Parrots Versus Quail

It isn't only rodent species that have a wide enough range of longevity to intrigue researchers. Amongst the rodents, naked mole rats can live nine times longer than shorter-lived and similarly sized cousin species, but amongst birds it is the case that parrots on average live more than five times as long as quail. The hope is that by comparing in detail the biochemistry of similar species with very different life spans, the research community will gain important new knowledge of aging - such as which of the mechanisms known to be associated with aging are more important determinants of life span. That understanding could help to steer research priorities in rejuvenation biotechnology by knowing which issues in the aging body will lead to greater benefits if repaired.

But back to the parrots and the quails: here is an example of the sort of research taking place in which researchers compare two species with different life spans. The context you should consider leading into the article is that there is some basis for thinking that levels of naturally produced antioxidants should partially determine life span in a species: oxidative damage can be tied to aging via a number of theories and their supporting evidence, and there are points in the biology of the cell where targeted antioxidants appear to be beneficial. So it is an interesting puzzle that this really doesn't seem to be the case in a direct and straightforward manner when comparing species. Mole-rats, for example, have high indicators of levels of oxidative compounds while being perfectly healthy and long-lived.

The oxidative damage hypothesis of ageing posits that the accumulation of oxidative damage is a determinant of an animal species' maximum lifespan potential (MLSP). Recent findings in extremely long-living mammal species such as naked mole-rats challenge this proposition. Among birds, parrots are exceptionally long-living with an average MLSP of 25 years, and with some species living more than 70 years. By contrast, quail are among the shortest living bird species, averaging about 5-fold lower MLSP than parrots.

To test if parrots have correspondingly (i) superior antioxidant protection and (ii) lower levels of oxidative damage compared to similar-sized quail, we measured [total antioxidant capacity and indicators of oxidative damage] in three species of long-living parrots and compared these results to corresponding measures in two species of short-living quails (average MLSP = 5.5 years). All birds were fed the same diet to exclude differences in dietary antioxidant levels.

...

Only glutathione peroxidase was consistently higher in tissues of the long-living parrots and suggests higher protection against the harmful effects of hydroperoxides, which might be important for parrot longevity. The levels of oxidative damage were mostly statistically indistinguishable between parrots and quails. ... Despite indications of higher protection against some aspects of oxidative stress in the parrots, the pronounced longevity of parrots appears to be independent of their antioxidant mechanisms and their accumulation of oxidative damage.

This is largely a null result - a lot of science is that way, as much a matter of eliminating leads or adding to a pile of data that may later, as a whole, contribute to a full understanding. For more on oxidative damage, birds, and mammals, you might look back into the archives:

Comments

Post a comment; thoughtful, considered opinions are valued. New comments can be edited for a few minutes following submission. Comments incorporating ad hominem attacks, advertising, and other forms of inappropriate behavior are likely to be deleted.

Note that there is a comment feed for those who like to keep up with conversations.