Modeling the spread of invasive nutrias (Myocastor coypus) over Iran

Nutria (. Myocastor coypus) is a native aquatic rodent to South America, and was introduced to Europe, Asia, Africa and North America for fur farming. The South American nutria or coypu is now considered a pest in the area of introduction, because of its negative impact on biological diversity and ecological relationships. Having information on the invasion range of exotic species is crucial for understanding the ecology of invasive spread and for making good conservation and management planning to address this problem. At the beginning of the 20th century, nutria was introduced into Asia. Nutria was recorded for the first time in Iran in 1995. In the present study we proposed a multiple spatial scale approach to predict the invasion trends of the nutria in Iran, and to define up the "suitable scale" for predicting the invasion trends of this species. Our results highlighted the importance of environmental variables including vegetation density (for food and nesting) and water resource (streams, rivers, and lakes) in distribution of the nutria. Potential areas for the presence of the nutria are located near the Caspian Sea, west and central Iran which receive more precipitation than other parts of the country. Therefore, these parts of Iran may face a much greater risk of invasion risk in the future. Moreover, these results can show the possible risk of nutria invasion to the northern and western neighbors of Iran

Identifying biodiversity hotspots for threatened mammal species in Iran

Conservation biology has much more attention for biodiversity hot spots than before. In order to recognize the hotspots for Iranian terrestrial mammal species that are listed in any red list, nationally or globally, ten Species Distribution Models (SDMs) have been applied. The SDMs evaluation results based on the TSS and AUC values showed that all ten models of habitat suitability perform significantly better than the random selection for all studied species. According to the results, biodiversity hotspots for threatened mammal species are located in north, west and central of Iran, along the Zagros and Alborz mountain range. Therefore, habitats for threatened mammal species have been limited to small parts of Iran (approximately 27% of the country). These areas are severely fragmented and only 57% of them have been announced protected by the current conservation system. The suggestion is that, as the sustainability of these habitats would strongly depend on maintaining dispersal corridors to facilitate the movement of animals among the habitat fragments, conservation efforts should focus on those hotspots which are not formally protected under conservation laws

Wintering geese trade-off energetic gains and costs when switching from agricultural to natural habitats

Migratory birds need considerable energy reserves to fuel long-distance flights to their breeding grounds in spring. To attain sufficient energy deposits before departure, birds require high daily intake rates, which can be reached by utilizing high-quality food. During such periods of high energy demand, animals often track changes in the nutritious value of their food, for example by switching to a more profitable habitat or diet. Pre-migratory Barnacle Geese Branta leucopsis staging along the Wadden Sea coast are known to switch from pastures to salt marshes during spring. Previous studies have suggested that Barnacle Geese switch habitat to track changes in protein levels, which drop in pastures as spring progresses, and to avoid high levels of disturbance. Here we made use of detailed information on pre-migratory habitat use of individual Barnacle Geese tracked by GPS/accelerometer tags to assess which factors may drive a habitat switch. We analysed habitat use and time budgets of individual birds and combined this with data on food quality in two habitats to analyse differences in food intake. We found large individual variation in pre-migratory habitat use, both in the extent of salt marsh use, as well as in the timing of a switch from pastures to salt marshes. In salt marshes, geese spent more time grazing and made fewer flight movements, potentially as they experienced lower levels of disturbance compared to geese in pastures. By increasing grazing time and reducing flight movements, geese in salt marshes may compensate for reduced food quality. Our results show that Barnacle Geese trade-off high intake rates and high costs in pastures with low intake rates and low costs in salt marshes

Expert system for modelling stopover site selection by barnacle geese

The study of stopover sites has received a lot of attention in avian ecology, being especially important for many long-distance migrants, some of which have to pause several times during migration. The survival of many migratory birds depends primarily on food availability at these stopovers. However, previous studies show that there is a lack of knowledge about site selection where migratory birds stop to refuel energy stores. In the present study, a Bayesian expert system has been used to incorporate environmental parameters, to determine their relationship with the presence of barnacle geese at stopover sites. Data on stopover sites was obtained from satellite-tracked barnacle geese (Branta leucopsis) for three different breeding populations in the Western Palearctic (i.e. Russian, Svalbard and Greenland). The results from the present study showed that the posterior probability of presence at the stopover sites obtained from the Bayesian model was close to one. Therefore, the Bayesian expert system detected the stopover sites of the geese correctly and can be used as a proper method for modelling the presence of barnacle geese at the stopover sites in the future. This study introduces a new method into movement ecology to identify and predict the importance of different environmental parameters for stopover site selection by migratory geese. This is particularly important from both a conservation and an agro-economic point of view with the goal of reducing possible conflicts between geese and agricultural interests

Modeling the spread of invasive nutrias (Myocastor coypus) over Iran

Nutria (. Myocastor coypus) is a native aquatic rodent to South America, and was introduced to Europe, Asia, Africa and North America for fur farming. The South American nutria or coypu is now considered a pest in the area of introduction, because of its negative impact on biological diversity and ecological relationships. Having information on the invasion range of exotic species is crucial for understanding the ecology of invasive spread and for making good conservation and management planning to address this problem. At the beginning of the 20th century, nutria was introduced into Asia. Nutria was recorded for the first time in Iran in 1995. In the present study we proposed a multiple spatial scale approach to predict the invasion trends of the nutria in Iran, and to define up the "suitable scale" for predicting the invasion trends of this species. Our results highlighted the importance of environmental variables including vegetation density (for food and nesting) and water resource (streams, rivers, and lakes) in distribution of the nutria. Potential areas for the presence of the nutria are located near the Caspian Sea, west and central Iran which receive more precipitation than other parts of the country. Therefore, these parts of Iran may face a much greater risk of invasion risk in the future. Moreover, these results can show the possible risk of nutria invasion to the northern and western neighbors of Iran