Vigilance towards raptors by nuclear species in bird mixed flocks in a Brazilian savannah

A nuclear or leader species is the one around which foraging activity is organized. In the campo-cerrado (Brazilian savannah) up to four bird species (Saltator atricollis, Cypsnagra hirundinacea, Mimus saturninus, and Neothraupis fasciata) may function as nuclear or leader species in mixed species flocks. The aim of this study was to assess the features shown by these nuclear species. I quantified parameters of sociality, communication and alertness of nuclear bird species in mixed flocks with different composition. Parameters related to sociality (mean intraspecific group size) and communication (frequency of contact calls) were not correlated with the leadership. on the other hand, the most alert species was in the front of a given mixed flock most of the time. The leader species spent more time in vigilance and gave most alarm calls due to approaching raptors earlier. The results of this study strongly suggest that the alertness of a species is the major character of nuclear bird species in mixed flocks of the campo-cerrado.

Raptors and campo-cerrado bird mixed flock led by Cypsnagra Hirundinacea (Emberizidae:Thraupinae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avian communities in woodlots in the Parque das Neblinas, Bertioga, São Paulo, Brazil

Parque das Neblinas (PN) is a 2,800 ha nature reserve contiguous with an Atlantic Forest fragment known as Parque Estadual da Serra do Mar located in the municipality of Bertioga, in the state of São Paulo, Brazil. The area originally contained Eucalyptus trees grown for paper pulp production. The aims of the study were the following: (1) to characterize the diversity of the bird community in PN; (2) to compare bird species observed in PN to species found in the Atlantic Forest; and (3) to list the percentages of species endemic to the Atlantic Forest and present in PN. Quantitative surveys used the point count method. The number of avian species recorded in PN totaled 222, of which 150 (66.4%) were associated with forest environments, 66 (29.3%) with open areas, and 10 (4.3%) with aquatic environments. The quantitative survey recorded 141 species and 2,527 contacts in 120 samples for an average of 21.05 contacts per sample. The general diversity index was H´=3.82. The study identified 15 bird species that actively participated in mixed flocks and 25 species endemic to Atlantic Forest, two of which present some kind of concern relating to conservation. Areas with Eucalyptus trees and a dense understory displayed the greatest bird species diversity, as opposed to areas with less developed or non-existent understories.

EXAMINATION BY ELISA OF SERA OBTAINED FROM CHICKEN BREEDER AND LAYER FLOCKS SHOWING EVIDENCE OF FOWL TYPHOID OR PULLORUM DISEASE

An indirect ELISA using soluble whole cell antigen was used to screen serum samples obtained from breeder and layer flocks some of which had shown clinical or bacteriological evidence of infection with Salmonella Gallinarum or S. Pullorum. There was good correlation between Salmonella infection and the presence of serum samples showing high optical density (OD) values. Sera from seven flocks showing high values were retested using group D (0-1, 9, 12) lipopolysaccharide (LPS) and g,m-H flagella as detecting antigens. Sera from six flocks produced high OD values with LPS and low values with flagella confirming infection with a non-flagellate, group D Salmonella while one produced high values with both antigens indicating mixed infection with another group D serotype.