Great Green Macaw Census Report, 2022-2023

Abstract

The Great Green Macaw (Ara ambiguus) is a critically endangered neotropical psittacine, native to Costa Rica, Colombia, Ecuador, Honduras, Nicaragua, and Panama. Two international censuses of the species were conducted in five of the six countries, in 2022 and 2023. Only Nicaragua is missing from this study. The censuses were conducted during the non-breeding season when the species more commonly occurs in flocks and use communal roosts. 653 Great Green Macaw individuals were counted in 2022, while 328 individuals were counted in 2023. There were 30 more participants in the 2023 census than in 2022, however there were 15 additional observation sites in 2022. The results do not confirm a decline in population, as additional studies are needed to determine a true population trend. However, the results do indicate that Costa Rica is the stronghold for the species.

1. Background

The Great Green Macaw (Ara ambiguus) is a neotropical psittacine species native to 6 Latin American countries: Costa Rica, Colombia, Ecuador, Honduras, Nicaragua and Panama. The species was listed as Critically Endangered by the Red List of the International Union for the Conservation of Nature (IUCN), after its last review in 2021 (BirdLife International, 2020). Knowing the status of the wild populations is crucial to understand the impact of the conservation strategies currently implemented, as well as in establishing new strategies.

The first estimation of Great Green Macaw individuals in Costa Rica was carried out in the 90’s under the supervision of researcher George Powell. At that time, Powell estimated the population to be approximately 200 individuals (Figure 1). This estimate was based on the observation of flocks that were found in the breeding range and in adjacent areas of the Atlantic lowlands and mountains (Powell et al., 1999). After this effort, it was not until 2009 when the Tropical Science Center (Centro Científico Tropical) carried out another population census during the reproductive period. On this occasion, the estimate was 302 individuals across 16 counting points (Monge et al., 2009).

After this last count in 2009, ten years passed until, in 2019, the Macaw Recovery Network and the Tropical Science Center began conducting annual counts of the Great Green Macaw population in Costa Rica. These counts have provided important reference information to estimate the minimum population size in the country, with the aim of understanding population trends of the species. This knowledge is fundamental in our efforts to increase population size, improve the habitat they occupy, and promote conservation activities for this highly threatened species. Numerous organizations and citizen scientists have been able to contribute to this important activity.

The up-listing of the Great Green Macaw’s status to critically endangered in 2021 created an urgency to implement strategies that could benefit the species across its entire range. Therefore, efforts of Macaw Recovery Network and the Tropical Science Center worked together to organize the first international Great Green Macaw census in 2022. Organizations Ecovida/Lapa Verde and the Horizon Conservation Foundation joined us as promoting institutions for the 2023 census.

2. Counting methodology

1st International Census 2022

The 2022 census took place between September 28 and October 4, 2022, in five countries. For this count, they differentiated two types of counting procedures: depending on whether the count is carried out at a fixed point (roost) or along a transect (road, trail or any place where walking is possible). For each procedure they followed the following instructions:

A. List of equipment needed for the census

• Printed data sheet.
• Pencil or pen, preferably the use of pencil.
• Binoculars.
• Watch or cell phone and compass.
• GPS.

B. Counting at fixed points (roost)

• Prepare for the count by getting all the necessary equipment ready. Remember to be prepared for weather conditions.
• The first time you visit the counting point, make sure you arrive with plenty of time before the census starts (16:00 in afternoon counts, or 5:00 in morning counts). Some count points are more challenging to access than others and require extra time.
• Arrive at your count point at least 20 minutes before the count begins.
• Before beginning the count, fill in the information at the top of the printed data sheet.
• The count will involve counting the number of individuals that can be seen or heard, up to 400 meters from the fixed counting point, noting whether birds were seen or heard.
• At each counting site, at least one afternoon and one consecutive morning count will have to be repeated. The counting begins in the afternoon from 16:00 to 18:00pm or until dark, and the next morning between 5:00 and 7:00am. This guarantees to cover the hours of greatest bird movement and it will be necessary to record each found in the printed data sheet.

