ENFRENTANDO LA TOXICIDAD: PRIMER REPORTE SOBRE LA DEPREDACIÓN DE Siphonops paulensis (CAECILIDAE) POR Athene cunicularia (STRIGIDAE)

La diferenciación trófica entre rapaces cumple un rol esencial para su coexistencia, situación que se hace especialmente relevante cuando existe transformación del hábitat, lo que lleva a modificaciones en la disponibilidad de recursos. En diciembre de 2018 examinamos la dieta de Milvago chimango y Athene cunicularia en Chile Central, en una zona próxima a un relleno sanitario en la localidad de Montenegro. Colectamos 226 egagrópilas de M. chimango y 68 egagrópilas de A. cunicularia, y observamos que ambas especies concentraron una alta proporción de presas en torno a artrópodos (principalmente de la clase Insecta, con un 54% y un 64% para M. chimango y A. cunicularia, respectivamente), con variaciones en el consumo de los distintos órdenes y familias en cada caso. A pesar de que tuvieron diferencias en torno al consumo de aves (5.36% para M. chimango y 1.42% para A. cunicularia) y mamíferos (2.53% para M. chimango y 7.13% para A. cunicularia), ambas especies presentaron una alta sobreposición dietaria (S = 0.94), donde las diferencias espaciales y de caza de cada especie serían los mecanismos que explicarían su coexistencia en el área de estudio.

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RECORDS OF Sauromalus ater (DUMÉRIL, 1856) HATCHLINGS AND SUBADULTS ON SAN FRANCISCO ISLAND, GULF OF CALIFORNIA, MÉXICO

Revista Latinoamericana de Herpetología ◽

10.22201/fc.25942158e.2019.2.92 ◽

2019 ◽

Vol 2 (2) ◽

pp. 15

Author(s):

Adrián Cerdá-Ardura

Keyword(s):

San Francisco ◽

Sonoran Desert ◽

Gulf Of California ◽

Baja California ◽

Small Island ◽

Athene Cunicularia ◽

Burrowing Owl ◽

Important Sign ◽

The Common ◽

Abundance And Diversity

Six hatchlings of the Common or Sonoran Desert Chuckwalla (Sauromalus ater) ranging from 60 mm to 93 mm (SVL) as well as 10 subadult individuals (mostly ♀) ranging from 110 mm to 146 mm (SVL) were recorded during three casual walks on the small island San Francisco, Baja California Sur, Gulf of California, México, in January and February, 2019. The presence of these hatchlings and subadult females could be an important sign of chuckwallas’ recovery and of continued population’s recruitment following eradication of feral cats and goats from the island in 1999 and 2000 respectively, and despite the intense presence of humans (fishermen and tourists) on the island. The chuckwalla population seems to be growing and becoming conspicuous on San Francisco after almost two decades of rare and infrequent records of individuals. Also, the vegetation shows more abundance and diversity, and more extensive covering than in previous years. Other vertebrate species, like the Baja California Rattlesnake (Crotalus enyo) and the Burrowing Owl (Athene cunicularia) were recorded as well during the walks. All these observations possibly indicate a whole and progressive biota restoration on this tiny island after devastation by invasive fauna, combined with previous good wet years.

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Evolution of genomic variation in the burrowing owl in response to recent colonization of urban areas

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2018.0206 ◽

2018 ◽

Vol 285 (1878) ◽

pp. 20180206 ◽

Cited By ~ 20

Author(s):

Jakob C. Mueller ◽

Heiner Kuhl ◽

Stefan Boerno ◽

Jose L. Tella ◽

Martina Carrete ◽

...

Keyword(s):

Urban Areas ◽

Demographic History ◽

Genomic Variation ◽

Rural Populations ◽

Urban Habitat ◽

Restricted Gene Flow ◽

Athene Cunicularia ◽

Urban Populations ◽

Burrowing Owl ◽

Standing Variation

When a species successfully colonizes an urban habitat it can be expected that its population rapidly adapts to the new environment but also experiences demographic perturbations. It is, therefore, essential to gain an understanding of the population structure and the demographic history of the urban and neighbouring rural populations before studying adaptation at the genome level. Here, we investigate populations of the burrowing owl ( Athene cunicularia ), a species that colonized South American cities just a few decades ago. We assembled a high-quality genome of the burrowing owl and re-sequenced 137 owls from three urban–rural population pairs at 17-fold median sequencing coverage per individual. Our data indicate that each city was independently colonized by a limited number of founders and that restricted gene flow occurred between neighbouring urban and rural populations, but not between urban populations of different cities. Using long-range linkage disequilibrium statistics in an approximate Bayesian computation approach, we estimated consistently lower population sizes in the recent past for the urban populations in comparison to the rural ones. The current urban populations all show reduced standing variation in rare single nucleotide polymorphisms (SNPs), but with different subsets of rare SNPs in different cities. This lowers the potential for local adaptation based on rare variants and makes it harder to detect consistent signals of selection in the genome.

