Hylocharis Leucotis Research Articles

Reporte de un colibrí oreja blanca (Hylocharis leucotis) afectado por el trastorno de queratina aviar

El trastorno de la queratina aviar ocasiona un crecimiento anormal del pico y afecta a varias especies de aves en América y Europa. Sin embargo, hasta la fecha, no se había registrado en el grupo de los colibríes. En este trabajo reportamos a un individuo de Hylocharis leucotis con dicho trastorno, el cual fue capturado en la localidad de San Bernardino Lagunas, Vicente Guerrero, Puebla. Es posible que esta alteración afecte la alimentación y polinización de los colibríes que la padecen.

Visitantes florales en el cultivo de Phaseolus coccineus (Fabaceae) en el Altiplano de Puebla, México: importancia del manejo agrícola y color de flor

Antecedentes y Objetivos: Phaseolus coccineus es una planta alógama, con variación en color de la flor, que depende de polinizadores para su reproducción. La especie se cultiva bajo dos modalidades, una en la cual no se emplean agroquímicos para controlar arvenses y plagas (manejo tradicional) y otra en la que sí se usan (manejo tecnificado). No existen estudios que hayan evaluado la importancia del manejo agrícola y color de flor sobre los visitantes florales de esta especie, por lo que nuestro objetivo fue analizar cómo influyen estos factores en la diversidad y frecuencia de visitantes florales de P. coccineus. Métodos: Se estudiaron dos variedades de P. coccineus (de flor blanca y roja), cultivadas bajo dos sistemas de manejo diferentes. En el pico de floración, durante ocho días, se realizaron observaciones simultáneas, contabilizando el número de visitantes florales y de visitas. Se calculó la riqueza específica y los números de especies efectivas como medida de diversidad, se aplicaron pruebas de chi-cuadrada, se practicó un análisis de correspondencias y se construyeron gráficos de rango-abundancia. Resultados clave: Se registraron 42 morfoespecies, agrupadas en seis órdenes; predominaron Apis mellifera e Hylocharis leucotis. El número de visitas registradas fue de 1613 y 1105 en manejo tradicional de flores blancas y rojas, respectivamente, y de 1427 y 815 en el manejo tecnificado, existiendo diferencias estadísticas consistentes entre manejos, no así para color de flor. En flores blancas, el manejo tradicional fue dos veces más diverso que el tecnificado; en flores rojas, la diferencia fue de 1.26 veces. Conclusiones: La diversidad y frecuencia de visitantes florales de P. coccineus se ven favorecidas por el manejo agrícola tradicional, ello fundamenta la conveniencia de fomentar esta modalidad de cultivo. Bajo las condiciones estudiadas, el color de flor no influyó en la riqueza de especies, ni mostró tendencias definidas en la frecuencia de visitas.

True grit: ingestion of small stone particles by hummingbirds in West Mexico

BackgroundGrit is used by birds mainly for grinding hard food items but can also serve a nutritional role as a source of minerals. Ingestion of grit by birds has been documented primarily in species that feed on seeds and invertebrates. Although feeding mainly on nectar and small arthropods, hummingbirds also ingest grit, but why they do so is unclear. We quantified the number of grit particles in the stomachs of six species of hummingbirds during an annual cycle in a seasonal ecosystem of West Mexico.MethodsWe compared the number of grit particles in the stomachs of different hummingbird species (Mexican Violetear Colibri thalassinus, Amethyst-throated Mountaingem Lampornis amethystinus, White-eared Hummingbird Basilinna leucotis, Rivoli’s Hummingbird Eugenes fulgens, Broad-tailed Hummingbird Selasphorus platycercus, and Rufous Hummingbird S. rufus), and between sex and age categories during the different seasons of a year. To determine if grit was used to grind ingested arthropods, we examined the relationships between the number of grit particles, the biomass of arthropods ingested, and their chitin content.ResultsAlthough species did not differ in the number of grit particles in their stomachs, we found that grit was mostly ingested by female individuals, with only one male of one species (Mexican Violetear) presenting grit in its stomach. We also found that female hummingbirds had grit in their stomachs during the rainy and the cold-dry season (June–February) but not during the warm-dry season (March–May). Our analyses revealed no relationship between the number of grit particles and the amount of ingested arthropods and arthropod chitin content. However, high grit consumption was related to wasp ingestion on Mexican Violetears.ConclusionsOur results indicate that grit is used mainly by female hummingbirds. The seasonal variation in the ingestion of grit by female individuals suggests that it can be used to meet mineral requirements related to breeding; however, this topic needs further exploration. Additionally, the use of grit was proportionally higher in juvenile individuals, suggesting it is used for grinding arthropods during a period of fast development.