C. Count on transects (road, trails or any place where it is possible to walk)

• Prepare for the count by getting all the necessary equipment ready. Remember to be prepared for weather conditions.
• The first time you visit the transect, make sure you arrive in plenty of time before the census begins (16:00 in afternoon counts, or 5:00 in morning counts). Sometimes finding the transect is complicated and takes time.
• Arrive at least 20 minutes before the count begins.
• Before beginning the count, fill in the information at the top of the printed data sheet.
• During the transect route, the observers will remain close to each other, walking at a constant pace.
• The count will involve counting the number of individuals that can be seen or heard, up to 200 meters distance on each side of the transect, noting whether birds were seen or heard.
• At each counting site, at least one afternoon and one consecutive morning count will have to be repeated. The counting begins in the afternoon from 16:00 to 18:00pm or until dark, and the next morning between 5:00 and 11:00am. These are the hours of greatest bird movement (most activity).

D. General considerations regardless of the type of counting

• You must record each new detection of an individual.
• If the individual is perched when you first identify it, you should not record it a second time when it starts to fly.
• If the individual is flying when you detect it, you should record its direction of travel.
• You must fill out all columns for each entry. If a column does not apply, simply put N/A.
• If an individual is only heard and not seen, make recordings where possible, either with professional recording or with a personal or cell phone recorder, noting the file number of recording.

E. Data form

2nd International Census 2023

The 2023 census took place between September 29 and October 2, 2023 in five countries. Like the year previously, two types of counting procedures were differentiated, depending on whether the count is carried out at a fixed point (roost) or along a transect (road, trail or any place where it is possible to walk). For each type of counting, the following instructions were followed:

A. List of equipment needed for counting

• Link for data registration (Kobotoolbox).
• Binoculars.
• Cell phone.
• Compass.
• GPS.

B. Data collection

When collecting data, different factors must be considered, such as:

• The data must be taken through a form, this form is found in the following link: https://ee.kobotoolbox.org/x/eQBHZvq5
• It is important to familiarize yourself with the form before starting the count, this way, if you have any questions, you may ask the promoters of the count prior to the Census beginning.
• The form link must be loaded before going out into the field when you have internet access. This way, when you go to collect the data, regardless of the internet access, data can be uploaded and archived.
• It is important before starting the count to know the location of north, south, east and west; this is to facilitate the collection of data regarding the flight direction of individuals.

If for some reason you cannot collect data using the electronic form, you can collect the data using the data collection sheet, however, once the count is completed you must contact the promoters to enter this data into the electronic form. Only data that is issued through the form will be analyzed.

C. Counting at fixed points (exclusively for Costa Rica and organizations from other countries that already have passage or roosting sites identified) (September 30-October 1, 2023)

• Prepare for the count by getting all the necessary equipment ready. You can be even more comfortable during the activity with a coffee, a snack, a folding chair and umbrella/poncho.
• Make sure you arrive with plenty of time before the census starts (about 15 minutes before).
• Consider sites with good visibility to carry out the count, for example: mountains or open sites. Some sites are more difficult to find, give yourself plenty of extra time.
• When you know the counting point, be sure to arrive at the counting point and be prepared before the census begins.
• Before starting the count, fill in the data about the observer and the site in the registration link.
• The count consists of counting the number of individuals seen around the fixed counting point.
• At each counting site, at least one afternoon and one consecutive morning count will have to be repeated. The counting begins on the afternoon of September 30 from 16:00 to 18:00pm, and the morning of October 1 from 5:00 to 7:00am.

D. Count on transects (road, trails or any place where it is possible to walk) (exclusively for organizations that do not know passage or roost sites) (September 29-October 2, 2023)

• Prepare for the count by getting all the necessary equipment ready. You can be even more comfortable during the activity with a drink and a snack.
• Make sure you arrive and are prepared at your site before the count begins (counting hours are from 5:00 to 9:00am and from 16:00 to 18:00pm).
• Before starting the count, fill in the data about the observer and the site in the data link.
• During the transect route, the observers will remain close to each other, walking at a constant pace and in silence.
• The count consists of counting the number of individuals seen on each side of the transect, noting their behavior at the time of sighting.
• Each counting transect will have to be repeated at least one afternoon and one morning consecutively. The counting has a minimum duration of 2 hours each day (morning and afternoon). These are the hours of greatest bird movement and it will be necessary to register each encounter in the data link.

E. General considerations, regardless of the type of counting

• Avoid counting individuals if you are not completely sure it is a new record.
• If the individual is perched when you encounter them for the first time, you should not record them a second time if they start to fly.
• If the individual is flying when you detect it, you should record its direction of travel.
• You must fill in all the spaces in the data link.

