Albatrosses put their partners' needs before their own

Wandering albatrosses are the bird species with the largest wingspan (three meters on average) and can live up to 50 years of age. They usually mate for life, breeding with the same partner every two years. After the female lays a single egg, the prospective parents spend the next 78 days – one of the longest incubation periods among birds – taking turns to incubate the egg, while their mate goes to sea to search for food. Such foraging trips take about 12 days on average, during which the nest-bound parent must stay without food. This can have a negative impact on their body condition, which usually gets worse the longer their partner is away.

Now, a team of researchers led by the University of Liverpool has found that wandering albatrosses with older partners tend to spend less time on foraging trips than those with younger partners, so that their mates spend less time without food. The experts believe this might be because the birds are able to assess how long their partner can go without food. Since older birds may struggle more to withstand the pressures of prolonged fasting, their partners may choose to return faster – a behavior which ultimately benefits both parents, who rely on each other to rear their offspring.

“On paper, this behavior looks very caring: one parent gives up feeding time to help protect the other. In reality, this behavior benefits both parents. Albatrosses cannot be single parents; the conditions are too harsh. If one parent runs the other one ragged by making them do too much work, they will lose the chick which is disastrous for both partners,” explained study lead author Finn McCully, a PhD student in Environmental Sciences at Liverpool.

“Our findings suggest that the birds have a way of telling how much pressure their partner is able to take. This familiarity may develop over the years they spend breeding together, as they get to know each other’s limits, but more research is required to test this theory. So if you are a wandering albatross and your partner is that little bit older and less able to recover from a long fast, it’s in your best interests to take extra steps to help keep them fighting fit.”

While previous research has suggested that wandering albatrosses adjust their own foraging behavior as they get older, this is the first study to show that their partner’s age may also play a major role in these behavioral changes.

“We thought that birds would care more about their own age than that of their partner when making decisions, so these results were truly unexpected. Our results just go to show how complicated the lives of animals can be and how nature is full of surprises!” McCully concluded.

The study is published in the journal Ecology and Evolution.

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By Andrei Ionescu, Earth.com Staff Writer

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