African Sacred Ibis

Themes

Invasive species

PSBR model type

Pressure (P)

Corresponding targets

SDGs

15.8 By 2020, introduce measures to prevent the introduction and significantly reduce the impact of invasive alien species on land and water ecosystems and control or eradicate the priority species.

Aichi Biodiversity Targets

Target 9: By 2020, invasive alien species and pathways are identified and prioritized, priority species are controlled or eradicated, and measures are in place to manage pathways to prevent their introduction and establishment.

Biodiversity Action Plan

D41050 Prevention of invasive species:

1. Develop an emergency eradication plan for new invasive species and conduct regular drills with local governments.

2. Establish a long-term control plan for invasive species to minimize the economic loss and ecological impact caused by invasive species.

Key performance indicator of the action plan:

• Number of existing invasive species, affected areas, and eradication cases handled/executed in the invasive species control plan.

• The reduction rate of distribution range/number of existing invasive species. The reduction in the number of individuals of existing invasive species.

Background

The Egyptian Sacred Ibis is native to Africa and the Middle East. In 1984, the wild individuals of the Egyptian Sacred Ibis were first recorded in Guandu, Taipei. Nowadays, it has widely spread all over the western coastal wetlands in Taiwan. There is a lot of overlap between the Egyptian Sacred Ibis and local herons in terms of food, nest trees, and other ecological resources. Egyptian Sacred Ibis is highly adaptable to the environment and has a wide range of diets, which causes competitive exclusion on the survival and reproduction of native herons. Therefore Egyptian Sacred Ibis needs to be monitored on its population changes and removed gradually to reduce their threats to native species.

Definition and Calculation

• The data of 1995-2010 came from the project of the Taiwan Wild Bird Federation sponsored by the Forest Bureau— The impact of invasive Egyptian Sacred Ibis on native birds in Taiwan, 2009. In order to compare the data year to year, the data was standardized: the summation of the maximum population numbers from each county and city in a certain year is used to represent the population of Egyptian Sacred Ibis of that year.

• Due to the lack of relevant project as the reference from 2011 to 2014, the data is based on the eBird records. After removing missing or unreasonable records of the data, the Egyptian Sacred Ibis population of the year is represented by the summation of the maximum population of each county and city in the year.

• The data of 2015-2017 is from the African Sacred Ibis management pilot project of Forestry Bureau, Council of Agriculture (2015 -2017). The surveys of the pilot project are synchronously conducted on the last weekend of each month from each August to November. In the western coastal regions and wetlands, bird-watching societies in different locations conducted synchronized surveys using the method of area searching in locations where the African Sacred Ibis are likely observed. The population size of each year was then estimated after collecting the survey data of each county and city.

• The data of 2018 is from the annual project report of "2018 Population Control for Invasive Species-The African Sacred Ibis", Forestry Bureau, Council of Agriculture and eBird records. The population size of African Sacred Ibis is represented by the summation of the maximum population numbers of each county and city (after removing the missing and unreliable records from eBird) and the number of eggs, fledglings, juveniles, and adults removed in the project.

The data and temporal range

The population size of African Sacred Ibis from 1995 to 2017. The locations and population size of African Sacred Ibis from 1996 to 2018.

Updates

There was no population size estimation in 2018 because only individuals were removed that year, but no survey conducted on population size. Therefore, the population size data were all from eBird. According to the data from January to December 2018, there were 3,544 records, and Tainan had the highest records, 295 individuals, among all counties and cities. Also, there was a reproductive control program for African Sacred Ibis in the same year. A total of 311 eggs, 216 fleglings, 200 juveniles, and three adults had been removed.

Trends

The indicator trend chart shows that the distribution range and number of African Sacred Ibis have increased year by year. After 2005, the population size has shown exponential growth, indicating that its threat has become more and more serious. In the 2017 Research Report of the Forestry Bureau, it was pointed out that the current population size of African Sacred Ibis has threatened the survival of native bird species. The reason for the decline in population size from 2011 to 2014 is data error instead of the real reduction in population size. Because eBird was officially promoted in Taiwan in 2013, the data records from 2011 to 2012 are fewer and there were more data errors. After the promotion, many bird watchers have imported the data into the eBird database, and the number of African sacred ibis obtained is highly reliable. At present, the African sacred ibis is distributed in the coastal areas of Taiwan's counties and cities, gradually spreading from the central north to the south, and there have been many observation records in the south. It is recommended that responsible agencies take a more active and direct approach to control the number of African sacred ibis.

Data Management Authorities

eBird team, Forestry Bureau, Council of Agriculture, Executive Yuan, Taiwan Wild Bird Federation, Birdway Control Co., Ltd., Wildlife Research Laboratory in School of Forestry and Resource Conservation, National Taiwan University

References

• eBird website
• Forestry Bureau, Council of Agriculture, Executive Yuan (2018) Project report of "Population Control for Invasive Species—African Sacred Ibis"
• Forestry Bureau, Council of Agriculture, Executive Yuan (2017) Project report of "Population Control for Invasive Species—African Sacred Ibis"
• Forestry Bureau, Council of Agriculture, Executive Yuan (2016) Project report of "Population Control for Invasive Species—African Sacred Ibis"
• Forestry Bureau, Council of Agriculture, Executive Yuan (2015) Project report of "Population Control for Invasive Species—African Sacred Ibis"
• Forestry Bureau, Council of Agriculture, Executive Yuan (2011) Project report of "Population Control for Invasive Species—African Sacred Ibis"
• Forestry Bureau, Council of Agriculture, Executive Yuan (2010) Project report of "Population Control for Invasive Species—African Sacred Ibis"
• Forestry Bureau, Council of Agriculture, Executive Yuan (2009) Project report of "Population Control for Invasive Species—African Sacred Ibis"