The Birds

Natural History

The Newell’s Shearwater (‘A‘o), Hawaiian Petrel (‘Ua‘u), and Band-rumped Storm-Petrel (‘Ake‘ake) all belong to the taxonomic order Procellariiformes, a group of birds that also includes Albatrosses and Diving-Petrels.  They are commonly referred to as tubenoses, because of the cylindrical shape of their nostrils. Unlike most birds, the tubenoses all have an excellent sense of smell, which they use to find food out in the vast open ocean. 

Since they don’t have any fresh water out on the open ocean, they have developed a clever way of getting rid of salt in seawater – a salt gland at the base of the bill collects the concentrated salt, which is then sneezed out or can drip down the nostrils. It’s their own personal salt-removal system!

Tubenoses lead remarkable lives, forever tied to the sea to feed, and to the land to breed. In most cases, they do not begin breeding until 4-6 years of age, and will often stay at sea for the first few years of life. Tubenoses are long-lived, and in many cases have a life expectancy of up to 40 years. In fact, some albatross species have been recorded living up to 67 years of age! They are typically monogamous, staying with the same mate for their entire life. They are also very site faithful, returning to the same colony to breed each year. Tubenoses have a low reproductive rate, raising only one chick per year. This low fecundity means that they cannot recover quickly from negative impacts on their colonies and thus are more prone to population crashes.

At sea, these birds can cover incredible distances, with many polar species like the Sooty Shearwater migrating each year from the Southern Ocean to the Bering Sea. Members of the shearwater family are also known to be deep divers, with some species able to dive below 50 meters! Fish, squid and krill are the bulk of the tubenose diet and, apart from the Giant Petrels which can scavenge carcasses on land, the vast majority of species only feed at sea.

As marine animals, the Newell’s Shearwater, Hawaiian Petrel, and Band-rumped Storm-Petrel spend the majority of their lives at sea. The only reason they come to land is to find a mate and breed. Typically, colonies are found mauka (towards the mountains) in cliffs, steep slopes, and near barren mountain summits, with nest sites (burrows) found beneath the ground in natural or excavated cavities.

When considering what conservation measures would be most effective in recovering these species, biologists must therefore take into account the fact that Hawaiʻi’s endangered seabirds depend on two completely different habitat types in order to survive.

Hawaii’s endangered seabirds are bound to both the sea and the mountains (photo by Andre F. Raine)