Social bonds are key to breeding success among pelicans

Pelicans have more breeding success when they are given the freedom to choose their social relationships, according to a new study from the University of Exeter.

Based on a social network analysis, the researchers found that reproductive success was improved among pelicans with partnerships that formed naturally. 

The investigation was focused on the social behavior of a breeding flock of great white pelicans at Blackpool Zoo during two research periods.

The study revealed that the pelicans chose their specific social relationships. The experts also discovered a social structure across the flock in which “teenagers” spent more time with each other than with adult birds.

The researchers noted that while pelicans are commonly found in zoos, their captive breeding record is poor. This is because pelicans receive little research attention compared to other popular zoo-housed birds such as penguins.

“Despite their popularity with visitors and representation in many zoos globally, ex situ populations of pelicans may not be fully sustainable, with some flocks achieving only sporadic breeding success,” explained the study authors.

“Even in well‐established flocks, poor breeding results caused by infertility, trampling of eggs and limited display of breeding activity can be noted.”

At Blackpool Zoo, the research team collected data on the space use, social preferences, and behavior of great white pelicans during two nesting events in 2016 and 2017.

“Evaluating space use and behavior to ensure that pelicans have the choice to behave in a way that they wish is essential to good animal welfare,” said study lead author Dr. Paul Rose.

“Social network analysis enables us to identify the strongest bonds and discover who is influential in the flock. Therefore we can work out which birds might initiate breeding and encourage this activity in others.”

“This is important for flock management. If birds are to be moved between flocks, we should preserve these important bonds and the experience they provide.”

“Alongside the good care the birds get from zoo staff, this experience of what to do and when to do it is likely why the flock we analyzed nested successfully on multiple occasions.”

The experts also identified specific behavioral changes across the season that may signal when breeding is about to take place. For example, data showed that the flock was more vigilant before the pelicans started nesting, which indicates that vigilance is a precursor for courtship or nesting activity.

The study is published in the journal Zoo Biology.

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By Chrissy Sexton, Earth.com Staff Writer