Irma Franke
Quantitative Working with Birds of the Andean highlands.
quantitative work Peruvian birds is generally quite limited and relatively recent. At the outset these works were focused mainly on aquatic environments known for its rich birdlife and Lake Junin and Lake Parinacochas (Morrison 1939, Harris 1980, Koepcke and Koepcke 1956), a few economically important species such as sea birds ( Jordan 1963) and endangered species of special concern such as Guan (Ortiz and Diaz 1997). The quantitative assessments of bird populations is of utmost importance, because only if we have reliable baseline information, future monitoring will be informative about the changes that occur in populations.
In the initial work efforts were focused on single species or a small group of species inhabiting a single general type of environment, water or land. In order to obtain satisfactory results, was selected the method considered most appropriate among the various methods that have been developed (Bibby et al 2000). This method was used consistently throughout the study.
With the fairly recent development of quantitative assessments on large areas, such as specially protected areas and areas where investment projects are developed, the issue of appropriate methods has become more complex. This is mainly due to the wide variety of habitats, natural and man, present in these large areas. The Andean highlands is perhaps the best example of a seemingly rather complex environment, but nevertheless presents a significant number of difficulties in planning a quantitative study of the avifauna.
In the initial work efforts were focused on single species or a small group of species inhabiting a single general type of environment, water or land. In order to obtain satisfactory results, was selected the method considered most appropriate among the various methods that have been developed (Bibby et al 2000). This method was used consistently throughout the study.
With the fairly recent development of quantitative assessments on large areas, such as specially protected areas and areas where investment projects are developed, the issue of appropriate methods has become more complex. This is mainly due to the wide variety of habitats, natural and man, present in these large areas. The Andean highlands is perhaps the best example of a seemingly rather complex environment, but nevertheless presents a significant number of difficulties in planning a quantitative study of the avifauna.
is to use more than one method for evaluating the birds of a large area? All
average area of \u200b\u200bthe high Andes above 3000 m has a set of characteristic habitats. Among terrestrial habitats, the puna grassland is usually the most extensive and generally dominates the landscape. However, they may be in addition shrubland, forest patches of Polylepis, SIT, rock, crops, stands, etc., of different sizes. Among aquatic habitats dominated by small lakes, wetlands very different extents and which often form a mosaic with the puna grasslands, springs, streams and rivers and wetlands resulting from human activity such as water reservoirs.
Since the predominant habitat is the highland grassland, the method used (transects, counting points, etc..) is usually selected to obtain the best results in this environment. The method chosen is usually also appropriate for other terrestrial habitats quite extensive. However presents a problem when there are different habitats so small extension that allows you to use the selected method. These small areas of different habitats such as shrubland in small streams and stands of barbs, may be attractive to some species and be a gathering place for them especially during the dry season. Hence the importance to include in the assessment to be made.
In these small areas, however, would be appropriate to use other methods. Even if they are not quantitative, are important. The results of an inventory of species are attractive to clarify whether species avoided open habitats surrounding. When considering total species abundance, it is possible to obtain ratios that tell the most abundant species.
would be appropriate to use the same method for the avifauna of aquatic and terrestrial environments?
In studies in terrestrial environments has tended to use methods to find the relative density of bird species, such as methods of transect and point count. In studies in environments Water the trend has been to make or direct total counts to find the density. Use different methods for both types of birds is appropriate, given the differences in social characteristics between the terrestrial and aquatic birds.
Waterfowl are generally markedly more social than terrestrial birds, forming flocks of varying size. According to the habits of the Andean species described by Fjeldsa and Krabbe (1990), 66% of aquatic species tends to form aggregates, while only 19% of the land birds have this habit. Because of this feature, waterfowl tend to cluster in the sector or that they preferred offers best resources of the water body. In this area are often found gathered nearly all individuals of the species present. With the exception of the situation in the few large lakes, flocks usually consist of fewer than 300 individuals. These small and medium flocks are best surveyed by total counts or direct (Zamora-Orozco et al. 2007).
average area of \u200b\u200bthe high Andes above 3000 m has a set of characteristic habitats. Among terrestrial habitats, the puna grassland is usually the most extensive and generally dominates the landscape. However, they may be in addition shrubland, forest patches of Polylepis, SIT, rock, crops, stands, etc., of different sizes. Among aquatic habitats dominated by small lakes, wetlands very different extents and which often form a mosaic with the puna grasslands, springs, streams and rivers and wetlands resulting from human activity such as water reservoirs.
Since the predominant habitat is the highland grassland, the method used (transects, counting points, etc..) is usually selected to obtain the best results in this environment. The method chosen is usually also appropriate for other terrestrial habitats quite extensive. However presents a problem when there are different habitats so small extension that allows you to use the selected method. These small areas of different habitats such as shrubland in small streams and stands of barbs, may be attractive to some species and be a gathering place for them especially during the dry season. Hence the importance to include in the assessment to be made.
