Fish and Wildlife Service - Salt Plains National Wildlife Refuge

Great Blue Heron on Island - Photo by Ron Toews

Ralstin Island

When you look out into the Great Salt Plains Lake, you may notice an island. Depending on the time of year, the island may appear covered in white dots. You are seeing Ralstin Island - a very important rookery at Salt Plains National Wildlife Refuge.

Colonial birds, such as herons, egrets and ibis use the island each year to nest. The birds will arrive in the spring and stay on the refuge until early fall. Over 20 species of birds use the island, which is only about 7 acres. To reduce erosion of the island (it used to be over 20 acres!), you can see square, steel islands around the western tip. These islands add acreage to the habitat and keep winter ice from eroding more of the main island.

Typical Tree on Ralstin - Photo by David Metscher

Rookery: A place where certain birds or animals gather to breed.

Colonial Nesting
Ralstin Island is covered with cottonwood, mulberry and saltcedar trees. The wading birds use this as a rookery because it offers protection from predators and is near to the birds' food supply.

By nesting together, there is a degree of safety in numbers. From each bird's perspective, if a predator intrudes upon the rookery, the chance is good that another bird's nest will be attacked.

The birds can also assist eachother in protecting the nests and chasing off predators.

Each tree on the island can have upwards of 10 nests in it. The baby birds are difficult to tell apart, but over time, their colorations develop and they begin to resemble their parents.

Survival of the Fittest
There are also a lot of risks associated with colonial nesting. Large birds may eat the young of the smaller birds and the chances for disease are increased.

Even in the nest, a young bird competes with its siblings for food. Sometimes the first born, being larger, will keep the younger birds from getting necessary food from the parent birds, thus many baby birds do not survive.

This harsh fact is one way that nature ensures that the wildlife population does not exceed the ability of the habitat to provide food and shelter.

Each year, over 20,000 nesting pairs use the island - that's a lot of birds!

The island and the area around it are closed to all visitors to minimize disturbance to the birds. Use your binoculars to find the birds on and around the island through the year.

Come into the refuge office from April to October to view live camera footage of the birds on Ralstin Island.

Last updated: August 6, 2007