A second decade of overwintering hummingbirds in Florida and Alabama

For a second decade, from November 2008 to March 2018, we examined the species diversity, return rate, longevity, and migration routes of hummingbirds overwintering in southern Alabama and the panhandle, northern peninsula, and central peninsula of Florida. We captured and banded 11 species of hummingbirds (n= 1,870 individuals), including 931 Rufous Hummingbirds (Selasphorus rufus; 49%), 583 Ruby-throated Hummingbirds (Archilochus colubris; 31%), 219 Black-chinned Hummingbirds (A. alexandri; 12%), 49 Buff-bellied Hummingbirds (Amazilia yucatanensis), 49 Calliope Hummingbirds (S. calliope), 19 Allen's Hummingbirds (S. sasin), 11 Broad-tailed Hummingbirds (S. platycercus), 6 Broad-billed Hummingbirds (Cynanthus latriostris), 1 Anna's Hummingbird (Calypte anna), 1 Costa's Hummingbird (Calypte costae), and 1 White-eared Hummingbird (Hylocharis leucotis). Site fidelity was high, with 299 hummingbirds of 5 species returning at least once. Two Rufous Hummingbirds migrated to our study area in the autumn from the West (Oklahoma and Texas). One Ruby-throated Hummingbird banded in Lakeland, Florida, was recovered in Utopia, New Brunswick, Canada, suggesting the overwintering Ruby-throated Hummingbirds in our study area are migratory and not sedentary.

Breeding in the cold? A White-eared Hummingbird (Basilinna leucotis) winter nest record from the mountains of Southern Oaxaca, Mexico

We report the finding of a White-eared Hummingbird (Basilinna leucotis) nest during the winter. The observation took place on 9 February 2019 in San José del Pacífico, Oaxaca, Mexico, in the Sierra Madre del Sur. The hummingbird nest was located in the understory, 115 cm above the ground. The nest was placed within a plot of a pine-oak forest at 2,857 m a.s.l. and had 2 nestlings with complete juvenile plumage. Floral phenology is known to be a key factor that determines the biological cycles of hummingbirds, which rely heavily on nectar resources to fulfill their nutritional needs in the breeding season. Around the nest, we observed Salvia punicans Epling, a plant that blossoms during the winter months in the Mexican mountains and is visited by White-eared Hummingbirds. Previous winter nest records in Southern Oaxaca date from more than 50 years ago. We briefly discuss the implications of winter reproduction for the species and the potential commonness of this event.

Phylogeography of the widespread white-eared hummingbird (Hylocharis leucotis): pre-glacial expansion and genetic differentiation of populations separated by the Isthmus of Tehuantepec