F. How to fill in the data in the data registration link?

Before starting the count, fill out the site and observer data in the electronic form, such as:

1. Date
2. Name of the organization (if it does not have one, then it is “Individual”)
3. Name of the observer or observers
4. Counting site (this information will be provided automatically by the form by clicking on the location symbol. If auto-entry doesn’t work, you can add the location manually in the following sections (latitude N and longitude W).
5. Start time
6. Habitat type
7. Cloudiness
8. Methodology
9. Presence of rain.

Report of individuals: if no birds are observed, select “No”. In case of reporting if you find any findings, select “Yes” and complete the questions that appear.

Final hour.

Send form.

3. Results

General Count 2022

At the regional level, between September 28 and October 4, 2022, the first count was carried out. International, in which 5 countries participated (Colombia, Costa Rica, Ecuador, Honduras and Panama), only Nicaragua is missing to complete the 6 countries in which the species is distributed worldwide. This count included 49 participants across 20 different organization. 653 Great Green Macaw individuals were counted across 77 sites (Figure 2).

General Count 2023

At the regional level, the 2nd count was carried out between September 29 and October 2, 2023. International, in which 5 countries participated (Colombia, Costa Rica, Ecuador, Honduras and Panama), only Nicaragua is missing to complete the 6 countries in which the species is distributed worldwide. 32 organizations and 76 participants participated in this count, accounting for 328 Great Green Macaw individuals in 62 sites (Figure 3).

Colombia 2022

For 2022, 3 organizations participated, with a 4-day sampling effort, accounting for a maximum of 12 individuals in 4 counting sites.

Colombia 2023

By 2023, 5 organizations and 12 participants participated, with a 4-day sampling effort counting a maximum of 16 individuals in 7 counting sites, of which 13 were recorded in 3 protected areas (Figure 4).

Costa Rica 2022

By 2022, 14 organizations and 39 participants participated, with a 7-day sampling effort, counting a maximum of 567 individuals in 25 counting sites (Figure 6).

Costa Rica 2023

By 2023, 18 organizations and 44 participants participated, with a 2-day sampling effort counting a maximum of 266 individuals in 26 counting sites (Figure 5). For Costa Rica, this would be its fifth consecutive year carrying out population counts of the Green Macaw.

Ecuador 2022

2 organizations and 4 participants participated, with a sampling effort of 4 days, accounting for a maximum of 8 individuals in 4 counting sites.

Ecuador 2023

3 organizations and 13 participants participated, with a sampling effort of 4 days, counting a maximum of 10 individuals in 2 counting sites. (Figure 7).

Honduras 2022

Only the Apu Pauni Project participated, with 4 participants, with a sampling effort of 4 days, counting 45 individuals in 2 counting sites.

Honduras 2023

Only the One Earth Conservation organization participated, and they counted a total of 24 individuals (Figure 8).

Panama 2022

1 organization participated, with a sampling effort of 2 days, counting a maximum of 21 individuals at 3 counting sites.

Panama 2023

1 organization and 5 participants participated, with a sampling effort of 4 days, accounting for a maximum of 12 individuals in 2 counting sites (Figure 9).

4. Conclusions and recommendations for future counts

• Carry out a more detailed review of the counting methodologies (transect and fixed point).
• Carry out two counts, one in the nesting season and one outside the nesting season (one in March and another in September?).
• Extend the number of counting days and counting periods, to have a better appreciation of the dynamics of the population.
• Prior to the September count, identify roost sites; and as for the March count, locate the nesting sites.

Special thanks to everyone who participated in this important project, including Horizon Conservation, Ara Manzanillo, Caño Palma Biological Station, Centro Cientifico Tropical, ECOVIDA, Las Arrieras Nature Reserve, Las Brisas Reserve, OET, SINAC, and Works for Nature.

5. Bibliography

1. BirdLife International. 2020. Ara ambiguus. The IUCN Red List of Threatened Species 2020: e.T22685553A172908289.https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T22685553A17290828. 2024. Accessed on 01 January 2024.

2. Monge, G., Chassot, O., Ramírez, O., Alemán, I., Figueroa, A., Brenes, D. (2012). Season 2009 nesting of Ara ambiguus and Ara macao in Southeastern Nicaragua and Northern Costa Rica. Zeledonia: 16:1 June.

3. Powell, G., Wright, P., Guindon, C., Aleman, U., Palminteri, S. and Bjork, R. (1999). Results and Recommendations for the conservation of the Green Macaw (Ara ambiguus) in Costa Rica.