Follow that bird!
Vol.9. 29th June 2017
Guest post by Paloma Calabria Carvalho
Paloma Calábria Carvalho is doctoral researcher in biological sciences at the University of Manitoba, Canada. She is aboard the RRS Discovery as a member of the Seabird Team, observing and catching seabirds in order to investigate their diet and record other important data.
One of the main goals of our expedition is to catch seabirds and release them equipped with data-loggers that will allow us to record important data. We’ve already harvested a lot of information on bird distribution and abundance as we do our daily seabird surveys (identifying and counting birds as we go). However, loggers can give us much more information about habitat use and the movement of these birds in this area and it surroundings.
Paloma Calabria Carvalho © Marguerite Tarzia
Based on previous tracking data from different species, the ‘Evlanov Seamount & Basin’ has been identified as an important area for seabirds. For Sooty shearwaters, Evlanov is important as a staging area after their long trans-equatorial migration and before moving to coastal areas of Canada. For these incredible migrant species that cross the hemisphere to enjoy the best of the both worlds (austral and boreal summer), identifying these areas and how they use this habitat is critical for the conservation of the species.
Data-logger © Marguerite Tarzia
Birds of a feather
Seabirds need to replace their feathers at least once a year as they become worn with time, a process known as moulting. While growing their long flight feathers (primaries), flying can become more energetically demanding as flight may become impaired by the gaps between feathers and reduced area of the wing.
Great shearwaters feeding © Marguerite Tarzia
Part of my doctoral research is to look at moult for Great and Sooty shearwaters. So far, we have compiled good information on moult occurring in coastal waters off Canada during July and August. However, these species start their moult long before arriving in coastal areas and information about offshore moult is lacking. This expedition seems to be the first to investigate the area for moulting species. So far, most fulmars caught (12 of 13) were moulting in the area and based on hours of observation and countless pictures, great and sooty shearwaters are also using the area to moult, which highlight the importance of the area for those species.
Releasing a Leaches storm petrel © Marguerite Tarzia
Food for thought
In addition to deploying loggers, we gather a lot of information from the birds we catch. With a bird in our hands, we follow a protocol to harvest all the information that we need. We begin with biometric measures, including the weight and size of the wing. We also collect information about moult by looking at newly grown, growing and old feathers (and collecting some samples). We also collect blood for sexing and dietary analysis, as well as regurgitations, so we can determine what they are feeding on in the area. So far, our cephalopod expert Vladimir Laptikhovsky has identified some amphipods, small crustaceans, squid, fish, shrimp on their diet and, sadly, some plastic.
Stomach contents from a fulmar © Marguerite Tarzia
Follow the RSS Discovery's position on the National Oceanography Centre's 'Vessel Tracker'.