it is believed that jerboa developed his extraordinary powers through his baptism in the river juru ( a river 1900 km ( 1200 miles ) in length which rises in east central peru and flows north east across nw brazil to join the amazon ) in the rainforest , wherein his parents , keen botanists searching for the rare and wonderful juru flower , ( a large fern-like plant with vivid maroon and orange flowers ) , were killed and eaten by marauding jaguars .