The new research, led by Oxford University scientists, examined how the mortality rates of parents and offspring and the fertility of adults influence the evolution of how much parents care for and feed their young.

The team found that unpredictable environments, which impact on adult mortality rates and fertility, increase the benefits to species of evolving a more caring strategy in which parents invest more resources in bringing up their offspring.

A report of the research is published this week in the Journal of Evolutionary Biology.

"We already know that some animals, such as different populations of European kestrel, alter the levels of care they give their offspring in response to unpredictable environments," said Dr Mike Bonsall of Oxford University's Department of Zoology, an author of the report. "What this new research shows is that many more species are likely to 'hedge their bets', changing how much they care for their offspring depending on how challenging the environment is."

The team set out to investigate how parental care evolved from a state of 'no care' in which parents leave offspring to fend for themselves. The researchers used mathematical models to study the costs and benefits of different levels of parental care in unpredictable environments.

Dr Bonsall said: "People tend to think of parental care as something that is 'hard-wired', that either species care for their young or not, what our research shows is the precarious balance between the costs and benefits of caring which may have caused parental care to have evolved, or been lost, many times in the history of life."

Note: If no author is given, the source is cited instead.

• Child Development
• Child Psychology

• Mating and Breeding
• Nature

• Sustainability

• Public Health
• Ocean Policy

• R/K selection theory in ecology
• Hinny
• Genetic recombination
• Heritability
• Fertility
• Speciation