An amusing paper (geek alert - you should understand the basics of TCP before wading in...) The analogies are interesting. Flow control, slow start and time out ...
The Regulation of Ant Colony Foraging Activity without Spatial Information
Balaji Prabhakar1, Katherine N. Dektar2, Deborah M. Gordon3*
1 Departments of Computer Science and Electrical Engineering, Stanford University, Stanford, California, United States of America, 2 Biomedical Computation, School of Engineering, Stanford University, Stanford, California, United States of America, 3Department of Biology, Stanford University, Stanford, California, United States of America
Abstract
Many dynamical networks, such as the ones that produce the collective behavior of social insects, operate without any central control, instead arising from local interactions among individuals. A well-studied example is the formation of recruitment trails in ant colonies, but many ant species do not use pheromone trails. We present a model of the regulation of foraging by harvester ant (Pogonomyrmex barbatus) colonies. This species forages for scattered seeds that one ant can retrieve on its own, so there is no need for spatial information such as pheromone trails that lead ants to specific locations. Previous work shows that colony foraging activity, the rate at which ants go out to search individually for seeds, is regulated in response to current food availability throughout the colony's foraging area. Ants use the rate of brief antennal contacts inside the nest between foragers returning with food and outgoing foragers available to leave the nest on the next foraging trip. Here we present a feedback-based algorithm that captures the main features of data from field experiments in which the rate of returning foragers was manipulated. The algorithm draws on our finding that the distribution of intervals between successive ants returning to the nest is a Poisson process. We fitted the parameter that estimates the effect of each returning forager on the rate at which outgoing foragers leave the nest. We found that correlations between observed rates of returning foragers and simulated rates of outgoing foragers, using our model, were similar to those in the data. Our simple stochastic model shows how the regulation of ant colony foraging can operate without spatial information, describing a process at the level of individual ants that predicts the overall foraging activity of the colony.
Author Summary
Social insect colonies operate without any central control. Their collective behavior arises from local interactions among individuals. Here we present a simple stochastic model of the regulation of foraging by harvester ant (Pogonomyrmex barbatus) colonies, which forage for scattered seeds that one ant can retrieve on its own, so there is no need for pheromone trails to specific locations. Previous work shows that colony foraging activity is regulated in response to current food availability, using the rate of brief antennal contacts inside the nest between foragers returning with food and outgoing foragers. Our feedback-based algorithm estimates the effect of each returning forager on the rate at which foragers leave the nest. The model shows how the regulation of ant colony foraging can operate without spatial information, describing a process at the level of individual ants that predicts the overall foraging activity of the colony.
a tip of the hat to Alan for noticing this
mitt's tendency to roofrack whoever or whatever serves his immediate purpose
To cover his own bungling and other local issues. Not a whole lot of character there.
dissing Eastwood is a reasonable reaction - such vile hate and racism. But they were incompetent to have left that to chance... and in Mitt's book it is so easy to roofrack the most convenient victim.
(tip 'o the hat to Jim for the link)
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