126 Wildfowl

Comments on Waterfowl Habitat and Management Problems in Argentina

MILTON W. WELLER1

Interest in foreign waterfowl is at an all- Based on my own observations, a clas­ time high because of (1) our concern for sification of Argentine avifauna by Dab­ rare species, (2) our desire to learn of the bene (1910), plus waterfowl distributional biology of species in other lands which data by Casares (1933, 1934, 1945), I have may aid in our understanding our own tentatively classified Argentine wetlands species and conservation problems, and according to their gross topographic and (3) the desire to share management and vegetative features as well as their water­ conservation skills with other nations. fowl use (Figure 1). I profited greatly During my studies of the Black-headed from discussions and field trips with duck Duck Heteronetta atricapilla in Argen­ hunters and naturalists, outstanding tina in 1964-65 (Weller 1968b), I had an among whom are Peter Miles, Maurice opportunity to visit a number of water­ Rumboll, Phillip Runnacles, and profes­ fowl habitats in that country in search of sional ornithologists Dr. C. Olrog and the Black-headed Ducks and other species. late William Partridge. The work was funded by N.S.F. Grant The major populations of nesting GB-107. The behavioural and ecological waterfowl probably occur in the belt of observations have been summarized else­ fresh tule Scirpus califomicus marshes where (Weller 1967a, 1967b, 1968a) but (Figure 1, Zone A). Because this area also there are certain general observations of a has the highest human population and is non-quantitative nature that may aid other the major agricultural zone, it is a zone biologists in assessing and improving our of actual and potential competition be­ knowledge of the ecological, biological tween livestock or farming activities and and sociological problems of waterfowl wildlife resources. Plant communities and conservation in Argentina. avian associates in these lakes and marshes are similar to those in our western desert Wetland types and waterfowl marshes but also share some similarities The unique and diverse waterfowl species with southern marshes. Coots, gulls, complex of Argentina cannot be under­ egrets and ibises are common in addition stood without reference to the habitat to the complex of anatids: Black-necked which has produced and supports this Swans Cygnus melanocoryphus, Cosco­ group. Approximately one-third the size roba Swans C. coscoroba, Rosybills Netta of the United States, Argentina has at pepo saca, Fulvous Whistling Ducks D en- least 35 species of breeding waterfowl. drocygna autumnalis, Argentine Red Many are unique taxonomically and un­ Shovelers Anas platalea, Yellow-billed or doubtedly are the product of centuries of Speckled Teal A. flavirostris, Cinnamon isolation from northern forms. Others are Teal A. cyanoptera and Versicolor or Sil­ taxonomic and ecological equivalents of ver Teal A. versicolor. The south-west- northern hemisphere species. Only a few ward extension of Zone A represents species are identical. slightly rolling country with the large, Habitat diversity is great and ranges highly saline Guamini Lakes, which pos­ from the sub-antarctic marine and desert sibly should be regarded as a separate conditions of southern Patagonia to ex- zone. This area is utilized some by the tentive subtropical forest or desert in huge flocks of wintering sheldgeese of north-central Argentina, and even to true three species: Upland Goose Chloëphaga tropics in the Province of Missiones in picta, Ashy-headed Goose C. polioce- north-eastern Argentina. From east to phala and Ruddy-headed Goose C. rubi­ west, the level pampas change to desert diceps (Plotnik 1961). Yellow-billed Pin­ in the rain shadow of the Andes, the lat­ tails or South Georgian Teal Anas geor­ ter rising abruptly to a maximum of gica, Cinnamon Teal, Argentine Red 23,000 feet altitude— the highest peaks in Shovelers, Chiloe Wigeon Anas sibilatrix, the western hemisphere. In its northern and Yellow-billed Teal also use this area portion, this mountain range has an ex­ in winter but little is known about the tensive plateau, the ‘ puna’ zone, which summer nesting period. has a unique avifauna of its own. The open - country, warm desert marshes (Zone B) have some of the vege­ 1 Journal Paper No. J-6248 of the Iowa Agriculture and Home Economics Experi­ tation of temperate marshes (Zone A) and ment Station, Ames, Iowa. Project No. 1504. some of more sub-tropical areas. Some Waterfowl in Argentina 127 tropical ducks like Ringed Teal Anas leu- plex but differ in the more tropical wood­ cophrys and Comb Duck Sarkidiomis ed vegetation in the Chaco. Both areas melanotos frequent the area but there are have Ringed Teal, Brazilian Ducks Ama­ also large populations of what appear to zone tta brasiliensis and Masked Ducks be wintering Rosybills and Yellow-billed Oxyura dominica but Comb Ducks, Mus- Pintails and other species of the southern covys Cairina moschata and White-faced temperate marshes. Whistling Ducks Dendrocygna viduata The river marshes along the Parana apparently nest only in the northern sub­ (the north-south portion of Zone C in tropical areas of the wooded Chaco. Figure 1) and the Chaco swamps and I have had limited personal experience marshes (east-west portion o f Zone C) with the remaining zones. The small but are considered as one zone. They seem to unique tropical forest area in the Province have much of the same waterfowl com­ of Missiones (Zone D ) is part of the

