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Effects of Time of Day and Weather on Spider Catches with a Sweep Net
Author(s) -
Lowrie Donald C.
Publication year - 1971
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.2307/1934595
Subject(s) - trampling , ecology , vegetation (pathology) , spider , environmental science , grazing , population , sampling (signal processing) , geography , physical geography , biology , demography , medicine , filter (signal processing) , pathology , sociology , computer science , computer vision
The effects of time of day, season, trampling by the collector, cattle grazing, wetness of vegetation, and air temperature are analyzed for the size of sample catches of four species of oxyopid spiders living in a long—leafed pine community of northern Florida. All of these factors modify the sizes of sample catches although there are only slight changes, if any, in the population size. Therefore, changes due to these variables can cause erroneous population size estimates and judgments on the effects of ecological factors. Night collecting, warm winter weather, periods of heavy dew, and lack of cattle grazing contribute to greater catches of Oxyopes. Sweeping as a population sampling device may be inaccurate due to the inconsistency of these factors. Sampling must be supplemented with observation of spider activities (and the same probably applies to other inhabitants of the vegetation) to evaluate properly the results of sweepings and the causes of variation in catch sizes.