AbstractThe Pleistocene glacial cycles had a strong influence on the demography and genetic structure of many species, particularly on northern-latitude taxa. Here we studied the phylogeography of the white-eared hummingbird (Hylocharis leucotis), a widely distributed species of the highlands of Mexico and Central America. Analysis of mitochondrial DNA (mtDNA) sequences was combined with ecological niche modelling (ENM) to infer the demographic and population differentiation scenarios under present and past conditions. Analyses of 108 samples from 11 geographic locations revealed population structure and genetic differentiation among populations separated by the Isthmus of Tehuantepec (IT) and the Motagua-Polochic-Jocotán (MPJ) fault barriers. ENM predicted a widespread distribution of suitable habitat for H. leucotis since the Last Inter Glacial (LIG), but this habitat noticeably contracted and fragmented at the IT. Models for historical dispersal corridors based on population genetics data and ENM revealed the existence of corridors among populations west of the IT; however, the connectivity of populations across the IT has changed little since the LIG. The shallow geographic structure on either side of the isthmus and a star-like haplotype network, combined with the long-term persistence of populations across time based on genetic data and potential dispersal routes, support a scenario of divergence with migration and subsequent isolation and differentiation in Chiapas and south of the MPJ fault. Our findings corroborate the profound effects of Pleistocene climatic fluctuations on the evolutionary history of montane taxa but challenge the generality of expanded suitable habitat (pine-oak forests) during glacial cycles.

The spatial analysis of biological interactions: morphological variation responding to the co‐occurrence of competitors and resources

By sharing geographic space, species are forced to interact with one another and the contribution of this process to evolutionary and ecological patterns of individual species is not fully understood. At the same time, species turnover makes that species composition varies from one area to another, so the analysis of biological interaction cannot be uncoupled from the spatial context. This is particularly important for clades that show high degree of specialization such as hummingbirds, where any variation in biotic pressures might lead to changes in morphology. Here, we describe the influence of biological interactions on the morphology of Hylocharis leucotis by simultaneously considering potential competition and diet resources. We characterized the extent of local potential competition and local available floral resources by correlating two measurements of hummingbird diversity, floral resources and the size of morphological space of H. leucotis along its geographic distribution. We found that H. leucotis shows an important morphological variability across its range and two groups can be recognized. Surprisingly, morphological variation is not always linked to local hummingbird richness or the phylogenetic similarity of. Only in the southern part of its distribution, H. leucotis is morphologically more variable in those communities where it coexist with closely related hummingbird species. We also found that morphological variation in H. leucotis is independent from the availability of floral resources. Our results suggest that abiotic factors might be responsible for morphological differences across populations in Hylocharis leucotis being biological interactions of minor importance.

Superciliums in white-eared hummingbirds as badges of status signaling dominance.

The role of badges as indicators of contest ability has been previously described. In hummingbirds, the exhibition of a badge is expected to save energy expenditure in agonistic interactions and to favor energy intake. Here, we investigate whether variable supercilium size in the white-eared hummingbird has a role in dominance status signaling. Firstly, 45 hummingbird males were captured and their superciliums were photographed to investigate variation in size and any possible allometric relationships. Secondly, 42 male birds were used to analyze whether the supercilium has a role in dominance status signaling in a dyadic contest. We found that supercilium size varied continuously but that despite variability between individuals, there was no relationship between supercilium size and body size. However, our dyad experiment indicated that birds with larger badges were able to make more visits to the feeders than individuals with smaller badges. We suggest a status signaling function of the supercilium.

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

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.

LA CONDUCTA TERRITORIAL DEL ZAFIRO OREJA BLANCA (HYLOCHARIS LEUCOTIS) ES AFECTADA POR LA DISPONIBILIDAD DE ENERGÍA

White-eared Hummingbird (Hylocharis leucotis) territorial behavior is affected by energy availability. – Territoriality is a costly-foraging strategy. As a result, territorial animals must ensure that the energy within their territories is sufficient to support the costs of its defense. Hummingbirds are territorial and depend on nectar-containing flowers as their main energy source. In this study, we hypothesized that White-eared hummingbirds (Hylocharis leucotis), depending on the amount of energy (nectar) available in the environment, modify four aspects of their behavior (i.e., time spent for perching, foraging, and actively and passively defending territory), as well as territory size and response to intrusions into their territory. We monitored 30 individual territories during the winter flowering season at El Chico National Park, Mexico, and did not detect a significant effect of the energy available on time spent for perching or foraging, respectively. However, White-eared hummingbirds invested significantly more time in active and passive defense when the intrusion pressure was higher, and successful intrusions increased when the territories were bigger. Moreover, although territory size increased or decreased, a similar amount of energy therein was maintained throughout the duration of the study. Our results indicate that in this hummingbird species energy availability determines the size of their territories and the time spent on its defense.

