Mother’s Day: Maternal Care, Long Lives and Helpful Daughters

Across the animal kingdom, mothers “of all stripes” care for their offspring, playing a vital role in nurturing and protecting them, and teaching them essential skills. They also provide comfort and security, enabling young animals to thrive and reach maturity. In many species, a mother’s presence is vital for long-term survival and the transmission of cultural knowledge.

Now, say scientists, this mother-child bond may offer clues to the mystery of why humans live longer than expected for their size—and, in the process, shed new light on what it means to be human.

The importance of the mother-child relationship goes the other way, too; offspring are important to their mothers. In the bird world, though, it’s the daughters who are more helpful to mothers than the sons. A new study shows that male bird progeny help their parents less than females because they’re too busy scouting for new places to live and breed.

Extended maternal care equals animal longevity

One of the mysterious things about humans, according to scientists, is that given our stature, we live longer than we probably should when we compare ourselves to other animals. Now, we may have discovered the first clue for solving this puzzle—and it involves mothers.

In a paper titled “Maternal Care Leads to the Evolution of Long, Slow Lives” that was published in the journal Proceedings of the National Academy of Sciences in June 2024, researchers from New York’s Cornell University state that part of the explanation for our long lifespan is the relationship between a mother and her child.

The Cornell researchers’ work builds off the mother and grandmother hypothesis (often called the “grandmother hypothesis”), which is based on observations of 18th- and 19th-century human populations that show that offspring are more likely to survive if their mothers and grandmothers are in their lives. This theory has been used primarily as a rationale for menopause in humans, as ceasing reproduction decreases the risk of death and allows older females to focus on grand-offspring care.

The Cornell scientists recently created new models that are both broader and more specific than those used in developing the mother and grandmother hypothesis, incorporating more of the ways that a mother’s presence or absence in her children’s lives impacts their fitness. They included the results from newer previous research on baboons and other primates about how youngsters fare if a mother dies after weaning but before the offspring’s sexual maturation, which leads to short-term and long-term—even intergenerational—negative effects on the primate offspring and grand-offspring.

The findings from the Cornell University team consistently show that as the links between maternal survival and offspring fitness grow stronger, animals live longer and reproduce less often, the same pattern seen in humans. This model is general to mammals overall, conclude the scientists, since we know that these links exist in other species outside of primates, such as in elephants, whales and hyenas.

Bird daughters surpass bird sons in helpfulness

In many animal societies, one sex tends to invest more in helping within the family than the other. To find out why, researchers at the Center for Ecology and Conservation at England’s University of Exeter recently launched an examination into the cooperative behavior and movement patterns of social birds called white-browed sparrow-weavers, which live in the Kalahari Desert. These birds live in family groups in which only a dominant pair breeds, and their grown-up offspring—particularly females—help to feed nestlings.

White-browed sparrow-weavers were chosen as study subjects because the female birds contribute more to cooperative nestling care than the males, and they also stay for longer in their family groups than the males do. The leading hypothesis is that the sex that lives for longer in its family group cooperates more because it stands to gain in the future, such as receiving more help in return from the family members they’ve helped in the past.

But after more than a decade of field research monitoring the cooperative behavior of these birds and a groundbreaking study in which the birds’ movements were tracked, the scientists found that this is not the case, after all. Their findings, which were published in the journal PLOS Biology in October 2024, point instead to an alternative explanation: males appear to help less because they spend more time prospecting for opportunities to live and breed elsewhere, and these efforts trade off against their investments in cooperation at home.

The University of Exeter team suggests that this “dispersal trade-off hypothesis” may provide a more general explanation for the evolution of sex differences in cooperation across animal societies than the more widely held view that “the longer you stay, the more you’ll benefit from having helped out.” It’s an example of a universal challenge that all organisms face, including us: there is never enough time or energy available to do everything well at once.

U.S. bird population numbers rapidly plunge

Unfortunately, the release of the 2025 U.S. State of the Birds Report, produced by a consortium of conservation and scientific organizations and entities led by the North American Bird Conservation Initiative, reveals continued widespread declines in American bird populations across all mainland and marine habitats, with 229 species requiring urgent conservation action. The report comes six years after a landmark 2019 study that documented the loss of 3 billion birds in North America over 50 years.

Key findings from the new report show that more than one-third of U.S. bird species are of high or moderate conservation concern, including 112 “tipping-point species” that have lost more than 50% of their populations in the last 50 years. That includes 42 red-alert species facing perilously low populations, such as Allen’s hummingbirds, saltmarsh sparrows and tricolored blackbirds—birds that could disappear without immediate intervention.

Proactively working to protect America’s birds would not be just about the birds, write the authors of the report. Supporting bird conservation boosts the U.S. economy. With nearly 100 million Americans engaged in birding activities, their contributions to local and state revenues are substantial. The report highlights findings from the 2022 National Survey of Fishing, Hunting, and Wildlife-Associated Recreation, which demonstrate that the total economic output related to bird-watching is $279 billion and birding-related activities support 1.4 million jobs.

But sadly, bird populations in almost every habitat are declining. Most notable are duck populations, which have been a bright spot in past State of the Birds Reports but have trended downward in recent years.

This rapid decline in bird numbers signals the intensifying stressors that both wildlife and people are experiencing around the world because of environmental degradation, extreme weather events and habitat loss. The authors of the report say that when we see decreases like those just outlined in the 2025 report, we need to remember that many of the actions that are good for birds are also good for us. When we protect the habitats that birds rely upon, we also protect the ecosystem services that sustain us.

Surprisingly, though, the report is also a cause for hope. Public interest in birds and the economic benefits from birding are at unprecedented levels, as is the information available about the status of every one of our bird species.

And, on another positive note, the report highlights the economic significance and well-being that derives from bird-watching as additional reasons to support conservation efforts. It recognizes that birds and nature are vital for Americans’ mental health, citing research indicating that encounters with birds have been proven to reduce anxiety, depression and stress.

There’s clear evidence that conservation works in halting species declines. What is needed is funding that matches the scale of the great challenges that birds face today. We know how to reverse the damage: a proven blueprint for success is science-based planning and collaborative investment in habitat preservation and restoration.

Conservation partnerships and private-lands programs—such as coastal restoration, conservation ranching, forest renewal and seabird translocation—demonstrate how concerted efforts and strategic investments can recover bird populations. For example, decades of aggressive and strategic wetland habitat conservation projects championed by corporations, hunters, landowners, and state and federal agencies has boosted numerous waterbird and waterfowl species.

Mothers multiply when we honor them all

Traditionally, Mother’s Day recognizes our mothers and celebrates maternal bonds, as well as our moms’ positive contributions to our families and societies. But there are far more mothers than just human ones; they come in many forms, sizes, colors, spots and stripes.

Both human and more-than-human mothers take extraordinary steps to protect, nurture and raise their young; often prioritizing their children’s needs over their own—sometimes even putting themselves at risk.

Let’s give them all a moment of thought this Mother’s Day; whether they’re equipped with fur, feathers, scales or skin; no legs, two, four or more; or arms, fins, paws or wings.

Here’s to finding your true places and natural habitats,

Candy