Article Abstract:
The diurnal and nocturnal visual function in two tactile foraging waterbird species was compared. The two birds in the study were the daytime feeder American white ibis and nighttime forager black skimmer. Results indicate that the retina of the black skimmer is suited for night vision while that of the ibis is useful for daytime vision. The ERG responses showed that the retinal sensitivity of the skimmer to low light intensity under scotopic conditions is typically greater than that of the ibis. This finding has a correlation with differences in the photoreceptor ratios and densities.
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Article Abstract:
The territorial behavior of four insectivorous passerines living in a tropical mangrove was studied. The Bicolored Conebills, Yellow-throated Spinetails and Streak-headed Woodcreepers settle in territories immediately after breeding, holding long-term territories for the rest of the year. Their territoriality during the non-breeding season ensures a breeding site for the following year. Birds in temperate climate use their territoriality to ensure survival during food shortage. The Pied Water-tyrants have territories only before the start of the breeding season.
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Article Abstract:
A study of 137 bird species from 29 families and subfamilies living in humid forest and mangrove sites proves that the diet evaluation of nectarivores tropical birds by the regurgitation process using tartar emetic is more effective in comparison to fecal analysis. It helps in determining the flower groups visited by nectarivorous birds and the amount of arthropod intake. The dosage of emetic varies according to the species to reduce mortality rates. Trochilidae are sensitive to the chemical.
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