The Mississippi Sandhill Crane

The Rarest Bird In North America-Mississippi Sandhill Crane

Among all endangered species, the most vulnerable are those that survive in small numbers living within a limited range. In biological terms, subspecies refers to a unity of populations of a species living in a subdivision of the species’ global range and varies from other populations of the same species by morphological characteristics. The Mississippi Sandhill Crane is one of these creatures. North America is home to roughly 600,000 Sandhill Cranes divided among six subspecies, three that migrate (the lesser, greater and Canada) and three that do not (the Cuba, Florida and Mississippi). The species ranges are as far north as the Arctic and as far south as Mexico and Cuba. It is among the oldest of all surviving bird species, with fossil records dating back at least 5 million years. But even though the Sandhill Crane is the most successful of all crane species, individual subspecies are not necessarily in good shape. The birds need an equal amount of grasslands and wetlands to survive, and many of the habitats upon which they depend are degrading or disappearing at alarming rates. The Mississippi Sandhill Crane and its dwindling homeland illustrates the challenges the birds face. Protecting them and their habitat is crucial. Historically, the Mississippi Sandhill Cranes were found in flocks of thousands in the natural open plains of Mississippi, Louisiana, Alabama and Western Florida. However, the population started decreasing as cities grew and took over their natural habitat. With severe habitat decline and other problems, a single person, Jake Valentine, realized the cranes were at great risk and called for some action. In the 1970s during the ensuing “cranes and lanes” controversy, stoppage of interstate I-10 construction, and a case in federal court, Jake’s expertise, courage, and determination led eventually to the creation of the Mississippi Sandhill Crane National Wildlife Refuge. Without him, there would simply have been no refuge. He continued his involvement with the cranes and the newly formed refuge until his passing, a period spanning over 30 years. The U.S. Fish and Wildlife Service had added the Mississippi Sandhill Crane to the endangered species list in 1973 and the Mississippi Sandhill Crane NWR was the first refuge established under the 1973 Endangered Species Act, which calls for the government “…to provide a means whereby the ecosystems upon which endangered species and threatened species may be conserved, to provide a program for the conservation of such endangered species and threatened species, and to take steps as may be appropriate to achieve the purposes of the treaties and conventions set forth…” With this decline in natural habitat, the Mississippi Sandhill Crane population in the 1970s fell to between 30-35 wild birds, giving the subspecies the honor of being the rarest member of the federal endangered species list. The Mississippi Sandhill population now stands at about 135 birds in the wild. In large part their recovery is due to a captive-breeding program that supported the largest and longest crane reintroduction project anywhere in the world. The program started at the U.S. Geological Survey’s Patuxent Wildlife Research Center in Laurel, Maryland, in the 1960s. Recently, the vast majority of captive-bred birds have come from the Audubon Center for Research of Endangered Species in New Orleans, Louisiana and the rest from the White Oak Conservation Center in Yulee, Florida. One of the biggest challenges for maintaining the refuge birds is chick mortality. From the 1970’s to 2000, an average of only one chick annually survived its first year of life. In the past 18 years, average annual recruitment has increased roughly to three. However, that number is still far below the 10 to 15 birds needed to balance annual adult mortality. Refuge staff has had to supplement the wild population with yearly releases of up to 20 captive-raised birds. Today, all but 10% of the adult birds are of wild decent, the majority being from captive-bred birds. Solving the natural recruitment problem is overwhelming, but scientists believe it can be done. Sandhill Cranes mature slowly, taking up to eight years to reach adulthood. They are monogamous, so when they lose a mate, it may signal the end of their breeding, but some do seek out another mate. In the early spring, single cranes will start pairing up. The loudest and most noticeable call made by a Sandhill Crane is during the mating season. Males and females will perform unison calling to create a bond. During mating, Sandhill Cranes perform dancing displays. If there is a hole in your bucket list, I would suggest watching them dance into the wee hours of the evening. Although the dancing is most common in the breeding season, the cranes can dance all year long. Sometimes the dance involves wing flapping, bowing, and jumping. They might also throw a stick or some plants into the air. They nest on the ground, as they cannot roost in trees and build the nest out of plant materials. They often have two eggs. The pair will take care of the nest together with the male standing guard. Breeding is not always successful every season. All of these factors mean a very slow growth in their population and extreme fragility to the loss of a member of their species. Reducing predation is also a major challenge. Predators such as coyotes, bobcats and foxes are of major concern. Along with red-tailed hawks, eagles and other birds of prey, raccoons and domestic dogs are known to cause mortality among eggs, chicks, and released adult birds. Human changes on the landscape and the elimination of top natural predators like the wolf and mountain lion have increased mid-sized predator populations, and predator control alone will never be enough to reduce their numbers. Habitat availability is another factor that limits the crane population, so a long-term restoration effort is necessary to cut and burn vegetation and sculpt the refuge to restore degraded areas to wet-pine-savanna habitat. Many different units on the refuge need to be burned every two to three years to restore and maintain the open character of the landscape and to keep woody vegetation at bay. Growing urbanization near refuge borders is making the use of fire increasingly difficult because of the very specific weather and wind conditions needed to keep smoke from adjacent roads and nearby neighborhoods. Still, in areas that have been managed with fire and other tools over the years, more of the former savanna continues to be restored. However, high intensity fires require complex operations, constant communication, and consistent coordination to ensure safety and success. But the most important factors that are needed are political support and financial resources to fund this effort. Mississippi Sandhill Crane population is currently somewhere around 130 wild birds with approximately 30 to 35 wild breeding pairs, that small number is all that the refuge can support. The birds will always need to be managed intensively to avoid extinction. Of the lessons from these projects that we have learned, in the future we, the people, can’t wait for a population of a species to become nearly extinct before we act. These lifesaving measures could be avoided. The land needs to be managed with fire, predator and invasive-species controls. The birds and other animals need to be constantly monitored. As for the Mississippi Sandhill Crane, they will always need new captive-reared birds to be released into their population to replace those that die. And there will always be the risk that a devastating event like disease or weather could wipe out the entire subspecies in the wild. Until I know for sure, I can only recall, capture and document the beauty of the cranes, their enjoyable behavior and their native habitat with a strange anxiety. Will they become extinct?  Did they expand their territory to a larger native habitat? Did we continue to provide a sanctuary for them? I’d like to believe that the birds would continue life at the refuge and eventually spread to the savannahs of the past. The sound of silence that I so often hear during my outings is a strange, somber silence to the land. There is no other sound than the sound of the cranes to make the Mississippi and surrounding savannas come alive. Let’s hope that doesn’t happen there.