SINUSOIDAL PROJECTION

Figure 1. Classification of some Argentine wetlands in reference to waterfowl use and plant life-form. Dots show areas where I did some field work during 1964-65. 128 Wildfowl

Brazilian plateau and has some slow to hunting will increase in popularity as has moderately swift streams which are hunting of the quail-like tinamous. separated by waterfalls from the lower Because of the lack of pressure for slow-moving streams which harbour the shooting sites, hunting methods are predacious fish, the dorado Salminus simple. Pass-shooting is common but maxillosus. It is in these dorado-free marsh hunting without decoys produces streams that the rare Brazilian Merganser excellent bags. Roadside shooting of sit- Mergus octosetaceus breeds (Partridge ting-ducks is still more common than it 1956). It is one of only two mergansers should be. recorded from the southern hemisphere, There are 22 provinces, and each the other being extinct. apparently is able to set seasons on all The Andes (Zone E) probably should game species without Federal influence. be subdivided into streams and lakes, and Some provinces consider ducks more of differences probably exist in northern a nuisance than game but others have versus southern areas. This area contains specific shooting seasons and bag limits. the torrential streams which are the home During 1964-65, the Province of Buenos of the unique and little-studied Torrent Aires had a three month season from 1st Duck Merganetta armata. The more May until 31st July with bag limits of 20 southerly, larger and slower moving ducks per day. This limit probably is streams are used by the beautiful Bronze­ reasonable with present hunter activity winged Duck Anas specularis, both sexes but the timing of the season may need of which have a bold white crescent in evaluation. Regulations on tinamous seem front of the eye. The alpine sedge marshes to have a strong influence on duck hunt­ of the northern part of this zone harbour ing: seasons in the Province of Buenos Andean Geese Chloëphaga melanoptera Aires were set concurrently when the as well as Andean Crested Ducks timing of the reproductive periods dif­ Lophonetta specularioides, Puna Teal fered. Anas puna (possibly a sub-species of the Species composition of the kill was Silver Teal), Cinnamon Teal, and the assessed by bag checks in northeastern ubiquitous Yellow-billed Pintail. In the Buenos Aires Province, southern Santa deeper southern lakes, Flying Steamer Fe Province and in the seasonally flooded Ducks Tachy eres patachonicus also occur. marsh areas of north-central Province of The marine zone (Zone F in Figure 1) Santiago del Estero (Table I). Rosybills of lower Patagonia, Tierra del Fuego and and Yellow-billed Pintails were preferred the Falkland Islands has a harsh climate species everywhere and Yellow-billed Pin­ in which several unusual species have tails were the number one species ob­ evolved. These forms are unique among served and shot in all areas checked. the waterfowl of the world in their restriction to the marine environment Table I. Anatids examined in hunters’ and include the Kelp Goose Chloëphaga bags, 4th March — 23rd July 1965 in hybrida, and the huge, boat-like Flight­ eastern Buenos Aires and south-eastern less Steamer Ducks Tacky eres pteneres. Santa Fe Provinces (Zone A). Other nesting ducks include migratory No. % species like Chiloe Wigeon, Silver Teal and Yellow-billed Pintails and other dab­ Yellow-billed (Brown) Pintail 122 46 bling ducks. Yellow-billed Teal 27 10 Red Shoveler 23 8 There are additional lakes and reser­ Rosybill 16 6 voirs along the foothills of the Andes Black-headed Duck 16 6 (Zone G) which with the slow moving Chiloe Wigeon 13 5 streams are utilized by sheldgeese, Versicolor Teal 12 4 Crested Ducks, Chiloe Wigeon, Yellow­ Cinnamon Teal 12 4 billed Pintails and a larger, taxonomically Bahama Pintail 12 4 confusing Ruddy Duck Oxyura sp. Coscoroba Swan 6 2 Fulvous Whistling Duck 2 2 Argentine Ruddy Duck 2 2 Hunter harvest By northern hemisphere standards, water­ 263 fowl hunting is not popular but is favour­ ed mainly by the Anglo-Argentines and Some management problems American businessmen. However, accord­ ing to residents, interest is gaining as the Depredations standard of living increases, and there is Crop damage is characteristic of all areas evidence of increasing interest in all out­ of the world where ducks, water and door activities. Undoubtedly, waterfowl crops come together. The rice-growing Waterfowl in Argentina 12 9 areas of the Paraná River Basin are no periods. Some of these key production exception and ducks are on the outlawed areas need to be set aside now for preser­ list. Wintering ducks from Zone A appear vation of nesting-habitat. These can be to be the chief nuisance but probably fenced to allow cattle access to water some ducks reared in the flooded rice without destroying all cover adjacent to fields also are involved. Yellow-billed the marsh, and hunting may not be detri­ Pintails, Rosybills and Fulvous Whistling mental if limited to the non-breeding Ducks were most mentioned. Hunters season. are hired to shoot ducks in the fields and One of the most successful dabbling one rice grower reported that aerial appli­ ducks in the tule marsh zone (A) is the cations of pesticides have been used on Yellow-billed or ‘ tree ’ Teal, a close blackbirds and ducks. This same grower relative of the American Green-winged suggested that poor farming practices Teal Anas crecca carolinensis. Its success were responsible for the puddles which probably is due to the fact that it has attracted ducks. Apparently, no other adapted to using