REVIEWS AND RECORDS

Dyer, Michael. 1983. Effect of nest helpers on growth of Redthroated Bee-eaters. Ostrich 54:43-46. The effect of nest helpers on the growth of Redthroated beaters was studied at Samaru, northern Nigeria. Nestlings in broods raised by pairs with helpers grew heavier and faster than in those raised by unassisted pairs. The most significant improvements in growth were found in late-hatched nestlings of larger broods. Possible benefits of heavier and faster growth are considered in terms of prefledging development and postfledging survival.     

8. CURIOUS POINTS IN THE BEHAVIOUR OF SOME MEMBERS OF THE RALLIDAE

Avian mortality on power lines in South Africa is currently recorded on the Central Incident Register (CIR), which is a collation of incidentally reported cases. The true scale of the problem is unknown, so we report here on a survey of representative power lines in the Overberg region of the Western Cape. On the 199 km surveyed, 123 birds of at least 18 species were found. Collisions were more common than electrocutions, apparently killing 88% of the birds found on distribution lines. Large terrestrial birds were the most numerous victims, with large numbers of Blue Cranes Anthropoides paradiseus and Denham's Bustards Neotis denhami killed. In comparison with mortality rates from the CIR, we estimate that only 2.6% of power-line mortalities are reported, emphasising the importance of systematic surveys in quantifying mortality and directing mitigation. Our survey highlights the general hazard that power lines pose to avifauna, and the urgent need for further research into the population impacts of the high incidence of collisions.