Santa Rosalia Reconsidered: Size Ratios and Competition

Simberloff, Daniel; Boecklen, William J.

doi:10.1111/j.1558-5646.1981.tb04990.x

Cited by 259 publications

(221 citation statements)

References 63 publications

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“…Even as the primacy of natural selection as the engine of evolutionary change was under attack (1,6), parallel arguments were being leveled against character displacement. Statistical analyses showed that, in many cases, differences between sympatric species were no greater than would be expected by chance (7,8). Moreover, even when sympatric species were significantly different in morphology, ecological character displacement was but one of many possible explanations.…”

mentioning

confidence: 95%

Ecological character displacement and the study of adaptation

Losos

2000

Proc. Natl. Acad. Sci. U.S.A.

165

131

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mentioning

confidence: 95%

Ecological character displacement and the study of adaptation

Losos

2000

Proc. Natl. Acad. Sci. U.S.A.

165

131

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“…These factors include: (1) intensified competition with other bumblebee species (Inouye, 1977;Simberloff and Boecklen, 1981;Ranta, 1982;Williams P.H., 1985Williams P.H., , 1988; (2) narrower climatic range (Williams P.H., 1985(Williams P.H., , 1988(Williams P.H., , 2005Fitzpatrick et al, 2007;Williams P.H. et al, 2007); (3) closer proximity to climatic range edge (Williams P.H., 1985(Williams P.H., , 1988(Williams P.H., , 2005Fitzpatrick et al, 2007;Williams P.H.…”

Section: Characteristics Of the Most Susceptible Speciesmentioning

confidence: 99%

Bumblebee vulnerability and conservation world-wide

2009

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-We review evidence from around the world for bumblebee declines and review management to mitigate threats. We find that there is evidence that some bumblebee species are declining in Europe, North America, and Asia. People believe that land-use changes may be having a negative effect through reductions in food plants in many parts of the world, but that other factors such as pathogens may be having a stronger effect for a few species in some regions (especially for Bombus s. str. in North America). Evidence so far is that greater susceptibility to land-use change is associated world-wide with small climatic ranges, range edges, and late-starting colony-development cycles. More evidence is needed on the roles of pollen specialization, nest sites, hibernation sites, and pesticides. It is still too early to assess the success of schemes aimed at improving forage in agricultural and conservation areas. However, schemes aimed at raising public awareness have been very successful. Until proven safe, we recommend that live bumblebees should not be moved across continents or oceans for commercial pollination.bumblebee / Bombus / threat / vulnerability / decline / conservation

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“…They are based on the assumptions that: (i) species with strong overlap in resource use or other niche dimensions cannot coexist (Gause 1934, Hardin 1960, Simberloff & Connor 1981 and (ii) species that do coexist differ in body size or functional morphology which allows their exploitation of different resources (Brown & Wilson 1956, Hutchinson 1959, Simberloff & Boecklen 1981. These two assumptions have been incorporated into the ecological niche theory that describes the existence of rules for the structuring and coexistence of species within communities.…”

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Assembly rules in Muscid Fly assemblages in the grasslands Biome of Southern Brazil

Krüger¹,

Carvalho²,

Ribeiro³

2010

Neotrop. entomol.

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-The distribution of muscid species (Diptera) in grasslands fragments of southern Brazil was assessed using null models according to three assembly rules: (a) negatively-associated distributions; (b) guild proportionality; and (c) constant body-size ratios. We built presence/absence matrices and calculated the C-score index to test negatively-associated distributions and guild proportionality based on the following algorithms: total number of fi xed lines (F L ), total number of fi xed columns (F C ), and the effect of the average size of the populations along lines (W) for 5000 randomizations. We used null models to generate random communities that were not structured by competition and evaluated the patterns generated using three models: general, trophic guilds, and taxonomic guilds.All three assembly rules were tested in each model. The null hypothesis was corroborated in all F L X F C co-occurrence analyses. In addition, 11 analyses of the models using the W algorithm showed the same pattern observed previously. Three analyses using the W algorithm indicated that species cooccurred more frequently than expected by chance. According to analyses of co-occurrence and guild proportionality, the coexistence of muscid species is not regulated by constant body size ratios. In fl ies of the grasslands, no rule was identifi ed. Yet, a consensus did emerge from our analyses: species co-occur more frequently than expected by chance, indicating that aggregation is a recurring phenomenon among fl ies with saprophagous adults and predatory larvae. Therefore, competition does not seem to play an important role in the determination of muscid assemblages in the grasslands in Southern Brazil.

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Santa Rosalia Reconsidered: Size Ratios and Competition

Cited by 259 publications

References 63 publications

Ecological character displacement and the study of adaptation

Ecological character displacement and the study of adaptation

Bumblebee vulnerability and conservation world-wide

Assembly rules in Muscid Fly assemblages in the grasslands Biome of Southern Brazil

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