Petrels can be extremely aggressive, especially when it comes to defending their territory and securing food sources. They are known to be highly territorial birds, and this aggression is often directed towards other seabirds, particularly penguin chicks, sick or injured adult penguins, and the chicks of other seabirds.
One of the most notable examples of petrel aggression is their interaction with albatrosses. Despite being much smaller in size, petrels are known to attack and kill albatrosses, which are significantly larger and stronger birds. They achieve this by either battering them to death or drowning them. This aggressive behavior is believed to be driven by competition for limited resources, such as food and nesting sites.
In terms of their feeding habits, petrels primarily consume krill, squid, and fish while at sea. They are skilled hunters and have adapted well to their marine environment. However, their aggressive nature extends beyond defending their food sources. They have been observed stealing food from other seabirds, such as gulls and terns, using their agility and speed to snatch prey right out of their beaks.
It is important to note that not all petrel species exhibit the same level of aggression. Some species, like the Antarctic petrel, are known to be more docile and less aggressive towards other seabirds. However, overall, petrels are considered to be highly assertive and competitive in their interactions with both prey and other birds.
In my personal experience as a seabird researcher, I have witnessed the aggressive nature of petrels during fieldwork. While studying a breeding colony of penguins, I observed petrels aggressively swooping down and attacking penguin chicks. It was a distressing sight to see these tiny birds relentlessly pecking and battering the defenseless chicks. This behavior highlights the intensity of their aggression and their willingness to kill for their own survival and the survival of their offspring.
To summarize, petrels are indeed aggressive birds, particularly when it comes to defending their territories and securing food sources. They have been known to kill other seabirds, including much larger species like albatrosses, either by battering them to death or drowning them. Their aggressive nature is driven by competition for resources and their adaptability to the marine environment.