Birds without own brood help other birds with parenting, but not selflessly

October 23, 2017, Netherlands Organisation for Scientific Research (NWO)
Credit: Seychellen Rietzanger

Birds will sometimes care for the offspring of other birds of their own species if they anticipate future benefits. Being tolerated in another bird's territory and the chance to inherit that territory later are considered rewards for which some birds are willing to postpone their own chance of reproduction. On 23 October 2017 veni researcher Sjouke Kingma from the University of Groningen has published an article on this subject in Nature Communications.

In almost 10 percent of bird species around the world, certain individuals postpone their own chance of reproduction to help birds of the same species to care for their offspring. This behaviour has also been observed in certain mammals, fish and insects. Since the days of Charles Darwin, biologists have assumed that all creatures are selfish, and do everything they can to maximize the chance of passing their genes to their offspring. So why do some birds sacrifice themselves for the sake of others? What do they gain by not producing their own brood and wasting energy to help others?

One hypothesis is that they only help their relations, i.e. younger brothers and sisters with whom they share their genes. This is thought to be a way for the helpers to pass on their genes, without reproducing themselves. In a recent study, evolutionary biologist Sjouke Kingma refutes this widely accepted vision by showing that these individuals are also trying to improve their own future prospects. Kingma compared 44 species of birds, some of which help other birds while denying themselves their own brood. Although some birds only help family members, his research showed that a lot of birds are even more keen to help non-family members if they stand to inherit their territory in the future.

Kingma concludes: "Birds see their territory in the same way as we see our house. Some species of "home-owners" allow other birds to live in their territory and help them to care for their offspring. This may seem logical if the birds living in the same territory and helping each other are related. But this isn't always the case. My research reveals that the home-owners get much more help if the helpers stand to inherit their territory in the future. After all, you'd be much more inclined to help someone maintain their home if you thought you'd inherit it one day. This is precisely what a lot of do: they help the current owner so that the territory will be worth more when they inherit it."

Kingma sees two benefits in this principle. "Showing that you're prepared to help increases the chance that the nesting pair will tolerate you in their territory, which may ensure that you inherit the territory later on. In addition, if you help with the current owners' kids, you'll create your own future little helpers. By the time the territory is handed over, the helpful bird will have its own army of little helpers ready and willing to assist."

The concept of helping each other is not strange to humans, but biologists have been puzzling about why wild animals would do this. This research shows that animals are capable of planning and modifying their behaviour to achieve future goals. Kingma's research was funded by a Veni grant from the Netherlands Organisation for Scientific Research (NWO).

Explore further: New research suggests bird songs isolate species

More information: Sjouke A. Kingma. Direct benefits explain interspecific variation in helping behaviour among cooperatively breeding birds, Nature Communications (2017). DOI: 10.1038/s41467-017-01299-5

Related Stories

New research suggests bird songs isolate species

September 13, 2017

Two birds that look the same, but have songs so different they can't recognize each other, should be considered distinct species, suggests new University of British Columbia (UBC) research.

Fairy wrens: Accountants of the animal kingdom

March 18, 2011

A puzzling example of altruism in nature has been debunked with researchers showing that purple-crowned fairy wrens are in reality cunningly planning for their own future when they assist in raising other birds' young by ...

Babysitting birds gain from growing pains

May 2, 2011

(PhysOrg.com) -- The baffling question of why some animals help raise offspring which aren’t their own is closer to being answered, thanks to new research from The Australian National University.

Even modest oil exposure can harm coastal and marine birds

October 12, 2017

Many birds and other wildlife die following an oil spill, but there are also other potential long-terms effects of oil exposure on animals. In a recent Environmental Toxicology and Chemistry study that examined blood samples ...

Cooperative species can invade harsher environments

February 20, 2017

Through cooperation, animals are able to colonise harsher living environments that would otherwise be inaccessible, according to a new study from Lund University in Sweden, together with researchers in England and USA. The ...

Recommended for you

Meteorite source in asteroid belt not a single debris field

February 17, 2019

A new study published online in Meteoritics and Planetary Science finds that our most common meteorites, those known as L chondrites, come from at least two different debris fields in the asteroid belt. The belt contains ...

Diagnosing 'art acne' in Georgia O'Keeffe's paintings

February 17, 2019

Even Georgia O'Keeffe noticed the pin-sized blisters bubbling on the surface of her paintings. For decades, conservationists and scholars assumed these tiny protrusions were grains of sand, kicked up from the New Mexico desert ...

Archaeologists discover Incan tomb in Peru

February 16, 2019

Peruvian archaeologists discovered an Incan tomb in the north of the country where an elite member of the pre-Columbian empire was buried, one of the investigators announced Friday.

Where is the universe hiding its missing mass?

February 15, 2019

Astronomers have spent decades looking for something that sounds like it would be hard to miss: about a third of the "normal" matter in the Universe. New results from NASA's Chandra X-ray Observatory may have helped them ...

What rising seas mean for local economies

February 15, 2019

Impacts from climate change are not always easy to see. But for many local businesses in coastal communities across the United States, the evidence is right outside their doors—or in their parking lots.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.