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Contrast response functions in the visual wulst of the alert burrowing owl: a single-unit study

Journal of Neurophysiology ◽

10.1152/jn.00505.2015 ◽

2016 ◽

Vol 116 (4) ◽

pp. 1765-1784 ◽

Cited By ~ 1

Author(s):

Pedro Gabrielle Vieira ◽

João Paulo Machado de Sousa ◽

Jerome Baron

Keyword(s):

Single Unit ◽

Goodness Of Fit ◽

Dynamic Range ◽

Information Criterion ◽

Future Research ◽

Response Functions ◽

Athene Cunicularia ◽

Low Contrast ◽

Burrowing Owl ◽

Contrast Response

The neuronal representation of luminance contrast has not been thoroughly studied in birds. Here we present a detailed quantitative analysis of the contrast response of 120 individual neurons recorded from the visual wulst of awake burrowing owls ( Athene cunicularia). Stimuli were sine-wave gratings presented within the cell classical receptive field and optimized in terms of eye preference, direction of drift, and spatiotemporal frequency. As contrast intensity was increased from zero to near 100%, most cells exhibited a monotonic response profile with a compressive, at times saturating, nonlinearity at higher contrasts. However, contrast response functions were found to have a highly variable shape across cells. With the view to capture a systematic trend in the data, we assessed the performance of four plausible models (linear, power, logarithmic, and hyperbolic ratio) using classical goodness-of-fit measures and more rigorous statistical tools for multimodel inferences based on the Akaike information criterion. From this analysis, we conclude that a high degree of model uncertainty is present in our data, meaning that no single descriptor is able on its own to capture the heterogeneous nature of single-unit contrast responses in the wulst. We further show that the generalizability of the hyperbolic ratio model established, for example, in the primary visual cortex of cats and monkeys is not tenable in the owl wulst mainly because most neurons in this area have a much wider dynamic range that starts at low contrast. The challenge for future research will be to understand the functional implications of these findings.

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Burrowing Owl (Athene Cunicularia) Population Genetics: A Comparison of North American Forms and Migratory Habits

The Auk ◽

10.1093/auk/122.2.464 ◽

2005 ◽

Vol 122 (2) ◽

pp. 464-478 ◽

Cited By ~ 1

Author(s):

Nicole M. Korfanta ◽

David B. McDonald ◽

Travis C. Glenn

Keyword(s):

Genetic Differentiation ◽

North American ◽

Habitat Structure ◽

Gene Diversity ◽

Athene Cunicularia ◽

Population Declines ◽

The West ◽

Burrowing Owls ◽

Burrowing Owl ◽

Patchy Habitat

Abstract We assessed the effects of range disjunction, migratory habit, coloniality, and habitat structure on the genetic differentiation of North American Burrowing Owl (Athene cunicularia) populations. Burrowing Owls in North America comprise two forms or subspecies: A. c. floridana in Florida, separated by ∼1,500 km from the western form, A. c. hypugaea, which ranges from Texas to California and north to southern Canada. Burrowing Owls tend to be loosely colonial, and both the Florida populations and southerly populations of A. c. hypugaea from California to Texas are nonmigratory. To assess genetic structure, we examined 201 individuals from nine western and six Florida populations at seven highly variable microsatellite DNA loci. Mean gene diversity (Hexp) was higher in the west than in Florida (0.539 and 0.341, respectively; P < 0.05). Populations within subspecies were essentially panmictic (A. c. floridana: θ = 0.038, ρ = 0.014; A. c. hypugaea: θ = 0.014, ρ = 0.009) and even genetic differentiation across subspecies was modest (θ = 0.051, ρ = 0.014). Nevertheless, the western and Florida forms were easily distinguished by any of several criteria, such as allelic absences in Florida, assignment tests, and well-supported branches on the inferred phylogenetic tree. Genetic differentiation was at least twice as great in resident Florida (θ = 0.038) and California (θ = 0.021) populations as in migratory western populations (θ = 0.012), though 95% confidence intervals of theta estimates overlapped. We found no evidence of a genetic bottleneck that would result in evolutionary disequilibrium within subspecies. In the west, high observed heterozygosity values and evidence of gene flow suggest that population declines and patchy habitat, which currently imperil this species throughout much of its range, have not led to inbreeding or biologically meaningful genetic differentiation among the sampled populations.

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