Fine‐scale climatic variation drives altitudinal niche partitioning of tabanid flies in a tropical montane cloud forest, Ecuadorian Chocó

Abstract

1. In montane systems, global warming may lead communities to disassemble by forcing organisms to shift their distributions to higher elevations or by causing the extinction of those that are unable to adapt. To predict which species are most at risk from environmental change, physiological responses to multiple factors must be measured in natural conditions at fine spatial and temporal scales.2. To examine the potential drivers of elevational distributions in tabanid flies, specimens were exhaustively sampled at three altitudes within a tropical montane cloud forest in Western Ecuador. Observed abundances were then correlated with seven environmental variables measured in situ. It was hypothesised that (1) tabanid distributions were significantly associated with particular environmental conditions measured in each altitudinal habitat, and (2) a greater proportion of lowland species were limited to a specific elevation than highland species.3. Most species occupied well-defined altitudinal niches corresponding to optimal climatic conditions. Colder weather, higher daily temperature variability, and higher levels of moisture seemed to limit most species from establishing in high elevation sites of this mountainous ecosystem.4. Despite the high dispersal potential of tabanids within the study area, results suggest that most tabanid flies are limited to the subset of altitudes where their climatic requirements are satisfied.

Forest stratification shapes allometry and flight morphology of tropical butterflies

“…The use of trait-based approaches to explore species responses to their biotic and abiotic environment are central to our understanding of the structure of natural assemblages [95], proving effective in tropical rainforests (e.g. [96,97]). Here, we report a consistent pattern of habitat specialization linked to the evolution of flight traits.…”

Tabanids in South America

“…This genus includes species with long antennal tooth, short proboscis, soft and pollinose labella, some setae on basicosta, eyes often pilose and wings with a dark band with a fenestrae on discal cell [19]. In Ecuador, Dicladocera macula (Macquart) was recorded in both side of Andean cordillera between 1600-3400 m, in montane forest, paramo and Andean shrubs [98]. Coscarón re-described the female e described the male of Dicladocera nubipennis (Rondani), a species from Argentine Subandean subregion [141].…”

“…In 2009, Cárdenas, Buestán and Dangles published studies on the diversity and distribution of tabanofauna of Ecuador and a catalog listing 198 species; in this study, the authors discussed the distribution of Chrysops varians tardus, Dicladocera macula and Fidena rhinophora using georeferenced localities and niche modeling analyses[99]. More recently, Cárdenas studied the distribution of tabanids according to altitudes and climatic factors, finding that most specimens have their activities limited by extremes temperature and humidity[98,100].In Peru, the first specific publication on Peruvian tabanofauna was Soukoup's in 1945, which listed 81 species in the country[208], most of them were already mentioned in Kröber's catalog of 1934[31]. In 1951, Kröber reported the result of the expedition held in southern Peru, adding 14 species to those known[209].…”

Temporal niche partitioning of Swiss black scavenger flies in relation to season and substrate age (Diptera, Sepsidae)

“…both seasonal and diurnal patterns of occurrence, which equally reflect their thermal niches and competitive interactions (e.g. Cárdenas et al 2016). For example, the heat-sensitive yellow dung fly abounds on pastures in early spring and late autumn but largely disappears from their mating sites (dung pats) during the hottest summer months, and also shows corresponding diurnal activity patterns, being active midday on cool days but in the late afternoon on warm days (Parker 1970, Jann et al 2000, Blanckenhorn 2009).…”