Laurance W.F.,James Cook University |
Laurance W.F.,Smithsonian Tropical Research Institute |
Carolina Useche D.,Smithsonian Tropical Research Institute |
Shoo L.P.,James Cook University |
And 52 more authors.
Biological Conservation | Year: 2011
Tropical species with narrow elevational ranges may be thermally specialized and vulnerable to global warming. Local studies of distributions along elevational gradients reveal small-scale patterns but do not allow generalizations among geographic regions or taxa. We critically assessed data from 249 studies of species elevational distributions in the American, African, and Asia-Pacific tropics. Of these, 150 had sufficient data quality, sampling intensity, elevational range, and freedom from serious habitat disturbance to permit robust across-study comparisons. We found four main patterns: (1) species classified as elevational specialists (upper- or lower-zone specialists) are relatively more frequent in the American than Asia-Pacific tropics, with African tropics being intermediate; (2) elevational specialists are rare on islands, especially oceanic and smaller continental islands, largely due to a paucity of upper-zone specialists; (3) a relatively high proportion of plants and ectothermic vertebrates (amphibians and reptiles) are upper-zone specialists; and (4) relatively few endothermic vertebrates (birds and mammals) are upper-zone specialists. Understanding these broad-scale trends will help identify taxa and geographic regions vulnerable to global warming and highlight future research priorities. © 2010 Elsevier Ltd.
Herzog S.K.,Asociacion Armonia |
Hamel-Leigue A.C.,Museo de Historia Natural Alcide dOrbigny |
Larsen T.H.,The Betty and Gordon Moore Center for Ecosystem Science and Economics |
Mann D.J.,University of Oxford |
And 3 more authors.
PLoS ONE | Year: 2013
Insect macroecology and conservation biogeography studies are disproportionately scarce, especially in the Neotropics. Dung beetles are an ideal focal taxon for biodiversity research and conservation. Using distribution and body size data on the ecologically important Phanaeini, the best-known Neotropical dung beetle tribe, we determined elevational patterns of species richness, endemism, body size, and elevational range in Bolivia, specifically testing Bergmann's and Rapoport's rule. Richness of all 39 species and of 15 ecoregional endemics showed a hump-shaped pattern peaking at 400 m, but overall declined strongly with elevation up to 4000 m. The relationship between endemic and total species richness appeared to be curvilinear, providing only partial support for the null hypothesis that species-rich areas are more likely to be centers of endemism by chance alone. An elevational increase in the proportion of ecoregional endemics suggests that deterministic factors also appear to influence endemism in the Andes. When controlling for the effect of area using different species-area relationships, the statistically significant richness peak became more pronounced and shifted upslope to 750 m. Larger species did not have higher elevational mid-points, and mean body size decreased significantly with elevation, contradicting Bergmann's rule. Rapoport's rule was supported: species with higher elevational mid-points had broader elevational ranges, and mean elevational range increased significantly with elevation. The elevational decrease of phanaeine richness is in accordance with studies that demonstrated the combined influence of temperature and water availability on species diversity, but also is consistent with niche conservatism. For invertebrates, confirmation of Rapoport's and refutation of Bergmann's rule appear to be scale-invariant general patterns. Analyses of biogeographic patterns across elevational gradients can provide important insights for identifying conservation priorities. Phanaeines with narrow elevational ranges on isolated low-elevation mountains in eastern Bolivia are at greatest climate-change related extinction risk from range-shift gaps and mountaintop extinctions. © 2013 Herzog et al.
Swenson J.J.,NatureServe |
Swenson J.J.,Duke University |
Young B.E.,NatureServe |
Beck S.,Higher University of San Andrés |
And 22 more authors.
BMC Ecology | Year: 2012
Background: The Andes-Amazon basin of Peru and Bolivia is one of the most data-poor, biologically rich, and rapidly changing areas of the world. Conservation scientists agree that this area hosts extremely high endemism, perhaps the highest in the world, yet we know little about the geographic distributions of these species and ecosystems within country boundaries. To address this need, we have developed conservation data on endemic biodiversity (~800 species of birds, mammals, amphibians, and plants) and terrestrial ecological systems (~90; groups of vegetation communities resulting from the action of ecological processes, substrates, and/or environmental gradients) with which we conduct a fine scale conservation prioritization across the Amazon watershed of Peru and Bolivia. We modelled the geographic distributions of 435 endemic plants and all 347 endemic vertebrate species, from existing museum and herbaria specimens at a regional conservation practitioner's scale (1:250,000-1:1,000,000), based on the best available tools and geographic data. We mapped ecological systems, endemic species concentrations, and irreplaceable areas with respect to national level protected areas.Results: We found that sizes of endemic species distributions ranged widely (< 20 km 2to > 200,000 km 2) across the study area. Bird and mammal endemic species richness was greatest within a narrow 2500-3000 m elevation band along the length of the Andes Mountains. Endemic amphibian richness was highest at 1000-1500 m elevation and concentrated in the southern half of the study area. Geographical distribution of plant endemism was highly taxon-dependent. Irreplaceable areas, defined as locations with the highest number of species with narrow ranges, overlapped slightly with areas of high endemism, yet generally exhibited unique patterns across the study area by species group. We found that many endemic species and ecological systems are lacking national-level protection; a third of endemic species have distributions completely outside of national protected areas. Protected areas cover only 20% of areas of high endemism and 20% of irreplaceable areas. Almost 40% of the 91 ecological systems are in serious need of protection (= < 2% of their ranges protected).Conclusions: We identify for the first time, areas of high endemic species concentrations and high irreplaceability that have only been roughly indicated in the past at the continental scale. We conclude that new complementary protected areas are needed to safeguard these endemics and ecosystems. An expansion in protected areas will be challenged by geographically isolated micro-endemics, varied endemic patterns among taxa, increasing deforestation, resource extraction, and changes in climate. Relying on pre-existing collections, publically accessible datasets and tools, this working framework is exportable to other regions plagued by incomplete conservation data. © 2012 Swenson et al; licensee BioMed Central Ltd.
