Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Social status influences infection risk and disease-induced mortality

07.03.2018

Spotted hyena cubs of high-ranking mothers have a lower probability of infection with and are more likely to die from canine distemper virus (CDV) than cubs of low-ranking mothers. In subadults and adults, the picture is reversed – high-ranking females exhibit a higher infection probability than low-ranking females whereas mortality was similar for both groups. These are the surprising and interesting results of a long-term study conducted by scientists at the German Leibniz Institute for Zoo and Wildlife Research (IZW) who investigated how social status and age influence the risk of infection with CDV and its consequences for survival. They have just been published in the scientific journal “Functional Ecology”.

Epidemics of infectious and contagious diseases spread through contact or proximity in social species, including humans. Spotted hyenas are highly social animals that live in socially structured clans and have strict dominance hierarchies. Mothers keep their offspring together in the clan’s communal den, akin to human schools and kindergartens in which diseases can easily spread.


Hyenas at clan communal den

Sarah Benhaiem/Leibniz-IZW

In 1993 / 1994 an epidemic of canine distemper virus swept through the Serengeti ecosystem in Tanzania and Kenya. The epidemic was caused by a novel, virulent CDV strain which was well adapted to spotted hyenas and other non-canid carnivores. During this epidemic, communal dens of hyenas were hotspots of CDV infection, and many juveniles were observed who either showed clinical symptoms of being infected with CDV or died from CDV.

The scientists used two decades of detailed demographic, social and infection data from individually recognized hyenas in three clans in the Serengeti National Park in Tanzania. “We followed 625 females and 816 males in total. In this long-term study we monitored their health status by recording the start and end of clinical signs of CDV and by collecting hundreds of samples, mainly saliva and faecal samples from known individuals to screen for the presence of CDV”, says Dr Sarah Benhaiem, scientist at the Leibniz-IZW.

The results illustrate that two different mechanisms drive infection patterns among cubs and older animals. Cubs from high-ranking mothers were less likely to be infected and, once infected, less likely to die than cubs from low-ranking mothers. These cubs of high-ranking mothers were nursed more frequently than those of low-ranking mothers and therefore could allocate more energy to immune processes.

This reduced their risk of disease, improved their immunocompetence and thus reduced subsequent mortality. In contrast, high-ranking subadults and adult females were more likely to be infected than low-ranking ones, reflecting the more intense social life of high-ranking individuals. This increased chance of infection did not result in an increase in adult mortality, however, because, in contrast to cubs and subadults, adult hyenas rarely die from CDV.

In many mammalian societies, such as baboons and spotted hyenas, high-ranking individuals have more social interactions with other members of their group. Elevated social contacts directly increase the risk of infection during an epidemic. This study shows for the first time that a high social status can mitigate the negative impact of a pathogen on mortality in younger age classes whereas a low social rank can hinder its transmission among subadults and adults in a free-ranging group-living mammal.

“It would be interesting to investigate the impact of this epidemic at the population level, and to assess how high-ranking and low-ranking individuals contributed to the possible recovery of the Serengeti spotted hyena population”, says Dr Marion East, one of the senior authors of the study. “To our knowledge, our study is the first to disentangle the importance of social processes for individual exposure and resource allocation to immune processes in a wildlife population“, says Dr Lucile Marescot, scientist at the Leibniz-IZW.

Publication:
Marescot L*, Benhaiem S*, Gimenez O, Hofer H, Lebreton JD, Olarte-Castillo XA, Kramer-Schadt S**, East M** (2018): Social status mediates the fitness costs of infection with canine distemper virus in Serengeti spotted hyenas. Functional Ecology. DOI: 10.1111/1365-2435.13059
http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.13059/full
* contributed equally to this study
** contributed equally to this study

Contact:
Leibniz Institute for Zoo and Wildlife Research (IZW)
in the Forschungsverbund Berlin e.V.
Alfred-Kowalke-Str. 17
10315 Berlin
Germany

Scientific questions:
Dr Lucile Marescot
Phone +49 30 51 68 251
Email Lucile.MARESCOT@cefe.cnrs.fr

Dr Sarah Benhaiem
Phone +49 30 51 68 520
Email benhaiem@izw-berlin.de

Press office
Steven Seet
Phone +49 30 5168 125
Email seet@izw-berlin.de

Weitere Informationen:

http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.13059/full

Dipl.-Geogr. Anja Wirsing | Forschungsverbund Berlin e.V.

More articles from Life Sciences:

nachricht Microscope measures muscle weakness
16.11.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

nachricht Good preparation is half the digestion
16.11.2018 | Max-Planck-Institut für Stoffwechselforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>