Reproductive biology and nectar production of the Mexican endemic Psittacanthus auriculatus (Loranthaceae), a hummingbird-pollinated mistletoe.

Many mistletoe species produce 'bird'-pollinated flowers; however, the reproductive biology of the majority of these species has not been studied. Psittacanthus auriculatus is a Mexican endemic mistletoe, most common in open, dry mesquite grassland. Knowledge of the reproductive biology of P. auriculatus is essential for understanding species formation and diversification of Psittacanthus mistletoes, but it is currently poorly understood. Thus, we studied floral biology and phenology, nectar production and breeding system and pollination of this species. The hermaphroditic red-pink flowers open from the middle to the tip and petals are curly, but remain partially fused forming a floral tube of ca. 20-mm long. Flowers are partially protandrous, produce large amounts of nectar, last 2 days, and stigma receptivity is highest during the second day. We recorded hummingbirds (Cynanthus latirostris, Hylocharis leucotis, Amazilia beryllina, A. violiceps, Calothorax lucifer, Archilochus colubris) and less commonly butterflies (Agraulis vanillae, Anteos clorinde, Papilio multicaudatus, Phocides urania, Phoebis sennae) as floral visitors. P. auriculatus flowers are self-compatible. However, this mistletoe is an obligate animal-pollinated species, as the sensitive stigma avoids self-pollination. Under natural conditions, reproductive success was higher than in manually selfed or cross-pollinated flowers, likely due to the traplining foraging behaviour of hummingbirds. We suggest that the apparent efficient foraging behaviour of hummingbirds maintains gene flow among P. auriculatus, promoting outcrossing.

Female hummingbirds do not relocate rewards using colour cues

Males generally outperform females in spatial tasks. This difference in spatial performance may reflect differences in cue preference because males often use both spatial cues (distance and direction) and feature cues, whereas females prefer to use feature cues. However, studies in birds are few and results are conflicting. As wild male rufous hummingbirds, Selasphorus rufus, prefer to use spatial cues to relocate a rewarded flower, in the present study we tested free-flying wild female hummingbirds of three different species (rufous, white-eared, Hylocharis leucotis, and magnificent hummingbird, Eugenes fulgens) and males of one species (white-eared) for their cue preference in the same task in which rufous males have been tested previously. Birds were allowed to feed once from a four-flower array in which only one flower was rewarded. When the birds returned, the colour and the spatial cue designating the rewarded flower had been dissociated. Although we had expected females to visit the flower of the correct colour (feature cue) first, during the test phase most of the birds (males and females) went to the correct spatial location (spatial cue). It appears, then, that preference for spatial cues is not specific to males and it seems more likely to depend on the relevance or value of a cue to the solution of the task.

Testosterone levels in feces predict risk‐sensitive foraging in hummingbirds

Risk taking decisions related to the unpredictability of resource availability (risk‐sensitive foraging theory) have typically been explained by behavioral ecology and psychology approaches. However, little attention has been given to the physiological condition of animals as a factor that can influence the direction of foraging preferences. We evaluated the role of steroid hormones testosterone (T) and corticosterone (CORT) on the foraging preferences expressed by white‐eared hummingbirds Hylocharis leucotis in a risk‐sensitivity experiment. We recorded choices made by male individuals to floral arrays with constant and variable rewards (sugar concentration), and associated these with steroid hormone levels quantified at the start of the experiments. We found that males with higher T levels behave as risk‐prone foragers as they perform more visits to flower arrays with variable rewards. Interestingly, CORT levels were similar regardless whether individuals visited both types of array. According to our results, T seems to influence the foraging preferences of male hummingbirds. Individuals with higher levels of this hormone, made more rapid, frequent visits to flowers with variable rewards, and behave consistently as risk‐prone foragers, compared to males with low T levels. These are exciting avenues for future work, particularly considering recent evidence that individuals may exhibit behavioral differences, denoting an apparent personality, which may be associated with phisiological condition influencing how they respond behaviorally to environmental variation.

