Constitutive immune function in European starlings, \u3cem\u3eSturnus vulgaris\u3c/em\u3e, is decreased immediately after an endurance flight in a wind tunnel

Life-history theory predicts that animals face a trade-off in energy allocation between performing strenuous exercise, such as migratory flight, and mounting an immune response. We experimentally tested this prediction by studying immune function in European starlings, Sturnus vulgaris, flown in a wind tunnel. Specifically, we predicted that constitutive immune function decreases in response to training and, additionally, in response to immediate exercise. We compared constitutive immune function among three groups: (1) ‘untrained’ birds that were kept in cages and were not flown; (2) ‘trained’ birds that received flight training over a 15 day period and performed a 1-4 h continuous flight, after which they rested for 48 h before being sampled; and (3) ‘post-flight’ birds that differed from the ‘trained’ group only in being sampled immediately after the final flight. A bird in our trained group represents an individual during migration that has been resting between migratory flights for at least 2 days. A bird in our post-flight group represents an individual that has just completed a migratory flight and has not yet had time to recover. Three of our four indicators (haptoglobin, agglutination and lysis) showed the predicted decrease in immune function in the post-flight group, and two indicators (haptoglobin, agglutination) showed the predicted decreasing trend from the untrained to trained to post-flight group. Haptoglobin levels were negatively correlated with flight duration. No effect of training or flight was detected on leukocyte profiles. Our results suggest that in European starlings, constitutive immune function is decreased more as a result of immediate exercise than of exercise training. Because of the recent emergence of avian-borne diseases, understanding the trade-offs and challenges faced by long-distance migrants has gained a new level of relevance and urgency

Ecological Factors Underlying the Nonbreeding Distribution of Western Sandpipers

Avian species in which males and females migrate to different nonbreeding areas provide candidate systems to study ecological factors underlying distribution patterns. Western Sandpipers (Calidris mauri) are such \u27differential migrants\u27. They breed mainly in Alaska and overwinter along the American Pacific and Caribbean coastlines. In this thesis, I document an increasing proportion of females at more southerly latitudes. I review existing explanatory hypotheses for differential migration, propose two novel hypotheses, and test these with data collected at four latitudes. According to the feeding niche hypothesis, intertidal invertebrates are buried more deeply towards the south, possibly due to higher ambient temperature andlor desiccation. Longer bills enable probing (foraging on buried prey) to greater depths. Females have disproportionately long bills, and therefore can exploit a feeding niche at greater vertical depth. Bill length residuals, corrected for tarsus length, were predicted to increase towards the south. This was only found in males. No clear change of feeding mode with latitude was detected. Females probed more than males at all locations, even though aspects of the ultrastructure of female bills did not indicate greater specialisation for probing. At the one site where the relationship was measured, both sexes probed more with increasing sediment temperature. According to the predation danger hypothesis, predator escape ability of males and females, indexed by wingloading, differs consistently across latitudes. Escape ability is generally reduced with higher wingloading. Individuals with poorer escape ability were therefore predicted to prefer southern sites, where less fat is required as insurance against environmental variability. Wingloading was higher overall for females. At one site I compared the sex ratio of carcasses, assessed molecularly, to that of fiee-living birds, but found no evidence for any sex-bias in predator-induced mortality. Wingloading increased with latitude in both sexes, but an index of predation danger remained constant across latitudes. Within latitudes, wingloading was lower at smaller, and presumably more dangerous, sites. My results provide evidence for both hypotheses, while other hypotheses for differential migration were not supported. I suggest that both escape performance and feeding niche divergence are important factors in determining large-scale spatial distribution in Western Sandpipers

Declines of Aerial Insectivores in North America Follow a Geographic Gradient

North American birds that feed on aerial insects are experiencing widespread population declines. An analysis of the North American Breeding Bird Survey trend estimates for 1966 to 2006 suggests that declines in this guild are significantly stronger than in passerines in general. The pattern of decline also shows a striking geographical gradient, with aerial insectivore declines becoming more prevalent towards the northeast of North America. Declines are also more acute in species that migrate long distances compared to those that migrate short distances. The declines become manifest, almost without exception, in the mid 1980s. The taxonomic breadth of these downward trends suggests that declines in aerial insectivore populations are linked to changes in populations of flying insects, and these changes might be indicative of underlying ecosystem changes

Erratum:Length of stopover, fuel storage and a sex-bias in the occurrence of two sub-species of Red Knots Calidris c. canutus and C.c. islandica in the Dutch Wadden Sea during southward migration. (Ardea (2000) 88:2 (165-176))

Debido al auge de la hotelería en el Perú, se vuelve necesario saber si las personas que trabajan en este campo están debidamente preparadas, y no me refiero al aspecto técnico de la profesión, sino al aspecto emocional. La presente investigación buscó saber la manera en que los profesionales hoteleros hacen uso de sus competencias emocionales. Se eligió un hotel 4 estrellas ubicado en el distrito de Miraflores de la ciudad de Lima donde se evaluó a trabajadores de las diferentes áreas que conforman un hotel. Por tratarse de un fenómeno poco estudiado en el rubro hotelero de nuestro pais se realizó una investigacion del tipo exploratoria cualitativa y se utilizó la entrevista de profundidad como herramienta de recolección de la información. Los resultados demostraron que todos ellos habían escuchado hablar de la inteligencia emocional y sabían de su importancia. Asimismo, señalaron a la experiencia adquirida a través de los años y el haber pasado por diferentes áreas de un hotel antes de ocupar el puesto actual como los factores que contribuyeron al desarrollo de sus competencias emocionales, lo que al mismo tiempo les ha dado las herramientas necesarias para lidiar con situaciones de diversa índole para asegurar de esta manera la satisfacción del huésped. Se sugiere el reconocimiento de la inteligencia emocional como factor clave para conectar con los huespedes, crear vinculos efectivos que van mas allá de lo comercial, y que será determinante en la satisfacción del cliente