Conservation Research and Education

Conservation Research: Saskatoon Forestry Farm & Zoo Contributes to Turtle and Tortoise Study Challenging Evolutionary Theories of Aging

Even though humans live longer lives compared to their historical counterparts, we cannot escape the inevitability of aging. However, testudines – the order to which tortoises and turtles belong – may buck this trend by following a different pattern of aging compared to humans and other species.

In a new study published in the journal Science, researchers used data contributed by Saskatoon Forestry Farm & Zoo in collaboration with other zoos and aquariums to examine 52 species of turtles and tortoises. The data recorded by Saskatoon Forestry Farm and Zoo in the Species360 Zoological Information Management System (ZIMS) enabled researchers to discover that, unlike humans and other species, turtles and tortoises defy common evolutionary theories and may reduce the rate of aging in response to improvements in environmental conditions.

Evolutionary theories of aging predict that all living organisms weaken and deteriorate with age (a process known as senescence) – and eventually die. Now, using data captured by Saskatoon Forestry Farm and Zoo and others, researchers from the Species360 Conservation Science Alliance and the University of Southern Denmark show that certain animal species, such as turtles and tortoises, may exhibit slower or even absent senescence when their living conditions improve.

Out of 52 turtle and tortoise species, 75% show extremely slow senescence, while 80% have slower senescence than modern humans.

"We find that some of these species can reduce their rate of aging in response to the improved living conditions found in zoos and aquariums, compared to the wild," said study co-author, Prof. Dalia Conde, Species360 Director of Science, Head of the Species360 Conservation Science Alliance. “In addition, modern zoological organizations play an important role in conservation, education and research, and this study shows the immense value of zoos and aquariums keeping records for the advancement of science.” 

Turtles keep growing after sexual maturity

Some evolutionary theories predict that senescence appears after sexual maturity as a trade-off between the energy an individual invests in repairing damages in its cells and tissues and the energy it invests in reproduction, so its genes are passed to the next generations.

This trade-off implies, among other things, that, after reaching sexual maturity, individuals stop growing and start experiencing senescence, a gradual deterioration of bodily functions with age.

Theories predict that such trade-offs are unavoidable, and thus senescence is inevitable. In fact, this prediction has been confirmed for several species, particularly mammals and birds.

However, organisms that keep growing after sexual maturity, such as turtles and tortoises, are believed to have the potential to keep investing in repairing cellular damages and are thus thought to be ideal candidates for reducing and even avoiding the harmful effects of aging.

"It is worth noting that the fact that some species of turtle and tortoise show negligible senescence does not mean they are immortal; it only means that their risk of death does not increase with age, but it is still larger than zero. In short, all of them will eventually die due to unavoidable causes of mortality such as illness," said another of the researchers behind the study, Dr. Fernando Colchero, Principal Statistical Analyst, Species360 Conservation Science Alliance, and Associate Professor at the Department of Mathematics and Computer Science, University of Southern Denmark.

The article is available here: https://www.science.org/doi/10.1126/science.abl7811

For more information about the study and other projects using ZIMS data, please visit: https://conservation.species360.org/in-the-news/ 

About Species360:

• Species360 is a global non-profit that facilitates international collaboration in collecting, sharing, and analyzing knowledge on wildlife.
• Species360 maintains the Zoological Information Management Systems (ZIMS), which is trusted and used by more than 1,200 aquariums, zoos, wildlife centers, sanctuaries, universities, and governmental organizations in 101 countries around the world.
• ZIMS is the world's most comprehensive database of knowledge on more than 22,000 species, increasing vital information about the animal kingdom.
• ZIMS is used to establish best practices in aquatics, husbandry, enrichment, medical care, animal welfare, reproduction, population management, and conservation, and to provide Global Medical Resources to wildlife professionals worldwide.
• The Species360 Conservation Science Alliance is a global alliance of 240 research partners, led by Species360's Director of Science, Prof. Dalia Conde. It includes a team based at the University of Sothern Denmark.
• The Conservation Science Alliance harnesses the power of aggregated data in ZIMS and transforms it into scientific information to inform animal welfare and conservation decisions.
• For more information: www.species360.org

The Saskatoon Forestry Farm Park & Zoo is proud to participate in Association of Zoos and Aquariums (AZA) cooperatively managed Species Survival Plan® (SSP) Programs. SSP Programs are led by expert advisors who cooperatively work together to maximize genetic diversity, appropriately manage the demographic distribution and long-term sustainability. Species at the Saskatoon Forestry Farm Park & Zoo that currently participate in SSP Programs include:

• Goeldi's Monkeys
• Snowy Owls
• Snow Leopard

The Saskatoon Forestry Farm Park & Zoo and Environment and Climate Change Canada (ECCC) deployed multiple autonomous recording units to determine the density and diversity of breeding bird habitat on our National Wildlife Areas and Migratory Bird Sanctuaries.  This project will contribute to ECCC’s broader National Ecological Monitoring plan initiative and will help to understand the movement and breeding of migratory birds in and around Saskatoon.

Alex Fisher with Environment and Climate Change Canada installing one of three autonomous recording units at the Saskatoon Forestry Farm Park & Zoo.