Vascular, cardiac, and renal lesions attributed to primary systemic hypertension in western pygmy marmosets (Cebuella pygmaea)

In a retrospective study of a western pygmy marmoset ( Cebuella pygmaea) colony, postmortem examination of 1/8 juvenile and 29/47 adult animals identified vascular, cardiac, and renal lesions consistent with systemic hypertension. This included frequent renal arteriolar hypertrophy, hyaline and proliferative arteriolosclerosis, fibrinoid necrosis of arterioles, glomerulosclerosis, and nephrosclerosis. Affected animals ranged from 0.6 to 12 years of age (mean 6 years) and had an observed male predominance. Genealogical relatedness was evident in several breeding pairs and spanned multiple generations. Concurrent cardiac and renal disease was commonly identified, although frequently subclinical, and both were important causes of morbidity and mortality in affected animals. Cardiomegaly and hypertrophy were typical features and were accompanied by left atrial thrombosis in 10 animals. Signs of heart failure included chronic pulmonary edema in 20 cases and body cavity effusions in 17. In the kidneys, 19 cases had glomerular disease and hypertensive vasculopathy, and 26 cases had nephrosclerosis or glomerulosclerosis. Common extrarenal secondary causes of hypertension were excluded by necropsy examination. The pathogenesis is suggested to involve primary hypertension leading to renal and cardiac disease. Elevated sympathetic activity might be an underlying factor in the frequent development of primary systemic hypertension in the pygmy marmoset, as for the owl monkey.

The life of Fabian, an Azara’s owl monkey (Aotus azarae) of the Argentinean Chaco

Species-life history patterns provide insights into the adaptative strategies and importance of social behaviours. The cathemeral activity pattern of Aotus azarae allowed researchers from the Owl Monkey Project of Formosa, Argentina, to witness remarkable life changing events over the complete lifespan of several individuals. Here we summarize the life of Fabian, a male owl monkey we followed from the moment he started searching for a mate until he died. Although still not consistently considered in models of social evolution of mammals, our discovery of a subpopulation of solitary owl monkey floaters forced us to rethink some aspects of their characteristic social organization and mating system. Through the life of Fabian we present some representative examples of the intrasexual competition regulating the social system of the members of this genus during the different stages in the life of individuals, while reporting the first case of extra-pair copulation in wild owl monkeys.