True friends, as most would agree, support one another. This can mean offering emotional encouragement or lending a hand during a move. For a vibrant Sterling—a lively songbird from the African savanna—this includes feeding insects to your friends’ offspring, with the expectation that they will do the same for you in return.
Research has shown that social animals tend to form bonds primarily with their relatives. However, according to a study published in the Journal Nature Wednesday, researchers analyzed two decades of field data, revealing new interactions among unrelated members of great starling communities.
“These findings are the core of our study,” stated Dustin Reubenstein, an ecology professor at Columbia University and the paper’s author.
Alexis Earle, a biologist from Cornell University and co-author, noted that great starlings exhibit unique cooperative breeding behavior, blending family units with newcomers. New parents often depend on as many as 16 helpers.
Dr. Reubenstein’s lab has maintained a 20-year field survey of the species, encompassing 40 breeding seasons. They recorded thousands of interactions among hundreds of vocal birds and collected DNA samples to explore genetic linkages. When Dr. Earle, then a graduate student, began analyzing the data, she and her colleagues were not surprised to find that the birds predominantly assisted their relatives.
However, they were taken aback to discover that starlings also assisted non-relatives, even opting to help others when they could have aided their family members. Newcomers in the flock offered assistance to birds born within it, and vice versa. As great starlings frequently shift between parenting and supportive roles, the research team found that individuals who aided non-relatives tended to reciprocate those good deeds over time.
“Starlings consistently invest in the same valued social partners over their lives,” Dr. Earle remarked. “To me, that resembles friendship.”
Gerald Carter, an animal behavior expert at Princeton University and co-author, noted the controversy surrounding the idea of animals forming friendships with non-related individuals. Yet, increasing research supports the presence of long-term interactions among primates, elephants, crows, and whales. There are even vampire bats that share their blood meals with unrelated members of their colonies, alongside unrelated male lance-tailed manakins who act as each other’s “wingmen” to attract female attention.
Detecting long-term relationships, however, can be challenging, as Dr. Reubenstein points out. The research team required 27 seasons of data to reveal signs of reciprocity among starlings, and he believes they may still be underestimating it.
Dr. Reubenstein suggested that mutual support relationships may be more crucial than lab data indicates. “Having substantial long-term data is essential to uncovering these dynamics.”
The study presents a strong case, according to Jorg Massen, a behavioral ecologist at Utrecht University in the Netherlands who was not involved in the research. A key next step is to determine how these long-term relationships are sustained on a daily basis.
“Is it merely based on reproductive support, or does it involve other behavioral factors?” he posed.
Moreover, the behavior of great starlings suggests that everyone benefits from maintaining relationships with unrelated peers. “Birds residing in larger groups tend to have longer lifespans and produce more offspring over their lifetimes,” stated Dr. Reubenstein. In the harsh and unpredictable environments of the African savanna, maximizing resources is vital, and incorporating migrant birds enhances group stability.
According to Dr. Reubenstein, this mirrors the evolutionary trajectory of humans.
Amid growing concerns over the epidemic of human loneliness, experts may find valuable lessons in the lives of starlings. In essence, strong relationships often emerge from a foundation of support.
But you don’t need to feed your friends’ kids bugs! Luckily, there are always babysitting services available.
Source: www.nytimes.com
