Within the heat solar of A late spring day, a small island bustles with fowl life. There on the Oder, the second largest river in Poland—which additionally defines a part of its border with Germany—the sandy island teems with a wide range of gulls, terns, and plovers. The birds feed small fish and bugs to their keen chicks, argue with neighbors, mate, and clear their nests, hardly ever pausing for relaxation throughout this busy season of rebirth and renewal. Their conduct is pure, however their dwelling shouldn’t be. The island’s sharp angles reveal it’s the work of people.
“There is no such thing as a different,” says environmentalist and wildlife photographer Piotr Chara, who constructed eight of those synthetic islands. “On pure or half-natural islands, most chicks would have been eaten.”
The predators are raccoons and American minks. Native to North America, the mammals have just lately turn into invasive in lots of elements of Europe, together with northwestern Poland. Within the Decrease Oder valley, the invasion has been significantly brutal: Habitat degradation made the river an all-you-can-eat buffet for the predators. That’s, till Chara started constructing fortress-like refuges for birds in danger.
Within the 18th and nineteenth centuries, when the Decrease Oder area was a part of Germany, levees have been constructed alongside many of the river to cut back seasonal flooding and regulate its course, permitting ships to move coal, wooden, and different cargo. The development destroyed sandy islands the place 1000’s of waterbirds nested, forcing lots of the animals to relocate. When Chara visited the world for the primary time in 2001, nonetheless, he says he was amazed on the richness of the birdlife that had continued, due to a few third of the Decrease Oder—about 42 kilometers, or 26 miles—remaining levee- free on the east aspect, now a part of Poland.
Traditionally, this stretch of the river was largely undeveloped, other than a number of exploratory pits dug by folks thinking about quarrying gravel. The water desk was too excessive, nonetheless, and the pits flooded, typically so shortly that piles of excavated sand and gravel have been left behind. The summits of those deserted mini-mountains, uncovered above the water, appeared like islands to terns and different species, which established breeding colonies on them—to their peril. Because the birds repopulated the valley, a brand new risk crept into their midst.
Raccoons (procyon lotor) and American minks (neovison mink) have been launched into Europe within the early twentieth century for fur. Just a few escaped from farms, however others have been launched into the wild deliberately, largely in Germany and Russia, “to ‘enrich’ the animal world for hunters,” says Magdalena Bartoszewicz, an impartial researcher who has studied raccoons and different invasive species in Poland for many years.
“In Poland, the primary American minks have been noticed within the Nineteen Fifties,” says Marcin Brzeziński, a College of Warsaw zoologist and coauthor of a e-book concerning the animals. Within the many years that adopted, the invasive minks established populations in northern Poland. By the Nineties, says Brzeziński, the animals began transferring south. Wherever they confirmed up, they modified ecosystems and extirpated whole species.
“Till the Nineties, virtually each lake in northern Poland was inhabited by tons of of Eurasian coots,” says Brzeziński. The hanging birds, virtually completely black with white beaks and white patches on their heads, often nest in reeds alongside shorelines or in shallow bays, the place they have been simple targets. “After the mink’s invasion,” Brzeziński says, “coots disappeared from many lakes.”
Dariusz Bukaciński, an ornithologist from Wyszyński College in Warsaw, has been finding out frequent gulls for 25 years. “Within the mid-Nineties, we had 4,300 pairs of those birds in Poland,” he says. By 2009, there have been solely 2,300 pairs left, thanks largely to predation by minks.
The raccoon invasion, by way of Germany, started within the mid-Nineties with just some people. Now, whereas the animals are nonetheless uncommon in a lot of the nation, “In western Poland, the raccoon is without doubt one of the most quite a few carnivorous mammals,” says Bartoszewicz.
Chara witnessed the devastating impression of each invasive species on Decrease Oder valley birdlife. It started with the arrival of the American minks, that are considerably bigger and extra aggressive than critically endangered European minks. “At any time when there’s a stay fowl, a mink will kill it. It is intuition,” says Chara, who says he recollects seeing a single American mink kill tons of of gulls over a interval of just some days in 2002. “Our birds usually are not tailored to cope with such a predator.”
Just a few years later, the raccoons moved in. “Though it doesn’t have such a killing intuition like a mink, it’s a sensible, agile animal,” says Chara. “I noticed how one raccoon killed all 180 chicks and eggs in a single colony.”
Chara watched in despair because the birds, nesting on the semi-artificial islands of uncovered particles in outdated gravel pits, misplaced their clutches 12 months after 12 months. “For 10 years, some gulls and terns have been notable to boost a single chick,” he says, nonetheless emotional as he remembers the losses.
The birds had no defenses in opposition to the predators—till Chara realized he might present them with some. Utilizing small, flat-bottomed navy surplus boats heaped with sand, he created the primary synthetic nesting island in 2015. The graceful steel sides of the watercraft stop minks and raccoons from climbing onto them.
That Might, the primary pair of birds to make a nest on the fortified island took Chara’s breath away: “It was the Eurasian oystercatcher.” On the time, there have been solely a dozen pairs of the birds in all of Poland. Inside a number of weeks, terns additionally started to nest on the island, adopted by noisy, extremely sociable gulls. By the tip of the 12 months, Chara had constructed two extra island forts. In 2017, he constructed one other 5, this time using a welder to attach thick steel sheets, slanted on the base to repel minks and raccoons much more effectively. Now, frequent and little terns, oystercatchers, frequent ringed plovers and black-headed gulls nest yearly on all eight islands. “If we didn’t construct them, these birds would haven’t any probability to outlive,” says Chara.
“People launched invasive species, so people have to assist the endangered birds,” says Brzeziński, echoing feedback from others observing the fowl forts’ success.
Now, each fall, Chara cleans and repairs the islands, making ready them for spring nesting. The fowl forts, he says, are defending one thing people might by no means create: nature itself. “It’s so stunning,” Chara says. “I wish to go away as a lot of the wonder as attainable.”