scholarly journals The response of foraging Argentine ants, Linepithema humile, to disturbance

2001 ◽  
Vol 49 (1) ◽  
pp. 59 ◽  
Author(s):  
Julianne D. Halley ◽  
Mark A. Elgar

Reducing the risk of predation is an important feature of the feeding behaviour of most animals. In social insects, foraging workers are particularly vulnerable, and the ability to trade-off mortality risk against food value may provide a considerable competitive advantage for the colony. We investigated the response of Argentine ants, Linepithema humile, to different kinds of disturbance while workers foraged on food of differing quality. The behaviour of disturbed individuals was influenced by group size, by the behaviour of nearby nestmates and by how much food had already been consumed. When in large groups, workers were less likely to leave the foraging arena and resumed feeding more rapidly. This response was even more marked among workers whose gasters were only partially replete. However, individuals took more time to resume feeding and became more likely to run away from a food source when greater numbers of ants were disturbed. These influences may allow foraging groups to maximise food intake while minimising the mortality of workers.

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Silu Lin ◽  
Jana Werle ◽  
Judith Korb

AbstractOrganisms are typically characterized by a trade-off between fecundity and longevity. Notable exceptions are social insects. In insect colonies, the reproducing caste (queens) outlive their non-reproducing nestmate workers by orders of magnitude and realize fecundities and lifespans unparalleled among insects. How this is achieved is not understood. Here, we identified a single module of co-expressed genes that characterized queens in the termite species Cryptotermes secundus. It encompassed genes from all essential pathways known to be involved in life-history regulation in solitary model organisms. By manipulating its endocrine component, we tested the recent hypothesis that re-wiring along the nutrient-sensing/endocrine/fecundity axis can account for the reversal of the fecundity/longevity trade-off in social insect queens. Our data from termites do not support this hypothesis. However, they revealed striking links to social communication that offer new avenues to understand the re-modelling of the fecundity/longevity trade-off in social insects.


2006 ◽  
Vol 24 (7) ◽  
pp. 2049-2056 ◽  
Author(s):  
Holger Kittner ◽  
Heike Franke ◽  
Julia I. Harsch ◽  
Ibrahim M. El-Ashmawy ◽  
Bertholt Seidel ◽  
...  

2003 ◽  
Vol 77 (3) ◽  
pp. 429-437 ◽  
Author(s):  
D. Renaudeau ◽  
J.-L. Weisbecker ◽  
J. Noblet

AbstractTwenty-seven multiparous Large White sows were used to determine the effect of season in a tropical climate and dietary fibre on their feeding behaviour during lactation. The experiment was conducted in Guadeloupe (French West Indies, latitude 16°N, longitude 61°W) between October 1999 and January 2001; climatic conditions in the farrowing room were equivalent to outdoor conditions. Two seasons were determined a posteriori from climatic criteria recorded continuously in the farrowing room. During the warm season, ambient temperature and relative humidity averaged 25°C and 0·868, respectively. The corresponding values for the hot season were 27·5°C and 0·835. Experimental diets offered during lactation were a control diet (C; 140 g neutral-detergent fibre (NDF) per kg) and a high fibre diet (HF; 200 g NDF per kg). Sows were offered food ad libitum between the 6th and the 27th day of lactation. Daily food intake between day 6 and day 27 decreased during the hot season (P < 0·001; 3226 v. 5571 g/d during the warm season). This was achieved by a reduction of both meal size (P < 0·05; 460 v. 718 g per meal) and ingestion and consumption time (P < 0·01; -11·1 and -15·3 min/day, respectively) whereas the number of meals remained constant (8·4 meals per day on average). During warm season, hourly food intake peaked twice daily near sunrise and sunset. During the hot season, peaks were attenuated and food intake was reduced during the hotter periods of the day and increased during the fresher period of the day, especially in early morning. As a result the diurnal partition of food intake was significantly affected by season; proportionately 0·62 and 0·47 of total food intake occurred during the day in warm and in hot seasons, respectively. Standing duration averaged 138 min/ day with no significant difference between seasons. Feeding behaviour criteria were not influenced by diet composition. In conclusion, the season in a humid tropical climate significantly affects the feeding behaviour of lactating sows.


