Abstract The period of migration can pose significant energetic challenges as birds attempt to reach their destinations. Suitable stopover habitat is, therefore, important to the success of migrating ...individuals, especially as they move along major migration corridors and geographic features, like coastlines. In this study, we used metrics of individual body condition (i.e. fat score, size-corrected body mass, and refueling rate) of fall migrants as they moved across the Gulf of Maine region, a complex coastal landscape. We investigated the extent to which these body condition indices varied by stopover site geography (island vs. mainland) and how these spatial patterns varied with species-specific characteristics such as migratory distance, foraging guild, and age. Geography was an important factor explaining variation in all 3 condition indices, and age explained additional variance in 2 of the 3. In general, individuals captured on islands exhibited significantly lower energetic condition than individuals on the mainland, and this pattern held true across all migratory strategies and foraging guilds. Immature individuals had, on average, lower energy reserves, with less fat and lower size-corrected mass than adults among all stopover sites. We also found that at all sites, size-corrected body mass, on average, significantly increased over the capture day, providing evidence that both island and mainland sites provided energetically beneficial stopover habitat. Our finding that birds offshore are in lower body condition at capture than those along the coast is suggestive that birds use mainland sites for longer stopover bouts than island sites, or that poorer condition birds reorient to land during over-water movements disproportionately use off-shore islands as their initial landing area. Decreases in either island or mainland stopover site availability or quality may affect individual fitness, with population-level consequences, but through different ways.
A new species of whitefly, Aleuropleurocelus petenensis sp. nov. Carapia-Ruiz & García-Ochaeta, found on leaves of a plant belonging to the genus Acalypha (Euphorbiaceae) in Petén, Guatemala, is ...described based on characteristics of the pupa. This new species exhibits a black venter and has microtubercles on the subdorsal and submedian areas, whereas the most closely related species, A. mixtecus Carapia-Ruiz, presents a pale venter and has not microtubercles on the corresponding areas. In both species the transverse suture of the molt ends before the apparent margin and the dorsal surface presents folds; these features support the close relationship between these species. Microphotographs of morphological structures of the new species puparium are provided.
This study focuses on species richness, abundance, diversity, and seasonal variation of spiders in two coffee plantations with different crop management and a portion of tropical forest in two ...municipalities of La Costa region of Oaxaca, Mexico, using manual collection, foliage beating and pitfall traps. We collected 2,210 spiders belonging to 35 families, 100 genera and 146 species. The inventory includes 51 new species records for Oaxaca. Completeness values for two estimators indicate that the level of representation of inventories range from 68.25% to 78.44%, and the proportion of singletons range from 33.72% to 38.14%. Spider abundance in the rainy season was significantly lower than during the dry season. Spider abundance in the Tropical Forest was significantly lower than Monoculture site with the foliage beating method. Polyculture was the site with the lowest spider abundance with the pitfall traps. Rarefaction curves did not show significant differences in species richness between the sites and seasons. Hutcheson t-test showed that spider diversity was significantly lower in Monoculture than Tropical Forest during the rainy season. This study contributes to the knowledge of the arachnofauna of Mexico and particularly of the state of Oaxaca.
Se presenta la información hasta la fecha del género pantropical Holocompsa Burmeister, 1838, con énfasis en México. Adicionalmente, se describe una nueva especie con base en material colectado en ...Yucatán, México. Se propone una guía taxonómica para las especies americanas.
Abstract Migratory birds encounter the Great Lakes while moving through eastern North America toward breeding grounds to the North, which offers a good opportunity to study variation in migratory ...behavior as birds face a potentially influencing topographical feature. Using passive infrared technology, we documented the direction of relatively low-flying, nocturnal, mostly passerine migration in spring along the southern coast of Lake Erie’s western basin. We examined the extent to which spring migrants flew across Lake Erie as a continuation of the inland, northeasterly broad front migratory direction, as determined by weather radar and infrared observations, or displayed a tendency to deviate to more closely follow the direction of the coastline. We found that an estimated 62% of all low-flying migrants deviated their flight directions toward the coast of Lake Erie at 2 coastal sites, Cedar Point and Ottawa, which were characterized by northwest–southeast oriented coastlines. Migrants at a third coastal location, Maumee Bay, which has a more east–west oriented coastline, did not display similarly deviated flight directions. We found that even when winds were energetically favorable for a lake crossing, many migrants still routinely displayed deviated flight directions that approached paralleling the coastline. Further, the mean flight direction at one site, Ottawa, shifted more in the direction of the coastline as the night progressed, suggesting that time of night could influence the shift to a more coastal flight direction. The data indicate that the western basin of Lake Erie acts as a salient topographical feature influencing the flight directions of nocturnal migrants. The data further suggest that birds are making active decisions while in flight, based on current environmental and physiological conditions, about whether to continue to cross Lake Erie or take a coastal detour.