Risk indifference in white-eared hummingbirds (Hylocharis leucotis) confronting multiple foraging options

Variations in the quality or quantity of a food source determines if an animal takes the risk of spending energy searching for or eating it. Hummingbirds have been traditionally catalogued as risk-averse foragers. However, the inclusion of more than 2 options in a foraging set for risk-sensitive experiments has resulted in the observation that some hummingbird species preferred intermediate risk even if they had been risk-averse in a traditional binary risk experiment. These contrasting results suggest an effect of having multiple foraging options that had been ignored due to the design of previous risk experiments. Here, we studied the influence of varying reward volume (Experiment 1) or sugar concentration (Experiment 2) on choice behavior of white-eared hummingbirds, Hylocharis leucotis, by recording their visits to feed from a sucrose solution located in 4 artificial floral arrays associated with constant, low, medium, and high variance. In both experiments, each of the vertical arrays was evaluated in a training stage and a test stage. The birds visited all the arrays without discriminating among them, and thus were indifferent to variations in the volume or sugar concentration of reward. Thus, there was no influence of variance of nectar volume and sugar concentration on the choice behavior of the birds, ruling out the possibility that white-eared hummingbirds are risk sensitive under these conditions of 4 foraging alternatives.

Sensibilidad al riesgo durante el forrajeo en los colibríes Hylocharis leucotis y Selasphorus platycercus

La sensibilidad al riesgo es la capacidad de una especie de responder conductualmente ante la variabilidad de las recompensas en un ambiente dado. Un organismo puede ser aversivo, propenso o indiferente al riesgo. A la fecha aún no se ha probado simultáneamente el tipo de sensibilidad al riesgo y el efecto de la experiencia previa en las especies de colibríes Hylocharis leucotis y Selasphorus platycercus. Debido a que ambas especies son similares en cuanto a su estatus de residencia, territorialidad y especies de plantas sobre las que forrajean, hipotetizamos la misma respuesta en ambos factores. En este estudio determinamos el tipo de sensibilidad al riesgo que presentan estas dos especies al exponerlas experimentalmente a una experiencia breve de 10 min visitando flores artificiales variando la calidad de la recompensa. Hylocharis leucotis no mostró preferencia por ningún tipo de recompensa (constante o variable) por lo que se comportó como indiferente al riesgo, mientras que S. platycercus mostró preferencia por el tipo de recompensa constante, por lo que se comportó como aversivo al riesgo. La breve experiencia previa no influyó significativamente en la sensibilidad al riesgo de dichas especies. Nuestros resultados indican que estas especies tienen diferente sensibilidad al riesgo y que una experiencia de 10 min no modificó su preferencia de recompensa.

Abundancia de colibríes y uso de flores en un bosque templado del sureste de México

Hummingbird abundance varies with plant bloom phenology used for feeding. However, the information on hummingbird-flower interaction is limited for tropical mountain environments. We evaluated hummingbird abundance using mist nest and estimated monthly flowering phenology visited by hummingbirds in three different habitats (oak forest, cloud forest and bush) from January to August 2010 in Huitepec Ecological Reserve. We recorded four hummingbird species (Hylocharis leucotis, Lampornis amethystinus, Lamprolaima rhami and Eugenes fulgens), and their abundance varied among habitats (H3.8=14.8, p=0.001). Seven plant species were visited for hummingbirds and showed the highest number of flower species during dry season. Bush had the highest blossom. Fuchsia paniculata had the highest blossom period but only was visited by H. leucotis. Passiflora membranacea was the only species visited for all hummingbird species. The only positive association was E. fulgens abundance with P.a membranacea bloom (r(S)=0.93, p=0.02). Hummingbird abundance fluctuations in this study are determined for interactions with floral resources and their habitat distribution.

Is energy in nectar a good predictor of hummingbird activity at landscape scale?

