HOW IS CORONAVIRUS AFFECTING THE ENVIRONMENT?
BECAUSE IT MATTERS
6/6/21
Mississippi Sandhill Crane
There are 15 types of cranes across the world, many of them endangered and 11 of which are close to extinction. In North America, there are the Sandhill cranes. The Mississippi sandhill crane (Grus canadensis pulla) is a subspecies of this species and was only distinctly noted as such in 1972. Mississippi sandhill cranes are more dark grey than other sandhills, and have one gene unique to sandhills in general and one gene unique only to Mississippi sandhills.
Mississippi sandhill cranes are 3-4 feet tall and have a wingspan of 7 feet, and can live for more than 20 years in the wild. They are grey with a red crown and white cheek. They are omnivores. They are found only in one spot in Mississippi, in and around a wildlife refuge, where they live mostly in wet pine savannah habitat. Mississippi sandhill cranes often make a loud trumpeting sound to create territory and bond with mates, whom they will also dance with for the same reason.
In the fall and early winter, any cranes without a mate will find one and create their territory. Mississippi sandhill cranes mate for life. During the winter, cranes pairs mostly court, reinforcing their bonds. They also prepare for nesting and chicks. In the late winter and early spring, the Mississippi sandhills lay their eggs, usually two. Both parents will incubate together for a month, also protecting their eggs from predators. Then the chicks, called colts, are hatched. They can walk soon after birth but have to wait about 75 days to fly. Mississippi sandhill colts will stay with their parents for ten months, and then they will go off on their road. There are about 20-25 breeding pairs left in the wild, but despite this there is a reasonable amount of genetic diversity.
These cranes have a 7 foot wingspan! Image courtesy of the U.S. Fish and Wildlife Service.
The entirety of the Mississippi Sandhill cranes population, only about 100-130, are only found in and around the Mississippi Sandhill Crane National Wildlife Refuge. Mississippi Sandhills are now critically endangered, but once they numbered in the thousands. The main reason for this decline is habitat loss. Once the Mississippi sandhill crane’s habitat stretched into southern Louisiana, eastern Alabama, and western Florida, but have been gone from those areas since the 1910s in Louisiana and the 1960s in Alabama. However, much of this habitat was turned from pine savanna into pine plantations after World War II. Suppression of natural fires also impacts the habitat. Urbanization also impacted this, as thousands of people moved to the Mississippi Gulf Coast, fragmenting the sandhill’s habitat. Cranes have also been directly impacted by people, as they may be harassed, shot, and poisoned by contaminants.
During the 1960s-1990s, sandhill cranes were repeatedly listed in Endangered species lists, and recovery plans were formed. In 1975, the Mississippi Sandhill Crane National Wildlife Refuge was created in Gautier, Mississippi to protect the eligible habitat left, and most cranes now live in the Refuge or on private lands around it. In the refuge, biologists spend a lot of time restoring habitat and ecosystems and tracking cranes. Tracking the cranes allows biologists to know more about the cranes habits, population and mortality, and is often done by waiting in blinds or using radio transmitters and telemetry. In the winter on the refuge, biologists will give the cranes new transmitters, and band new young birds and replace fallen off bands. Biologists will also test egg viability by floating eggs in water. If it is viable, there will be small movements of the egg in the water.
There are many predators that naturally threaten the Mississippi sandhill cranes nests and eggs, including owls, bobcats, armadillos, and raccoons. Parents are generally good at protecting their eggs.
To try and grow the population of cranes, captive breeding programs are also in place. 10-15 young birds are released into the refuge each year. Since 1965, some of the second viable eggs have been taken from nests and sent to captive flocks. The captive flock is used for genetic diversity and observations, and by 1980, to produce juveniles for reintroduction. To prevent the colts from imprinting on humans, handlers will wear crane costumes and puppets to teach colts life skills and ensure they don’t become domesticated. Another method is for the colts to be raised by foster-crane parents. To prepare for their release, colts are trained to protect themselves from fake stuffed predators. Then, when they are ready, colts are released into enclosed areas on the refuges, and after a month will be released for real. This program is so successful that 90% of wild cranes were reared in captivity.
Works Cited
Mississippi Sandhill Crane - MISSISSIPPI sandhill Crane - U.S. fish and Wildlife Service. (2014, November 21). Retrieved April 27, 2021, from https://www.fws.gov/refuge/Mississippi_Sandhill_Crane/wildlife_and_habitat/mississippi_sandhill_crane.html
Mississippi Sandhill Crane. (2020, September 08). Retrieved April 27, 2021, from https://www.whiteoakwildlife.org/wildlife/mississippi-sandhill-crane/
Recovering Mississippi Sandhill Cranes. (n.d.). Retrieved April 27, 2021, from https://audubonnatureinstitute.org/mississippi-sandhill-cranes
Cover image courtesy of the U.S. Fish and Wildlife Service