Birds of Rice Fields in the Americas

Bernabe Lopez-Lanus

2010

Abstract
AI

This research focuses on the distribution of avian species found in rice fields across the Americas, highlighting the significance of this habitat for various bird species. It identifies the predominant countries involved in rice production and explores the diversity of bird species utilizing these areas, emphasizing the ecological importance of ricelands as critical habitats for both resident and migratory birds.

Figures (16)

Figure 1. (A) Area and (B) percentage of total land sur- face planted in rice by country in the Americas (FAOSTAT 2006). Br = Brazil, USA = United States of America, Co = Colombia, Pe = Peru, Ec = Ecuador, Ve = Venezuela, Cu = Cuba, Ur = Uruguay, Ar = Argentina, Pa = Panama, Bo = Bolivia, Gu = Guyana, Do = Dominican Republic, Ni = Nicaragua, CR = Costa Rica, Ha = Haiti, Su = Suriname, Me = Mexico, Pr = Paraguay, Ch = Chile, TT = Trinidad and Tobago.

Table 1. Dates, sampling effort and data sources for information included in the current compilation. N/A = infor mation not available species detected in rice fields in the ten countries (Fig. 2). The family Anatidae con- tained the greatest number of species report- ed, followed by Scolopacidae, Rallidae, Ar- deidae, Laridae and Threskiornithidae. Six species were present in rice fields in all ten countries: Western Cattle Egret (Bubulcus ibis), Western Great Egret (Ardea alba), Snowy Egret (Egretta thula), Black-crowned Night Heron (Nycticorax nycticorax), Lesser Yellowlegs (Tringa flavipes) and Greater Yel- lowlegs (Tringa melanoleuca) (Table 3). Plega- dis ibises were common in the USA (both species) and in Argentina, Cuba, Uruguay and Brazil (one species recorded in each country). Similarly, relative abundance was high for whistling ducks (Dendrocygna spp.) in several countries, with two (Cuba, Costa Rica and Brazil) or three species (Argentina and Trinidad) present in most countries. Ducks from the genus Anas (Anatidae) were common in several countries, with Blue- winged Teal (Anas discors) reported most widely. Shorebirds, particularly species from the genus Calidris, made considerable use of most ricelands. Costa Rica, Argentina, Uru- guay, Trinidad, Suriname and Cuba report- ed two to eight species from this genus. zuela and Suriname reported the lowest numbers of waterbird species (Table 2). Richness of waterbird species by country ranged from 35 to 90 species, and rice fields were used predominantly for foraging and resting (Hurtado 2003; Dias and Burger 2005; Acosta and Mugica 2006; Blanco et al. 2006; Taft and Elphick 2007). About 96% of the waterbirds that used rice paddies belong to four orders. Species from the order Charadriiformes (shorebirds, gulls, terns) were the most common in all countries ex- cept Venezuela and Colombia, where Pele- caniformes (herons, egrets, ibises) was the best represented order. Countries with more influence from North American flyways tended to have a higher percentage of the highly migratory Charadriiformes (Suri- name, Trinidad and Tobago, Costa Rica and Cuba). Twelve species of Gruiformes (rails, crakes, cranes) were recorded in Argentina and Uruguay, but the order was poorly repre- sented in other countries; this difference, however, may relate to differences in the ef- fort invested in detecting secretive species rather than biogeography. Species from five of the 21 families re- species were present in rice fields in all ten

Figure 2. Number of species of the main families that have been reported in rice fields in the Americas. “ Data from six countries were available to evaluate avian use of rice paddies during the growing season. Successive stages of rice pro- duction for each country were taken into ac- count and a general pattern of use of the rice habitats emerged (Fig. 4). Waterbird use was greatest during the first (sowing prepara- tion) and last (post-harvest flooding) stages of production. In Cuba, Suriname and Costa Rica, dynamics of bird use corresponded with similarities in the rice farming process. Use of fields during the sowing stage was higher in Brazil, Argentina and Uruguay (Blanco et al. 2006) than in those countries (Fig. 4).

Table 3. Relative abundance and proportion of countries in which the species occurs in rice fields (p) for waterbirds registered in the ricelands of ten American countries. The species present in all countries are in bold. X = present, but relative frequency not determined, R = rare, C = common, B = abundant, A = accidental.

Table 3. (Continued) Relative abundance and proportion of countries in which the species occurs in rice fields (p) for waterbirds registered in the ricelands of ten American countries. The species present in all countries are in bold. X = present, but relative frequency not determined, R = rare, C = common, B = abundant, A = accidental. ray

Table 3. (Continued) Relative abundance and proportion of countries in which the species occurs in rice fields (p) for waterbirds registered in the ricelands of ten American countries. The species present in all countries are in bold. X = present, but relative frequency not determined, R = rare, C = common, B = abundant, A = accidental.

Table 3. (Continued) Relative abundance and proportion of countries in which the species occurs in rice fields (p) for waterbirds registered in the ricelands of ten American countries. The species present in all countries are in bold. X = present, but relative frequency not determined, R = rare, C = common, B = abundant, A = accidental.

Table 3. (Continued) Relative abundance and proportion of countries in which the species occurs in rice fields (p) for waterbirds registered in the ricelands of ten American countries. The species present in all countries are in bold. X = present, but relative frequency not determined, R = rare, C = common, B = abundant, A = accidental.

Figure 4. Waterbird use of successive stages of rice cul- tivation in six American countries. Data from Argentina, Brazil and Uruguay only considered shorebirds. and our results indicate that rice fields pro- vide important habitats for both waterbirds and terrestrial birds. The significance of rice culture for waterbirds is well known world- wide (Czech and Parsons 2002; Elphick and Oring 2003; Taft and Elphick 2007), but the use of paddies by landbirds may have been underestimated, inasmuch as not all coun-

Figure 3. Proportion of the ten countries studied where each species has been reported to occur in rice fields. Species not named, but ranked on x axis from most to least ubiquitous.

Figure 5. Genera in which all recorded species were allo- patric, showing number of species and number of coun- tries where the genus was reported to occur in rice fields.

tries reported them (Appendix). The impor- tance to landbirds might be even greater than the current analysis suggests, because detailed surveys of these species have not been made in most countries, only in parts of

Table 4. Mean, standard deviation (SD) and coefficient of variation (CV) for the relative abundance of those species that were present in rice paddies in all ten American countries studied. Statistics are based only on those countries for which quantitative information is presented in Table 3 (n = 7).