Natural History of BirdsA Guide to Ornithology. By Leonard W. Wing. Pp. xi + 539. (New York: The Ronald Press Company, 1956.) 6.75 dollars.Recent Studies in Avian BiologyEdited by Albert Wolfson. Pp. ix + 479. (Urbana, Ill.: University of Illinois Press, 1955.) 7.50 dollars.

The biology of birds

This study investigated the nest predator community and factors contributing to avian nest predation in the Amurum Forest Reserve and some surrounding farmlands, north-central Nigeria, May 2015. A total of 240 artificial nests were randomly and equally placed; elevated in shrubs and on ground vegetation within different habitats. Of this total, 160 nests were visited every third day (visited nests) while 80 nests were only visited on the last day of the experiment to determine their fate (unvisited nests). We tested the effect of vegetation parameters on the Daily Survival Rate (DSR) of visited nests as well as the influence of visitation on the predation probability of the two groups of nests. Overall, 69% of the artificial nests were predated and the potential predators captured on camera traps were the African Giant Pouched Rat Cricetomys gambianus, Tantalus Monkey Chlorocebus tantalus and Black Rat Rattus rattus. DSR was significantly influenced by nest position only in the rocky outcrop and savannah, although it seemed higher for the elevated nests in all the habitats. We found no significant effect of the vegetation parameters on DSR. The significantly lower predation probability recorded for visited compared to unvisited nests suggests that nest predators in the study area tend to avoid areas that are frequently visited by humans, an indication of anthropogenic impacts and anti-predation strategy. The findings of this study can enhance our understanding of potential nest predators in the study area as well as how nesting behaviour of bird species can influence predation risk.
Key words: Daily Survival Rate, nest predation, model egg, camera trap, predation probability

Patterns in Avian nest predation in North-Central Nigeria: An experimental study

Detailed investigation of the foraging site utilised by avian species may reveal the habitat factors important in their conservation. This study compared the foraging sites of the Sunlark, Galerida modesta and Familiar Chart, Cercomela familiaris (both African resident insectivorous birds) a week after fire engulfed about one third of the 300 ha of the Amurum Forest Reserve, Nigeria. Foraging sites were compared based on proxies of food availability (ant, grasshopper and other insect abundance) and vegetation structure. Data on food availability and vegetation structures were obtained by quadrate sampling while foraging spots were determined from four stratified transects each surveyed four times during the study. Food availability was not a significant predictor of foraging site characteristics between the two bird species. However of the nine vegetation variables measured, grass height and proportion of burned grass cover per foraging site significantly distinguished the foraging sites of the two bird species; Sunlark foraged more at sites with shorter grasses and high proportion of burned grass cover as compared to the Familiar Chat. The characteristics of the foraging sites observed might have implications on the foraging success of the birds in line with literature on the Influences of vegetation structure on avian foraging behaviour. Key words: Foraging site, Insectivorous birds, Burn, Vegetation structure, Food availability

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AA Chaskda

Papers

A Comparison of Foraging Site Characteristics of Two African Resident Insectivorous Birds in a Burned Habitat