Scilly's Nature Scilly's Special Species Common Tern Name: Common Tern | Sterna hirundo Size: 77-98cm wingspan Life span: 12 years Diet: Common Tern mainly eat fish (i.e. Sand eels), but also consume shrimps and other crustaceans, small squid, marine worms, and leeches. Reproduction: Common terns are monogamous, which means they mate with only one partner during a breeding season; with a female laying 2-3 eggs between April and June. When to see: Spring and Summer (April to September) Where to see: Common terns breed along coasts with shingle beaches and on rocky islands, but are on the verge of extinction in Scilly after a long period of decline. Conservation status: ICUN Red List | Least Concern (Global). Birds of Conservation Concern 4 | Amber (UK) Population Trend: Decreasing Threats: Lack of a consistent availability of prey, human disturbance through increases in recreational activities, spring tides flooding their nest sites and habitat loss from storm-driven erosion or and invasive vegetation swamping shingle nesting sites. Fun Fact: A Common Tern, when incubating eggs, flies off the nest in order to poo at a distance of 5-50 m (16-160 ft), doing so in water nearby or on the territory of another tern. Description: Often called "sea swallows" due to their long tails, Common Terns are summer visitors. They have a sliver-grey-white colouration with a black head and red bill. Their flight is graceful and they are mainly seen hovering over water before diving, arrow-like into the sea for fish. They are generally seen in Scilly in small numbers where their distinctive high-pitched chattering call can be heard. Sadly, numbers of Common Terns in Scilly have dropped hugely and they are now at risk from being lost as a breeding species here. The reasons for their decline here is unclear, but it is suspect to be largely to due with lack of consistent availability of suitable fish prey, perhaps driven by climate change. Want to know more? Check out our latest Seabird Monitoring & Research Technical Report for the most up to date information about how this charismatic species is fairing in Scilly. Do remember that we rely on donations to continue our work. If you have searched, found and learned about Scilly's wildlife on our website, please Support Us and give what you can. Thank you 💚 Support Us With thanks to Joe Pender for the Common tern image