Effects of dispersion, travel, and environmental heterogeneity on populations of the earwig Forficula auricularia L.

1975 ◽  
Vol 53 (12) ◽  
pp. 1855-1867 ◽  
Author(s):  
R. J. Lamb
Keyword(s):  
Social Interaction ◽  
Intraspecific Competition ◽  
Environmental Heterogeneity ◽  
Early Initiation ◽  
Intraspecific Aggression ◽  
Forficula Auricularia ◽  
Feeding Sites ◽  
Competition For Food

Local earwig populations were increased by the addition of artificial shelters which protected them against an inhospitable microclimate and predation by birds. The spacing of shelters and the availability of nearby food limited the use of shelters and thus the size of populations, through intraspecific competition for food. This competition was increased by the active aggregation of earwigs in shelters. Aggregation probably assists in the location of suitable shelter and provides a focus for social interaction. Enhanced growth and early initiation of foraging were observed for earwigs reared in groups.Foraging earwigs showed intraspecific aggression, especially at feeding sites. Earwigs that had not fed during the current foraging period were less likely to join aggregations early in the night. Foraging earwigs showed no ability to home to shelters or locate aggregations from a distance of more than a few centimetres, but were capable of travelling many metres in one night. These factors resulted in the exclusion of new occupants when shelter use reached a maximum.

The Food and the Food Supply of Sockeye Salmon (Oncorhynchus nerka Walbaum) in Cultus lake, British Columbia.

1937 ◽  
Vol 3 (5) ◽  
pp. 450-468 ◽  
Author(s):  
William E. Ricker
Keyword(s):  
Low Temperature ◽  
Intraspecific Competition ◽  
Sockeye Salmon ◽  
Abundant Species ◽  
Minor Importance ◽  
Important Food ◽  
Total Food ◽  
Competition For Food ◽  
Summer Feeding ◽  
Food Consumed

The analysis of several hundred stomachs of sockeye salmon taken from Cultus lake at all seasons shows that pelagic plankton crustaceans are practically the only food of the fingerlings, and are the most important food of the older fish. The total food consumed by fingerlings, per unit bulk, is greatest in July and August, least in winter. The entomostracan food available in the lake, as determined from plankton samples, varies seasonally in a similar manner. The percentage utilization of each of the four species of Entomostraca by a fingerling sockeye population is related directly to the plankter's abundance, and inversely to its size. Individual sockeye, however, occasionally exhibit preference for smaller or less abundant species. The summer feeding of fingerlings appears to be chiefly confined to the region between 5 and 15 metres depth, which includes the thermocline and adjacent narrow strips of the epilimnion and hypolimnion. Foraging is limited upward by scarcity of food, and downward by poor illumination or low temperature. Other fish in the lake are known to compete with sockeye for plankton, but such interspecific competition is believed to be quantitatively of minor importance, in summer at least. Intraspecific competition for food in years of large sockeye populations is sufficient to reduce their rate of growth, and is probably responsible for an unusually early decline, in those years, of the summer's supply of Entomostraca.

Interactions between free-ranging, adult male polar bears (Ursus maritimus Phipps): a case of adult social play

1981 ◽  
Vol 59 (9) ◽  
pp. 1775-1783 ◽  
Author(s):  
Paul B. Latour
Keyword(s):  
Social Interaction ◽  
Adult Male ◽  
Annual Cycle ◽  
Intraspecific Competition ◽  
Social Play ◽  
Polar Bears ◽  
Dyadic Interactions ◽  
Socialization Process ◽  
Free Ranging ◽  
Motor Acts

I observed 73 dyadic interactions (bouts) between adult male polar bears (> 6 years) at Cape Churchill, Manitoba, from 4 October to 9 November 1978. All bouts involved at least one marked bear. I classified these bouts as social play and in this paper I discuss the criteria used for this classification. Social play bouts were composed of discrete motor acts and showed some predictability and structure. Two bouting bears respond to one another in a predictable manner as indicated by the mutuality of initiator-receiver acts. Structuring was suggested by a major three-act sequence for both initiators and receivers. Aggressive acts were found to be characteristic of initiators; the less aggressive, withdrawing acts were characteristic of receivers. The results are interpreted from both the structuralist and functionalist approaches to social play. I hypothesize that social play between adult male polar bears during the noncompetitive period of their annual cycle serves as a socialization process facilitating both opponent assessment and the refinement of social interaction. Both of these are probably important at times of the year when intraspecific competition is more intense.

