7/30/2023 0 Comments Dordogne region two species![]() After this, only sparingly has it been observed by science. Illustration of a Type D male and female (© Uko Gorter)įound in the Southern hemisphere, the Type D has first been described in a mass stranding event in New Zealand in 1955. Then there’s the almost ridiculously small eye patch, which is a great way to identify this type of orca. The dorsal fins are more pointed and less prominent. They lack a snout and the heads are more blunt. Type D’s, on the other hand, differ substantially in terms of morphology. Then there are the Types B (divided in a large and small form) and C, which subtly differ in the shape of the dorsal fin and more obviously in the positions and shapes of the eye patches, saddle patches and colour. The Type A is the quintessential orca people are familiar with. In terms of morphology, Type D orcas are very different from other types in the Southern hemisphere. Analyses of its mitochondrial DNA have given reasons to declare this type as its very own species. There are currently discussions going on within the scientific community, surrounding this type. The most remarkable of these has to be the Type D. Five such ecotypes have currently been described in the Southern Ocean. ![]() These ecotypes differ in morphology, diet, behaviour and genetics. Worldwide, orcas are being divided into subspecies, also called ecotypes. I therefore consider myself lucky that I have met these animals. Not many people have seen this unique type of orca with their own eyes. One animal which does indeed deserve this title is a virtually unknown ecotype of the orca: Type D. The rivers and the dams upstream are now a vital resource for those who depend more and more on freshwater supply including agricultural irrigation, energy production, industry and new residential and tourist demands.It’s not often for large animal species to remain a mystery nowadays. With 1.2 million habitants, the Dordogne’s catchment area has a low density (51 inhabitants per km²) comparing with the national average (112 inhabitants per km²).įor around fifty years, the transformation of rural areas in the Dordogne watershed into agricultural land and to recreational spaces has led to a spatial and social reorganization. It has an important variety of fishes (39 species) and it is especially valuable because it is the last refuge of all major diadromous fish of Western Europe. The Dordogne basin is home to a rich biodiversity of plant and animal species remarkable at national and European levels. This ecoregion is characterized by temperate coniferous forests, temperate forests with deciduous trees and Mediterranean woodlands and scrub. The transition is also related to the topographical variations between the mountain area of the source and the alluvial area of the mouth of the river. Given its size, the Dordogne watershed consists of two main biogeographical regions and one transition region: a continental region, located to the east of the basin and characterized by temperate coniferous forests, an Atlantic region in the western part of the basin in Aquitaine, characterized by temperate forests of deciduous trees and finally, between the two regions there is a transition region that is a crossroads of climatic influences and a Sub-Mediterranean and Atlantic floristic area. The river traverses a variety of landscapes and functions - mountains, hydropower, large meanders -before flowing into the Gironde at the "Ambès beak", north of the city of Bordeaux, forming the Gironde estuary, the largest estuary in Europe. Its catchment area is about 280 km in its longest part and 150 km at its widest zone. The Dordogne rises on the flanks of Puy de Sancy (1,658 m) in the town of Mont Dore, from the confluence of two small torrents: the Dore and Dogne.
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