The index of relative importance: an alternative approach to reducing bias in descriptive studies of animal diets

Hart, Ronan; Calver, Michael C.; Dickman, Chris R.

doi:10.1071/wr02009

Cited by 77 publications

(51 citation statements)

References 28 publications

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“…The index of relative importance has mostly been applied to fish diets, but some authors have suggested that it could be successfully applied to dietary studies in other animal groups (Hart et al 2002). The present study constitutes the first application of IRI to the study of bee diets.…”

Section: The Importance Of Iri To Assess Bee Dietsmentioning

confidence: 96%

“…The advantage of IRI is that it combines number, frequency, and volume values avoiding the underestimation of food items (i.e., pollen types) with large volume but scarcely foraged, or reverse, which happens when these values are considered separately. Furthermore, food eaten by many individuals but in small numbers or small volumes will have a high frequency of occurrence, but may not be highly important in the diet (Pinkas et al 1971;Hart et al 2002).…”

Section: The Importance Of Iri To Assess Bee Dietsmentioning

confidence: 99%

“…For ranking the relative importance of the pollen types found in the provisions, the index of relative importance (IRI) was estimated using the formula: IRI=(N +V )F, where N is the numerical percentage, V is the volumetric percentage, and F is the frequency of occurrence percentage (Pinkas et al 1971;Hart et al 2002). The numerical percentage was calculated by counting the number of grains per pollen type (or tetrads for Ludwigia ) and then they were added across the 17 nests.…”

Section: Irimentioning

confidence: 99%

“…Although this deeper analysis has only been carried out for a few bee species (Malagodi-Braga and Kleinert 2009;Vossler et al 2010;Rech and Absy 2011a, b), its importance is highlighted in this study. On the other hand, a combination of three measures into a single estimation of the relative importance of food types has been comprehensively used in other organisms, mainly fish, but never in bees (Hart et al 2002). This index of relative importance (IRI) was proposed by Pinkas et al (1971) and combines the counting of particular food items (such as prey species), estimation of their volume, and frequency of their occurrence (Hart et al 2002).…”

Section: Introductionmentioning

confidence: 99%

“…On the other hand, a combination of three measures into a single estimation of the relative importance of food types has been comprehensively used in other organisms, mainly fish, but never in bees (Hart et al 2002). This index of relative importance (IRI) was proposed by Pinkas et al (1971) and combines the counting of particular food items (such as prey species), estimation of their volume, and frequency of their occurrence (Hart et al 2002). Although IRI does not include nutritional values of food items, it reduces bias in cases when only one of the components is used.…”

Section: Introductionmentioning

confidence: 99%

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Assessment of the pollen diet in a wood-dwelling augochlorine bee (Halictidae) using different approaches

Dalmazzo

Vossler

2014

Apidologie

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-Most studies on bee pollen diet are based on the abundance of each pollen type composing honey or pollen stores of whole nests (pollen counts). In an effort to characterize the diet of the augochlorine bee Augochlora amphitrite , we employed nest and intra-nest pollen analyses and bee flower visitation. In addition, we tested a novel approach, the index of relative importance (IRI), a method that combines pollen counts, pollen volume, and frequency of pollen occurrence. Using nest pollen analysis, we found that the Ludwigia type dominated pollen counts, comprising 56 % of whole nests, and thus would have concluded that this is the only most important pollen source in the diet. Instead, we found seven other important sources including Ipomoea alba , Ipomoea cairica , Gymnocoronis spilanthoides , and Pavonia types as well as 26 new floral hosts using all four methods in combination. Thus, we recommend that other studies of bee diet include these other approaches when possible and, especially, the novel approach of IRI.Augochlora amphitrite / floral visitation / index of relative importance (IRI) / intra-nest pollen analysis / Ludwigia

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Section: The Importance Of Iri To Assess Bee Dietsmentioning

confidence: 96%

Section: The Importance Of Iri To Assess Bee Dietsmentioning

confidence: 99%

Section: Irimentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Assessment of the pollen diet in a wood-dwelling augochlorine bee (Halictidae) using different approaches

Dalmazzo

Vossler

2014

Apidologie

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Appendix B: Study Methods

Elliott¹,

Franco²,

Ramos³

et al. 2022

Fish and Fisheries in Estuaries

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Nearshore seascape connectivity enhances seagrass meadow nursery function

Olson

Hessing‐Lewis

Haggarty

et al. 2019

Ecological Applications

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Diverse habitats composing coastal seascapes occur in close proximity, connected by the flux of materials and fauna across habitat boundaries. Understanding how seascape connectivity alters important ecosystem functions for fish, however, is not well established. For a seagrass‐dominant seascape, we predicted that configuration and composition of adjacent habitats would alter habitat access for fauna and trophic subsidies, enhancing nursery function for juvenile fish. In an extensive Zostera marina seagrass meadow, we established sites adjacent to (1) highly complex and productive kelp forests (Nereocystis luetkeana), (2) unvegetated sand habitats, and (3) in the seagrass meadow interior. Using SCUBA, we conducted underwater observations of young‐of the‐year (YOY) rockfish (Sebastes spp.) recruitment across sites. Using generalized linear mixed effects models, we assessed the role of seascape adjacency relative to seagrass provisions (habitat complexity and prey) on YOY recruitment. YOY rockfish collections were used to trace sources of allochthonous vs. autochthonous primary production in the seagrass food web, via a δ13C and δ15N isotopic mixing model, and prey consumption using stomach contents. Overall, seagrass nursery function was strongly influenced by adjacent habitats and associated subsidies. Allochthonous N. luetkeana was the greatest source of energy assimilated by YOY rockfish within seagrass sites. In seagrass sites adjacent to N. luetkeana kelp forests, YOYs consumed higher quality prey, which corresponded with better body condition relative to sites adjacent to sand. Moreover, kelp forest adjacency enhanced YOY rockfish recruitment within the seagrass meadow, suggesting that habitat complexity is a key seascape feature influencing the nursery function of nearshore habitats. In general, to promote seascape connectivity, the conservation and restoration of nursery habitats should prioritize the inclusion of habitat mosaics of high structural complexity and productivity. We illustrate and emphasize the importance of using a seascape‐level approach that considers linkages among habitats for the management of important nearshore ecosystem functions.

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The index of relative importance: an alternative approach to reducing bias in descriptive studies of animal diets

Cited by 77 publications

References 28 publications

Assessment of the pollen diet in a wood-dwelling augochlorine bee (Halictidae) using different approaches

Assessment of the pollen diet in a wood-dwelling augochlorine bee (Halictidae) using different approaches

Appendix B: Study Methods

Nearshore seascape connectivity enhances seagrass meadow nursery function

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