The Mississippi sandhill crane is a critically endangered species of crane that is endemic to the coastal plain of southeastern Mississippi in the United States. The total population of Mississippi sandhill cranes has declined significantly over the last century due to habitat loss, with only an estimated 130-150 birds remaining in the wild as of 2023.
Historical Population
The Mississippi sandhill crane was once more widespread across the Gulf coastal plains from Louisiana to Florida. Estimates suggest there were 1,000-2,000 Mississippi sandhill cranes before European settlement. However, the population started declining in the late 1800s as their wet pine savanna habitat was converted to agricultural land and timber plantations. By the 1930s, the crane population had dropped to around 100 individuals.
In the 1940s, only 19 Mississippi sandhill cranes were observed at the Arcadia Zoo refuge site. The population continued to decline over the next few decades due to habitat loss, fire suppression, predation, and illegal hunting. By 1965, there were only 40-45 birds remaining in the wild.
Endangered Species Act Protection
The dire situation of the Mississippi sandhill crane led to it being one of the first species listed under the Endangered Species Preservation Act of 1966, a precursor to the modern Endangered Species Act. The Mississippi sandhill crane was officially listed as endangered in 1973. This protection made it illegal to hunt or harm the cranes and spurred some conservation efforts.
In the 1970s, the population rebounded slightly to around 60-80 birds. But habitat loss and degradation continued to pose significant threats. There were estimated to be only around 40 Mississippi sandhill cranes left by 1980.
Captive Breeding and Reintroduction
To save the Mississippi sandhill crane from extinction, a captive breeding program was established in 1965. Eggs were collected from the wild to hatch and raise captive-born chicks. The goal was to build up the captive flock and eventually release captive-bred cranes to bolster the wild population.
The first successful captive breeding was achieved in 1981. Since then, over 200 captive-bred cranes have been released into the Mississippi Sandhill Crane National Wildlife Refuge and neighboring protected lands. These reintroduction efforts helped the overall population recover to over 100 birds by the early 2000s.
Captive Population
As of 2023, there are approximately 150 Mississippi sandhill cranes in the captive breeding program, which includes birds spread across four facilities:
- White Oak Conservation Center in Yulee, Florida – 65 cranes
- Audubon Species Survival Center in New Orleans, Louisiana – 28 cranes
- Memphis Zoo in Memphis, Tennessee – 32 cranes
- Freeport-McMoRan Audubon Species Survival Center in New Orleans, Louisiana – 25 cranes
The captive birds serve as a genetic reservoir for the species. Offspring produced through the breeding program help maintain the genetic diversity of the wild population through periodic releases.
Reintroduction Results
Since 1981, over 200 captive-bred Mississippi sandhill cranes have been released into the wild. Initial releases had high mortality rates as the young cranes struggled to adapt and survive. But techniques have improved over time, and recent releases have had higher success rates in boosting the wild flock.
Between 1981 and 2008, 157 captive-bred cranes were released. However, only 16% of those birds were alive a year after release. From 2010 to 2018, 81 cranes were released with a one-year survival rate of 50%. The improved survival rate has helped stabilize and grow the wild population.
Current Wild Population
According to the latest surveys and estimates, there are between 130-150 Mississippi sandhill cranes remaining in the wild as of 2023. This marks a substantial recovery from a low of around 40 birds in the 1980s. But it is still an extremely small population size that leaves the cranes vulnerable to extinction.
Nearly the entire wild population is concentrated within the 19,000 acres of protected habitat at the Mississippi Sandhill Crane National Wildlife Refuge near Gautier, Mississippi. A few scattered pairs nest just outside the refuge boundaries.
The table below summarizes the fall census results for the Mississippi sandhill crane wild population over the past decade:
Year | Fall Population Count |
---|---|
2012 | 119 |
2013 | 133 |
2014 | 110 |
2015 | 119 |
2016 | 127 |
2017 | 138 |
2018 | 148 |
2019 | 142 |
2020 | 152 |
2021 | 146 |
2022 | 136 |
The population has fluctuated between 110-150 over the past decade, likely due to variations in breeding productivity and mortality from year to year. But the overall trend has been relatively stable, indicating the conservation measures are working to sustain the flock. Continued monitoring and management will be needed to maintain the Mississippi sandhill crane population at its current size.
Threats and Recovery Challenges
While the Mississippi sandhill crane population has rebounded from the brink of extinction, the species remains critically endangered and faces multiple threats to its recovery:
Habitat Loss
The cranes are dependent on open wet pine savanna habitat that was historically widespread across the Southeast. Over 90% of this habitat has been lost to urbanization, agriculture, and forestry practices. Fire suppression in remaining areas has allowed scrub and woodlands to encroach on the open savannas favored by the cranes.
Small Population Size
With only 130-150 individuals, the Mississippi sandhill crane has a high risk of extinction due to random events, inbreeding depression, and loss of genetic diversity. Their limited numbers also make breeding and recruitment more challenging.
Climate Change
Projected sea level rise and stronger coastal storms threaten to degrade and destroy the low-elevation wetlands that the cranes rely on. Hotter droughts may also reduce wetland habitat and food resources.
Predation
Natural predators like bobcats, foxes, and coyotes take a toll on young cranes and eggs. Feral dogs have also been an increasing threat around the margins of the protected refuge areas.
Recovery Plan Goals
The U.S. Fish and Wildlife Service has updated the Mississippi Sandhill Crane Recovery Plan several times, most recently in 2015. The current goals for stabilizing and recovering the Mississippi sandhill crane population include:
- Maintaining and expanding the protected habitat areas within the Mississippi Sandhill Crane National Wildlife Refuge to allow for population growth
- Establishing at least two additional self-sustaining subpopulations of 30-40 nesting pairs at separate sites across the cranes’ former range
- Releasing captive-bred cranes annually to bolster the wild flocks and maintain genetic diversity
- Continuing research into predator management, breeding ecology, habitat needs, and modeling extinction risk to refine conservation actions
- Monitoring wild crane numbers and survival rates to track progress
Achieving these recovery goals will require long-term commitment and resources for habitat management, supplemental breeding and release, predator control, and population monitoring. With intensive ongoing conservation efforts, the outlook for the Mississippi sandhill crane is hopeful, but they will remain dependent on human intervention for their survival far into the future due to their critically low numbers and limited habitat.
Conclusion
In summary, the Mississippi sandhill crane has rebounded from the brink of extinction but remains critically endangered with only an estimated 130-150 birds in the wild as of 2023. The population was decimated by habitat loss and overhunting, declining from the thousands in the 19th century to just 40 individuals by the 1980s. Captive breeding and release programs have been crucial to saving the cranes from vanishing completely. However, the population faces ongoing threats from small population size, habitat degradation, climate change, and predation. Intensive management of the protected refuge habitat, supplemental breeding and release, and monitoring programs continue to be needed to sustain the Mississippi sandhill crane population at its current precarious level. Any relaxation of conservation efforts could easily tip this iconic but fragile species back towards extinction.