old nests of Monk Para­ diversionary tactics have been tried and keets Myopsitta monarcha which are 30- ducks remain generally unpopular in rice 60 feet up in eucalyptus trees planted areas. near most estancias. These Teal are Competition for grazing areas by cattle known to nest on the ground but it is and sheldgeese is a major conflict in rare in Zone A. Although tree nest sites southern Buenos Aires Province. Crop­ would seem safe and permanent, there is land is not common in the area but some presently a major campaign to eliminate damage to forage crops is reported. the parakeets because of crop damage and Methods of control are mainly scaring because of their possible role as vectors with aircraft, a system in use for 20 years of psittacosis. The loss o f these nest sites or more and considered satisfactory be­ would place these Teal back in competi­ cause of the great fear these birds have tion with cattle— a condition which at for aircraft. Apparently, sheldgeese can present would provide few ground nest- be driven many miles and some pilots ing-sites. However, I feel sure that arti­ even try to drive them out to sea in an ficial nesting boxes would be used if par­ effort to drown them. All sorts of control rot nests are ever eliminated; we need to measures have been suggested, including learn this now to plan for the future. shooting females on the breeding areas, but the farmers’ co-operatives seem con­ tent to pay pilots to drive them to some Lack of biological data less important field. Comparatively speaking, little is known about the nesting habits, productivity or Habitat Loss movements of even the most common Although waterfowl presently are an ducks. The banding programme of Dr. C. abundant and little-used resource, habi­ Olrog (1962) of the Lillio Institute is a tat destruction of various types is moving promising endeavour but this and similar at such a rate that the resource is being efforts must be initiated with stronger endangered before public sentiment financial backing. reaches a level of concern and action. There is considerable variability in This already has happened with larger timing of nesting periods because of the land mammals. Much loss of habitat lack of importance of seasonal changes already has occurred. Huge agricultural and the great importance of water avail­ drainage ditches remove excessive rain ability (Weller 1968a). This produces water from the rich tule marshes of serious problems in the timing of the eastern Buenos Aires Province. This harvest seasons. Although harvesting of a apparently has reduced both the size and few breeding birds may not be serious at permanence of some wetlands. Some of this time, there is a need for better data. the canals have control structures which Moreover, in the northern regions, water allow tidal action to influence marsh availability induces both breeding by levels to a degree where flooding of nests ducks and hunting. Because of annual is possible. Apparently these marshes variation in any given area, some index remain essentially fresh water, however. to breeding of subtropical birds is badly Grazing is sufficiently severe in many needed so that seasons may be set quickly areas adjacent to marshes that production and effectively. Harvest seasons, where o f dabblers must be seriously affected. they occur, now are set by provinces but Fencing o f marsh areas is rare and some I do not know the basis for the timing. destruction of emergent vegetation occurs Whether Federal regulations would pro­ because of cattle trampling during dry vide a more sound basis for setting sea­ 130 Wildfowl sons according to biological zones needs independent organization could encou­ to be considered. rage management-oriented research by local as well as foreign workers. In addi­ tion, this organization could stimulate A needed stimulous and co-ordinate programmes of the pro­ There is serious need now for an active vincial federal governments, and develop national— not necessarily governmental— licensing and enforcement systems which research and management organization. eventually could finance a research, man­ Some of the better work being done is by agement and conservation scheme. Such the national agricultural organization, the a group might also co-ordinate the activi­ National Institute of Agricultural Tech­ ties of ornithological workers as well, be­ nology (I.N .T.A.) but this seems to vary cause there appears to be some unneces­ with interested staff. Several amateur sary friction between the ‘ birdwatchers ’ ornithologists have contributed greatly and hunters. toward a knowledge of distribution, nest One other problem this organization sites and general habits of waterfowl but could tackle is the issue of international much still is to be done. I learned of no management agreements. At present, provincial governments which are spon­ there is little interest in problems of soring management - orientated research wildlife movements across national bor­ projects on waterfowl. ders in South America. Waterfowl move­ Because of sensitivity by provincial ments do occur between Uruguay, Brazil governments about Federal control of and Argentina (Olrog 1962) and presum­ activities, it is possible that a private ably between Chile and Argentina. organization financed by contributions Although it does not seem a major prob­ from interested businesses and sportmen lem, the development of co-operative would be best. Financing by any national programmes of these nations will lead to license seems unlikely, and provincial further study and improved attitudes licenses have not been well enforced. An towards all migratory species.