Habitat and Food Segregation of Dwarf and Normal Arctic Charr (Salvelinus alpinus) from Vangsvatnet Lake, Western Norway

1982 ◽  
Vol 39 (7) ◽  
pp. 1030-1045 ◽  
Author(s):  
Kjetil Hindar ◽  
Bror Jonsson
Keyword(s):  
Environmental Conditions ◽  
Intraspecific Competition ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Habitat Segregation ◽  
Growth Season ◽  
Western Norway ◽  
Lake Morphology ◽  
Food Segregation ◽  
Competition For Food

The aim of the present study was to test possible habitat and food segregation between two charr morphs in Vangsvatnet Lake. The charr population of Vangsvatnet consists of one pale phenotype with parr marks along the flanks and poorly developed spawning coloration (dwarf charr), and another phenotype with silvery flanks in nonbreeding condition and bright red spawning colors (normal charr). The habitus of the two morphs indicated that they were adapted to different niches during the growth season. The analyses of distribution and food showed that there was marked habitat and food segregation between the two morphs during summer, when dwarf charr dwelled deep-benthic and normal charr roamed in the limnetic zone. The segregation broke down in periods of food abundance, indicating that the habitat segregation was due to intraspecific competition for food. A comparison of charr morphs of Vangsvatnet with the nearby Lønavatnet Lake suggested that the number of charr morphs is adapted to local environmental conditions, among which lake morphology, food availability, and other fish species are important. We hypothesize that the number of charr morphs within a locality depends on the number of available niches during the growth season.Key words: polymorphism, camouflage, distribution, ontogeny, intra- and inter-specific competition

Primeros datos sobre la población de lagarto negro (Gallotia simonyi simonyi STEIND.) de la Isla de Hierro1

1981 ◽  
Vol 2 (4) ◽  
pp. 369-380 ◽  
Author(s):  
Juan Pablo Martinez Rica
Keyword(s):  
Canary Islands ◽  
Intraspecific Competition ◽  
Daily Activity ◽  
Plant Cover ◽  
The Sun ◽  
Protective Measures ◽  
Industrial Facilities ◽  
Vertebrate Fauna ◽  
The Status ◽  
Competition For Food

AbstractThis paper presents the first data on the ecology of the Giant Hierro Lizard (Gallotia simonyi simonyi) from Canary Islands; this animal was believed to be extinct until its recent finding, in 1975. The biotope, a very steep rocky cliff, almost inaccessible in many places, is described; the climate of the area is subdesertic and the plant cover, very sparse, is xerophytic; the vertebrate fauna is poor, but insects are abundant and diverse. The colour of this lizard is almost black, with large dull grey patches at the sides in the adults, while in the youngs the colour is earthly brown with whitish dorsal stripes. The largest specimen we measured was near 70 cm from snout to tail's end. Daily activity begins in young specimens when the sun reaches the area, while in the adult ones activity begins somewhat later, even at noon for the oldest animals. The diet consists entirely of plants, and includes lignified stems and other non-nourishing parts from several species (Kleinia neriifolia, Lavandula abrotanoides, etc.). Obviously there exists a strong intraspecific competition for food. The number of animals was very low in September 1975, about 200 specimens, half of them or more being young. This number might have been increased by now through protective measures recently adopted. Nevertheless, the status of the population is still critical and the danger of its extinction is strong. Some recent plans to modify the area, building industrial facilities nearby, may have, of course, very bad effects on this lizard.

Social epistemic actions

2020 ◽  
Vol 43 ◽  
Author(s):  
Giovanni Pezzulo ◽  
Laura Barca ◽  
Domenico Maisto ◽  
Francesco Donnarumma
Keyword(s):  
Social Interaction ◽  
Joint Action ◽  
Niche Construction ◽  
Cultural Practices ◽  
Learning Processes ◽  
Epistemic Actions ◽  
Target Article ◽  
Online Social Interaction

Abstract We consider the ways humans engage in social epistemic actions, to guide each other's attention, prediction, and learning processes towards salient information, at the timescale of online social interaction and joint action. This parallels the active guidance of other's attention, prediction, and learning processes at the longer timescale of niche construction and cultural practices, as discussed in the target article.

Reduction of spermatogonia and testosterone in rat testes flown on space lab-3

1986 ◽  
Vol 44 ◽  
pp. 248-249
Author(s):  
Delbert E. Philpott ◽  
W. Sapp ◽  
C. Williams ◽  
T. Fast ◽  
J. Stevenson ◽  
...  
Keyword(s):  
Social Interaction ◽  
Social Status ◽  
Population Size ◽  
Physiological Response ◽  
Social Rank ◽  
Reproductive Function ◽  
Testicular Development ◽  
Organ Weights ◽  
Reproductive Maturation ◽  
Metabolic Activities

Space Lab 3 (SL-3) was flown on Shuttle Challenger providing an opportunity to measure the effect of spaceflight on rat testes. Cannon developed the idea that organisms react to unfavorable conditions with highly integrated metabolic activities. Selye summarized the manifestations of physiological response to nonspecific stress and he pointed out that atrophy of the gonads always occurred. Many papers have been published showing the effects of social interaction, crowding, peck order and confinement. Flickinger showed delayed testicular development in subordinate roosters influenced by group numbers, social rank and social status. Christian reported increasing population size in mice resulted in adrenal hypertrophy, inhibition of reproductive maturation and loss of reproductive function in adults. Sex organ weights also declined. Two male dogs were flown on Cosmos 110 for 22 days. Fedorova reported an increase of 30 to 70% atypical spermatozoa consisting of tail curling and/or the absence of a tail.

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