Territorial contests within and between two species of flies (Diptera: Richardiidae) in the wild

Abstract

Males and females of two syntopic phytophagous fly species (O. nitens and O. ferruginea, Diptera: Richardiidae) compete over small ephemeral feeding territories. We assessed fight frequency of both sexes of two species in the wild, and the simultaneous effects of potential fight asymmetries, sex and species, on the outcome of territorial contests in relation with resident status. Our results showed that residents won most of the fights, although the proportion of fights won by the resident depended on the sex of the resident, the interaction between the sex of the resident and size, and the year. Furthermore, even though some combinations of species and sex categories could be found on the same tree more than expected by chance, this did not imply a significantly high fight frequency for such combinations.

Territorial battles between fiddler crab species

“…This is interesting since the two species potentially have different burrow structures (H.L.C. 2016, personal observation) which would represent different resource qualities and should, therefore, affect the male's decision on who to fight [ 7 ]. However, T. elegans evicted both conspecifics and heterospecifics.…”

“…Studies on shore birds demonstrated a decline in numbers after events resulting in local habitat loss, as a result of increased intraspecific and interspecific competition [ 5 , 6 ]. Increased competition is costly as it results in reduced fitness or even survivorship for individuals [ 7 ] or even entire species [ 8 ].…”

“…Consequences resulting from competition include loss of valuable resources (e.g. food or shelter, [7,9]), increased exposure to predators or environmental conditions [11], or if the competitive encounters are of an aggressive nature, injury or death [12][13][14] competitive processes may aid in predicting biodiversity losses associated with habitat losses and/or restrictions. Interspecific competition occurs when two species occupy the same ecological niche and require the same resource [8,9].…”

“…Resource quality may also influence a T. elegans male's decision on who to fight for a new territory [7]. We know that resource quality is an important factor in conspecific fights [19,29].…”

Why can't we all just get along? Interspecific aggression in resident and non‐residentPodarcis melisellensislizards

“…A residency advantage to interspecific territorial disputes has been demonstrated in several insects (Resende, ; e.g. Becerril‐Morales & Macias‐Ordonez, ), but has seldom been tested explicitly in vertebrates (but see Smith & Pough, for an example). Understanding the role of residency in affecting interspecific aggression is important for understanding interspecific interactions because it may potentially explain why some species consistently dominate heterospecifics in aggressive and competitive interactions.…”