Effects of Severe Floods and Droughts on Wildlife of the Pantanal Wetland (Brazil)—A Review

Abstract

Simple SummaryThe Pantanal is a wetland in the center of South America, (140,000 km² in Brazil), in the Upper Paraguay River Basin. Because of its diverse and abundant wildlife, it is recognized as one of the most important freshwater ecosystems in the world. Many endangered species occur there, including jaguar; waterfowl are exceptionally abundant. Relief varies between the low, and flat floodplain, and the surrounding non-flooded plateau areas. Rainfall shows inter-annual variability, influencing the flooding patterns. Historical climate instability of severe multi-annual flood and dry events has affected animals’ habitats as well as their community structure, population size and behavioral ecology. AbstractFlooding throughout the Pantanal is seasonal. The complex vegetative cover and high seasonal productivity support a diverse and abundant fauna. A gradient in flood level supports a range of major habitats in a complex mosaic with annual seasonality. The rivers and streams are lined with gallery forests, and other arboreal habitats exist in the more elevated areas. The remainder is either grasslands or seasonally flooded grasslands. The regional flora and fauna are adapted to annual water fluctuation. However, an inter-annual series of higher or lower rainfalls has caused either severe floods or drastic dry seasons. Large scale climate phenomena such as greenhouse gases, El Niño and La Niña influence the seasonality of floods and droughts in the Pantanal. Knowledge of severe floods and droughts, which characterize natural disasters, is fundamental for wildlife management and nature conservation of the Pantanal. Plants and wild animals, for example, are affected by tree mortality in riparian forest after extreme flooding, with consequent habitat modification for wild animals. In addition, human activities are also affected since cattle ranching and ecotourism are economically important in the region, and when seasons with unusual floods or droughts occur, areas with human settlements are impacted.

Trypanosoma cruzi Infection in Neotropical Wild Carnivores (Mammalia: Carnivora): At the Top of the T. cruzi Transmission Chain

“…We also observed a gradual increase in the prevalence of T. rangeli (3%–[44]; 7%–[45]; 20% this study). It is well-known that the striking variation of the flooding intensity in the Pantanal, as well as other environmental changes, has a strong effect on the local community structure, modulating vectors, hosts and consequently their parasites density, distribution and interrelationships [27], [47]. In the same manner changes in the hosts’ environment are expected to impact the parasite subpopulation (in this case, T. cruzi DTU’s), but the outcome of this impact might be different according to each subpopulation dynamics.…”

“…The research station is covered by a mosaic of forest patches, savannas, scrub savannas, seasonally flooded grasslands and several permanent or temporary lakes. This area is subjected to annual and multi-annual variations of flooding intensity, with an alternation of high-flood and severe drought years [27]. The second site is the Serra da Canastra National Park – SCNP (20° 15.32′S, 46° 27.75′ W) and surroundings, a conservation unit in the southwest of the Minas Gerais State.…”

Flood-mediated use of habitat by large and midsized mammals in the Brazilian Pantanal

“…data). Also, arboreal mammals, such as capuchin monkeys and howler monkeys, are less affected by hydrological cycles because they inhabit the canopy of forested habitats, finding food resources during floods (Alho & Silva 2012).…”

“…Some mammals are better adapted than others to explore flooded and/or dry land (Mamede & Alho 2006, Alho 2008, in addition forested habitats are generally laid at higher elevations and are used as a refuge during flood peaks (Desbiez et al 2010). Consequently, habitats are differently used by distinct species, and species abundance and/ or population distribution are influenced by these environmental variations (Desbiez et al 2009, Alho & Sabino 2011, Alho & Silva 2012.…”

Changes in spatial and temporal trends in wet, dry, warm and cold spell length or duration indices in Kansas, USA

“…Extended periods with excessive or no rainfall or high or low temperatures cause stress on plants (Gray et al , ; Anandhi et al , 2013), animals (Alho and Silva, ) and humans (Smith et al , ). Such periods also have many ecological and hydrological consequences (Regonda et al , ; Gray et al , ; Anandhi et al , 2013).…”