Oystercatcher
Irish Name: | Roilleach |
Scientific name: | Haematopus ostralegus |
Bird Family: | Waders |
amber
Conservation status
Conservation status
Status
Resident & winter visitor (from Iceland and the Faeroes) - largest numbers in Ireland between September & March
Identification
Large, distinctive wader with long orange-red bill, black head, chest and upperparts and white underparts.
Voice
Noisy - call is shrill, loud 'beep'. Piping call usually from the ground comprises phrases often run together and accelerating 'kip kip kip-kip-kip' and fast 'kli-klikli', and bubbling trill 'prrrr…'. Flight song, usually made in wide-circling display-flight is slower 'plee-ah plee-ah' repeated in time with wingbeats.
Diet
The main food resource includes the larger invertebrates, particularly mussels and cockles that proliferate along sandy coasts. They also occasionally feed on grasslands where they prey on tipulid larvae and earthworms. They feed by both sight (for polychaete worms) and touch (bivalve mussels).
Breeding
Nests principally on shingle beaches, dunes, salt marshes and rocky shores around the coast, but also on some large inland lakes.
Wintering
Use all coastal habitats, and particularly favour open sandy coasts. Around 60,000 Oystercatchers spend the winter around the Irish coast, which is a decline of around 28% since the early 2000's.
Monitored by
Blog posts about this bird
Starting 2020 with a (literal) BANG!! Catching and colour-ringing waders in Dublin Bay
In January 2020, the Dublin Bay Birds Project Team put in a huge effort to fit colour-rings (safely, and under license) to the legs of a portion of the wintering waders in Dublin Bay. Over four days and nights, we caught and ringed 235 waders of 6 species, with 23 ‘re-trapped’ birds, two of which were Icelandic-ringed Oystercatchers! The precise tally is 199 Oystercatchers, 23 Black-tailed Godwits, 5 Redshank, 4 Dunlin, 3 Curlew, and 1 Knot.
We used a highly specialised technique called ‘cannon-netting’ (firing a large net outwards using weighted projectiles propelled from cannons) to capture the birds. To do this, we once again drafted in the skills of licensed cannon-netters from the Highland and Grampian Ringing Groups in Scotland. The catching effort involved pre-dawn starts, night-time mist-netting, hole-digging, hiding in saltmarsh and marram grass, tide-watching, precision placement of cannons and nets, lots of waiting and hoping, and running at speed to the net when it fired over a flock of birds!
Once the birds are captured and safely removed from the net they are kept calm until they are ‘processed’. This means swiftly and carefully recording some biometric measurements, like wing length, bill length, and assessing the birds age from plumage characteristics, and each bird is fitted with colour-rings. The DBBP uses a combination of carefully planned colours on each bird, including one ring that is inscribed with a unique, two-digit alphanumeric code (see photo of colour-ringed Oystercatcher).
Essentially, the fitting of colour-rings to the legs of these wintering waders in Dublin and the subsequent reading and reporting of them (and similarly the fitting of small GPS-devices to birds) is all about trying to understand where they go for roosting and foraging at a local level, and about their migratory and breeding movements at international, flyway level. In this case, the colour-ring observations provide information about what areas of Dublin Bay the waders use during different tidal states and if they appear to be particularly reliant or show fidelity to certain areas, all helping to identify and thus conserve important areas. Colour-ringing can also generate valuable information about the timing of migratory arrivals and departures, and confirm migratory links between Ireland and breeding grounds elsewhere. The map with green red and yellow dots shows the locations of international resightings of waders colour-ringed in Dublin. Colour-ringing work is something that the Dublin Bay Birds Project, supported by Dublin Port Company, has been carrying out over the last few years (see other escapades here! dublinbaybirds.blogspot.com) with constant management of a database now containing in excess of 4,500 ‘resightings’ (observations) of individually colour-marked birds at various locations, yielding some fascinating information, see HERE for an example.
Bolstering this, detailed data was generated in 2016 when we fitted a selection of waders (Redshank, Curlew and Oystercatcher) with small GPS tracking devices (in addition to colour-rings) that provided un-biased daily data about the location of the individual birds, across entire tidal cycles, both day and night. The map shows the downloaded tracks (red dots) of a Curlew in the winter of 2016/17 at Bull Island and the Tolka Estuary. This GPS-tracking work was co-funded by SEAI and Dublin Port Company.
Now the work is to go out and look for all of these colour-ringed birds, read those inscriptions and submit them to us!
Submit your resightings HERE!
The Dublin Bay Birds Project is very lucky to be supported by Dublin Port Company who keenly recognise the value of this work and the data it generates.
This work was carried out under license from the National Parks and Wildlife Service and the British Trust for Ornithology.