Search

During spring and autumn 2001, we screened 13,260 migrating birds at Ottenby Bird Observatory, Sweden, and found 3.4% were infested with ticks. Four birds, each a different passerine species, carried [...]

We conducted large-scale, systematic sampling of influenza type A virus in migratory waterfowl (mostly mallards [Anas platyrhynchos]) at Ottenby Bird Observatory, southeast Sweden. As with previous studies, we found a [...]

A small percentage of wood ants crawl up trees to gather food and return to the ground by free-falling. A field experiment was conducted to test the hypothesis that 'ant rain' increases in the presence of birds. The findings lend support to the hypothesis. The percentage of ants falling from trees where birds came to forage ranged from 2.9% to 28.4%, while the percentage of falling ants in trees without birds dropped to a mean of 3.7%.

Fear of humans and its effect on animal behavior is increasingly being recognized as an important structuring force in ecological landscapes, with consequences for ecological interactions and communities. When aggressive, physically dominant species are displaced by anthropogenic disturbance, physically weaker species exploit competitor and predator downtimes to forage in previously risky places. Birds feeding at outdoor restaurants and cafés in association with humans are exposed to fluctuating levels of perceived danger caused by frequently changing densities of human diners. Consequently, birds must make decisions about which dining tables to visit based on trade‐offs between foraging gain and perceived danger from avian competitors and humans. We tested the hypothesis that interspecific differences in response to perceived danger, combined with varying densities of human diners, dynamically alter which bird species predominates at dining tables. We found that house sparrows (Passer domesticus) tolerated higher human diner‐densities than larger‐sized, more physically dominant Eurasian jackdaws (Coloeus monedula). Sparrows were usually the first birds to visit diner‐occupied tables and spent more time there than jackdaws. However, at diner‐abandoned tables, this pattern changed: During low diner‐densities at surrounding tables, jackdaws were usually the predominant species in first visits and minutes spent visiting, while at high diner‐densities sparrows usually predominated. Moreover, along a gradient of increasing human diner‐density, sparrows gradually replaced jackdaws as the predominant species in first visits and time at abandoned tables. However, at diner‐occupied tables, once a sparrow chose which table to visit, factors other than diner‐density influenced its choice of where to forage there (table‐top or ground). To our knowledge, our research is the first scientific study of table‐visiting behavior by birds at outdoor restaurants and cafés, and the first to reveal interspecific differences in table‐visiting behavior by birds there. [ABSTRACT FROM AUTHOR]

We studied Mycobacterium avium lymphadenopathy in 183 Swedish children ( ********** Myncobacterium avium is the most common of the ontuberculous mycobacteria that infect otherwise healthy children (1). It manifests as [...]

During the spring of 1996, an estimated 581,395 Ehrlichia-infected ticks were imported into Sweden by migrating birds. Ehrlichia gene sequences found in ticks collected from these migrating birds were identical [...]

Acanthamoeba-Campylobacter coculture (ACC) method is described for isolating and enriching low concentrations of Campylobacter pathogens. The findings have shown that ACC method is a promising tool for the enrichment of Campylobacter species, particularly from water samples with low bacterial concentrations.

The Florentine Codex is a Renaissance-era illuminated manuscript that contains the earliest-known regional work on the birds of México. Its Nahuatl language texts and scholia (the latter later incorporated into its Spanish texts) were written in the 1560s by Bernardino de Sahagún's research group of elite native Mexican scholars in collaboration with Aztecs from two cities: Tlatelolco and Tenochtitlan. In the present study, I compared the contributions from these two cities and found many differences. While both cities contributed accounts and descriptions of land and water birds, those from Tlatelolco were mainly land birds, while those from Tenochtitlan were mainly water birds. Tlatelolco contributed over twice as many bird accounts as Tenochtitlan, and supplied the only information about medicinal uses of birds. Tenochtitlan peer reviewed the Tlatelolco bird accounts and improved many of them. In addition, Tenochtitlan contributed all information on bird abundance and most information about which birds were eaten and not eaten by humans. Spanish bird names appear more frequently in the Aztec language texts from Tenochtitlan. Content analysis of the Tenochtitlan accounts suggests collaboration with the water folk Atlaca (a prehistoric lacustrine culture) and indigenous contacts with Spanish falconers. The Renaissance-era studies of Sahagún's research group, on a now lost island in the formerly vast, bird-rich wetlands of the Valley of México, constitute the birth of Mexican ornithology and, coincidently, give the history of Mexican ornithology a distinctive, Aztlán-like beginning, significantly different from the ornithological histories of neighboring countries. [ABSTRACT FROM AUTHOR]

The historical account of Aztec Emperor Auitztol's introduction of the great-tailed grackle Quiscalus mexicanus into the Valley of Mexico (1486-1502) is significant because it documents human translocation of wild birds in Mexico over 500 years ago, before the Spanish Conquest of that land. In the present paper, which defends the account from writings that dispute it, I first review the evidence of how the account was obtained and show that its many details are consistent with what is known from other sources about both the great-tailed grackle and the Aztecs (Nahuas). I then review and examine all published criticisms of the account and explain in detail why they are wrong. The critics have to date presented no persuasive evidence to support their speculation that the Aztecs confused, or might have confused, a natural invasion for an introduction. In contrast to these critics, Bernardino de Sahagún's research group in the 1500s presented a highly credible, peer-reviewed historical account that documented Aztec introduction of the great-tailed grackle. The pioneering work of these Renaissance Mexican scholars continues to stand as one of the most important records of invasive alien species introduction in ancient times. [ABSTRACT FROM AUTHOR]

The article discusses the historical record of Aztec Emperor Auitzotl's introduction of the Great-tailed Grackle (Quiscalus mexicanus) in Mexico. It is revealed that this is among the earliest documented instance of an exotic bird translocation which was explored and gathered by Fray Bernardino de Sahagun and his research group. It is stated that the research group used a knowledgeable native consultant to collect information and an early form of peer review to identify lapses and oversights.

