Residency in white-eared hummingbirds (Hylocharis leucotis) and its effect in territorial contest resolution

Abstract

BackgroundTerritory owners usually defeat intruders. One explanation for this observation is the uncorrelated asymmetry hypothesis which argues that contests might be settled by an arbitrary convention such as “owners win.” We studied the effect of territorial residency on contest asymmetries in the white-eared hummingbird (Hylocharis leucotis) in a fir forest from central Mexico.MethodsTwenty white-eared male adult hummingbird territories were monitored during a winter season, recording the territorial behavior of the resident against intruding hummingbirds. The size and quality of the territory were related to the probability that the resident would allow the use of flowers by the intruder. Various generalized models (logistical models) were generated to describe the probabilities of victory for each individual resident depending on the different combinations of three predictor variables (territory size, territory quality, and intruder identity).ResultsIn general, small and low quality territory owners tend to prevent conspecific intruders from foraging at a higher rate, while they frequently fail to exclude heterospecific intruders such as the magnificent hummingbird (Eugenes fulgens) or the green violetear hummingbird (Colibri thalassinus) on any territory size. Our results showed that the identity of the intruder and the size and quality of the territory determined the result of the contests, but not the intensity of defense.DiscussionInitially, the rule that “the resident always wins” was supported, since no resident was expelled from its territory during the study. Nevertheless, the resident-intruder asymmetries during the course of a day depended on different factors, such as the size and quality of the territory and, mainly, the identity of the intruders. Our results showed that flexibility observed in contest tactics suggests that these tactics are not fixed but are socially plastic instead and they can be adjusted to specific circumstances.

Patterns of territorial space use by Shining Sunbeams ( Aglaeactis cupripennis ), tropical montane hummingbirds

“…The territorial behavior of hummingbirds can be influenced by factors such as resource abundance and quality, prior‐residence effects, and the identity and density of co‐occurring competitors (Norton et al , Marchesseault and Ewald , Temeles et al , Kokko et al , Rousseu et al , Mendiola‐Islas et al ). The results of previous studies have highlighted how these factors can influence territory size, or the thresholds needed to maintain territorial behavior in some species (Norton et al , Eberhard and Ewald , Justino et al ).…”

Coexistence among morphologically similar hummingbird species is promoted via density compensation in a Mexican temperate forest

“…The temperate forests of Mexico are no exception. To date, studies conducted in these environments across the country indicate that hummingbird ensembles are dynamic, with the presence of resident and migratory species usually overlapping in their use of floral resources, and where territorial behavior and body size are initially the main indicators of competitive dominance (Lyon, ; Lara, ; Ortiz‐Pulido & Vargas‐Licona, ; Mendiola‐Islas, Lara, Corcuera, & Valverde, ; Rodríguez‐Flores & Arizmendi, ; López‐Segoviano, Arenas‐Navarro, Vega, & Arizmendi, ; López‐Segoviano, Bribiesca, & Arizmend, ). Given the morphological homogeneity of hummingbird species present in these environments, the mechanisms of coexistence evaluated to date have primarily focused on foraging behavior patterns (Lara et al, ; Márquez‐Luna, Lara, & Ortiz‐Pulido, ; Rodríguez‐Flores & Arizmendi, ).…”

Is bigger always better? Neither body size nor aggressive behavior are good predictors to measure the degree of specialization of hummingbird interaction networks in rocky outcrops

“…They can influence the composition of hummingbird species exploring a given food source, explaining in part the niche specialization observed in this group of birds (Wolf et al 1976, Feinsinger & Colwell 1978, Lopez-Segoviano et al 2018, Marquez-Luna et al 2019). Overall, larger hummingbird species tend to dominate, excluding smaller species from high-quality energy resources (Araujo-Silva and Bessa 2010; Justino et al 2012; Mendiola-Islas et al 2016, Marquez-Luna et al 2019). However, smaller species can also establish and defend foraging territories against larger contenders (Wolf et al 1976; Antunes 2003).…”