scholarly journals Bivouac Checking, A Novel Behavior Distinguishing Obligate from Opportunistic Species of Army-Ant-Following Birds

The Condor ◽  
2001 ◽  
Vol 103 (3) ◽  
pp. 629-633 ◽  
Author(s):  
Monica Beth Swartz
Keyword(s):  
Food Supply ◽  
New Method ◽  
Army Ants ◽  
Ant Colonies ◽  
Opportunistic Species ◽  
Army Ant ◽  
Checking Behavior ◽  
Novel Behavior ◽  
Forest Floors ◽  
The Many

Abstract As swarms of the army ant Eciton burchelli forage across forest floors of the lowland Neotropics, birds gather to eat arthropods flushed by the advancing ants. Past efforts to distinguish members of the obligate ant-following bird guild from the many species that forage opportunistically with army ants have been inadequate. Obligate ant-followers track the locations of multiple nomadic ant colonies in order to maintain a consistent food supply. Each morning, they visit the bivouac site of each colony they are monitoring to assess the ants' activity. Only species dependent upon foraging with army ants exhibit this specialized bivouac checking behavior. This paper proposes a new method for distinguishing between obligate and opportunistic ant-following birds by observing which species check bivouacs. Verificación de Vivaques, un Comportamiento Nuevo que Distingue a Especies Obligatorias de Especies Oportunistas Rastreadores de Hormigas-Ejército Resumen. Cuando enjambres de la hormiga ejército Eciton burchelli forrajean en los suelos de los bosques bajos Neotropicales, algunas aves se aglomeran para ingerir artrópodos espantados por las hormigas que avanzan. Esfuerzos pasados para distinguir entre aquellos miembros del gremio de aves que rastrean las hormigas obligatoriamente de las muchas especies que forrajean de manera oportunista con hormigas ejército han sido inadecuados. Seguidores obligatorios de las hormigas rastrean los sitios de varias colonias nómadas de hormigas a fin de mantener un suministro consistente de alimentos. Cada mañana, estas aves visitan el sitio de vivaque de cada una de las colonias que controlan con fin de evaluar las actividades de las hormigas. Sólo aquellas especies que dependen del forrajeo de las hormigas ejército manifiestan este comportamiento especializado de verificar los vivaques. Este artículo propone un nuevo método para distinguir entre las aves oportunistas y las aves obligatorias rastreadoras de hormigas mediante la observación de aquellas especies que verifican los vivaques.

scholarly journals Reduced foraging investment as an adaptation to patchy food sources: a phasic army ant simulation

2017 ◽  
Author(s):  
Serafino Teseo ◽  
Francesco Delloro
Keyword(s):  
Computational Approach ◽  
The Other ◽  
Food Sources ◽  
Army Ants ◽  
Phasic Activity ◽  
Ant Colonies ◽  
Eusocial Insects ◽  
Army Ant ◽  
Mixed Populations ◽  
Colony Level

AbstractColonies of several ant species within the subfamily Dorylinae alternate stereotypical discrete phases of foraging and reproduction. Such phasic cycles are thought to be adaptive because they minimize the amount of foraging and the related costs, and at the same time enhance the colony-level ability to rely on patchily distributed food sources. In order to investigate these hypotheses, we use here a simple computational approach to study the population dynamics of two species of virtual ant colonies that differ quantitatively in their foraging investment. One species, which we refer to as “phasic”, forages only half of the time, mirroring the phasic activity of some army ants; the other “non-phasic” species forages instead all the time. We show that, when foraging costs are relatively high, populations of phasic colonies grow on average faster than non-phasic populations, outcompeting them in mixed populations. Interestingly, such tendency becomes more consistent as food becomes more difficult to find but locally abundant. According to our results, reducing the foraging investment, for example by adopting a phasic lifestyle, can result in a reproductive advantage, but only in specific conditions. We thus suggest phasic colony cycles to have emerged together with the doryline specialization in feeding on the brood of other eusocial insects, a resource that is hard to obtain but highly abundant if available.

