What motivates the food bringing behaviour of the peregrine falcon throughout breeding?

Wild peregrine falcon pairs (Falco peregrinus brookéi) have been observed from courtship until fledgling stage. We analyse the typology of the food bringing behaviour and put forward explanations about the motivation underlying this behaviour throughout the breeding period. According to the stage of the breeding period and to the sex involved, the motivation underlying the food bringing behaviour is different.

Queen attractivity in the Argentine ant Iridomyrmex humilis (Mayr).

The origin of queen attractivity in the Argentine ant was estimated by presenting body parts (head, thorax, abdomen) of dead queens to workers. Whatever the preparation, crushed or intact, the thorax was always significantly more attractive than other parts of the body. The legs seemed to be highly attractive to the workers, mainly through lactile stimuli.

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Visually guided orientation is studied during ontogeny in field crickets (Gryllus bimaculatus) bred into complete darkness from egg stage. It is compared to control animals bred in normal 12L 12D light cycle conditions. Control animals are strongly scototactic: whatever their age, 85% of them step towards low reflecting targets.

Hypergravity and ageing in Drosophila melanogaster. 3. Viability.

The viability of Drosophila melanogaster was measured in three conditions: (1) of eggs from parents living at different gravity levels (1-5 g), developed at 1 g; (2) of eggs from parents living at 1 g, developed at different gravity levels, and (3) of eggs developed at the gravity at which their parents were kept. Hypergravity (HG) decreased viability to a low extent in all three cases (75% of emergence in the worst case). The effects of keeping parent flies in HG and of growing their offspring in HG were not cumulative.

Hypergravity and ageing in Drosophila melanogaster. 2. Longevity.

Longevity of Drosophila melanogaster flies was observed at various gravity levels in three different breeding conditions of decreasing quality. A slight longevity decrease was observed in the 1-4 g range of the two best conditions. In the third one, a large decrease was observed in all hypergravity groups.

Hypergravity and ageing in Drosophila melanogaster. 1. Fecundity.

In Drosophila melanogaster daily fecundity has been recorded throughout life of flies kept at various gravity levels (1-5 g). Hypergravity (HG) did not decrease total fecundity but modified its expression during life. The 1 g group could be opposed to the various HG groups, i.