**2. Methods**

#### **2.1 Databases**

I collected records of greater rheas with geographic references for all five countries that encompass their historical distribution: Brazil, Bolivia, Paraguay, Uruguay and Argentina. I used the three Citizen Science databases to obtain the data: WikiAves.com, EBird.org and INaturalist.org, chosen by the amount of available data and ease to extract it. Since my aim is to depict the species current distribution,

**115**

Rhea americana *Distribution: Range Expansion and Introductions of America's Largest Bird*

I used recent records from 2003 to 2021. The greater rhea is easy to visualize and photograph, thus common in those databases. Consequently, I rarefied the data to one record per county per database (i.e. maximum of three records per county). I scrutinized the data for duplicated records, removing these. I inspected records on the southwestern limit of the species occurrence with attention for lesser rheas (*Rhea pennata*), which were removed. I did the same procedure for captive individuals labeled as wild. Individuals living in fenced or partially fenced areas such as large urban parks, if not dependent of supplementary feeding, were included in de database as wild. All records and their geographic coordinates can be found in

**2.2 Criteria for defining populations as native, introduced, or range expansion**

I defined all population living within the diagonal of dry areas in South America (Caatinga, Cerrado, Chaco and Pampas domains [4, 6]) as native even if resulting from accidental or purposeful reintroductions if and only if within native range [33–35]. I made exceptions for individuals living in restingas (coastal savannahs over sand dunes) were the species did not occur historically. These populations on restingas were labeled as introduced. I used the same criteria for other populations outside of the dry area's diagonal, unless the population could result from natural emigration. Populations resulting from emigration towards forest domains—arising from forest degradation—were labeled as range expansion. Populations within ecotone areas were labeled as native, since several open-field species occur within grassland enclaves in a matrix of forest (e.g. marsh deer *Blastocerus dichotomus*,

I collected vegetation cover maps for depicting canopy closeness from MOD44B. v006, representing areas currently covered by tall wood vegetation, not appropriated for rheas. The MOD44B.v006 image layer in the MODIS Vegetation Continuous Fields product provides a continuous, quantitative representation of global tree cover (greater rhea non-habitat) at a 250 m spatial resolution [39]. I used vegetation ecoregions from WWF categorization [40], chosen because it defines ecoregions as relatively large landscapes, each containing a distinct assemblages of species, with boundaries similar to the original extent of natural communities—prior to modern

I collected a total of 777 occurrences. The largest number of records came from WikiAves (496), followed by EBird (205) and then INaturalist (76). Most data are fairly recent, with the average year being 2017 and the modal year being 2019. Nine records refer to introduced populations, 68 to range expansion, and 700 to native populations. The current distribution of the greater rhea throughout the Neotropics is shown in **Figure 1**. Our map suggests that the diagonal of dry areas in South America is still a stronghold for the species. The northern Cerrado scrubland to wooded savanna macromosaic, mainly located in central Brazil, has an extensive patch of greater rhea populations. Important habitat extensions remain in Pampas (Argentina, Uruguay and Brazil), Beni savannas (Bolivia), and Caatinga arid lands

Mendeley Data https://data.mendeley.com/datasets/fvwcwhwt9v/1.

pampas deer, and greater rheas themselves [36–38]).

**2.3 Mapping and vegetation cover**

land-use change.

in northeastern Brazil.

**3. Results**

*DOI: http://dx.doi.org/10.5772/intechopen.97761*

Rhea americana *Distribution: Range Expansion and Introductions of America's Largest Bird DOI: http://dx.doi.org/10.5772/intechopen.97761*

I used recent records from 2003 to 2021. The greater rhea is easy to visualize and photograph, thus common in those databases. Consequently, I rarefied the data to one record per county per database (i.e. maximum of three records per county). I scrutinized the data for duplicated records, removing these. I inspected records on the southwestern limit of the species occurrence with attention for lesser rheas (*Rhea pennata*), which were removed. I did the same procedure for captive individuals labeled as wild. Individuals living in fenced or partially fenced areas such as large urban parks, if not dependent of supplementary feeding, were included in de database as wild. All records and their geographic coordinates can be found in Mendeley Data https://data.mendeley.com/datasets/fvwcwhwt9v/1.