2011 ◽  
Vol 83 (4) ◽  
pp. 1269-1278 ◽  
Author(s):  
Fernando A. Abrunhosa ◽  
Darlan J.B. Simith ◽  
Joely R.C. Monteiro ◽  
Antonio N. de Souza Junior ◽  
Pedro A.C. Oliva

Feeding is an important factor for the successful rearing of larvae of the crab species. Further information on the morphological features of the foregut may to reveal larval feeding behaviour and or/whether there is a lecithotrophy in some or even in all stages of the larval cycle. In the present study, the structural development of the foregut and their digestive functions were examined in larvae of two brachyurans, Uca vocator and Panopeus occidentalis, reared in the laboratory. During larval development, the foreguts of the larvae in the first and last zoeal stages and in the megalopa stage were microscopically examined, described and illustrated. The zoeal foreguts of both species were well developed, showing specialization with a functional cardiopyloric valve and a filter press. The megalopa stage had a complex and specialized gastric mill similar to that found in adult crabs with the appearance of rigidly calcified structures. These results support the hypothesis that the feeding behaviour of each larval stage is directly related to the morphological structure of the foregut. Such facts strongly indicate that all larval stages of both . vocator and P occidentalis need an external food source before completing the larval development in a planktonic environment.


eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Syuan-Jyun Sun ◽  
Dustin R Rubenstein ◽  
Bo-Fei Chen ◽  
Shih-Fan Chan ◽  
Jian-Nan Liu ◽  
...  

The ability to form cooperative societies may explain why humans and social insects have come to dominate the earth. Here we examine the ecological consequences of cooperation by quantifying the fitness of cooperative (large groups) and non-cooperative (small groups) phenotypes in burying beetles (Nicrophorus nepalensis) along an elevational and temperature gradient. We experimentally created large and small groups along the gradient and manipulated interspecific competition with flies by heating carcasses. We show that cooperative groups performed as thermal generalists with similarly high breeding success at all temperatures and elevations, whereas non-cooperative groups performed as thermal specialists with higher breeding success only at intermediate temperatures and elevations. Studying the ecological consequences of cooperation may not only help us to understand why so many species of social insects have conquered the earth, but also to determine how climate change will affect the success of these and other social species, including our own.


1996 ◽  
Vol 1996 ◽  
pp. 174-174
Author(s):  
A.M. Sibbald

Voluntary food intake is generally inversely related to body condition or fatness in mature sheep (Foot, 1972). Since the intake of pelleted diets by housed sheep consists of a number of discrete feeding bouts or 'meals' (e.g. Bermudez et al., 1989), the relatively long-term effect of body condition on intake will be achieved through changes in feeding behaviour at the level of a single meal. The aim of this experiment was to compare the effects of body condition and short-term food restriction on meal patterns in sheep, to investigate the mechanism by which body condition influences daily food intake.


1998 ◽  
Vol 1998 ◽  
pp. 25-25
Author(s):  
B.L. Nielsen ◽  
N.C. Friggens ◽  
I. Kyriazakis ◽  
B.J. Tolkamp ◽  
G.C. Emmans

Short-term feeding behaviour (STFB) has been used to elucidate the physiological mechanisms which control eating. It has been proposed as a means by which to predict voluntary food intake, and could be used to quantify behavioural characteristics of the cow. The first step in assessing the usefulness of STFB for these purposes is to identify the major factors which influence STFB. The aim of the study reported here was to evaluate, in dairy cows, the differences in STFB resulting from two different foods, the effect of stage of lactation on STFB, and the effect on STFB of changing from one food to another.


2003 ◽  
Vol 2003 ◽  
pp. 7-7
Author(s):  
M. P. Yeates ◽  
B. J. Tolkamp ◽  
I. Kyriazakis

The analysis of short-term feeding behaviour may give insights into how food intake is regulated in farm animals. Food intake is often recorded in terms of feeding events, e.g. visits to feeders, which can be clustered into meals. This enables calculation of the probability of cows starting a meal in relation to time since the last meal, which is thought to give insight into intake regulation. Starting probabilities are often calculated after data have been pooled, e.g. across day and night or across individuals. Recent work suggested that such pooling might have strongly affected previously published conclusions. We therefore constructed simulation models to investigate how such pooling affects interpretation of feeding behaviour and consequently the biological significance attached to results.


2002 ◽  
Vol 2002 ◽  
pp. 27-27
Author(s):  
E. C. Whittemore ◽  
I. Kyriazakis ◽  
G.C. Emmans ◽  
B.J. Tolkamp ◽  
C. A. Morgan ◽  
...  

We need to improve our understanding of the factors that are important for the control of food intake on high bulk foods. The study of short term feeding behaviour (STFB) may help to do this. The objective of this experiment was to study the effects of giving foods differing in bulk content on the STFB of growing pigs. It was expected that the foods would result in different levels of daily intake and that this would be reflected as differences in STFB between the foods. Two hypotheses were developed based on ideas about the way in which a physical constraint to intake could arise. H1; there would be less diurnal variation in feeding on high bulk foods that limit intake. H2; feeding patterns on bulky foods would be less flexible than those on a control food when feeding time is limited by reducing time of access to the feeder.


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