Los picudos (Coleoptera: Curculionidae) son una de las principales plagas en los sistemas de producción citrícola debido a su distribución y forma de alimentación. El objetivo del presente trabajo ...fue identificar morfológicamente las especies de picudos asociados al cultivo de limón persa (Citrus latifolia Tanaka) en la zona citrícola del municipio de Huimanguillo, Tabasco, México. Las capturas de picudos se realizaron de manera directa en la copa de los árboles, de septiembre de 2019 a febrero de 2021, para un total de 17 muestreos en tres plantaciones de limón persa, dos con manejo convencional y una con manejo orgánico, cada una con parcelas útiles de dos hectáreas (624 plantas). Se colectaron 1,039 picudos correspondientes a cuatro morfoespecies, de las cuales 240 se identificaron morfológicamente como Epicaerus sp. (1), 355 como Epicaerus sp. (2), 112 como Exophthalmus opulentus y 332 como Cleistolophus subfasciatus.
ABSTRACT Natural history collections (NHCs) contain valuable information that can be used in different fields of knowledge, and aid in the development of society, science, and technology. The role of ...curators and taxonomists in maintaining and improving biological collections is essential, as these are fundamental for the understanding of biodiversity. However, the role of taxonomists and the importance of NHCs to society have been undervalued in recent years. We, while attending a graduate program on collections at PUCRS, noted a gap in knowledge about scientific collections. Was this gap, which continued from our undergraduate to graduate years, a mere coincidence or widespread in biological science programs in Brazil? We queried 126 Brazilian institutions of higher education to assess the presence of courses related to natural-history collections and taxonomy. A total of 25 private and 37 public universities from 126 institutions searched, have a program of study in biological sciences in the curriculum on their websites. About 16% offer some course related to NHCs or taxonomy, and all of them are public institutions. Despite the budget cutting made by the Brazilian government that make it even more difficult to recognize NHCs and related areas, we believe that there should be more links among researchers from different areas and especially between the levels of basic and higher education, so that students are exposed to this subject early in their education. We, as Brazilian students, believe that more information on NHC-related issues and taxonomic subjects is urgently needed in biological science programs.
RESUMEN El arbusto Bulnesia retama es un importante recurso natural de uso no maderable productor de cera. Nuestro objetivo fue evaluar el efecto de diferentes intensidades de poda en el crecimiento, ...supervivencia y producción de cera de Bulnesia retama en su ambiente natural. Se trabajó en una comunidad de B. retama, en Bermejo, San Juan. Se seleccionaron 15 parcelas. En cada parcela se marcaron diez individuos de B. retama, se midieron variables morfométricas y se aplicaron 4 niveles de poda y un control. Con lo obtenido se determinó producción de cera. Transcurridos cinco años se repitieron las podas evaluándose producción de cera, tamaño y supervivencia. El contenido bruto de cera, al igual que el rendimiento de cera por kg ramas totales cosechadas, el volumen y la supervivencia mostró diferencias significativas de acuerdo al nivel de poda efectuado. El manteni miento en el tiempo de la producción de cera permite establecer el manejo y conservación de la especie. El retamo tolera podas de baja intensidad y es utilizado por lugareños, lo que podría representar un recurso sustentable generando trabajo y asegurando el arraigo del campesino en zonas marginales.
Resumen Schinus fasciculata y S. bumelioides son especies que presentan amplia distribución y a menudo co habitan en Argentina, pero sus semejanzas en morfología foliar en los primeros estadíos de ...desarrollo dificultan la diferenciación entre los individuos de cada taxón. El objetivo de este trabajo fue caracterizar ejemplares de cada especie de tres y seis meses de edad, los que fueron obtenidos en cámara de germinación a partir de frutos colec tados de dos poblaciones en Guachipas, Salta. Se registraron las alturas de las plántulas y plantas y el número de nudos, y se describieron cotiledones, protófilos y nomófilos juveniles en los dos estadíos. Los caracteres útiles para el reconocimiento taxonómico en ambas edades de las plantas son principalmente la forma y tipo de margen de los protófilos y nomófilos juveniles.
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