Rare combination of genetic changes increases the virulence of canine distemper virus

Study explains how CDV killed lions, spotted hyenas in the Serengeti 

Date: December 8, 2016
Source: Forschungsverbund Berlin e.V. (FVB)

Summary:The long-running debate about why just one of several canine distemper virus (CDV) outbreaks in the Serengeti in Tanzania during the past 25 years was fatal for lions and spotted hyenas has been resolved. An international team of scientists conducted genetic analyses of CDV strains obtained from a range of carnivores between 1993 and 2012 and discovered that lethal CDV infections in lions and hyenas during the 1993/1994 epidemic was caused by a rare and genetically distinct CDV strain with three rare mutations not present in any other Serengeti strain isolated from domestic dogs or wild canids. Two of these rare mutations were found to increase the ability of CDV to invade lion cells.  

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New method for testosterone determination in spotted hyenas

Date: June 24, 2015

Source: Forschungsverbund Berlin e.V. (FVB)

Summary: For the first-time, researchers have succeeded in measuring metabolites of testosterone excreted in the feces of spotted hyenas. This innovative non-invasive research method is essential to avoid disturbance of animals.

In male mammals, testosterone plays a key role in both development and reproduction. Thus, measures of changes in testosterone concentration both within an animal's lifespan and across populations provide information essential for an understanding of growth, reproductive strategies and aging. However, hormone research normally requires the taking of blood samples, which in wild animals is difficult, and not always possible, particularly in protected areas where the capture of wild animals is often prohibited. Additionally, capture and blood sampling may cause stress in wild animals, thereby inducing a change in the hormone concentration being measured. In contrast, the non-invasive monitoring of hormones avoids all these problems. Thus, physiological data of free-ranging animals can be collected easily, thereby allowing repeated sampling from the same animal in its natural environment throughout its lifespan.

Details and verification of the efficacy of the first antibody-based enzyme immunoassay to monitor fecal testosterone metabolites in spotted hyenas are published in PLOS ONE. It is now possible to investigate the influence of age, social status and reproductive behavioural strategies on testosterone concentrations in wild spotted hyenas.

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