From 1906 to 1907 and from 1911 to 1912, he made research trips to Madagascar and 1916-1921 to Dutch India and Sulawesi (Celebes at the time), from where he returned to Sweden with rich zoological, botanical, anthropological and ethnographic collections.

In addition to the scientific papers, Kaudern published several books on his travels, På Madagascar[3] (1913) and I Celebes obygder[4][5] (2 volumes, 1921).

In 1906, Kaudern traveled to the northwest of Madagascar, where he spent 10 months to collect material for his doctoral dissertation on the reproductive organs of insectivorous and half-monkeys.

[3] In addition to the crown prince, he received financial support from the foundation Lars Hierta's memory, director M. Lindahl and bank manager Fraenckel.

[9] In December 1916, Walter Kaudern, with Mrs Teres and the two sons Sven Alexander and Johan Valter, went on an expedition to Celebes (today Sulawesi).

The purpose was initially zoological, but after meeting with the island's people, Kaudern and Teres mainly devoted themselves to exploring the culture and daily life.