“
“Advances in the understanding of ecological factors determining predator–prey interactions have provided a strong theoretical background on diet preferences of predators. We examined http://www.selleckchem.com/products/Roscovitine.html patterns of jaguar predation on caiman in southern Pantanal, Brazil. We investigated factors affecting predation rates and vulnerability of caiman to predation by jaguars. We recorded 114 caiman mortality incidents. Predation accounted for 62.3% (n = 71) of all caiman found dead, while other causes of mortality (nonpredation) accounted for 37.7% (n = 43). We found that jaguars prey on a broad size range of caiman body and caiman predation

was influenced by distance to forests. During dry seasons, 70% (n = 49) of deaths were due to predation, while 30% (n = 21) were AUY-922 clinical trial due to nonpredation causes. However, we found no significant relationship between annual and monthly killings of

caiman and rainfall totals by year and month (r = 0.130, r = −0.316). The annual flooding regime may be a more important factor influencing prey selection by jaguars. Although neotropical crocodilians are relatively well studied, their interactions with jaguars have been mostly ignored and should be prioritized in future studies. “
“For many polar species, climate change is likely to result in range contractions and negative population trends. For those species whose distribution is limited by sea ice and cold water, however, polar warming could result in population increases and range expansion. Population increases of great cormorants Phalacrocorax carbo in Greenland are associated MCE公司 with warmer sea surface temperatures, but the actual impact of environmental change on cormorant spatial ecology remains unclear. In the present study, we investigate how Arctic warming is likely to influence the distribution of cormorants in Greenland. Using geolocation data, we show that many individuals that breed above the Arctic Circle migrate south and winter at lower latitude.

We then couple estimates of migratory flight costs with a model that predicts daily energy expenditure during winter on the basis of water temperature, ambient illumination during diving, dive depth and day length. This model shows that the most energy efficient strategy predicted for any breeding location is to migrate as far south as possible, and that, for a given wintering location, it is more energetically expensive to breed at high latitude. We argue that cormorants currently undertake a winter migration to escape the polar night and reduce winter energy costs and that their wintering grounds in Greenland will remain largely unchanged under Arctic warming. This is because low levels of ambient illumination during the polar night will continue to restrict foraging opportunities at high latitude during winter.