The most important aspect that is considered while stating the difference between a ship and a boat is the size. It is said that the best way to differentiate between a ship and a boat is to remember that âA ship can carry a boat, but a boat cannot carry a ship.â. Credit: Jyoti Luthra.
Site and Date of Introduction: The brown tree snake was introduced into Guam in the 1950s. The snake was first sighted inland from the seaport and became conspicuous throughout central Guam by the 1960s.By 1968, brown tree snakes had successfully dispersed throughout the island.eason(s) Why it has Become Established: The brown tree snake has become established on Guam due to the absence of natural population controls and the abundance of vulnerable prey on the island. For example, introduced lizards are popular food items for young snakes.
An invasive species is defined legally in the USA as âAn alien species whose introduction does or is likely to cause economic or environmental harm or harm to human healthâ¦âAlien speciesâ means, with respect to a particular ecosystem, any speciesâ¦that is not native to that ecosystem.â.on-native species can be added to a community either by natural range extensions or because they are introduced as a result of human activity. Most non-native species have harmful ecological effects; these are referred to as invasive species.