Strigidae Research Articles

Post-Hatching Development of Posture and Behavior in the Barn Owl (Tyto alba): From a General Behavioral Pattern of Vertebrates to the Typical Owl Behavior.

Hatching captive barn owl chicks underwent four developmental phases. In the first 10 days (phase 1), behavior consisted of lateral movements that gradually changed to forward progression and peaked a few days before and after eye-opening. This behavior resembled a general developmental pattern that characterizes other vertebrates. Chicks also underwent a postural change, from head bent underneath the ventrum to resting on the rear end of the trunk with the head lifted in the air. Then, once their eyes were opened, chicks became more stationary and preoccupied with visual exploration, manifested in lateral head movements and peering episodes (phase 2, until day 20). The latter behavior, which is also typical of mature owls when not on the wing, characterized the chicks' behavior after post-hatching day 20 (phase 3), when their flight and contour feathers grew, along with shedding the down plumage and standing tall. Development culminated in active flight, first observed by days 50-60 (phase 4). Altogether, during post-hatching development, barn owl chicks gradually shifted from egg posture to the adult upright body posture. At the same time, their behavior consisted of speciation from the general developmental pattern to the typical stationary barn owl behavior, and, finally, flight was incorporated.

Diet of a Maghreb Owl Strix mauritanica individual at Kahf Lakhal cave on Jbel Moussa, northern Morocco

The diet of a single Maghreb Owl Strix mauritanica (family Strigidae) was examined within its natural habitat at Kahf Lakhal cave on Jbel Moussa, a mountain in northern Morocco. The two distinct batches of pellets collected contained a total of 190 prey items. Pellet analysis revealed a diet comprised of four primary taxonomic classes of prey: mammals, insects, birds and reptiles. We identified 29 prey species, representing 21 families. Mammals were the most prominent component, accounting for 49.5% of the diet items and included at least nine distinct species. Insects constituted 28.9% of the diet, representing at least eight species; birds comprised 20%, representing at least 11 species; and reptiles were represented by a single species (3.4%). Numerically, the most frequently captured prey species were the common bent-wing bat Miniopterus schreibersii (22.1%), black rat Rattus rattus (8.4%) and European rhinoceros beetle Oryctes nasicornis (7.9%). In biomass, black rats were the biggest component of the owl’s diet (31.8%), followed by Barbary Partridges Alectoris barbara and hares Lepus sp. (each 11.9%); together these three species comprised more than half the estimated biomass of the prey types consumed by the owl. This investigation significantly improves our knowledge of the diet of the Maghreb Owl in the North African region.

Range-wide phylogenomics of the Great Horned Owl (Bubo virginianus) reveals deep north-south divergence in northern Peru.

The Great Horned Owl (Bubo virginianus) inhabits myriad habitats throughout the Americas and shows complex patterns of individual and geographic morphological variation. The owl family Strigidae is known to follow ecogeographic rules, such as Gloger's rule. Although untested at the species level, these ecogeographic rules may affect B. virginianus plumage coloration and body size. Previous studies have indicated that, despite this species' morphological variability, little genetic differentiation exists across parts of their range. This study uses reduced representation genome-wide nuclear and complete mitochondrial DNA sequence data to assess range-wide relationships among B. virginianus populations and the disputed species status of B. v. magellanicus (Magellanic or Lesser Horned Owl) of the central and southern Andes. We found shallow phylogenetic relationships generally structured latitudinally to the north of the central Andes, and a deep divergence between a southern and northern clade close to the Marañón Valley in the central Andes, a common biogeographic barrier. We identify evidence of gene flow between B. v. magellanicus and other subspecies based on mitonuclear discordance and F-branch statistics. Overall differences in morphology, plumage coloration, voice, and genomic divergence support species status for B. v. magellanicus.