A new method in the many-body problem: II

1996 ◽  
Vol 29 (1) ◽  
pp. 133-142
Author(s):  
I V Krasovsky ◽  
V I Peresada
Keyword(s):  
Body Problem ◽  
New Method ◽  
Many Body ◽  
The Many

scholarly journals The persistence of ant-following birds in small amazonian forest fragments

1989 ◽  
Vol 19 (0) ◽  
pp. 249-263 ◽  
Author(s):  
Lee H. Harper
Keyword(s):  
Forest Fragments ◽  
Ant Colonies ◽  
Amazonian Forest ◽  
Army Ant ◽  
Continuous Forest ◽  
Introduced Birds ◽  
Small Forest

SUMMARYMist-net captures of army ant-following bird were monitored during the isolation of central Amazonian forest fragments of 1 ha (n = 5), 10 ha (n = 4) and 100 ha (n = 1). Post-isolation captures of the three obligate ant-following birds Dendrocinela merula, Pithys albifrons, and Gymnopithys rufigula decreased significantly in all fragments. post-isolation captures of four facultative ant-following species were not significantly different in forest fragments of 1 ha and 10 ha, although two species decreased significantly in the 100 ha fragment. Experimental introductions of obligate species into small forest fragments in the absence and presence of introduced Eciton burchelli army ant colonies resulted in significantly greater recaptures of introduced birds when active army ant colonies were present. Of the 105 birds introduced, 58 ' 55%) crossed 100-320 m od dedorested area an were recaptured in continuous forest.

Our Food Supply

2021 ◽  
pp. 11-13
Author(s):  
Michael P. Hoffmann ◽  
Carrie Koplinka-Loehr ◽  
Danielle L. Eiseman
Keyword(s):  
Food Supply ◽  
Food System ◽  
Consumer Spending ◽  
Food Supply Chain ◽  
Farmers Market ◽  
Tree Nuts ◽  
Changing Climate ◽  
Fresh Vegetables ◽  
The Many ◽  
The Right

This chapter describes where the food we love and need comes from and how it gets to our table. The fresh vegetables we enjoy may come from a local farmers market, the grapes from California, tree nuts from Vietnam, coffee from Brazil, spices from India, and fish from the Bering Sea, to name a few. This global interconnected and interdependent food system that feeds us also provides 40 per cent of global employment and accounts for 10 per cent of consumer spending. But it faces increasing risks from a changing climate. With a global view of the food system as a foundation, the chapter then considers how the many changes in the climate are affecting plants, the basis of life. Plants require the right temperatures, water, soil, air, and sunlight. All of these requirements except sunlight are changing, with subtle to profound implications. The air now has more of the greenhouse gas carbon dioxide, which means that most plants will grow faster and bigger, but any benefit will be offset by stress from increasing heat and drought. The chapter also looks at how the changing climate affects pests, pollinators, and the food supply chain.

Design and Evaluation of a New General-Purpose Device for Calibrating Instrumented Spatial Linkages

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Joshua A. Nordquist ◽  
M. L. Hull
Keyword(s):  
Measurement Error ◽  
Gold Standard ◽  
Measurement Errors ◽  
Mean Squared Error ◽  
General Purpose ◽  
New Method ◽  
Coordinate Measurement ◽  
Calibration Device ◽  
Spatial Linkages ◽  
The Many

Because instrumented spatial linkages (ISLs) have been commonly used in measuring joint rotations and must be calibrated before using the device in confidence, a calibration device design and associated method for quantifying calibration device error would be useful. The objectives of the work reported by this paper were to (1) design an ISL calibration device and demonstrate the design for a specific application, (2) describe a new method for calibrating the device that minimizes measurement error, and (3) quantify measurement error of the device using the new method. Relative translations and orientations of the device were calculated via a series of transformation matrices containing inherent fixed and variable parameters. These translations and orientations were verified with a coordinate measurement machine, which served as a gold standard. Inherent fixed parameters of the device were optimized to minimize measurement error. After parameter optimization, accuracy was determined. The root mean squared error (RMSE) was 0.175 deg for orientation and 0.587 mm for position. All RMSE values were less than 0.8% of their respective full-scale ranges. These errors are comparable to published measurement errors of ISLs for positions and lower by at least a factor of 2 for orientations. These errors are in spite of the many steps taken in design and manufacturing to achieve high accuracy. Because it is challenging to achieve the accuracy required for a custom calibration device to serve as a viable gold standard, it is important to verify that a calibration device provides sufficient precision to calibrate an ISL.

Army Ants on the Move: Relation Between Food Supply and Emigration Frequency

Science ◽  
1980 ◽  
Vol 207 (4435) ◽  
pp. 1099-1100 ◽  
Author(s):  
H. TOPOFF ◽  
J. MIRENDA
Keyword(s):  
Food Supply ◽  
Army Ants

A new method in the many-body problem

1995 ◽  
Vol 28 (6) ◽  
pp. 1493-1505 ◽  
Author(s):  
I V Krasovsky ◽  
V I Peresada
Keyword(s):  
Body Problem ◽  
New Method ◽  
Many Body ◽  
The Many
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