Phylogenetic analysis of the latitude‐niche breadth hypothesis in the butterfly subfamily Nymphalinae

Abstract

1. One possible explanation for the latitudinal gradient in species richness often demonstrated is a related gradient in niche breadth, which may allow for denser species packing in the more stable environments at low latitudes.2. The evidence for such a gradient is, however, ambiguous, and the results have varied as much as the methods. Several studies have considered the non-independence of species, but few have performed explicit phylogenetic analyses.3. In the present study, we tested for a correlation between diet breadth and latitude of distribution in Nymphalinae butterflies using generalised estimating equations (GEE) and accounting for phylogenetic independence.4. Using a simple model with only latitude of distribution as a predictor variable revealed a significant positive relationship with diet breadth. Previous studies, however, have shown that diet breadth is also correlated with butterfly range size, and in turn, that range size may be correlated with latitude of distribution. Including geographical range size in the model also turned out to have a profound effect on the results -to the extent that the relationship between latitude of distribution and diet breadth was effectively reversed.5. We conclude that, at least for this group of butterflies, there is no evidence for a positive correlation between latitude of species distribution and diet breadth when controlling for range size, and that the effect may actually even be reversed.

Latitudinal gradients in biotic niche breadth vary across ecosystem types

“…Alternatively, the higher productivity of the tropics [22] may result in a broader niche space [23], which could also sustain greater biodiversity even if niche sizes are globally similar. Although the assumptions of the latitude-niche breadth hypothesis are only equivocally supported [21], it remains a compelling potential mechanism for the latitudinal gradient in species richness [24][25][26].…”

Temporal and spatial variability of environments drive the patterns of species richness along latitudinal, elevational, and depth gradients

“…2). However, it is necessary to note that the return tendency when, for example, plant-pollinator interactions become more specialized with the increase of latitude, is also observed in studies (Ollerton and Cranmer, 2002;Slove and Janz, 2010). These facts may be explained by the progressive impoverishment of the flora moving north.…”

“…This increase, however, is not always monotonic (Roy, Jablonski, Valentine, and Rosenberg, 1998;Crame, 2000) and is often seriously disturbed by various factors. On land, among the most important of such factors are water deficit and extreme temperatures (O'Brien, 1993;Buckley and Jetz, 2007;Smith, de Oca, Reeder, and Wiens, 2007); in oceans-dissolved oxygen shortage (Levin, 2003), oceanic currents (Owen, 1981 and references therein; Veron, 1995), upwelling processes (Owen, 1981 and references therein; Macpherson, 2002) and large river outflow (Veron, 1995;Macpherson, 2002). In addition, the latitudinal change in species diversity may be different for different taxa (Macpherson, 2002;Powney et al, 2010), and some rare taxa.…”

Shifts in species richness, herbivore specialization, and plant resistance along elevation gradients

“…; Novotny et al. ; Slove and Janz ) and plant defense (Moles et al. ) along latitude, and these dimensions have never been simultaneously assessed.…”