scholarly journals Artificial Light at Night is Related to Broad-Scale Stopover Distributions of Nocturnally Migrating Landbirds along the Yucatan Peninsula, Mexico

2020 ◽  
Vol 12 (3) ◽  
pp. 395 ◽  
Author(s):  
Sergio A. Cabrera-Cruz ◽  
Emily B. Cohen ◽  
Jaclyn A. Smolinsky ◽  
Jeffrey J. Buler

The distributions of birds during migratory stopovers are influenced by a hierarchy of factors. For example, in temperate regions, migrants are concentrated near areas of bright artificial light at night (ALAN) and also the coastlines of large water bodies at broad spatial scales. However, less is known about what drives broad-scale stopover distributions in the tropics. We quantified seasonal densities of nocturnally migrating landbirds during spring and fall of 2011–2015, using two weather radars on the Yucatan peninsula, Mexico (Sabancuy and Cancun). We tested the influence of environmental predictors in explaining broad-scale bird stopover densities. We predicted higher densities in areas (1) closer to the coast in the fall and farther away in spring and (2) closer to bright ALAN and with lower ALAN intensity in both seasons. We found that birds were more concentrated near the coastline in the fall and away from it in spring around Cancun but not Sabancuy. Counter to our expectations, we detected increased bird densities with increased distance from lights in spring around Sabancuy, and in both seasons around Cancun, suggesting avoidance of bright areas during those seasons. This is the first evidence of broad-scale bird avoidance of bright areas during stopover.

2020 ◽  
Vol 71 (10) ◽  
pp. 1269
Author(s):  
Mischa P. Turschwell ◽  
Ben Stewart-Koster ◽  
Stephen R. Balcombe ◽  
Fran Sheldon ◽  
Erin E. Peterson

The distribution and population structure of organisms is governed by a broad suite of biotic and abiotic variables, interacting across multiple scales. Recruitment is a key demographic process critical to the maintenance of successful populations. Isolating and quantifying the multiscale environmental drivers of recruitment is vital for species conservation, especially for those species with traits that increase their susceptibility to local extirpation. We developed a Bayesian hierarchical model to quantify the relationship between the rate of recruitment in a locally threatened river blackfish (Gadopsis marmoratus) and environmental predictors across two spatial scales. There was a 0.99 probability that increased broad-scale stream temperature negatively affected juvenile recruitment rate. We also found that there was a 0.97 probability that the fine-scale relationship between recruitment rate and riparian foliage cover was dependent on temperature. This suggests that broad-scale thermal conditions provide the template upon which at least one local environmental variable influences recruitment rate. Understanding drivers influencing key population processes and the spatial scales at which they operate is critical to gaining an insight into likely changes in population persistence for potentially imperilled species, along with the potential future effects of habitat degradation and climate warming on freshwater fishes in general.


2017 ◽  
Vol 65 (4) ◽  
pp. 1448
Author(s):  
Rodrigo I. Pacheco-Díaz ◽  
Juan J. Schmitter-Soto ◽  
Birgit Schmook ◽  
Gerald A. Islebe ◽  
Holger Weissenberger

Aquatic environments face a variety of threats in the Hondo River basin, Southeastern Yucatan Peninsula. Some of these impacts, like pollution by pesticides, may depend on land use and cover. Our objective was to assess the effect of land use/cover using a previously published index of biotic integrity (IBI), based on fishes and designed for shallow streams in the Hondo River basin. Our hypothesis was that land uses that cause deforestation and pollution, such as urbanization, cattle breeding, or sugar cane fields, would be reflected in low IBI values, at least at some spatial scales. The 23 sites originally used in 2008-2009 to estimate by electrofishing the relative abundance and other characteristics of selected fish species and guilds to construct the IBI, were revisited in February 2010, to validate by direct inspection the type of land use/cover suggested by landscape information in digital databases. We analyzed the effect of seven types of land use/cover (agriculture, pasture, human settlements, water bodies, wetlands, forest, and secondary vegetation) on the IBI values, at four spatial scales, i.e., the percent of every land use/cover at progressively larger circles (125, 250, 500, and 1 000 m diameter) centered on the water body where the IBI value was measured. Correlations were established among the percent land/use cover by scale around 23 sites, and with their corresponding IBI values. Then, Student’s t tests were calculated to examine significant differences in land use/cover between groups of localities above and below the median IBI value, and Mann-Whitney’s U tests were applied to compare IBI values between localities with and without a given landscape cover. Agriculture, human settlements, and secondary vegetation correlated negatively with the IBI; forests positively.  Differences were significant (p < 0.05) for forest (higher in sites with higher IBI values) and human settlements (lower in sites with higher IBI). Of all the landscape categories located in the Hondo River basin, with the exception of pasture, those of anthropogenic origin tended to be detrimental to aquatic biotic integrity.