Summary Waterfowl habitat in Argentina is reviewed, and the main waterfowl species listed. Manage­ ment problems such as hunters, habitat loss and the lack of good data are discussed. An independent organisation is needed to stimulate and coordinate research, management and conservation.

References

c a s a r e s , J. 1933. Palmipedos Argentinos. El Homero 5 : 146-59. c a s a r e s , J. 1934. Palmipedos Argentinos. El Homero 5 : 289-306. c a s a r e s , j. 1945. Palmipedos Argentinos. El Homero 6 : 1-21. d a b b e n e , r . 1910. Ornitologia Argentina. An. Mus. Nac. Buenos Aires 18 : 1-513. o l r o g , C. C. 1962. El anillado de aves en La Argentina, 1961-1962, Part II. Neotropica (Supplement) 8 : 1-8. partridge, w. H. 1956. Notes o n the Brazilian merganser in Argentina. Auk 73 : 473-88. PLOTNIK, r . 1961. Migración de las avutardas. India (Instit. Nac. de Tecologia y Agropecaria, Argentina) No. 167 : 18-28. w eller, M. w. 1967a. Notes on some marsh birds o f Cape San Antonio, Argentina. Ibis 109 : 391-411. w e l l e r , m . w . 1967b. Distribution and habitat selection of the Black-headed Duck (Hetero- netta atricapilla). El Hornero 10 : 299-306. w e l l e r , m . w. 1968a. Notes on some Argentine anatids. Wilson Bull. 80 : 189-212. w e l l e r , m . w . 1968b. The breeding biology of the parasitic black-headed duck (Heteronetta atricapilla). The Living Bird 7 : 169-207.

Professor Milton W. Weller, Department of Zoology & Entomology, Iowa State University, Ames, Iowa 50010, U.S.A.