The article discusses research on the introduction of the exotic bird, great-tailed grackle Quiscalus mexicanus, into the Valley of Mexico during the period from 1486 to 1502 by Aztec Emperor Auitzotl. The ancient translocation of the said bird is considered as the earliest documented introduction of an exotic specie in the Western Hemisphere region. It offers an analysis of the four stages of Sahaguntine studies of exotic bird introduction including transport, establishment, and spread. It also stresses the importance of supplemental feeding and protection from human predation to ensure successful breed establishment.

Background: Over the past quarter century, the incidence of tick-borne encephalitis (TBE) has increased in most European nations. However, the number of humans stricken by the disease varies from year to year. A method for predicting major increases and decreases is needed. Methods: We assembled a 25-y database (1984--2008) of the number of human TBE victims and wildlife and climate data for the Stockholm region of Sweden, and used it to create easy-to-use mathematical models that predict increases and decreases in the number of humans stricken by TBE. Results: Our best model, which uses December precipitation and mink (Neovison vison, formerly Mustela vison) bagging figures, successfully predicted every major increase or decrease in TBE during the past quarter century, with a minimum of false alarms. However, this model was not efficient in predicting small increases and decreases. Conclusions: Predictions from our models can be used to determine when preventive and adaptive programmes should be implemented. For example, in years when the frequency of TBE in humans is predicted to be high, vector control could be intensified where infested ticks have a higher probability of encountering humans, such as at playgrounds, bathing lakes, barbecue areas and camping facilities. Because our models use only wildlife and climate data, they can be used even when the human population is vaccinated. Another advantage is that because our models employ data from previously-established databases, no additional funding for surveillance is required. [ABSTRACT FROM AUTHOR]

When humans, pets and livestock walk along roads, they may encounter questing ticks and tick-borne pathogens. A new field of environmental science called road ecology can help researchers study the complex epidemiology of tick-borne diseases in the unique roadside environment. This paper reviews some of the important ways that roads alter the distribution, abundance and behaviour of wildlife species that are involved in the enzootic cycles of tick-borne diseases. Compared to the surrounding landscape, roadways often constitute a different environment and hence there is no assurance that disease risk along roads will be the same as in the adjacent landscape, or that disease control measures taken in the surrounding landscape will work in the adjacent roadway. Since roadways have their own special ecological conditions, are used extensively by the human populace and play strategic roles in community security, we believe that roadways should be one of the habitats where tick-borne diseases are studied. It is amazing that at this late period of human history, epidemiological research along such important corridors has been almost completely ignored. [ABSTRACT FROM AUTHOR]

Analysing datasets from hunting statistics and human cases of tick-borne encephalitis (TBE), we found a positive correlation between the number of human TBE cases and the number of red fox (Vulpes vulpes). Time lags were also present, indicating that high numbers of red fox in 1 y translated into high numbers of human TBE cases the following y. Results for smaller predators were mixed and inconsistent. Hares and grouse showed negative correlations with human TBE cases, suggesting that they might function as dilution hosts. Combining our findings with food web dynamics, we hypothesize a diversity of possible interactions between predators and human disease - some predators suppressing a given disease, others enhancing its spread, and still others having no effect at all. Larger-sized predators that suppress red fox numbers and activity (i.e. wolf, Canis lupus; European lynx, Lynx lynx) were once abundant in our study area but have been reduced or extirpated from most parts of it by humans. We ask what would happen to red foxes and TBE rates in humans if these larger predators were restored to their former abundances. [ABSTRACT FROM AUTHOR]

Although interactions between species are often assumed to be fixed, theory and empirical evidence suggest that they may be quite variable, changing in the presence of other species or environmental conditions. The interaction between ants and nesting birds exhibits such variability, ants sometimes being predators of bird nests and other times protectors of them. Hypothesizing that predation risk might be a critical factor in altering the interaction of ants with birds, I investigated the interaction of wood ants Formica aquilonia with nesting birds under different levels of predation risk. In a controlled field experiment, I allowed tits (Parus major, P. caeruleus, P. ater) and pied flycatchers (Ficedula hypoleuca) to select nest boxes in trees with ants (ant trees) or trees without ants. I found that birds usually nested in trees without ants, apparently to avoid the danger of injury from encounters with ants. Nesting in ant trees occurred mainly in the habitat where risk of predation was highest (along the forest edge), and with the bird taxa that lost nests most frequently in trees without ants (tits). Tits nesting on the forest edge achieved significantly greater nesting success, and fledged significantly more young, in ant trees compared with trees without ants. As the season progressed, ant traffic increased in trees without nesting birds, but decreased in trees with nesting birds, indicating that the outcome of interference competition between ants and nesting birds was reversed under increased predation risk. These results support the idea that predation risk can shift species interactions from predominately competitive processes to predominately facilitative processes. [ABSTRACT FROM AUTHOR]