2018 ◽  
Vol 21 (3) ◽  
pp. 356-364 ◽  
Author(s):  
James D. McLaren ◽  
Jeffrey J. Buler ◽  
Tim Schreckengost ◽  
Jaclyn A. Smolinsky ◽  
Matthew Boone ◽  
...  

Author(s):  
Michael Oswaldo Uitzil-Colli ◽  
Juan P. Pinzón ◽  
Laura Guzmán-Dávalos

Resumen:Antecedentes y Objetivos: El género Thelephora pertenece a Thelephoraceae, Thelephorales, Agaricomycetes, Basidiomycota y corresponde a hongos ectomicorrizógenos, de los que se conocen al menos 50 especies alrededor del mundo. De ellas, 28 se encuentran en ecosistemas tropicales y subtropicales; no obstante, se considera que han sido escasamente estudiadas en los trópicos. Por consiguiente, el objetivo de este trabajo consistió en contribuir al conocimiento de los teleforáceos tropicales presentes en una zona relativamente no explorada desde el punto de vista micológico en México, como lo es el estado de Yucatán.Métodos: La recolecta se realizó en una selva mediana subcaducifolia al sur del estado de Yucatán, en el municipio Tekax, durante la temporada de lluvias de agosto-diciembre 2017 y de junio-agosto 2018. El material revisado se caracterizó macromorfológicamente a partir de ejemplares frescos, y micromorfológicamente mediante la observación al microscopio óptico de los basidiomas. Los ejemplares se encuentran depositados en los herbarios IBUG y UADY.Resultados clave: Thelephora dominicana solo se conocía de República Dominicana, por lo cual este registro amplía su rango de distribución. Se comenta su potencial asociación ecológica con especies de Fabaceae y Polygonaceae, en particular con Coccoloba spp. y Gymnopodium floribundum. Para México, únicamente se habían registrado nueve especies de este género. Thelephora dominicana constituye la décima especie mexicana y la séptima procedente del neotrópico mexicano. Para la península de Yucatán se conocía T. cervicornis, por lo que es la segunda especie en reportarse para la región.Conclusiones: Se reporta por primera vez para la micobiota mexicana a Thelephora dominicana y por segunda ocasión a nivel mundial.Palabras clave: Agaricomycotina, península de Yucatán, selva mediana subcaducifolia, taxonomía.Abstract:Background and Aims: The genus Thelephora belongs to Thelephoraceae, Thelephorales, Agaricomycetes, Basidiomycota, and corresponds to ectomycorrhizal macrofungi, with at least 50 species known around the world. Of these, 28 are found in tropical and subtropical ecosystems. Nevertheless, it is considered they are poorly known in the tropics. Therefore, the objective of this work was to contribute to the knowledge of tropical thelephoraceous fungi present in an area relatively unexplored in Mexico from the mycological point of view, such as the Yucatán state.Methods: Collections were made in a subdeciduous seasonal dry forest in the south of the Yucatán state, in Tekax municipality, during the rainy season of August-December 2017 and June-August 2018. All the material was examined using macromorphological data from fresh specimens, and micromorphologically by basidiomata sections observed with the optical microscope. The specimens are deposited in the herbaria IBUG and UADY.Key results: Thelephora dominicana was only known from Dominican Republic, hence this record increases its distribution range. Moreover, we report its potential association with species of Fabaceae and Polygonaceae families, such as Coccoloba spp. and Gymnopodium floribundum. In Mexico, only nine species were previously reported in Thelephora, T. dominicana being the tenth one and the seventh for the Mexican Neotropical region. From the Yucatán peninsula, T. cervicornis was the only known species of this genus, thus this is the second one from this area.Conclusions: This is the first report of T. dominicana for Mexico and the second time worldwide. Key words: Agaricomycotina, subdeciduous seasonal dry forest, taxonomy, Yucatán peninsula.


2018 ◽  
Vol 130 (1) ◽  
pp. 45-50 ◽  
Author(s):  
S Guillén-Hernández ◽  
C González-Salas ◽  
D Pech-Puch ◽  
H Villegas-Hernández

2019 ◽  
Author(s):  
Jonathan B. Martin ◽  
◽  
Andrea J. Pain ◽  
Caitlin Young ◽  
Arnoldo Valle-Levinson

Author(s):  
Philip James

Elements of the physical aspects of urban environments determine which micro-organisms, plants, and animals live in urban environments. In this chapter, climate, air, water, soil, noise, and light are discussed. Urban environments are affected by the climate of the region in which they are located, and in turn and create their own, distinctive urban climate. Air, water, and soil are all affected by urbanization. Pollution of these elements is common. High noise levels and artificial light at night (ALAN—a new phenomenon) are both strongly associated with urban environments. Details of both are discussed. The discussion in this chapter provides a foundation for further exploration of the diversity of life in urban environments and for later exploration of how organisms adapt to urban living, which will be discussed in Parts II and III.


2021 ◽  
Vol 197 ◽  
pp. 111012
Author(s):  
Jessica Stanhope ◽  
Craig Liddicoat ◽  
Philip Weinstein

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