A field experiment on the influence of load transportation and patch distance on the locomotion velocity of Dorymyrmex goetschi (Hymenoptera, Formicidae)

Abstract

Locomotion velocity during foraging activities is determined by factors such as travel distance, habitat structure and load mass among others. However, few studies on foraging behavior have analyzed the influence of spatial heterogeneity and food transportation on the locomotion velocity of ants under natural conditions. In order to study the mentioned factors, we selected 20 nests of the ant Dorymyrmex goetschi (subfamily Dolichoderinae), in a lower Andes locality of central Chile. Half of the nests were offered a food patch located at 10 cm from the nest entrance, and at 20 cm for the other half. We measured the duration of trips between nest and food patch and vice versa, and the distances traveled. We also recorded spatial heterogeneity of the substratum and soil temperature. Temperature was used as a covariate in the statistical analysis. Travel speed was significantly slower when worker ants returned to the nest with a food load, compared to the velocity of foragers without load that traveled from the nest to the patch. When the food patch was located at greater distance, locomotion velocity was significantly faster. Spatial heterogeneity did not affect movement speed. The reduction in locomotion velocity in ants carrying a load of 5.6 mg represents an energetic cost of transportation equivalent to 79 % of the costs involved in moving a body mass of 1.6 mg. Faster velocities at larger patch distances can be interpreted as a strategy to maintain an efficient resource exploitation, by way of decreasing the time exposed to higher predation risk.

How temperature influences displacements and corpse aggregation behaviors in the ant Messor sancta

“…Ant running speed increases with temperature. The detected positive correlation between running speed and temperature has already been found for the desert ant Ocymyrmex barbiger (Marsh, 1985), for three Pogonomyrmex species (Morehead and Donald, 1998) and for Dorymyrmex goetschi (Torres-Contreras and Vásquez, 2004). Temperature has also been shown to infl uence movement related activities such as foraging (e.g.…”

Efecto del uso de suelo en las hormigas (Formicidae: Hymenoptera) de Tikinmul, Campeche, México

“…De acuerdo a estos patrones, donde se presenta una dominancia del género Pheidole, también existe una alta representatividad de otros géneros de las subfamilias Mymicinae, de las Ponerinae y Pseudomyrmecinae y en contraste una baja presencia de los géneros de las subfamilias Formicinae y Ecitoninae; mientras para la subfamilia Dolichoderinae, los patrones son difusos, ya que aunque no es frecuente un desplazamiento al encontrarse presentes especies de Pheidole, eventualmente puede ocurrir (Fowler 1993, Lieberburg et al 1975. En cuanto al microclima muchas especies de hormigas tropicales han mostrado ser sensibles a factores ambientales que pueden incrementar el riesgo de desecación, como la insolación y la baja humedad (Lighton & Feener 1989, Kaspari & Weiser 2000, aunque también existen especies que presentan predilección por los hábitats abiertos y expuestos al sol (MacGown & Lockley 2009, Risch & Carroll 1982, Torres-Contreras & Vásquez 2004. De acuerdo a sus preferencias las especies de hormigas pueden inclinarse por hábitats más abiertos como el monocultivo (i.e.…”

“…también habitan lugares abiertos (MacGown & Lockley 2009, Torres-Contreras & Vásquez 2004 al igual que S. geminata. Posiblemente esta preferencia hace que ambas especies sean dominantes en el monocultivo; aunque no compartan el mismo espacio dentro de estos sistemas, ya que mientras S. geminata habita parcelas con manejo más intensivo, donde inclusive se han realizado aplicaciones de insecticidas, Dorymyrmex sp.…”

Ants use pheromone markings in emigrations to move closer to food-rich areas

“…This behavior would increase the probability that emigrating colonies will move closer to profitable food sources. Colonies nesting close to food may minimize foraging costs and retrieve larger quantities of food (Fewell et al, 1996;Nielsen, 2001;Torres-Contreras and Vasquez, 2004;van Wilgenburg and Elgar, 2007), which in turn can increase colony growth and reproduction (Oster and Wilson, 1978;Hölldobler and Wilson, 1990;McGlynn et al, 2002;McGlynn, 2006).…”