【生物学】人間の食料がクマの冬眠と細胞老化に影響を及ぼす可能性

Bears that forage on human food may hibernate less, which is associated with greater cellular aging, according to a study published in Scientific Reports. The research helps us to understand a potentially negative indirect impact of human food availability on animal aging at a biological level.

Although increased access to human food (such as rubbish, crops, or livestock) has been linked to delayed or shortened hibernation in wild animals, the consequences of human food consumption on fitness and longevity have been largely unknown.

Rebecca Kirby and colleagues investigated the relationship between foraging on human food, hibernation, and cellular aging in the American black bear (Ursus americanus). The researchers tracked and sampled 30 female bears near Durango, Colorado, USA from summer 2011 through to winter 2015. They found that bears that consumed more human foods during the summer hibernated for shorter lengths of time during the following winter. Reduced hibernation periods were associated with increased rates of telomere shortening. Telomeres are repetitive DNA sequences at the ends of chromosomes that can be used as markers for cellular aging, because they shorten as cells reproduce.

The findings suggest that bears consuming more human foods may lose some of the long-term fitness advantages associated with hibernation, such as reduced cellular aging. Continued growth in human development, and accessibility of human food, may alter wildlife behavior, with potential consequences at a molecular level, according to the authors.