities and should definitely continue in Bogotá for many years to come. © 2017 Stiles, Rosselli and De La Zerda.