Last. Peter H. Raven(Missouri Botanical Garden)H-Index: 59
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The ongoing sixth mass species extinction is the result of the destruction of component populations leading to eventual extirpation of entire species. Populations and species extinctions have severe implications for society through the degradation of ecosystem services. Here we assess the extinction crisis from a different perspective. We examine 29,400 species of terrestrial vertebrates, and determine which are on the brink of extinction because they have fewer than 1,000 individuals. There are...
Last. Gerardo Ceballos(UNAM: National Autonomous University of Mexico)H-Index: 42
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Extinctions are occurring at an unprecedented rate as a consequence of human activities. Vertebrates constitute the best-known group of animals, and thus the group for which there are more accurate estimates of extinctions. Among them, freshwater fishes are particularly threatened and many species are declining. Here we report the extinction of an endemic freshwater fish of Mexico, the Catarina pupfish Megupsilon aporus , the sole species of the genus Megupsilon. We present a synopsis of the dis...
Abstract It is becoming increasingly evident that many species can tolerate different degrees of habitat perturbation and that we often underestimate the capacity of some human-modified landscapes to support populations of declining species. We provide new insights into the distribution of the endangered Central American squirrel monkey and habitat changed over the last 20 years. The species has shown an approximate 60% decrease between the historic and the present extent of occurrence, with an ...
AIM: Geographic gradients in species richness have been traditionally attributed to variation in environmental conditions. However, untangling the importance of human activities in explaining spatial patterns in raptor species richness, still remains a challenge. We evaluated the relative importance of how human impacts and ecogeographical conditions shape the latitudinal patterns of resident (n = 140) and migratory (n = 35) raptor species richness in the American continent, and analysed whether...
Last. Boris Worm(Dal: Dalhousie University)H-Index: 55
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Many of the world's vertebrates have experienced large population and geographic range declines due to anthropogenic threats that put them at risk of extinction. The largest vertebrates, defined as megafauna, are especially vulnerable. We analyzed how human activities are impacting the conservation status of megafauna within six classes: mammals, ray‐finned fish, cartilaginous fish, amphibians, birds, and reptiles. We identified a total of 362 extant megafauna species. We found that 70% of megaf...
Last. Barbara L. Taylor(NOAA: National Oceanic and Atmospheric Administration)H-Index: 12
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The vaquita porpoise (Phocoena sinus) is Mexico's only endemic—and the world's most endangered—marine mammal. With a population of fewer than 30 individuals (Thomas et al. 2017, IUCN 2018), any delay in taking needed conservation actions will result in its extinction. A recent article in the journal Sustainability (Manjarrez-Bringas et al. 2018) reasserts, without providing any scientific evidence, the baseless claims that the vaquita is fundamentally an estuarine species and that decline in vaq...
#2Jesús Pacheco(UNAM: National Autonomous University of Mexico)H-Index: 11
Last. Gerardo Ceballos(UNAM: National Autonomous University of Mexico)H-Index: 42
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Resumen La lechuza de campanario ( Tyto alba ) es considerada el ave terrestre con la mayor distribucion mundial, por lo tanto sus habitos alimentarios presentan variaciones en toda su area de distribucion, esta lechuza tambien se encuentra en Mexico. En este articulo se revisaron un total de 307 egagropilas de dos localidades, “Rancho Ojitos” y “Ampliacion Casa de Janos”, ambas se encuentran dentro de la Reserva de la Biosfera Janos en Chihuahua. Se hallaron un total de 420 restos identificable...
#2Gerardo Ceballos(UNAM: National Autonomous University of Mexico)H-Index: 42
Last. Manuel Maass(UNAM: National Autonomous University of Mexico)H-Index: 12
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Abstract Understanding the consequences of biotic and abiotic variability on population dynamics is fundamental to assessing anthropogenic impacts, such as global climate disruption, on populations and species. Our understanding from studies to date is poor, although some long-term studies of small mammals in temperate ecosystems have elucidated the roles of climate and of interspecific interactions in their population dynamics. However, the lack of long-term studies in the tropics is a major im...