"De Petten" is a fairly small lagoon with a couple of artificial islands, covered with shells, and surrounding pastures. The area is used as a breeding area for many shorebird species, like Common Tern, Arctic Tern, Avocet, Common Redshank, Common Gull and Black-headed Gull. From the road, you'll have a very good overview of the lagoon and you can scan the area for foraging waders, like Ruddy Turnstone, Dunlin, Common Ringed Plover and many more species. Sometimes, small numbers of Eurasian Spoonbill can be present, foraging for prey in the brackish waters. Waterfowl is also present, like good numbers of Common Shelduck and Northern Shoveler. Greylag Goose can breed in the area, and sometimes in large numbers.
Just behind the "De Petten" lagoon, a smaller lagoon is present, called "'t Stoar". The species are similar to the first lagoon, but can be dificult to observe due to the landscape. Here, species bound to the surrounding pastures come to roost, like Black-tailed Godwit and Common Redshank. Surrounding this area, reedbeds are present. Here, European Marsh Harrier breeds and can often be seen.
For many years, "De Petten" was home to the only breeding colony of Sandwich Tern, but since about 2013 the numbers declined in the area and increased in other similar habitats on the eastern side of Texel.
During high tide, the area is used by very large numbers of waders. Numbers can go up to thousands of individuals of many species, like Bar-tailed Godwit, Red Knot, Dunlin and Eurasian Curlew. Smaller numbers of Whimbrel, Spotted Redshank and Ruff can be present too. When a predator is nearby, like a Peregrine Falcon or European Marsh Harrier, all birds will fly up and cause a very impressive sight.
The surrounding pastures are ideal for breeding birds, like Black-tailed Godwit and Common Redshank. Also Western Yellow Wagtail can be seen in larger numbers. In winter, these pastures are often used by large flocks of geese, like Brent Goose and Barnacle Goose. Sometimes, the scarcer subspecies of Brent Goose can be present, being White-Bellied Brent (B. b. hrota) or Black Brent (B. b. nigricans).
The area is easy accessable. You can park your car next to the road and observe the breeding birds from a fairly close distance. The area can be pretty busy with other birders, parking their car next to the road.