Unravelling feeding territoriality in the Little Blue Heron, Egretta caerulea, in Cananéia, Brazil

Brazilian Journal of Biology

E Moralez-silva²  Fjl Silva²  Ela Monteiro-filho¹ 

[1] ,Universidade Federal do Rio Grande do NorteNatal RN ,Brazil

关键词: used area;    estuary;    defense;    foraging behaviour;    territory;    área de uso;    comportamento alimentar;    defesa;    estuário;    território;   

DOI  :  10.1590/S1519-69842010005000020

来源: SciELO

【 摘 要 】

Habitat use by the Little Blue Heron (Egretta caerulea) and discovery of feeding territoriality are discussed here. The results showed the existence of a territorial individual defending an area (2,564.46 ± 943.56 m²) close to the mangrove, and non-territorial individuals (9.17 ± 2.54) in the rest of a demarcated area (mean area for the non-territorial: 893.25 ± 676.72). A weak positive correlation (r = 0.47, df = 46, p < 0.05) was found between the overlapping of territorial and non-territorial individuals (2.85 ± 3.07 m²) and the mean overlapped area for territorial individuals (171.41 ± 131.40 m²). Higher capture (1.52 ± 1.14 × 1.00 ± 1.37 catches/minutes) and success rates (0.45 ± 0.31 × 0.21 ± 0.27) and lower energy expenditure rates (45.21 ± 14.96 × 51.22 ± 14.37 steps/minutes; and 3.65 ± 2.55 × 4.94 ± 3.28 stabs/minutes) were observed for individuals foraging in areas close to the mangrove. The results suggest that the observed territorial behaviour is more related to a number of food parameters than to intruder pressure, and also that the observed territoriality might be related to defense of areas with higher prey availability.

【 授权许可】

CC BY   
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