For a few weeks each spring, one of the world’s most awesome wildlife spectacles occurs right here in Nebraska. Nearly half a million sandhill cranes descend upon the Platte River Valley to feed and rest before continuing their long northward migration to their breeding grounds in the northern United States, Canada and, for some, even Siberia. This is estimated to be approximately 80% of the world’s population of lesser sandhill cranes.
Typically, a few will arrive in mid-February, with more and more arriving, peaking in mid-March, then tapering off into April. The sights and sounds of cranes gathering along the Platte are unique and unforgettable.
Today, crane habitat is found primarily along an eighty-mile stretch of the central Platte River and the wetlands to the south. The birds’ migration paths funnel through this area, resulting in the congregation of the large numbers of cranes before they again spread out on their journey north. This was not always the case. Westward-traveling pioneers described the Platte as ‘a mile wide and a foot deep.’ Wet meadows and marshes, the ideal habitat for sandhill cranes, were found along much of the river. Cranes used many miles of the Platte for their migration stopover before the river was dammed for flood control and irrigation. Sediment collecting behind the dams, woody vegetation encroaching on the channel and reduced water flow have significantly decreased the area suitable for use by migrating cranes.
This spring, as they have for thousands of years before, the sandhill cranes will return to the Platte. They will share this migration oasis with endangered whooping cranes and many species of waterfowl, also migrating northward. People from all over the world will come to experience this spectacular event that occurs nowhere else on the planet – only in Nebraska.
During the fall, as the days grow shorter and the temperatures begin to cool, millions of birds are preparing for the most hazardous journey of their lives. Long migrations are deadly for birds.
It is estimated that about half of all migrating birds do not survive their combined trips north and south each year. The numerous hazards they face include bad weather, predators, exhaustion over large bodies of water resulting in drowning, collisions with towers and buildings, and starvation due to the loss of suitable stopover habitat.
Bird species that rely on insects and fruit for the majority of their diets must make this perilous trip in order to have adequate food through the winter months. The fact that the various species spread out across the tropics and sub-tropics, rather than all migrating to one location, assures more adequate food availability for all migrants.
With warm tropical weather in the south, why would a bird venture north in the first place? It all has to do with nesting space, food and day length. If you take a look at a globe, you will notice the northern hemisphere has much more land mass than the southern half does. It contains more space for millions of birds to spread out and establish larger nesting territories that offer less competition for food and a better chance of avoiding detection by predators.
In the spring, as birds migrate north, the hours of sunlight per day grow longer. This advantage allows birds nesting in the north to make many more feeding trips to their young every day. The young grow faster, leave the nest earlier, thus shortening the dangerous nesting period for both them and their parents.
The advantages of migration do outweigh the risks, maybe not for every individual bird, but for each species as a whole. So wish them well as they return south on that long and dangerous journey to their winter homes.
The Purple Martins continue their evening roost at 44th & Farnam in Omaha. Many hummingbirds have been reported at feeders and flowers in the greater metropolitan area this week. Reports of migrating warblers and common nighthawks are also coming in.
What birds are you seeing?
Masses of martins have begun returning to the trees by Nebraska Medical Center just south of 44th and Farnum Streets in Omaha. This happens every year. Each evening, the martins begin returning to these trees about half an hour before sunset, and numbers increase for about an hour as the birds settle into their roosting spots for the night. It is a spectacular sight, with tens of thousands of purple martins returning to the area each night through August and often into September – until all the birds have migrated. If you have the chance, stop in to watch it some evening.
Yesterday a customer reported seeing her first hummingbird of the fall migration. Another reported seeing a junco. And at the Fontenelle Nature Association Bird Club meeting last night, Rick Schmid reported seeing a Black-Throated Green Warbler in Fontenelle Forest. What are you seeing?