An ecologist observes that the diet of a bird species consists primarily of large grass seeds (as opposed to smaller grass seeds or the seeds of other herbaceous plants found in the area). he hypothesizes that the birds are choosing the larger seeds because they have a higher concentration of nitrogen than do other types of seeds at the site. to test the hypothesis, the ecologist compares the large grass seeds with the other types of seeds, and the results clearly show that the large grass seeds do indeed have a much higher concentration of nitrogen. did the ecologist prove the hypothesis to be true? can he conclude that the birds select the larger grass seeds because of their higher concentration of nitrogen? why or why not? smith, thomas m.; smith, robert leo. elements of ecology (page 15). pearson education. kindle edition.

In the given case, if the hypothesis is mainly because of the fact that the bigger seeds comprise more nitrogen than yes his hypothesis can be considered to be true.  

He could have concluded that one of the reasons in which the birds chose the larger seeds is because of their superior or increased nitrogen content. However, this may not be the sole reason of why they were chosen. Thus, for it is not an absolute.  

answer: tributaries flow into rivers.

wetland is a biome that develops when the water gets accumulated in a land exhibiting a huge depression. these form either seasonally or permanently. the water in the wetland comes from rivers, lakes, ocean, flood, rain or other sources. the wetlands includes mangroves, marshes and peatland.

tributaries flow into the rivers develops a wetland because such water will get deposited in the depression and will restrict the original flow of tributary water. hence, water with low drainage current combines with the river water.