The Eurasian Curlew is a bird like no other. Its distinctive beak has earned it affectionate nicknames such as the “big elephant” or “proboscis.” Only a few years ago, its population suffered a dramatic decline. Today, ornithologists are working to rebuild its numbers — and in an interview with OKO.press, they explain exactly how to save Curlews.
Author: PAWEŁ ŚREDZIŃSKI
THE BEST TIME to spot a Curlew is in spring, when they return to their natal grounds to begin the annual breeding season. Their call is so distinctive that even without a sighting, you can be certain one is close by.
For several years now, each spring, I have visited the Brzozówka River — a modest waterway that once marked the border between Poland and the Grand Duchy of Lithuania, and today flows as a tributary of the Biebrza. The Brzozówka valley has been altered by drainage and maintenance works, rendering the river inaccessible. Yet its banks still remain one of the few places where Eurasian Curlews can be found.
This is thanks to people who decided the species was worth protecting.
Protecting the Nests
I join ornithologists Grzegorz Grygoruk and Tomasz Tumiel, who are engaged into the Polish Society for Bird Protection (PL: PTOP) project: „Kulik WIELKI zagrożony. Ochrona kulika wielkiego Numenius arquata w Polsce” [Curlew in Danger. Protection of the Eurasian Curlew (Numenius arquata) in Poland], on the very day a group of young Curlews is being released.
“This time, we released five birds along the Brzozówka, while our colleagues released six more in the Wizna Marsh,” Grygoruk explains. – “It has been an unusual year — exceptionally dry. The spring grass that normally conceals the nests grew very low, leaving them exposed in the egg-laying areas.
In the village of Zabiele, a Lesser Spotted Eagle destroyed nearly all the nests. Here in Trzyrzecze, where we are now, we managed to fence three nests, and chicks have successfully hatched from them.”
Helping Curlews Through the Breeding Season
When Curlews lay their eggs, ornithologists protect the nest with an electrified fence to deter predators. In more critical situations, when the chances of successful hatching in the wild are slim, the eggs are collected and placed in an incubator, and later moved to a hatcher for the final stage. Here, the chicks emerge and are cared for until they are strong enough to fly, at which point they are returned to their original habitat. This method is among the most effective for boosting breeding success.
The release takes only moments: the Curlews burst from their transport boxes and we watch their first flight into the open air. From that moment, they must fend for themselves. Almost immediately, a Marsh Harrier begins to circle near one of the birds — but “our” young Curlew deftly avoids the potentially dangerous raptor.
According to the ornithologists, the greatest current threat — apart from the rise in terrestrial predator numbers — is the intensification of agriculture. Even here, drainage operations continue, with ditches re-dug every few years, exacerbating the impact of drought.
A Ringed Curlew Father
“From a camera trap at one of our fenced nests, we spotted a male with a leg ring. It turned out to be a bird that had also hatched in one of our protected nests — six years ago. After reaching breeding age, it returned to its old territory along the Brzozówka, built its first nest, and, thanks to the fencing, was able to raise its own chicks. We have had other success stories too,” Grygoruk recalls. “In one case, a pair of Curlews we observed had both been ringed by us — one hatched in the hatcher, the other in a fenced nest. Both were Brzozówka birds.”
Since joining Curlew conservation efforts in 2017, Grygoruk has saved more than a hundred chicks — either taken from the wild before hatching or born within fenced nests. These successes have been possible thanks to successive projects run by PTOP and the ‘Bocian’ Nature Society. Grygoruk stresses that humans can also be a threat. That is why each year, after finding and fencing nests, the ornithologists alert local farmers to the birds’ presence. The most vulnerable stage is when the chicks are still following their parents but cannot yet fly — a time that often coincides with meadow mowing.
For this reason, collaboration with farmers is essential. Both ornithologists praise the village head of Trzyrzecze, who keeps watch for Curlews each year and reports when pairs appear.
“The birds we released today all came from the incubator,” Grygoruk adds. “We collected the eggs from the Brzozówka, and now that these young birds can fly, we have brought them back so they will return to the same place in the future. Curlews form strong ties to their release site and begin breeding only after about three years. What is more, when we take eggs to the incubator — especially from the early April clutches — the parents often lay a second time. This gives us more young in a single season and gives the adults another chance to raise chicks.”
When Farmers Mow and Photographers Disturb
There is another issue the ornithologists point out. “Nature photographers often get far too close to nests, flushing the adults,” says Grzegorz. – “The Curlews leave their eggs and sometimes cannot return for quite some time. In the meantime, corvids may raid the nest. Some photographers even walk right up to fenced sites, despite the ban on disturbing or photographing the nests of protected species. We have also encountered birdwatching guides who lead groups directly into nesting meadows just to give tourists a closer look. But anyone who claims an interest in nature should know that under no circumstances should nesting birds be disturbed.”
Today, around 15 pairs of Eurasian Curlew inhabit the Brzozówka Valley. – “On one hand, it is a success — their numbers are no longer falling,” Grzegorz continues. “On the other, we still see nest losses every year.” Without human intervention, the decline would continue. These birds spend around 26 days incubating their eggs, yet their clutches can be destroyed not only by human disturbance but also during routine meadow work. The good news is that we are recording a record number of ring sightings, proving that birds from protected nests survive and return year after year.”
