Rare study on monkeys and other mammals of Paraguay

Johann Rudolf Rengger (1795-1832).

Naturgeschichte der Saeugethiere von Paraguay.

Basel, Schweighauser, 1830.

8vo. XVI, 394 pp. 19,5 x 12 cm.

Contemporary half calf with gold-tooled spine.

First and only edition of Johann Rudolf Rengger's study on mammals of Paraguay, in which he first describes the giant otter and makes important behavioural observations on monkeys that would influence Darwin's philosophy.
In 1818 Rengger, a Swiss doctor, embarked on a scientific journey to the understudied region of Paraguay with the aim to research the natural history of the region and to collect specimens. Though he amassed a large collection of flora and fauna much of it was later confiscated by the Paraguayan government. He made extensive trips during which he observed the physical-geographical as well as the social and ethnographic situation. In 1825 he returned to Europe. His findings were posthumously published in the well-known Reise nach Paraguay in den Jahren 1818 bis 1826 (Aarau, 1835). However, the present study on the mammals of Paraguay was published five years earlier while he was still alive but is little known due to its rarity. It is in fact his first printed scientific work about Paraguay and his principal contribution to the zoological literature. The research that he shares in this work is scientifically much more important than that in the Reise nach Paraguay, as can be discerned from Darwin's extensively annotated copy (Cambridge). Darwin was especially interested in Rengger's study of monkeys, one of the annotations reads: "mny species of S. America show the species small range — Now this agrees with Rengger". Besides monkeys, Rengger describes jaguars that use their tail for fishing, giant otters, which he coined Lutra paranensis Rengger and he described several taxa: an echimyid rodent, the long-tailed spiny rat: Proechimys longicaudatus; a chinchillid rodent, the plains viscacha: Viscacia; a cricetid rodent, the large vesper mouse: Calomys callosus (Rengger, 1830); a primate, the Azaras's capuchin: Cebus azarae, which is a species synonym for Sapajus cay; an orb web weaving spider: Parawixia bistriata.

Condition: owner's stamp on title page: Raul Vaz-Ferreira, Uruguayan zoologist and ichthyologist. Contents foxed. Binding slightly worn.

Reference: Henze IV, 579; Sabin 69614; WorldCat: 1 copy (Cambridge: Darwin's copy).

Gudger, E. W. "Does the Jaguar Use His Tail as a Lure in Fishing". In: Journal of Mammalogy, 27 (1), pp. 37-49.

Smith, P. "What is Lutra paranensis Rengger, 1830?". In: IUCN Otter Spec. Group Bull, 37 (1), pp. 53-65.