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The Center for Native Grasslands Management

Title: Nutrient and energetic characteristics of sweepnet-collected invertebrates
Year: 1995
Author(s): Robel, R. J., Press, B. M., Henning, B. L., Johnson, K. W., Blocker, H. D., Kemp, K. E.
Source Title: Journal of Field Ornithology
Source Type: Journal
pages: 44-53
Original Publication: http://  
Abstract: As a result of the importance of food resources, primarily invertebrate biomass, to the understanding of reproductive strategies of grassland birds, the nutrient and energy characteristics of invertebrate biomass were investigated during late spring and early summer. Sweepnets were used to collect invertebrate biomass on two sites in eastern Kansas and the collections were separated into order or family groups. Nutrient and energy characteristics of those taxonomic groups with sufficient biomass at the family or order level were measured, Fat contents of families ranged from 8% (dry mass) for Acrididae to 32% for Miridae. Crude protein ranged from 54% for a composite sample of Hemiptera to 77% for Araneida. Crude fiber ranged from 5-8% for Araneida to 17-18% for Hemiptera. Calcium levels varied from 1292 ppm in Diptera to 2560 ppm in Lepidoptera, and phosphorous levels ranged from 5840 ppm in a composite Hemiptera sample to 9360 ppm in Pentatomidae. Gross energy contents ranged front 4906 cal/g for a sample of Acrididae to 6452 cal/g for Cydnidae. Pooled invertebrate biomass collections from the two sites differed in fat, crude fiber and energy content. Implications of these results on studies of the interactions of food resources, foraging behavior, habitat fragmentation and reproductive strategies of birds are discussed.