In captivity, grey parrots are often kept in social isolation, which can have detrimental effects on their health and wellbeing.
So far there have not been any studies on the effects of long term social isolation from conspecifics on cellular aging. Telomeres shorten with each cell division, and once a critical length is reached, cells are unable to divide further (a stage known as ‘replicative senescence’). Although cellular senescence is a useful mechanism to eliminate worn-out cells, it appears to contribute to aging and mortality. Several studies suggest that telomere shortening is accelerated by stress, but until now, no studies have examined the effects of social isolation on telomere shortening.
Using molecular genetics to assess exposure to stress
To test whether social isolation accelerates telomere shortening, Denise Aydinonat, a doctorate student at the Vetmeduni Vienna, conducted a study using DNA samples that she collected from African grey parrots during routine check-ups. African greys are highly social birds, but they are often reared and kept in isolation from other parrots (even though such conditions are illegal in Austria). She and her collaborators compared the telomere lengths of single birds versus pair-housed individuals with a broad range of ages (from 1 to 45 years). Not surprisingly, the telomere lengths of older birds were shorter compared to younger birds, regardless of their housing. However, the important finding of the study was that single-housed birds had shorter telomeres than pair-housed individuals of the same age group.
Reading signs of stress by erosion of DNA
“Studies on humans suggest that people who have experienced high levels of social stress and deprivation have shorter telomeres,” says Dustin Penn from the Konrad Lorenz Institute of Ethology at the Vetmeduni Vienna. “But this study is the first to examine the effects of social isolation on telomere length in any species.” Penn and his team previously conducted experiments on mice, which were the first to show that exposure to crowding stress causes telomere shortening. He points out that this new finding suggests that both extremes of social conditions affect telomere attrition. However, he also cautions “further ‘longitudinal’ studies, in which changes in telomeres of the same individuals over time, are needed to investigate the consequences of stress on telomere shortening and the subsequent effects on health and longevity.”
Co-author, Franz Schwarzenberger from the Department of Biomedical Sciences at the Vetmeduni Vienna, points out that their results are exciting because they suggest, “telomere length may be useful as a ‘biomarker’ that enables to assess an individual’s exposure to chronic social stress.”
The study of telomere science has grown and developed in recent years allowing a better understanding of cellular substrates of stress, as stated in the article, the shortening of telomeres is associated with aging which can be accelerated by stress. There have been studies conducted that suggests that there is a link to parental stress and the programed length of new-born telomeres. This therefore makes the comparison of telomeres between different organisms of the same species more difficult as the lengths of telomeres are predetermined by parental stress, if the parental stress is high, then the offspring will have shorter telomeres which, as the article suggests, should result in the shortening of the organisms life span.
Furthermore, there are more studies that suggest that there are more factors other than stress that can cause telomere length to shorten. Examples of these factors are illnesses or poor health such as cardio vascular disease, mental illnesses such as major depressive disorder and lack of physical exercise, poor diet and smoking. As a result of these other factors, it is possible to purpose that stress factors are not the only factors that alter telomeres which could possible interfere in the results of the studies conducted by the researcher in this article.
The role of emotions in the well-being of organisms and therefore the relationship to the length of an organism’s lifespan has been the subject of many psychological studies. Studies on animals kept in captivity seem to show that it is the high levels of stress rather than isolation or crowding that shortens an animal’s lifespan: orcas kept in tanks experience different food, social grouping and water quality- all adding to the animals’ stress levels, resulting in shorter lifespans when compared to those in their natural habitat. Similarly these parrots are kept in cages, with their wings clipped and fed on a store-bought diet: logically they would experience stress.
I do not disagree that isolation could cause telomere shortening in these parrots.However, the telomere shortening could be caused by other stress-causing factors too. To produce valid and reliable results, further experiments should be done with rigorous controls put in place to ascertain if isolation is the causative factor. Also, would the ability of African Greys to bond with their owners not skew the results of the study?
This article gives an insight into how sociable African grey parrots really are and how reliant they are on the companionship of members of their own species. This serves as evidence of the effects that keeping African grey parrots in isolation, as pets, can have on both their mental and physical wellbeing. Bird keepers should take heed.
The fact that emotions can lead to such a significant physical change in DNA is remarkable. It will be interesting if the same process can be identified within other social organisms as well. It is daunting to think that the stress experienced in today’s increasingly complex world could significantly affect our lifespan.
Could these findings possibly have a basis in evolution? By the process of natural selection, less desirable traits, such as the inability to manage stress, are selected against. The shortening of telomeres could serve as the process by which the mortality of these organisms is increased.