PMID- 15753029 OWN - NLM STAT- MEDLINE DA - 20050308 DCOM- 20050607 LR - 20051116 PUBM- Print IS - 0960-9822 (Print) VI - 15 IP - 5 DP - 2005 Mar 8 TI - Ant navigation: reading geometrical signposts. PG - R171-3 AB - Ants often travel along complex pheromone trail systems between their nest and foraging areas. A new and surprising discovery is that Pharaoh's ants can work out from the geometry of individual branch points on the trail whether they are heading towards or away from the nest. AD - Department of Biology and Environmental Science, University of Sussex, Brighton BN1 9QG, UK. T.S.Collett@sussex.ac.uk FAU - Collett, Thomas S AU - Collett TS FAU - Waxman, David AU - Waxman D LA - eng PT - Journal Article PT - Review PL - England TA - Curr Biol JT - Current biology : CB. JID - 9107782 RN - 0 (Pheromones) SB - IM MH - Animals MH - Ants/*physiology MH - *Cues MH - Feeding Behavior/physiology MH - Locomotion/*physiology MH - Orientation/*physiology MH - Pheromones/physiology MH - Spatial Behavior/*physiology RF - 2 EDAT- 2005/03/09 09:00 MHDA- 2005/06/09 09:00 AID - S0960982205002150 [pii] AID - 10.1016/j.cub.2005.02.044 [doi] PST - ppublish SO - Curr Biol. 2005 Mar 8;15(5):R171-3. PMID- 15703745 OWN - NLM STAT- MEDLINE DA - 20050210 DCOM- 20050303 PUBM- Print IS - 1476-4687 (Electronic) VI - 433 IP - 7026 DP - 2005 Feb 10 TI - Directed aerial descent in canopy ants. PG - 624-6 AB - Numerous non-flying arboreal vertebrates use controlled descent (either parachuting or gliding sensu stricto) to avoid predation or to locate resources, and directional control during a jump or fall is thought to be an important stage in the evolution of flight. Here we show that workers of the neotropical ant Cephalotes atratus L. (Hymenoptera: Formicidae) use directed aerial descent to return to their home tree trunk with >80% success during a fall. Videotaped falls reveal that C. atratus workers descend abdomen-first through steep glide trajectories at relatively high velocities; a field experiment shows that falling ants use visual cues to locate tree trunks before they hit the forest floor. Smaller workers of C. atratus, and smaller species of Cephalotes more generally, regain contact with their associated tree trunk over shorter vertical distances than do larger workers. Surveys of common arboreal ants suggest that directed descent occurs in most species of the tribe Cephalotini and arboreal Pseudomyrmecinae, but not in arboreal ponerimorphs or Dolichoderinae. This is the first study to document the mechanics and ecological relevance of this form of locomotion in the Earth's most diverse lineage, the insects. AD - University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555, USA. FAU - Yanoviak, Stephen P AU - Yanoviak SP FAU - Dudley, Robert AU - Dudley R FAU - Kaspari, Michael AU - Kaspari M LA - eng PT - Journal Article PL - England TA - Nature JT - Nature. JID - 0410462 SB - IM MH - Animals MH - Ants/anatomy & histology/*physiology MH - Body Weight MH - Flight, Animal/*physiology MH - Locomotion/*physiology MH - Panama MH - Research Support, U.S. Gov't, Non-P.H.S. MH - Research Support, U.S. Gov't, P.H.S. MH - Trees/physiology MH - Video Recording EDAT- 2005/02/11 09:00 MHDA- 2005/03/04 09:00 PHST- 2004/09/16 [received] PHST- 2004/12/08 [accepted] AID - nature03254 [pii] AID - 10.1038/nature03254 [doi] PST - ppublish SO - Nature. 2005 Feb 10;433(7026):624-6. PMID- 15695763 OWN - NLM STAT- MEDLINE DA - 20050207 DCOM- 20050420 PUBM- Print IS - 0022-0949 (Print) VI - 208 IP - Pt 4 DP - 2005 Feb TI - Walking on inclines: energetics of locomotion in the ant Camponotus. PG - 707-19 AB - To assess energetic costs during rest and locomotion in a small insect, we measured metabolic rate in freely moving ants Camponotus sp. (average body mass 11.9 mg). The animals ran in a straight respirometric chamber in which locomotor speed and CO2 release were monitored simultaneously using flow-through respirometry and conventional video analysis. In resting intact ants, standard metabolic rate was on average 0.32 ml CO2 g(-1) body mass h(-1). During walking, the ants breathed continuously and metabolic rate increased between 4.3 times (level walking at 0-5 mm s(-1)) and 6.9 times (30 degrees ascent at 85-95 mm s(-1)) over resting rates. Metabolic rate increased linearly with increasing walking speed but superficially leveled off beyond speeds of about 70 mm s(-1). Walking on incline (uphill) or decline slopes (downhill) of up to 60 degrees had only a small effect on energy consumption compared to level walking. During slope walking, total metabolic rate averaged over all running speeds ranged from a minimum of 1.55+/-0.4 (horizontal running) to a maximum of 1.89+/-0.7 ml CO2 h(-1) g(-1) body mass (30 degrees downhill). The mean cost of transport in Camponotus was approximately 130 J g(-1) km(-1). The metabolic requirements in the comparatively small insect Camponotus for walking were mostly in the range expected from data obtained from other insects and small poikilotherms, and from allometric scaling laws. AD - Department of Neurobiology, University of Ulm, 89069 Ulm, Germany. FAU - Lipp, Alexandra AU - Lipp A FAU - Wolf, Harald AU - Wolf H FAU - Lehmann, Fritz-Olaf AU - Lehmann FO LA - eng PT - Journal Article PL - England TA - J Exp Biol JT - The Journal of experimental biology. JID - 0243705 RN - 124-38-9 (Carbon Dioxide) SB - IM MH - Animals MH - Ants/*physiology MH - Basal Metabolism MH - Biomechanics MH - Carbon Dioxide/metabolism MH - Comparative Study MH - Energy Metabolism/*physiology MH - Research Support, Non-U.S. Gov't MH - Uganda MH - Video Recording MH - Walking/*physiology EDAT- 2005/02/08 09:00 MHDA- 2005/04/21 09:00 AID - 208/4/707 [pii] AID - 10.1242/jeb.01434 [doi] PST - ppublish SO - J Exp Biol. 2005 Feb;208(Pt 4):707-19. PMID- 15602563 OWN - NLM STAT- MEDLINE DA - 20041216 DCOM- 20050103 PUBM- Print IS - 1476-4687 (Electronic) VI - 432 IP - 7019 DP - 2004 Dec 16 TI - Trail geometry gives polarity to ant foraging networks. PG - 907-9 AB - Pheromone trails are used by many ants to guide foragers between nest and food. But how does a forager that has become displaced from a trail know which way to go on rejoining the trail? A laden forager, for example, should walk towards the nest. Polarized trails would enable ants to choose the appropriate direction, thereby saving time and reducing predation risk. However, previous research has found no evidence that ants can detect polarity from the pheromone trail alone. Pharaoh's ants (Monomorium pharaonis) produce elaborate trail networks throughout their foraging environment. Here we show that by using information from the geometry of trail bifurcations within this network, foragers joining a trail can adaptively reorientate themselves if they initially walk in the wrong direction. The frequency of correct reorientations is maximized when the trail bifurcation angle is approximately 60 degrees, as found in natural networks. These are the first data to demonstrate how ant trails can themselves provide polarity information. They also demonstrate previously unsuspected sophistication in the organization and information content of networks in insect societies. AD - Department of Computer Science, University of Sheffield, Sheffield S1 4DP, UK. duncan@dcs.sheffield.ac.uk FAU - Jackson, Duncan E AU - Jackson DE FAU - Holcombe, Mike AU - Holcombe M FAU - Ratnieks, Francis L W AU - Ratnieks FL LA - eng PT - Journal Article PL - England TA - Nature JT - Nature. JID - 0410462 RN - 0 (Glass) RN - 0 (Pheromones) SB - IM MH - Animals MH - Ants/*physiology MH - *Cues MH - Feeding Behavior/*physiology MH - Glass MH - Locomotion/physiology MH - Orientation/*physiology MH - Pheromones/physiology MH - Research Support, Non-U.S. Gov't EDAT- 2004/12/17 09:00 MHDA- 2005/01/04 09:00 PHST- 2004/07/01 [received] PHST- 2004/10/06 [accepted] AID - nature03105 [pii] AID - 10.1038/nature03105 [doi] PST - ppublish SO - Nature. 2004 Dec 16;432(7019):907-9. PMID- 15477037 OWN - NLM STAT- MEDLINE DA - 20041012 DCOM- 20050114 LR - 20051116 PUBM- Print IS - 0928-4257 (Print) VI - 98 IP - 1-3 DP - 2004 Jan-Jun TI - How do insects represent familiar terrain? PG - 259-64 AB - We argue here that ants and bees have a piecemeal representation of familiar terrain. These insects remember no more than what is needed to sustain the separate and parallel strategies that they employ when travelling between their nest and foraging sites. One major strategy is path integration. The insect keeps a running tally of its distance and direction from the nest and so can always return home. This global path integration is enhanced by long-term memories of significant sites that insects store in terms of the coordinates (direction and distance) of these sites relative to the nest. With these memories insects can plan routes that are steered by path integration to such sites. Quite distinct from global path integration are memories associated with familiar routes. Route memories include stored views of landmarks along the route with, in some cases, local vectors linked to them. Local vectors by encoding the direction and/or distance from one landmark to the next, or from one landmark to a goal, help an insect keep to a defined route. We review experiments showing that although local vectors can be recalled by recognising landmarks, the global path integration system is independent of landmark information and that landmarks do not have positional coordinates associated with them. The major function of route landmarks is thus procedural, telling an insect what action to perform next, rather than its location relative to the nest. AD - Sussex Centre for Neuroscience, School of Biological Sciences, University of Sussex, Brighton BN1 9QG, UK. t.s.collett@sussex.ac.uk FAU - Collett, Thomas S AU - Collett TS FAU - Collett, Matthew AU - Collett M LA - eng PT - Journal Article PT - Review PL - France TA - J Physiol Paris JT - Journal of physiology, Paris. JID - 9309351 SB - IM MH - Animals MH - Distance Perception/physiology MH - *Environment MH - Homing Behavior/*physiology MH - Insects MH - Locomotion/physiology MH - Recognition (Psychology)/*physiology RF - 27 EDAT- 2004/10/13 09:00 MHDA- 2005/01/15 09:00 AID - S0928425704000853 [pii] AID - 10.1016/j.jphysparis.2004.03.012 [doi] PST - ppublish SO - J Physiol Paris. 2004 Jan-Jun;98(1-3):259-64.