Search

Inland vagrancy and overland dispersal by seabirds arc rare phenomena for which the causes and consequences are poorly understood. Studying inland occurrences of seabirds is important because continental land masses form barriers to dispersal of genes and parasites; thus, the permeability of land barriers influences the extent to which seabird populations evolve on separate trajectories and co-evolve with distinct parasite faunas. The boobies (Sulci spp.) arc a clade of saltwater-obligate species occurring in tropical and subtropical oceans. Booby species tend to exhibit population generic structure among oceanic regions. Although they rarely wander inland, the Brown Booby (Sula leucogaster) has occurred numerous times as a vagrant in interior North America. Previous inland records from far western North America originated from Pacific populations (subspecies brewsteri), whereas those from eastern and midwestern North America originated from Caribbean populations (subspecies leucogaster). In this paper, we describe 2 new specimens of 5. leucogaster, first state records for New Mexico and Colorado, salvaged from localities nearly equidistant from Pacific and Caribbean source populations. We used mitochondrial DNA sequences to conclusively demonstrate that both specimens originated in the Caribbean. We next examined the helminth parasite fauna of the 2 S. leucogaster specimens and an inland-vagrant Blue-footed Booby (S. nebouxii) from New Mexico. The guts of these boobies contained a suite of helminths, including multiple freshwater-obligatc taxa. Based on our findings, wc suggest that susceptibility to freshwater parasites may cause overland dispersal to fail for boobies, or other seabirds. Thus, freshwater parasites may contribute to explaining the relative rarity of transcontinental dispersal, maintenance of strong inter-ocean population genetic structure, phylogenetic conservatism of specialization on salt-water habitats, and the strictly pelagic distributions of ocean-dwelling species from several avian families. Received 16 September 2022. Accepted 11 August 2023. Key words: freshwater, helminth, parasite, specimen, Sula, vagrancy. La errancia y dispersion en tierra adentro de las aves marinas son fenomenos raros cuyas causas y consecuencias se entienden poco. Estudiar registros en tierra adentro de aves marinas es importante ya que las masas continentales forman barreras a la dispersion de genes y parasitos; por lo tanto, la permeabilidad de las barreras terrestres influye en que tanto las poblaciones de aves evolucionan en trayectorias distintas y co-evolucionan con faunas parasitas distintas. Los alcatraces (Sula spp.) constituyen un ciado de especies obligadas de agua salada que se encuentran en oceanos tropicales y subtropicales. Las especies de alcatraces tienden a exhibir estructura genetica poblacional entre regiones oceanicas. Aunque raramente deambula en tierra firme, el alcatraz pardo (Sula leucogaster) se ha reportado muchas veces como errante en tierra adentro de Noneamerica. Previos reportes de tierra adentro en el lejano oeste Norteamericano se originaron de poblaciones del Pacifico (subespecies brewsteri), mientras que los del este y el medioeste de Norteamerica se originan de poblaciones del Caribe (subespecie leucogaster). En este articulo, describimos 2 especimenes nuevos de S. leucogaster, primeros registros estatales para Nuevo Mexico y Colorado, procedentes de localidades casi equidistantes de poblaciones fuente de Pacifico y el Caribe. Utilizamos secuencias de ADN mitocondrial para mostrar conclusivamente que ambos especimenes se originaron en el Caribe. Luego, examinamos ia fauna de helmintos parasitos de ambos especimenes de S. leucogaster y de un alcatraz de patas azules (S. nebouxii) que vagaba tierra adentro en Nuevo Mexico. Los intestinos de estos alcatraces contenian una serie de helmintos, incluyendo varios taxa obligadas de agua dulce. Con base en nuestros hallazgos, sugerimos que la susceptibilidad a los parasitos de agua dulce puede ocasionar que la dispersion en tierra adentro no sea exitosa para los alcatraces u otras aves marinas. Por lo tanto, los parasitos de agua dulce pueden contribuir a explicar la relativa rareza de la dispersion transcontinental, el mantenimiento de la fuerte estructura genetica inter-oceanica, la conservacion filogenetica de la especializacion en habitats de agua salada y la distribucion estrictamente pelagica de especies oceanicas pertenecientes a varias familias de aves. Palabras clave: agua dulce, errancia, especimen, helmintos, parasito, Sula., At least 254 bird species from 11 families are restricted to saltwater habitats (Howell and Zufelt 2019). The volant seabird species are strong fliers, characterized by high aspect-ratio wings. It [...]

Background: One of the major migration routes for birds going between Europe and Asia is the Black Sea-Mediterranean route that converges on the Volga Delta, continuing into the area of the Caspian Sea. Cercarial dermatitis is a disorder in humans caused by schistosome trematodes that use aquatic birds and snails as hosts and is prevalent in areas of aquaculture in Northern Iran. Before the disorder can be addressed, it is necessary to determine the etiological agents and their host species. This study aimed to document whether domestic mallards are reservoir hosts and if so, to characterize the species of schistosomes. Previous work has shown that domestic mallards are reservoir hosts for a nasal schistosome. Results: In 32 of 45 domestic mallards (Anas platyrhynchos domesticus) (71.1%), the schistosome Trichobilharzia franki, previously reported only from Europe, was found in visceral veins. Morphological and molecular phylogenetic analysis confirmed the species designation. These findings extend the range of T. franki from Europe to Eurasia. Conclusion: The occurrence of cercarial dermatitis in Iran is high in areas of aquaculture. Previous studies in the area have shown that domestic mallards are reservoir hosts of T. regenti, a nasal schistosome and T. franki, as shown in this study. The genetic results support the conclusion that populations of T. franki from Iran are not differentiated from populations in Europe. Therefore, the schistosomes are distributed with their migratory duck hosts, maintaining the gene flow across populations with compatible snail hosts in Iran.

One consequence of introduction of exotic species is possible establishment of new host-parasite associations, potentially resulting in emergence of new diseases (1-3). Exotic parasites can be introduced into new locations [...]