Burrowing Owl (Athene cunicularia) Habitat Associations in Agriculture Fields and along Canal Trails in Phoenix, Arizona

2014 ◽  
Vol 45 (2) ◽  
pp. 52-58 ◽  
Author(s):  
Shaneen R. H. Beebe ◽  
Aaron B. Switalski ◽  
Heather L. Bateman ◽  
Kiril D. Hristovski
2019 ◽  
Vol 2 (2) ◽  
pp. 15
Author(s):  
Adrián Cerdá-Ardura

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.


2018 ◽  
Vol 285 (1878) ◽  
pp. 20180206 ◽  
Author(s):  
Jakob C. Mueller ◽  
Heiner Kuhl ◽  
Stefan Boerno ◽  
Jose L. Tella ◽  
Martina Carrete ◽  
...  

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.


2016 ◽  
Vol 116 (4) ◽  
pp. 1765-1784 ◽  
Author(s):  
Pedro Gabrielle Vieira ◽  
João Paulo Machado de Sousa ◽  
Jerome Baron

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.


The Auk ◽  
2005 ◽  
Vol 122 (2) ◽  
pp. 464-478 ◽  
Author(s):  
Nicole M. Korfanta ◽  
David B. McDonald ◽  
Travis C. Glenn

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.


2009 ◽  
Vol 54 (1) ◽  
pp. 87-90 ◽  
Author(s):  
Damon L. Williford ◽  
Marc C. Woodin ◽  
Mary Kay Skoruppa ◽  
Graham C. Hickman

2010 ◽  
Vol 10 (2) ◽  
pp. 93-101 ◽  
Author(s):  
Dárius Pukenis Tubelis ◽  
Welington Braz Carvalho Delitti

Fire management is a common practice in several reserves in the Cerrado, but its influences on bird reproduction remain unknown. In addition, the nesting biology of the Burrowing Owl (Athene cunicularia) has been studied in numerous environments, but not in tropical grasslands managed by fire. This study examined the effects of fire management on the nesting biology of A. cunicularia in Emas National Park, State of Goias, central Brazilian Cerrado. We compared the number of breeding pairs and their burrows in October and November 2009 at 15 study sites in grasslands managed by fire (firebreaks) and unmanaged grasslands adjacent to and distant from firebreaks. We visited active burrows two-four times and described the burrow entrances and sentinel sites and counted and observed adults and young. A total of 19 burrows were found at firebreaks. One and two burrows were found in grasslands adjacent to and distant from firebreaks, respectively. For all burrows found, one to three young reached the adult size, being able to fly and/or run in early November. The 22 burrows found were in the ground, associated or not with termite and ant nests. Most (86.4%) burrows had only one entrance. Only three burrows had two or three entrances. Structures used as sentinel perches by adults were mounds in front of the burrow entrances, termite nests, shrubs and trees. Most of these sentinel sites were shorter than 2 m high and located less than 10 m from the burrow entrance. At Emas National Park, firebreaks appear to provide more attractive conditions to the nesting of A. cunicularia than unmanaged grasslands, likely because of the short herbaceous stratum due to frequent burning of firebreaks. This study suggests that fire management provides suitable conditions for the successful reproduction of A. cunicularia in firebreaks at Emas National Park.


The Auk ◽  
2019 ◽  
Vol 136 (1) ◽  
Author(s):  
Kara A Navock ◽  
David H Johnson ◽  
Samantha Evans ◽  
Matthew J Kohn ◽  
James R Belthoff

ABSTRACT Host-parasite relationships between Western Burrowing Owls (Athene cunicularia hypugaea) and the fleas (Pulex irritans, Siphonaptera:Pulicidae) they harbor were studied to understand the extent to which migratory Burrowing Owls translocated fleas from wintering grounds to breeding grounds. This has implications for host-parasite relationships in Burrowing Owls and also potentially for the dynamics of plague, as Burrowing Owl distributions overlap plague foci, owls inhabit fossorial mammal colonies where epizootic outbreaks of plague occur, and owls may harbor species of flea that are competent plague vectors. We used hydrogen stable isotope analysis to help elucidate geographic origins of fleas collected from adults and nestlings in 2 migratory populations of Burrowing Owls in Idaho and Oregon, USA. For adults, we posited that bird-mediated dispersal would impart flea isotopic compositions representative of southern latitudes and be similar to owl toenail tissue recently grown on wintering grounds, but they would differ from contour feathers presumably grown on breeding grounds the previous year. We assumed nestling feathers and toenails would have isotopic compositions representative of the breeding grounds. We analyzed contour feathers and toenails from adults collected shortly after they arrived in breeding grounds following spring migration and from nestlings later in the breeding season, to which we compared isotopic compositions in fleas collected from individuals of both age classes. Fleas on nestlings in both populations had isotopic compositions that did not differ from nestling feathers and toenails, suggesting that nestling fleas had breeding ground origins. Fleas on adults in one population (Oregon) had breeding ground isotopic signatures, as flea compositions did not differ from nestling feathers or toenails. Adult owls in Idaho had fleas that similarly did not express a wintering ground signature, but they were enriched in the heavy isotope (deuterium) relative to nestling feathers and toenails. Therefore, we discuss the possibility that adult owls in Idaho acquired fleas at migratory stopover sites. While the latter indicates that Burrowing Owls have the potential to disperse fleas, there was no evidence of continent-wide movement of fleas by owls from wintering grounds to breeding grounds.


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