The Noorder IJ-plas is one of the wildest and quietest places in Amsterdam. There are large areas of scrubland and wild herbs that are alive with the song of Common Nightingale, Garden Warbler, Greater Whitethroat, Marsh Warbler, Lesser Whitethroat and Common Cuckoo in spring.
The park is one of the few place in Amsterdam with breeding Linnet. The quiet forest areas are home to Eurasian Woodcock, while in areas with water Common Kingfisher is quite common. Regularily scan the skies and pylons for raptors. Eurasian Sparrowhawk, Common Buzzard, Eurasian Kestrel and Northern Goshawk are most common but there's a good chance of seeing Peregrine Falcon.
The sandbanks along the lake sometimes have breeding Common Shelduck, Sand Martin and Little Ringed Plover. The more vegetated parts of the shore are home to Water Rail and Cetti's Warbler .
The lake itself has a wide variety of ducks in winter, as well as gulls including non-adult Caspian Gull and Yellow-legged Gull. A telescope will probably be necessary to identify everything on the lake, but it's only really worth bringing in winter when there is a lot to see. Little Grebe is very common on the lake. Common Sandpiper can be found both on the shores of the lake and the shores of the IJ canal to the south.
The many shrubs are filled with berries in autumn and attract large flocks of pigeons and thrushes, including Fieldfare and Redwing. The area has a herd of Scottish highland cattle and you have a chance of spotting Rabbit and Red Fox. Pine Marten have been sighted recently. There is an abundance of butterflies and dragonflies in summer, though only rather common species occur.
The area is hard to reach by car, there appear to be roads on Google maps to the south of the park, but those can only be accessed by buses. By far the easiest way to get there is by bike. There's a bus stop near the northern edge of the park, but it's quite a long walk from there to the most interesting parts in the southeast.
The park itself can really only be walked, a wheelchair or regular bicycle will get stuck in the mud, as there are no paved paths. Much of the Noorder IJ-plas consists of untended scrub and forest with a mountain bike course running through it. You can use the mountain bike course as a walking trail, but you'll have to keep an eye out for mountain bikers and the occasional illegal motocrosser.