Distance effects on resource profitability and recruitment in the giant tropical ant, Paraponera clavata

Abstract

We examine how cost and benefit components of resource profitability affect recruitment in the giant tropical ant, Paraponera clavata. To vary resource profitability, we changed the quantity of artificial nectar baits presented to foragers and the distance of nectar baits from the nest. Both distance to and amount of resource affected quantitative aspects of recruitment. At increased distances foragers were less likely to recruit, and fewer workers were recruited to the resource area. The amount of nectar affected the tendency of foragers to recruit, but had no effect on the number of ants recruited. Variation in resource distance was also associated with qualitative changes in recruitment strategy. Foragers at distant sites recruited from the canopy rather than from the nest, and often transferred nectar to other workers for transport to the nest. Nectar transfer and extra-nidal recruitment significantly reduced the time required for resource collection. It may also have increased the ability of workers to specialize in specific foraging tasks. A portion of the colony's foraging force specialized spatially by remaining in distant foraging areas without returning to the nest. The flexible recruitment system of P. clavata increases colonial net energetic gain rates by concentrating foraging effort on resources yielding the highest net energetic rewards, and increases the competitive abilities of individual colonies at resource sites by decreasing collection times.

Recruitment in a scent trail laying stingless bee (Scaptotrigonaaff.depilis): Changes with reduction but not with increase of the energy gain

“…In both these species of stingless bees and ants the number of recruits not only depended on food profitability, but also on the sequence of discovery of the food sources (ants: Beckers et al, 1990;Nicolis and Deneubourg, 1999;Sumpter and Pratt, 2003). In scent trail laying ants food profitability affected both the number of recruits and the recruitment activity of the individual forager (Breed et al, 1987;Pasteels et al, 1987;Beckers et al, 1990Beckers et al, , 1993Fewell et al, 1992;Mercier and Lenoir, 1999;Cassill, 2003;Sumpter and Beekman, 2003). Although in scent trail laying stingless bees the number of recruits was shown to be affected by food profitability (Schmidt et al, 2006) there are no studies yet clarifying the dependence of the recruitment activity on food profitability.…”

Forrageamento de Pachycondyla striata Smith, 1858 (Hymenoptera: Formicidae: Ponerinae) em ambiente urbano

“…Essa fidelidade traz vantagens, pois as forrageadoras percorrem o trajeto até o alimento rapidamente (Hölldobler, 1976). Logo, a experiência da forrageadora aumenta a sua familiaridade com a área de forrageamento, diminuindo as chances se perder (Fewell, Harrison, Stiller & Breed, 1992).…”

“…As forrageadoras utilizam informação individual ou social para obter alimento para a colônia, o que depende de diversos fatores, como: o tipo de alimento e a sua localização; o tamanho da colônia e das operárias, e o seu ciclo alimentar; e as interações com outros indivíduos (Carroll & Janzen, 1973;Fewell, Harrison, Stiller & Breed, 1992;Grüter, Czaczkes & Ratnieks, 2011). Elas podem ser bem-sucedidas ao se guiarem pela informação pessoal para obter alimento, porém, ao se guiarem pela informação social, diminuem os custos associados com gasto de energia, exposição a predadores e tempo de busca por alimento (Grüter & Leadbeater, 2014;Grüter, Leadbeater & Ratnieks, 2010).…”

“…Do ponto de vista adaptativo, quanto mais flexível for o comportamento de forrageamento, maiores serão as chances de a colônia sobreviver às mudanças ambientais. Para terem respostas adaptativas sobre o tipo de estratégia a ser realizada durante o forrageamento, as forrageadoras usam informações de diferentes fatores, como o tipo de alimento, a quantidade, a qualidade e sua distância do ninho (Fewell et al, 1992;Hölldobler, 1976). Portanto, a capacidade das forrageadoras avaliarem o alimento é uma forma de direcionarem os esforços para maximizar os ganhos energéticos para a colônia (Fewell et al, 1992).…”

“…Em consequência, quando a recompensa é menor o forrageamento permanece solitário, com a presença frequente de comportamento exploratório, enquanto, para recompensas maiores, há mais recrutamentos com marcação química e menos exploração (Mercier & Lenoir, 1999). (Fewell, Harrison, Stiller & Breed, 1992;Schoener, 1971).…”