The toroa/northern royal albatross is one of the largest seabirds in the world! They are referred to as graceful giants of the ocean, and with a wingspan of over 3 metres, it is easy to see why.
Toroa are of great significance to many iwi. The Moriori of the Chatham Islands called them hopo and would wear raukura (plumes) of the hopo as a way of showing their commitment as a people to their peaceful, non-violent ways of living.
Habitat and behaviour
Toroa spend about 85% of their time on the Southern Ocean, only coming to land during breeding season. They usually mate for life and produce only one chick every 2 years. There are a few nesting sites located in the Chatham Islands and a small mainland colony near Dunedin at Taiaroa Head. The male will nest close to where he hatched and will prepare the nest site for his mate. Both males and females share the incubation over 11 weeks. A chick will take 3–6 days to fully hatch. Chicks are cared for by both parents closely for the first 6 weeks. After that, they are left unguarded, visited by parents for feeding until they are able to fledge the nest at about 8 months old.
When old enough and no longer being fed by its parents, a chick will spread its wings and wait for a gust of wind to carry it off across the ocean. It will spend the next few years feeding in the South American waters until it is ready to breed, which can be any time between 3 and 8 years. The life span of toroa is about 40 years. The oldest known breeding female was called Grandma. She nested at Taiaroa Head and raised her last chick at the age of 62.
Outside the breeding season, they are foragers, feeding on a selection of squid, fish and other crustaceans that they find close to the surface of the ocean. They can travel vast distances – 190,000 km per year is not uncommon.
The toroa is endemic to Aotearoa New Zealand. The Department of Conservation lists them as at risk – naturally uncommon. This means they are at risk of the population declining, they are a naturally small population and are more susceptible to harmful influences and events like habitat changes, heat stress, fly strike and disease. Another growing risk is consuming plastic in the ocean. This can have devastating impacts from the toroa mistaking plastic on the surface of the ocean as food. The species has a relatively slow population growth, and therefore population decline can have long-term impacts.
Observation and monitoring of the toroa population is important to the success of any conservation efforts. Banding of toroa has been ongoing since the 1940s, and that has allowed data to be gathered about their behaviour and biology.
The breeding sites on isolated islands do not have any introduced predators. However, in 1985, there was a large storm that reduced vegetation and therefore the availability of nesting sites.
Both the island and mainland habitats have been through wet and dry cycles that have impacted population density. Hot spells create issues with the chicks overheating, and fly strike is a common issue. To protect the Taiaroa Head population, sprinklers have been installed to cool the site and cotton balls with peppermint essence are placed close to the nest to deter flies. Ongoing predator control has been essential to protecting the population’s nesting sites on the mainland.
The island populations are much harder to monitor. With new technology, tracking and monitoring populations has been more robust. Aerial photographs have been used for the mainland populations since 1937.
GPS has also been a useful tool to confirm toroa flight and feeding behaviour.
As technology progresses, scientists are finding new ways to gather data, which is increasingly important for offshore populations. The Chatham Islands are very hard to access, and the sea stacks where the toroa nesting sites are located are high and surrounded by cliffs. In the past, these sites have only been able to be monitored very infrequently.
Using satellites like the WorldView-3 to gather data is a significant innovation for a wide range of scientific research. The WorldView-3 is a commercial satellite owned by DigitalGlobe. It operates 617 km above the Earth and is capable of collecting up to 680,000 km² of imaging data per day. This satellite uses a high-resolution camera and has the ability to capture full-colour imagery at 31 cm resolution.
The satellite imagery from WorldView-3 provides robust and regular data, which scientists use to accurately monitor the offshore toroa population. Regular monitoring will ensure any issues with the toroa population are identified and shifts in conservation efforts can be implemented.
Have a go at building a fit-for-purpose satellite that can monitor toroa/northern royal albatross populations! Choose the ‘Albatross monitoring’ scenario. When you’ve captured the high-resolution images, use this activity to analyse the data you’ve collected.
Solander Island is home to albatross, and it’s a great example of why satellites may be the preferred option for species monitoring!
The New Zealand Subantarctic Islands group is another location many species of albatross use as breeding sites. A strict management plan restricts the number of people allowed ashore each year.
This albatross topic planner offers suggested pathways through some of the flight resources on the Science Learning Hub and connects to relevant programmes offered by the Royal Albatross Education Centre.
Analysing satellite data for albatross research uses satellite imagery of a Chatham Islands breeding site. The activity is useful for building student competence with ‘Gather and interpret data’ and ‘Interpret representations’.
The interactive Wings for flight matches birds (including the albatross) and aircraft with similar flight capabilities.
This resource has been produced with funding from the Ministry of Business, Innovation and Employment and the support of the New Zealand Space Agency.