‘Keystone Species that live in Ponds, Streams, & Wetlands’ (II)
This week, we’ll continue with remaining parts of ‘Keystone Species that live in Ponds, Streams, & Wetlands’ by Bonnie Hinman.
11. Beavers build a dam to make the stream or river deeper. Deep water is safer for young beavers. They can dive underwater quickly to escape predators like wolves, bears and coyotes. Most dams are less than 30m long but much longer ones have been recorded.
12. A lodge (house) is built the same way a dam is, with sticks and branches, but it is usually in the middle of the new pond. The lodge’s floor is above the water and it contains two or more ‘rooms’. The only entrance to the lodge is under the water.
13. Beavers create and maintain wetlands that are home to numerous species. When they cut down their favourite trees, other trees have less competition. These trees attract different kinds of birds and insects. Habitats with lots of different animals and plants are healthier and likely to stay that way.
14. A newt (蠑螈)looks like a lizard but is a different kind of animal. Newts are amphibians while lizards are reptiles. An amphibian always lives part of its life in water and part of its life on land. It doesn’t have scales like a reptile does.
15. Adult newts live in and near the water. Adults are not picky eaters. They will eat any small invertebrates that comes their way, but they especially love insects.
16. Eastern newts are often the first species living in the pond when it refills. If they were not around, a few species would quickly take over the pond and no other species could live there. The ecosystem would be out of balance.
17. Eastern newts also help protect humans from mosquito bites. Mosquito eggs are among their favourite foods.
18. Salmon are anadromous fish. They are born in fresh water, migrate to the ocean, and eventually return to the freshwater river or stream where they were born. Salmon live in both the Atlantic and Pacific oceans.
19. Some chinook salmon may stay in the ocean for a year or two before beginning the trip back upstream. Others may stay in the ocean up to seven or eight years. They grow quickly during the time they are in the ocean. Chinook salmon need to gain as much weight as possible before they begin their long migration back to freshwater to spawn. Salmon have an instinct that directs them to return to the freshwater stream or river where they were born.
20. A chinook who came from Canada may swim as far as 3200km in 60 days. Salmon do not eat during their migration. They survive on stored body fat, so their health gets worse as they get closer to the end of their journey.
21. During the salmon’s time in fresh water, they provide food for species like birds, bears, eagles, mink and otter. At least 138 species benefit from salmon in their environments. Scientists found that healthier plants grew in the soil along riverbanks where dead salmon had rotted.
Source: https://www.christies.com/en/lot/lot-6032454
