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SummaryThe Black-breasted Puffleg Eriocnemis nigrivestis is a hummingbird endemic to Ecuador and considered Critically Endangered, given its limited distribution, low population numbers, and ongoing habitat degradation. We investigated habitat use patterns using landscape and microhabitat variables. In addition, we explored a previously postulated competition hypothesis involving the Black-breasted Puffleg and the Gorgeted Sunangel Heliangelus strophianus. Our results suggest that landscape variables may play a role in the habitat selection process; specifically the distance to nearest forest border seems to have a significant effect on our habitat model. We speculate that, as the species is known to perform seasonal movements, the avoidance of forest border might reduce the physiological stress caused by altitudinal migration. At microhabitat level, Black-breasted Puffleg seems not sensitive to forest structure variables. Our findings suggest that ensuring forest tract connectivity, between the altitudinal extremes of the species’ range at the north-western flanks of the Pichincha volcano, might be crucial for survival of the species during its annual cycle. However, non-metric multidimensional scaling (NMDS) indicates that Black-breasted Puffleg and the Gorgeted Sunangel do not overlap spatially, but this finding is not conclusive considering our field observations.

SummaryThe Northern Silvery Grebe Podiceps juninensis is an aquatic bird species considered Vulnerable to extinction in Ecuador and Endangered in Colombia. Globally the species is considered Near Threatened. Herein we report recent changes in distribution and population trends for the subpopulation in the northern Andes (Ecuador, Colombia), which is small and isolated. The Northern Silvery Grebe has undergone two documented extirpations, and at least one colonisation event, over the last three decades. More than 90% of the subpopulation relies on two wetlands, La Mica and Colta lakes in Ecuador, with the latter facing an accelerated sedimentation process which jeopardizes the fate of the wetland, and the species, in the mid-term. The population of La Mica lost 80% of its birds in 2000 after the damming of the lake, but then remained stable over our census period (2004–2013). In contrast, the Colta population results from a recent colonisation in the early 2000s, and has experienced an exponential growth since then (annual population multiplication rate: 1.464). The growth of this population is so fast that it must include an important contribution of immigrants. The temporal coincidence between the drop in population size at lake La Mica and the colonisation of lake Colta suggests that the Colta population was founded by immigrants from La Mica. Finally, the absence of current reports of the species at wetlands in Colombia suggests that the species remains at very low numbers, bolstering the shrinkage in northern distribution.

Black‐breasted Pufflegs (Eriocnemis nigrivestis) are hummingbirds endemic to Ecuador and are considered critically endangered because of their limited distribution, a population estimated at fewer than 1000 individuals, and ongoing habitat degradation. From November 2013 to June 2016, we examined the foraging preferences of these hummingbirds using a combination of direct observations, time‐lapse cameras, and motion‐detection software. We first identified 21 species of ornithophilous plants distributed among five sites in the northwestern flanks of the Pichincha volcano in northwest Ecuador. We then monitored these plant species using time‐lapse cameras and recorded 144 visits by Black‐breasted Pufflegs to seven of the 21 species. Most visits (128 of 144 visits, 89%) were to just two species of plants, Macleania rupestris and Palicourea fuchsioides, the latter of which is also an endemic and threatened species. In addition, Black‐breasted Pufflegs were only observed in the most pristine habitats. Given the potential negative effects of climate change for species in the tropical Andes plus the possible loss and degradation of habitat resulting from human activities, efforts are needed to conserve habitats currently used by Black‐breasted Pufflegs, recover degraded habitats, and connect isolated patches of suitable habitat. Our results concerning species of flowering plants used most by Black‐breasted Pufflegs (P. fuchsioides and M. rupestris) should help guide any habitat restoration initiatives.

Resúmenes de la IV Reunión Ecuatoriana de Ornitología