Nell and Nate Kidd, heading home from Arizona with their mother, a well-known ecologist, change their plans when they receive word that condors have been spotted living in the wild near Landers Ridge.
Nell and Nate Kidd travel to the Amazon rain forest with their ecologist mother at the request of their friend, Torbi, who needs help discovering who has stolen an important harvest of Brazil nuts.
Nell and Nate Kidd, visiting Mexico with their mother, a well-known ecologist, try to help local villagers who are divided over a logging company's proposal to buy the land on which the Monarch butterflies spend the winter months.
Nell and Nate Kidd, visiting Monterey with their mother, a well-known ecologist, team up with the local sheriff to find out who is killing the sea otters that live along the California coast.
Nell and Nate Kidd, visiting Arizona with their mother, a well-known ecologist, team up with the son of the owner of their motel in an attempt to discover who is stealing giant saguaro cactuses.
