Why do birds typically live longer than mammals?

MAY 1, 2019

by Hamilton College

Why do birds typically live longer than mammals? A new paper offers a hint, albeit not a conclusive answer. Assistant Professors of Biology Cynthia Downs and Ana Jimenez at Hamilton College and Colgate University respectively have co-authored a paper with nine students, "Does cellular metabolism from primary fibroblasts and oxidative stress in blood differ between mammals and birds? The (lack-thereof) scaling of oxidative stress" in press with Integrative and Comparative Biology.

The research group focused on testing whether birds and mammals have differential patterns in cellular metabolism as expected because of their difference in whole-animal rates of energy use. They also tested whether birds had higher antioxidant concentrations to ameliorate the higher concentrations of reactive oxygen species. One of their goals was to determine if birds and mammals differ in the amount of damage caused by the balance of reactive oxygen species and antioxidants concentrations (oxidative stress). Because whole-organism rates of energy use also changes in a predictable manner, another goal was to determine if components of oxidative stress changed with body size.

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Blackbirds in the city: Bad health, longer life

Date:  March 22, 2018

Source:  University of Groningen

Summary:

Blackbirds live longer in cities than in forests. But their telomeres, the repetitive stretches of DNA at the ends of the chromosomes, show that these city birds have a much poorer health status than their rural cousins. These findings from a study in five European cities led by University of Groningen biologists were published in Biology Letters on 21 March.

Blackbirds are a common sight in many city gardens. The species has adapted well to this environment. 'But they also live in their original forest areas, which makes them ideal candidates for a study of the effect of city life on health', says University of Groningen postdoc Juan Diego Ibáñez-Álamo. He travelled to Granada, Seville, Madrid, Dijon and Turku to obtain blood samples from blackbirds in these cities and the adjacent rural areas.

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Predators predict longevity of birds, study concludes

Date:

April 30, 2014

Source:

Max-Planck-Gesellschaft

Summary:

Aging inevitably occurs both in humans and in other animals. However, life-span varies widely across species. Researchers have now found a possible general mechanism explaining differences in longevity. They investigated life history data of nearly 1400 bird species and found that avian life span varies considerably across the entire Earth, and that much of this variation can be explained by the species' body mass and clutch size and by the local diversity of predator species. The researchers were able to confirm a key prediction of the classical evolutionary theory of aging that had been proposed more than 50 years ago.

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Chromosome ends hold clues to a bird's longevity

The long and short of a bird’s life may be recorded in the tips of its chromosomes, a new study suggests.

A study of Seychelles warblers living on a small island in the Indian Ocean suggests that the length of telomeres — bits of DNA that cap chromosome ends — can predict a bird’s chance of dying better than its chronological age can. Warblers with shorter telomeres were less likely to survive another year, especially if the truncation happened rapidly, David S. Richardson, a molecular ecologist at the University of East Anglia in Norwich, England, and colleagues report online November 20 inMolecular Ecology.

The study “provides very important evidence that backs up what has been found in the laboratory — changes in telomere length matter a lot,” says animal ecologist Pat Monaghan of the University of Glasgow in Scotland.

Increasing age and body mass were also linked to shorter telomeres in the birds. That result stands in contrast to a recent large study of people in northern California that found telomeres get shorter with age, but that higher body mass is associated with longer telomeres (SN Online, 11/11/12).

Like shoestring aglets, telomeres stop chromosomes from unraveling or being eaten away at the ends. Cells with very short telomeres become decrepit or die, but it has been unclear whether that has any effect on whole body.

Continued:  http://www.sciencenews.org/view/generic/id/346616/description/Chromosome_ends_hold_clues_to_a_birds_longevity