In these small areas, however, would be appropriate to use other methods. Even if they are not quantitative, are important. The results of an inventory of species are attractive to clarify whether species avoided open habitats surrounding. When considering total species abundance, it is possible to obtain ratios that tell the most abundant species.
would be appropriate to use the same method for the avifauna of aquatic and terrestrial environments?
In studies in terrestrial environments has tended to use methods to find the relative density of bird species, such as methods of transect and point count. In studies in environments Water the trend has been to make or direct total counts to find the density. Use different methods for both types of birds is appropriate, given the differences in social characteristics between the terrestrial and aquatic birds.
Waterfowl are generally markedly more social than terrestrial birds, forming flocks of varying size. According to the habits of the Andean species described by Fjeldsa and Krabbe (1990), 66% of aquatic species tends to form aggregates, while only 19% of the land birds have this habit. Because of this feature, waterfowl tend to cluster in the sector or that they preferred offers best resources of the water body. In this area are often found gathered nearly all individuals of the species present. With the exception of the situation in the few large lakes, flocks usually consist of fewer than 300 individuals. These small and medium flocks are best surveyed by total counts or direct (Zamora-Orozco et al. 2007).
Combine multiple census methods over large areas and complex.
discussed aspects support the view that the most appropriate approach for quantitative studies on large areas with a variety of terrestrial and aquatic habitats is to select a method for determining the density census on terrestrial bird, with complementary methods in the habitats of small size and performing direct counts or totals for waterfowl.
And perhaps of equal or greater importance that assessments are consistent in the methods selected for the different habitats. Subsequent monitoring would be comparable with another way?
References Bibby, CJ, Burgess, ND, Hill, DA, and Mustoe, SH 2000. Bird Census Techniques, 2nd ed. Academic Press, London.
Harris, M. 1980. Avifauna of Lake Junin (Junin), Peru. Publications of the Museum of Natural History, National University San Marcos (A) 27:1 - 14. Lima.
Jordan, R. 1963. Graphic census results of guano birds held in November 1960 and January 1962. Callao, 1963. 21 pp.
Koepcke, H. and M. Koepcke, M. 1956. Parinacochas lake basin, ideal for national park region. Bulletin of the National Committee for the protection of nature, vol. XV - 1956. Lima: Peru.
Morrison, A. 1939. Notes on the birds of Lake Junin, Central Peru. Ibis 3 (4): 643-652. E. Ortiz
& Díaz V. 1997. Field Study and Reassessment of the Population of White-winged Guan (Penelope albipennis). Pp 218-232 In: The Cracidae: Their Biology and Conservation (SD Strahl, S. Beaujon, DM Brooks, AJ Begazo, G. Sedaghatkish and F. Olmos). Hancock House Publ.
Zamora-Orozco, EM, Carmona, R. & Brabata, G. 2007. Distribution of waterfowl in the oxidation ponds in the city of La Paz, Baja California Sur, Mexico. Rev. Biol Trop. (Int. J. Trop. Biol ISSN-0034-7744) Vol 55 (2): 617-626,
discussed aspects support the view that the most appropriate approach for quantitative studies on large areas with a variety of terrestrial and aquatic habitats is to select a method for determining the density census on terrestrial bird, with complementary methods in the habitats of small size and performing direct counts or totals for waterfowl.
And perhaps of equal or greater importance that assessments are consistent in the methods selected for the different habitats. Subsequent monitoring would be comparable with another way?
References Bibby, CJ, Burgess, ND, Hill, DA, and Mustoe, SH 2000. Bird Census Techniques, 2nd ed. Academic Press, London.
Harris, M. 1980. Avifauna of Lake Junin (Junin), Peru. Publications of the Museum of Natural History, National University San Marcos (A) 27:1 - 14. Lima.
Jordan, R. 1963. Graphic census results of guano birds held in November 1960 and January 1962. Callao, 1963. 21 pp.
Koepcke, H. and M. Koepcke, M. 1956. Parinacochas lake basin, ideal for national park region. Bulletin of the National Committee for the protection of nature, vol. XV - 1956. Lima: Peru.
Morrison, A. 1939. Notes on the birds of Lake Junin, Central Peru. Ibis 3 (4): 643-652. E. Ortiz
& Díaz V. 1997. Field Study and Reassessment of the Population of White-winged Guan (Penelope albipennis). Pp 218-232 In: The Cracidae: Their Biology and Conservation (SD Strahl, S. Beaujon, DM Brooks, AJ Begazo, G. Sedaghatkish and F. Olmos). Hancock House Publ.
Zamora-Orozco, EM, Carmona, R. & Brabata, G. 2007. Distribution of waterfowl in the oxidation ponds in the city of La Paz, Baja California Sur, Mexico. Rev. Biol Trop. (Int. J. Trop. Biol ISSN-0034-7744) Vol 55 (2): 617-626,