Hummingbirds are excellent models to test the relationship between animal activity and resource availability, because their primary food source is conspicuous and easily quantified. However, after three published studies done at landscape scale, there is no conclusive evidence of a positive relationship between the activity of a hummingbird species and nectar energy. Here we explore the relationship between the activity of White-eared Hummingbird (Hylocharis leucotis) and the energy contained in nectar in a landscape located in a temperate region of central Mexico. We did not find significant correlation pooling the data of 9 1-ha plots. However, there was not a significant difference between the regression statistical slopes of observed activity–nectar availability and expected individuals–nectar availability, which suggests to us that the relationship hummingbird–energy is occurring in the landscape.

Effects of a snowstorm event on the interactions between plants and hummingbirds: fast recovery of spatio-temporal patterns

The global climatic change could cause, in some places, appearance of meteorological phenomena considered rare. If we understand the effect of these phenomena on birds we can understand how birds respond to weather changes. We report here the effect of a severe snowfall on hummingbird activity, flower abundance and hummingbird-plant interaction in a temperate forest of central Mexico. During our study we registered 1 hummingbird species (Hylocharis leucotis) and 7 plant species (Fuchsia thymifolia, F. microphyla, Salvia amarissima, S. elegants, Cestrum roseum, Penstemon campanulatus and Lonicera mexicana). Before the sudden climatic phenomena we registered 66 records of hummingbirds, 8 700 flowers, and 6 hummingbird visits to flowers. During the phenomena, there were zero hummingbird records, 160 flowers and zero visits. A month after the event there were 67 hummingbirds records, 1 825 flowers and 13 visits. Hummingbird activity recovered rapidly after the snowstorm, but 6 of 7 plants species lost all their flowers, except for L. mexicana, which received all hummingbird visits a month after the climatic event.

Memory for location and visual cues in white-eared hummingbirds Hylocharis leucotis

Abstract In nature hummingbirds face floral resources whose availability, quality and quantity can vary spatially and temporally. Thus, they must constantly make foraging decisions about which patches, plants and flowers to visit, partly as a function of the nectar reward. The uncertainty of these decisions would possibly be reduced if an individual could remember locations or use visual cues to avoid revisiting recently depleted flowers. In the present study, we carried out field experiments with white-eared hummingbirds Hylocharis leucotis, to evaluate their use of locations or visual cues when foraging on natural flowers Penstemon roseus. We evaluated the use of spatial memory by observing birds while they were foraging between two plants and within a single plant. Our results showed that hummingbirds prefer to use location when foraging in two plants, but they also use visual cues to efficiently locate unvisited rewarded flowers when they feed on a single plant. However, in absence of visual cues, in both experiments birds mainly used the location of previously visited flowers to make subsequent visits. Our data suggest that hummingbirds are capable of learning and employing this flexibility depending on the faced environmental conditions and the information acquired in previous visits.

Temporal-spatial segregation among hummingbirds foraging on honeydew in a temperate forest in Mexico

Abstract Spatial and temporal variation in interactions between hummingbirds and plants have often been examined, and hummingbirds and insects are known to indirectly interact in networks of nectar plants. In a highland temperate forest in Hidalgo, Mexico some oak trees were heavily infested by honeydew-producing insects (family Margarodidae, tribe Xylococcini, genus Strigmacoccus) and the honeydew was consumed by hummingbirds. Here using survival analysis we investigate how the honeydew produced by dense populations of these margarodids is temporally and spatially partitioned by hummingbirds. We also measured the availability and quality of honeydew exudates, and then we recorded the time until a bird visited and used such resources. Four hummingbird species consumed this resource (Atthis eloisa, Hylocharis leucotis, Colibri thalassinus and Eugenes fulgens). Data from 294 hours of observation on seven focal trees suggested temporal and spatial segregation among visiting birds according to body size and territorial behavior during the most honeydew-limited time. Hummingbird species differed in the daily times they foraged, as well as in the location where honeydew-producing insects were visited on the trees. Temporal and spatial segregation among hummingbird species is interpreted as an adaptation to reduce the risk of aggressive encounters. This may facilitate multispecies coexistence and allow these birds to exploit honeydew more effectively.