The diet of Cattle Egret chicks in the lower Soummam valley, Algeria, was investigated in 1998 and 2006, when 145 and 23 regurgitates were collected, respectively. In 1998, 1 698 individual prey items were identified. Insects formed the bulk of the diet of chicks: 94% in terms of frequency, 71% in terms of mass. Orthopterans were dominant, especially in terms of biomass (22% by frequency, 58% by mass), whilst Dipterans were well represented in numbers (59% by frequency). Vertebrates, despite their lesser frequency (3%), contributed 23% by mass of the diet. In 2006, 441 prey items were identified. The contribution of insects decreased to 79% by frequency and 15% by mass (mostly Orthopterans) but vertebrates made up a higher frequency: 20% of prey items and 85% by mass of the diet. The availability of prey items was not correlated to their occurrence in the diet, suggesting that the Cattle Egret is a selective predator, with adults selecting prey species for their chicks. A drought in the spring of 2006 increased the availability of fish and lizards to the Cattle Egrets.

The objective of this study was to evaluate the effect of food supply in garbage dumps on the reproductive fitness of Cattle Egret Bubulcus ibis and offspring losses. A total of 236 nests were monitored during two distinct periods of 2 years for each: 146 nests during a period without food supply in dumps (1998–1999) and 90 with food supply in dumps (2007–2008). The study was carried out in the colony of El-Kseur in the Lower Soummam Valley (northeast Algeria). For the entire study period, the mean of clutch size, average number of hatched chicks, productivity, and breeding success varied significantly between years (Kruskal–Wallis test: p < .05). Also, the average calculated losses for eggs, chicks, and total offspring vary significantly (Chi2 test: p > .0001). The clutch size and the number of hatched chicks per nest were highest during the period with food supply in garbage dump (respectively: 3.46 ± 0.86; 2.85 ± 1.11), compared to the period when cattle egrets feed in natural or agricultural habitats (3.04 ± 0.87; 2.54 ± 1.03). However, productivity and breeding success were highest during the period without food supply (respectively: 2.11 ± 1.16 fledging’s/nest; 0.70 ± 0.35) than in the period with food supply (1.14 ± 0.91; 0.35 ± 0.30). While egg losses were substantially similar between the two study periods, chick’s mortality (59.9%) and total offspring losses (36.7%) were higher during the period with food supply. The generalized linear mixed model (GLMM) analysis indicated a large negative effect of food supply in dumps on the productivity, on the chick’s losses; and a positive effect on the total offspring losses ( p < .001). Also, feed in dump garbage revealed a significant negative effect on the breeding success linear mixed model (LMM, p = .01). However, no significant effects (GLMM, p > .05) of food supply in dumps were noted on average clutch size, the mean number of hatched chicks per nest, and egg losses.

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