We linger on the road for a moment longer. One of the recently released Curlews suddenly takes flight again. Perhaps it will return, and in a few years Grzegorz and Tomasz will be able to log another success — confirmed by the reading of its ring.
Curlews Beyond the Brzozówka
The current Eurasian Curlew conservation project, led by a consortium including the Polish Society for Bird Protection, the ‘Bocian’ Nature Society, Biebrza National Park, and the Regional Directorates for Environmental Protection in Poznań and Warsaw, is being carried out at several sites across Poland. My next interlocutor is Przemysław Obłoza, scientific coordinator of the project entitled “Kulik WIELKI zagrożony. Ochrona kulika wielkiego Numenius arquata w Polsce” [Curlew in Danger. Protection of the Eurasian Curlew (Numenius arquata) in Poland]. He is also a doctoral student at the Doctoral School of the University of Siedlce, Institute of Biological Sciences.
“It all began in 2013,” he recalls. “That was when I first conducted Curlew surveys and monitoring for the ‘Bocian’ Nature Society. We were estimating how many pairs might still be nesting in Poland. It is a fascinating species that requires active protection, which is why I am dedicating my PhD research to it. I have examined nesting site preferences, and I am now studying the survival rates and movement ecology of released Curlews. Our tracking shows that from the time of release until the start of migration, about 40 percent of Curlews fitted with GPS-GSM transmitters survived. Most losses occurred within the first few days and were always the result of predation — from both mammals and raptors."
Before 2000, Poland had an estimated 650 and 700 breeding pairs. By 2006, the figure had dropped to 450–500, and by 2013 to 250–300. In 2018, only about 160 pairs were thought to remain. A slow reversal began mainly thanks to targeted conservation projects. By 2019, the population had risen to around 170 pairs, in 2020 to 180, and in 2021 to 195. This marked the halting of the decline. Allowing for a margin of error in the counts, the national population today stands at roughly 200 breeding pairs.
The Long-Lived Curlew
“For the population to remain stable, its productivity must be at least half a chick per breeding pair,” explains the ornithologist. “In other words, two pairs need to produce at least one chick that survives to the point of independent flight. That is the threshold at which numbers should hold steady. Without intervention — taking eggs to incubators and rearing chicks in aviaries — Curlews would not be able to meet that benchmark. The Curlew is a long-lived species: the oldest known Curlew lived for 32 years.
That longevity means that declines often become visible only over the course of several years,” he adds.
The current project is being carried out at multiple sites simultaneously. The Regional Directorate for Environmental Protection in Poznań — which has carried out independent Curlew conservation work for years — operates in the Noteć Valley, the Warta Valley, and the Wielki Łęg Obrzański. These are small populations, numbering from just a few to a dozen or so breeding pairs, but protection has prevented them from disappearing entirely. There are also a dozen or so pairs in the Warsaw–Berlin Urstromtal, and occasional breeding attempts in the Świętokrzyskie region, in the Nida Valley. East of the Vistula, however, Curlews are more numerous.
“To the east of this river, Curlew populations are found in Mazovia — particularly in the Kurpie Zielone region, at the Pulwy Marsh, and along the Bug Valley. In Podlasie, Curlews are naturally present in the Biebrza Valley, with a strong local population along its tributary, the Brzozówka, as well as in the Wizna Marsh. Isolated sites occur along the Narew and in the Nurzec Valley. We also record Curlew presence in the Lublin region,” says Przemysław Obłoza.
Predators and Perils Facing the Curlew
“Our observations show that the red fox is a particular threat to Curlews,” says the expert. “Their numbers have risen due to widespread rabies vaccination campaigns and reduced hunting pressure. That is why our conservation work also focuses on limiting predator impact. We are also concerned by camera trap footage showing free-roaming dogs destroying nests. Fortunately, in eastern Poland we have not yet encountered the problem of predation by raccoons,” he adds.
Curlews face dangers far beyond their breeding grounds. Polish birds spend the winter mainly along the coasts of western Germany, the Netherlands, France, the United Kingdom, Spain, and Portugal, sometimes ranging as far south as Morocco. Until recently, hunting Curlews was still legal in France. Although a moratorium is now in place, it is not always respected. Other threats on the wintering grounds include collisions with wind turbine blades, pressure from coastal development, and littering.
“What we are doing through our projects is, in a sense, buying time for the Curlew,” says Przemysław Obłoza. “The question is always what happens next, after the project ends. We do not know if funding will be available to continue. The future of the Curlew population in Poland will depend on both sustained resources and the dedication of many people.”
An article about Curlew and our project has appeared on OKO.press. We thank the author, Paweł Średziński, for the interesting text and photos.
We encourage you to read it!
Here you will find original texts with photos:
https://oko.press/slon-wsrod-ptakow-jest-w-niebezpieczenstwie-jak-go-uratowac
Introductory photo to the article by Paweł Średziński
