Wingless arboreal ants must resist the force of gravity while traversing substrates in their environment. For leaf‐cutting ants like Atta cephalotes, foraging may also include a ca. 30 m vertical descent while carrying a load 1–6 times their body mass. We hypothesized that heavier and larger ants would carry heavier and larger loads and that adhesive performance would positively correlate with load mass. We found no relationship between ant mass, body length, head width, or adhesive performance, and the load size an ant carried. In addition to workers carrying vegetative loads (most often leaves), workers in an active foraging trail also include smaller workers riding on the leaves carried by larger workers, and large major workers, providing protection from aerial and ground attacks (Soldiers), respectively. Despite varying functional roles, all foraging ants require secure attachment to the substrate. We measured shear adhesive performance of each foraging role and found that Soldiers produced the highest shear adhesive forces. However, when controlling for tarsal pad area, we found that ants carrying loads have higher shear adhesive performance per unit area than those riding on leaves, and that Soldiers have the lowest shear adhesive performance per unit area. This suggests that while leaf choice does not appear to be dictated by size, mass, or shear adhesive performance of individual ants, overall, ants who carry leaves adhere more strongly given their pad size than those who do not. Abstract in Spanish is available with online material.

No abstract

In our previous article, Shear adhesive performance of leaf-cutting ant workers (Atta cephalotes), a technical error occurred when calculating shear adhesive performance divided by tarsal pad area of worker ants car

No abstract

to the Commanding General, USCONARC. The project was to obtain information on the following: (1) The respects in which higher-level leadership varies from leadership below division level. (2) The knowledge of psychology or sociology required by higher commanders. (3) The importance of traits of the leader in the exercise of high-level leadership. (4) The impact of the group being led, and of the situation, upon the exercise of high-level leadership. Although establishment of a regular research Task was not feasible, a special project for exploration on these questions was approved. Dr. Richard Snyder and Major General Edmund B. Sebree, USA (Ret.) of the Leadership Human Research Unit conferred with the Commandant, Command and General Staff College, and members of his staff having primary interest in the subject, to obtain insight into the problem and select a method of attack. It was pointed out at the conference that not very much has been done in the way of relating the high-level leader's qualities to actual practice, in part because those who are most knowledgeable about high-level leadership-the senior commanders-have not yet really worked on this type of analysis. There was general agreement that an approach limited to identifying and recapitulating the traits or attributes that have characterized successful and unsuccessful leaders was not likely to be profitable for a high-level command study. The method of attack selected for preliminary inquiry into the subject was to write personal letters to more than 100 "senior and experienced combat officers," both those with comrand and those with staff experience. Questions were posed in several aspects of high-level leadership, and the officers were asked to give detailed information based on their actual experience. (A list of the officers who contributed information and a copy of the letter used for the initial contact are reproduced in Appendices A and B of this paper.) Replies were received from more than 90 per centof the officers to whom the request was sent. Attempts tc codify the information received generated additional questions, which led to further inquiries and further contributions. This paper is a compilation of information obtained from this correspondence, supplemented by other source material such as official records and military biographies. The text includes profiles of six leaders successful at high levels of command. Each account is based on the personal recollections of one or more officers who had worked closely with the subject, and has been * reviewed by others thoroughly familiar with his career. These descriptionsall dealing with men strong of character and vigorous of personality-are pre-'.-, sented to illustrate the diversity in personality and techniques characterizing successful leaders facing a diversity of command problems.