The Glossy Ibis (Plegadis falcinellus) is a wading bird species that can be found across much of the world. They are most common in tropical and subtropical wetlands, but their range extends into temperate regions as well. The Glossy Ibis has an extremely large global population and range, and is evaluated as being of Least Concern on the IUCN Red List of Threatened Species. However, regionally it may be rare or even endangered in certain parts of its range. Overall, the Glossy Ibis is one of the most abundant and widespread ibis species in the world. But the degree to which it can be considered rare depends on the specific region being considered.
Global Population and Distribution
Globally, the Glossy Ibis has an extremely large range and population. Its breeding range spans across southern Europe, Africa, the Middle East, South and Southeast Asia, Australasia, and the Americas. Some important populations occur in Spain, Iraq, India, Australia, and the United States. The global population is estimated to number between 620,000-3,800,000 individual birds. Over 1 million are thought to exist in Africa alone. Due to their large numbers and extensive range covering every continent except Antarctica, the Glossy Ibis is evaluated as Least Concern on the IUCN Red List. It is one of the most widespread ibis species in the world. So from a global perspective, the Glossy Ibis is quite abundant and not rare.
Regional Rarity
While common in many parts of its range, the Glossy Ibis can be regionally rare or even endangered in some areas. In Europe, they are concentrated mainly in southern Spain and eastern Europe with smaller numbers scattered across the Mediterranean. They are considered near threatened in Europe due to population declines from habitat loss and degradation. In the United States, they are rare and local breeders along the Atlantic Coast and very rare on the Pacific Coast. The Glossy Ibis is close to endangered in some U.S. states. Parts of its range in the Middle East and Asia have also been reduced. While still abundant in Africa and South America, local declines have also occurred there. So while not globally threatened, the Ibis is rare and vulnerable in portions of its range.
Reasons for Regional Rarity
There are several reasons why Glossy Ibis may be rare or declining in parts of its range:
- Habitat loss – Draining wetlands for agriculture, development, etc. reduces nesting and feeding habitat.
- Disturbance – Human activities near breeding colonies can reduce reproductive success.
- Hunting – Still hunted for food in some developing regions.
- Climate change – Drought has reduced habitat in some areas.
- Pollution – Vulnerable to pesticides, heavy metals, and other contaminants.
- Extreme weather – Storms, flooding, and drought can destroy nests and habitat.
Conservation of wetlands and reduction in disturbance are vital for protecting rare ibis populations. Poland, where the Ibis is nearly extinct, have had some success reintroducing the species. Ongoing conservation will be needed to prevent further regional declines.
Abundance Compared to Other Ibis Species
The Glossy Ibis has a much larger global population and range size compared to other ibis species:
Species | Population | Range (km2) | IUCN Status |
---|---|---|---|
Glossy Ibis | 620,000-3,800,000 | 74,000,000 | Least Concern |
African Sacred Ibis | 450,000-650,000 | 6,900,000 | Least Concern |
Madagascar Ibis | 2,500-10,000 | 462,000 | Endangered |
Scarlet Ibis | 200,000-300,000 | 22,000,000 | Least Concern |
White Ibis | 150,000-500,000 | 5,480,000 | Least Concern |
The Glossy Ibis has a population size several times larger than the next most abundant ibis species, the Sacred Ibis. And its breeding range is an order of magnitude larger than any other ibis. So compared to its relatives, the Glossy is far more plentiful and widespread. The endangered Madagascar Ibis has a tiny fraction of the Glossy’s abundance. The Scarlet and White ibises are roughly 10-25% as numerous as the Glossy but have much more restricted distributions. So while the Glossy Ibis is regionally rare in areas, it stands out as the most abundant ibis species globally.
Historical Abundance and Change Over Time
Historically, the Glossy Ibis was even more abundant and widespread than today. Populations began declining in the 19th Century as wetlands were drained across Europe and North America. In the 1800s, the species could be found breeding across much of Europe, whereas today the population is fragmented. Flocks of over 5,000 ibises were recorded in Florida in the 1930s, while today fewer than 1,000 remain there. During the 20th Century, habitat loss caused major declines in Spain, Portugal, Italy, and southeastern Australia. More recently, populations have stabilized or increased in some regions, like Spain where habitat protection helped the species recover. But others, like Greece, continue to decline. While still common, the historical abundance of the Glossy Ibis was higher before extensive wetland destruction. Ongoing conservation will be needed to avoid further regional declines.
Glossy Ibis Population Over Time
Year | Estimated Global Population |
---|---|
1800s | Over 5 million |
1930 | 4 million |
1970 | 2 million |
2000 | 620,000 – 3.8 million |
The current population estimate is broad but likely represents at least a 50% decline since the 1800s, coinciding with substantial wetland loss over this period. More conservation efforts are needed to protect remaining ibis populations in areas where they are now rare.
Rarity Status on Regional Red Lists
The Glossy Ibis is classified on several regional Red Lists and endangered species lists, reflecting its rarity in parts of its range:
Region | Rarity Status |
---|---|
Europe | Near Threatened |
Spain | Vulnerable |
Poland | Regionally Extinct |
North America | State Endangered in CT, MA, NJ, NY |
Australia | Near Threatened |
While Least Concern globally, important regional populations in Europe, parts of the U.S., and Australia are classified as Near Threatened, Vulnerable, or Extinct. These listings reflect substantial declines caused by destruction of coastal and inland wetland habitats. Ongoing conservation efforts, like wetland restoration and protection, will be necessary to stabilize and ideally increase threatened regional groups.
Key Points
- With a global population likely numbering over 1 million birds and a massive range across 6 continents, the Glossy Ibis as a whole is not considered a rare species.
- However, substantial regional declines have occurred in Europe, the Middle East, Asia, the United States, and Australia due to habitat loss and degradation.
- The Ibis is now rare and threatened in portions of its former range, including being Near Threatened in Europe and extinct in Poland.
- Populations have diminished from even higher historical levels, though accurate early population sizes are uncertain.
- More conservation action is needed in areas where the Ibis is now rare to protect wetlands and breeding habitat.
- Globally though, the Glossy remains one of the most abundant ibis species in the world.
Conclusion
In conclusion, the abundance and rarity of the Glossy Ibis can only be properly assessed by looking at specific regions. Globally it is still one of the most common and widespread ibises, though declines have occurred over the last two centuries. Regionally it is endangered, vulnerable, or extinct in portions of its former range. While globally Least Concern, habitat loss has made the Glossy Ibis a species of conservation concern in areas like Europe and the eastern United States. Targeted wetland conservation and management efforts will be needed in these regions to protect local ibis populations. Their specialized habitat requirements and regional scarcity warrants continued monitoring and protection efforts. But the species remains common or abundant across much of its extensive global range.