An important area for whooper swans

If you noticed two men parked on the side of the road recently - leaning across their car bonnet with big telescopes focused on the fields below - chances are it was Tom Broe and Michael McKiernan. The Cavan birdwatchers had their eyes peeled on the flood and pasture lands- the place to be for whooper swans.

On a mid-January weekend, as frost clung to rushes and the low winter sun stretched across the drumlins, Cavan became a patchwork of vantage points. Worn documents with previous sightings were compared to Google Maps. Across the county, eight volunteers and National Parks and Wildlife Service staff fan out to cover what Tom says are “approximately 194 sub-sites”- lakes, flooded fields, pastureland and quiet corners where swans gather – or at lease used to. Finding out if the Icelandic migratory birds have returned or have found new areas, is part of the data.

“Cavan,” Tom explains, “is an important county for whooper swans, with 813 individuals recorded in the last census in 2020.”

Cornakilly, Lough Ramor, Lough Oughter, the East Ballinamore Lakes and Annalee River are among the most important, but smaller flocks have been spotted all over. Places where water offers safety, and surrounding grasslands provide the short, nutritious pasture the birds desire.

The survey is part of the International Swan Census, carried out every five years across the entire Icelandic-breeding flyway population. Over a single coordinated weekend, counters in Ireland, Britain and Iceland record every whooper swan they can find. A small proportion of birds remain in Iceland for winter, but the majority travel south and west. In 2020, a total of 43,255 birds were recorded: roughly 49% in Britain; 44% on the island of Ireland; and around seven per cent left in Iceland.

Ireland recorded 19,111 birds that year - the highest number to date - representing a 24.9% increase in the Republic and a 32% increase in Northern Ireland compared to 2015. Yet while overall numbers are up, Ireland’s share is gradually decreasing.

Tom and Michael are interested in finding out why. “The aim is to look for patterns in the numbers,” Tom explains.

Storms can complicate things, but consistency is key.

Patterns emerge only when counting is done, carefully and repeatedly. Comparing numbers from England has shown a rapid increase at key sites there, leading to Michael’s assumption: “It could be that they have more space or better feeding ground.”

Unlike standard annual Irish Wetland Birds Surveys(I-WeBS), the Whooper Swan census must extend beyond lakes. “As whooper swans feed on pasture and arable land, there wouldn't be full coverage of these sites if only I-WeBS was relied on and that is why a specific survey of the wintering swans is required,” Tom says.

While the swans roost on water at night for protection, they often feed far from lakes during the day. That means long hours driving rural roads, scanning “all possible foraging areas in proximity”, and checking fields that might otherwise go unnoticed.

Technology has sharpened the search. Kane Brides, Senior Research Officer with the Wildfowl and Wetlands Trust, provided GPS data from birds he satellite-tagged in Iceland. Six flew to the Republic; with one settling in Cavan. The data revealed daily movements between roosting sites on water and foraging grassland.

“For this bird we could see that the journey it was taking between roosting and foraging was pretty much the same every day, which helped narrow down the search area considerably,” Tom explains. Another flock of 54 Whoopers was identified. The tagged individual was not singled out - the white neck tags are designed to blend in.

The migration itself is a feat of endurance. Kane told the team that some tagged birds complete the trip from Iceland to Ireland in as little as five hours, while another take over 70 hours. Others estimate eight to 14 hours for a direct crossing without breaks.

Michael McKiernan is chair of Cavan BirdWatch and a retired electrician from Ballyjamesduff. He compares watching birds to “being on safari”.

“There’s nothing like 1000 birds lifting off from the water surface at once,” he marvels.

“It really creates a sense of wonder,” agrees Tom, who is particularly drawn to the Whooper swan for its unique sound. “It’s the whooping sound of the swans flying above your head,” he says. The deep, resonant calls are accompanied by the rhythmic thrum of wingbeat. It is from that call - clear and trumpet-like - that the species takes its name.

Counting also means paying attention to family structure. Juveniles are recorded alongside adults, their greyer plumage and duller beaks distinguishing them from the bright yellow and black of mature birds. In fields, flocks subtly subdivide into family groups: two adults feeding alongside two young. These details offer insight into breeding success back in Iceland months earlier.

There are curiosities as well. Some groups appear in areas with no obvious floodlands nearby. “That is very peculiar,” Michael notes. Which is why Tom hopes the Cavan branch can do its own monitoring annually so “we can be aware of trends in real time”. As the swans are large and the yellow beak makes them identifiable quickly he believes it would be easy for newcomers to swoop into birdwatching and help out.

The swans are drawn to fresh pasture, and the wet weather hasn’t impacted them much, Tom remarks: “Since the census weekend it’s been fascinating watching the swans move feeding grounds due to flooding and shows how’s how the weather impacts upon the birds.”

Nature offers many unexpected scenes. Michael recalls a recent “serendipitous” encounter with a North American bufflehead blown far off course. “It’s like a polar bear appearing in your backyard,” he laughs. First seen in Galway, Mullagh, then Scotland, the stray duck became a reminder of how wind can redraw a map.

Such stories unfold against a broader environmental backdrop. Recent reporting has highlighted declines in several migratory species linked to habitat loss and climate pressures. Whooper swans, however, do not appear to be experiencing the same level of threat. Their numbers have risen in recent decades and the country’s dispersed landscape does seem to suit them. Nevertheless, with Ireland supporting such a significant share of the global Icelandic-breeding population, continued monitoring is critical.

Aisling Kinsella, Coordinator of the Irish Wetland Bird Survey, emphasises their value: “By combining population monitoring programmes, such as the International Swan Census, with migration and movement tracking carried out by researchers like Kane Brides, we gain valuable insights into the ecology of these birds,” she says.

“This approach helps us understand both long- and short-term trends in the numbers arriving in Ireland, as well as how the birds use the land on a regular basis. With this growing knowledge, we can make better-informed conservation decisions and identify key priority areas for their protection.”

The census is only conducted every five years, making each count a snapshot of real significance. In 2020, Whooper Swans were recorded in every county in Ireland for the first time. The population is widely dispersed compared to Britain, where vast numbers concentrate at relatively few sites. While final figures for 2026 are not yet available, Tom and Michael see that the Cavan numbers overall have increased again.

At least the swans seem appreciative of the vast availability of flood lands.