Mendez D.R.,Asociacion Armonia |
Soria-Auza R.W.,Asociacion Armonia |
Vargas F.H.,The Peregrine Fund |
Herzog S.K.,Asociacion Armonia
Journal of Field Ornithology | Year: 2015
Andean Condors (Vultur gryphus) are a Near Threatened species that was formerly distributed along the entire length of the Andes from western Venezuela to Tierra del Fuego. Populations have been severely reduced north of Peru, but several thousand Andean Condors still exist in the southern portion of their range in Argentina and Chile. Little is known, however, about the size of the Andean Condor population in the central part of their range in Peru and Bolivia. From June to September 2012, we used feeding stations to attract Andean Condors and estimate the size and structure of the population in the eastern Andes of central and southern Bolivia. We estimated a minimum population of 253 condors, an adult male-to-female ratio of 1:0.6, an immature male-to-female ratio of 1:0.9, and an adult-to-immature ratio of 1:1.1. At our five survey areas, estimated abundance ranged from 15 to 100 condors per area. Males outnumbered females in three areas and the opposite was true in two areas. Our estimated adult-to-immature ratio, overall and in each area, suggests that the populations could be reproducing at a high rate. As previously observed in other Andean Condor populations, skewed sex ratios could be associated with differences between sexes and age classes in habitat selection. Although our results suggest that Bolivian populations of Andean Condors are still reasonably large, population monitoring is urgently needed, including use of feeding stations throughout the entire Bolivian range of the species and intensive searches for roosting and nesting sites. © 2015 Association of Field Ornithologists.
Herzog S.K.,Asociacion Armonia |
Maillard Z. O.,Asociacion Armonia |
Embert D.,Amigos y Amigos |
Caballero P.,Amigos y Amigos |
Quiroga D.,Amigos y Amigos
Journal of Ornithology | Year: 2012
Accurate extent of occurrence (EOO) estimates are essential for reliable conservation assessments. Recent studies suggest that current EOO maps often significantly overestimate range sizes of birds, particularly for narrow-ranging, threatened and ecological specialist species. Such species may therefore be at danger of being falsely overlooked by conservation assessments. Using species distribution modeling combined with 'expert' review and according corrections of inductive models, we estimated historic range sizes of 15 Bolivian endemics, which were compared to BirdLife International's 2011 EOO estimates. The same comparisons were made for 65 additional species modeled by Young et al. (Auk 126:554-565, 2009) to corroborate the general validity of our results. Species distributions were modeled deductively for eight, with a hybrid approach for six and inductively for one species. For 67 % of Bolivian endemics, EOO estimates were 1. 48-4. 22 times larger than our estimates (1. 75-4. 33 larger for 89 % of the species in Young et al.). Overestimation can largely be attributed to inclusion of areas outside a species' elevational range and of portions of ecoregions or extensive habitat areas uninhabited by a species. For 33 % of Bolivian endemics (all threatened species), EOO estimates were 21. 2-75. 3 % smaller than our estimates (30. 3-72. 2 % smaller for 11 % of the species in Young et al.). This can partly be attributed to more sophisticated range size analyses for threatened species by BirdLife, differences between historic versus current range sizes, and overly conservative EOO estimates. EOO definition and estimates are in serious need of improvement. Exclusion of discontinuities within overall distributions of species needs to be applied rigorously at small spatial scales, using spatially explicit environmental data such as digital elevation models and ecosystem classifications. Incorporating national expert knowledge into range size estimation can be similarly important for reducing overestimation. We recommend prioritizing species with EOO estimates of <200,000 km 2 for a revision of these estimates. © 2012 Dt. Ornithologen-Gesellschaft e.V.
Hennessey A.B.,Asociacion Armonia
Wilson Journal of Ornithology | Year: 2011
The Swallow-tailed Cotinga (Phibalura flavirostris) has traditionally been considered to consist of two subspecies, P. f. flavirostris of southeastern Brazil's foothill forest and, isolated by ∼2,500 km, a population of P. f. boliviana in central-western Bolivia. The plumage of the two taxa is distinctly different; boliviana males have a longer tail, and body plumage is significantly less sexually dimorphic. The iris of boliviana is mustard yellow, distinct from the blood red iris of flavirostris. P. f. boliviana has dull to bright orange-yellow feet whereas flavirostris has pink feet. Only one vocalization type is recorded for P. f. flavirostris, whereas at least five calls and a song are known for P. f. boliviana, which vocalizes significantly more often. The Brazilian P. f. flavirostris has strong seasonal movements, whereas P. f. boliviana has no seasonal movements. Given the diagnosable differences between the two taxa, it is highly probable they are separate lineages. P. boliviana qualifies as critically endangered for its declining small population due to continual habitat loss. © 2011 by the Wilson Ornithological Society.