The anhinga, also known as the American darter or snakebird, is a water bird found across the southeastern United States and parts of Central and South America. With its long neck and sharply pointed bill, the anhinga is a distinctive sight as it swims low in the water with just its neck exposed, looking for fish to spear. So is this unique bird actually endangered?
Quick Facts on the Anhinga
Here are some key facts about the anhinga:
- Scientific name: Anhinga anhinga
- Average length: 36 inches
- Wingspan: around 45 inches
- Identifying features: long neck, sharply pointed bill, long tail
- Habitat: freshwater lakes, swamps, rivers, coastal areas
- Diet: mainly fish but also amphibians, crustaceans, small reptiles
- Breeding: Nests in colonies in trees or bushes near water. Clutch size is 2-6 eggs.
Anhinga Population and Conservation Status
The anhinga has a very large global population estimated to be somewhere between 350,000 to 500,000 individuals. Its numbers today remain relatively stable, leading the IUCN Red List to classify the anhinga as a species of Least Concern. The anhinga is not considered threatened or near threatened with extinction at the present time.
In the United States, the anhinga is protected under the Migratory Bird Treaty Act. It is considered a Species of Special Concern in North Carolina but does not have any special conservation status in most other states. Overall, the anhinga population in the US is estimated at around 100,000 breeding pairs and is believed to be stable.
Population Trends
Historically, the anhinga population in the US declined in the first half of the 20th century due to hunting and habitat loss. However, protections were put in place and its numbers recovered across much of its range. Populations are now considered stable or even increasing in many regions.
For example, Breeding Bird Survey data from 1966-2019 shows a +0.81% annual increase in anhinga numbers in the US and Canada. Christmas Bird Counts also showed a +4.1% annual increase from 1960-2016. In Florida, which hosts the densest anhinga populations, numbers have rebounded from around 10,000 pairs in the 1930s to over 100,000 pairs today.
Threats and Conservation Actions
While not globally threatened, some key threats to the anhinga include:
- Habitat destruction – Draining of swamps and wetlands for development
- Disturbance of nesting colonies
- Pollution and water quality declines
- Entanglement in fishing gear
Conservation actions that can benefit anhingas include protecting key breeding and foraging sites, managing water levels and improving water quality, public education campaigns, and enforcing restrictions on disturbance of nesting birds.
Comparison to Other Species
The anhinga’s population status can be put into perspective by comparing it with some other water birds:
| Species | Population Estimate | Conservation Status |
|---|---|---|
| Anhinga | 350,000-500,000 | Least Concern |
| Whooping Crane | ~800 | Endangered |
| Wood Stork | 150,000-180,000 | Threatened |
| Roseate Spoonbill | 100,000-120,000 | Least Concern |
This table illustrates that while not as rare as the endangered whooping crane, the anhinga is still fairly common compared to birds like the wood stork and roseate spoonbill which face more conservation risks.
Anhinga Behavior and Ecology
To understand the anhinga’s conservation needs, it helps to look at some key aspects of its behavior and ecology:
Feeding
The anhinga is a skilled fisher, spearing prey with its sharp beak. It swims low in the water, submerging its body while keeping its snake-like neck above the surface. The anhinga does not have waterproof feathers, so after a diving session it needs to perch somewhere and dry its wings in order to regain the ability to fly.
Breeding
Anhingas breed in colonies in trees and bushes located near waterways. Breeding season is determined by local water levels, with peak activity in spring/summer in temperate areas and fall/winter in the tropics. Males attract females with elaborate courtship displays and build a nest out of sticks in a bush or tree. Females lay eggs in intervals so one male may care for chicks of differing ages.
Migration
Northern populations of anhingas migrate south for the winter, while southern populations are year-round residents. Migratory routes are based around coastlines and major river systems.
Understanding aspects like the anhinga’s feeding needs, breeding habitat requirements, and migratory patterns helps inform conservation actions such as protecting key wetland habitats and managing water flows.
Anhinga Population Forecast
Based on current trends and conservation assessments, the outlook for the anhinga population is relatively positive:
- Global populations are large and widespread
- No evidence of rapid declines in recent decades
- Legal protections in place (e.g. Migratory Bird Treaty Act)
- Not at high risk from climate change impacts
If current conditions continue, the anhinga population is expected to remain stable or even gradually increase across most of its range. However, localized declines could occur in areas of severe habitat loss or degradation. Continued monitoring and conservation action focused on protecting key wetland habitats will be important for the long-term security of anhinga populations.
Conclusion
In summary, the anhinga is a wide-ranging water bird with a large global population that is not considered to be at risk of extinction now or in the near future. While not reaching the extremely endangered status of some species like the whooping crane, the anhinga also does not face the levels of concern
some other wetland birds do. Thanks to legal protections and stable habitat conditions across much of its range, the anhinga population is forecast to remain healthy into the future as long as conservation efforts continue.