Re‐assessing the phylogenetic status and evolutionary relationship of Forest Owlet (Athene blewitti (Hume 1873)) using genomic data

Phylogenetic relationships are often challenging to resolve in recent/younger lineages when only a few loci are used. Ultra‐conserved elements (UCEs) are highly conserved regions across taxa that help resolve shallow and deep divergences. We utilized UCEs harvested from whole genomes to assess the phylogenetic position and taxonomic affiliation of an endangered endemic owlet in the family Strigidae, the Forest Owlet Athene blewitti. The taxonomic placement of this species has been revised multiple times. A multigene study attempted to address the question but showed a discrepancy across datasets in its placement of species within the genus Athene. We assembled a dataset of 5018 nuclear UCE loci with increased taxon sampling. Forest Owlet was found to be an early split from the Athene clade but sister to other Athene, consistently across three approaches – maximum likelihood, Bayesian and the multispecies coalescence. Divergence dating using fossil calibrations suggests that the Athene lineage split from its ancestor about 7.6 mya, and Forest Owlet diverged about 5.2 mya. This estimate is consistent with previous multigene approaches and confirms the role of climate‐aridification across the Indian peninsula in species diversification. Despite osteological differences from other Athene, we suggest placement of the Forest Owlet as a member of the Athene to emphasize its evolutionary relationship.

Extensive paraphyly in the typical owl family (Strigidae)

AbstractThe typical owl family (Strigidae) comprises 194 species in 28 genera, 14 of which are monotypic. Relationships within and among genera in the typical owls have been challenging to discern because mitochondrial data have produced equivocal results and because many monotypic genera have been omitted from previous molecular analyses. Here, we collected and analyzed DNA sequences of ultraconserved elements (UCEs) from 43 species of typical owls to produce concatenated and multispecies coalescent-based phylogenetic hypotheses for all but one genus in the typical owl family. Our results reveal extensive paraphyly of taxonomic groups across phylogenies inferred using different analytical approaches and suggest the genera Athene, Otus, Asio, Megascops, Bubo, and Strix are paraphyletic, whereas Ninox and Glaucidium are polyphyletic. Secondary analyses of protein-coding mitochondrial genes harvested from off-target sequencing reads and mitochondrial genomes downloaded from GenBank generally support the extent of paraphyly we observe, although some disagreements exist at higher taxonomic levels between our nuclear and mitochondrial phylogenetic hypotheses. Overall, our results demonstrate the importance of taxon sampling for understanding and describing evolutionary relationships in this group, as well as the need for additional sampling, study, and taxonomic revision of typical owl species. Additionally, our findings highlight how both divergence and convergence in morphological characters have obscured our understanding of the evolutionary history of typical owls, particularly those with insular distributions.

The complete mitochondrial genome sequence of Otus scops (Aves, Strigiformes, Strigidae)

The Eurasian scops owl Otus scops (Aves, Strigiformes, Strigidae) is small typical owl belonging to the family Strigidae. The complete mitochondrial genome sequence consisted of 17413 base pairs encoding 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and non-coding regions. The overall base composition of O. scops was G + C: 46.2%, A + T: 53.8%, apparently with a slight AT bias. Phylogenetic analysis showed that O. scops was closely related to the widespread owl genera Asio and Ninox.

The evolution of iris colour in relation to nocturnality in owls

Birds, due to their multiple colourful displays, constitute a classic paradigm for the study of colour evolution. Although avian eyes are remarkably coloured, the functional basis behind inter‐specific variability in iris colouration remains poorly understood. Owls are an ideal system to shed light on the role of ecology in promoting iris colour evolution as they show inter‐specific variation in iris colour and in niche specialization with some species being strictly nocturnal and others active during the day. Owls perching for hunting at night might be unnoticed by both predators and their prey if they had dark irises, which would predict that dark irises were more likely to evolve in strictly nocturnal species than in diurnal ones. Using phylogenetic comparative models, we tested the camouflage hypothesis for eye colour. The proportion of dark‐eyed owl species is higher among strictly nocturnal owls than among diurnal ones. Ancestral state reconstruction revealed that the owl ancestor of the family Strigidae was more likely bright‐irided whereas the ancestor of the family Tytonidae was more likely dark‐irided. Our results show robust support for the coevolution of iris coloration and nocturnality in the owls, and suggest that shifting to a nocturnal niche would be a prerequisite leading to the evolution of dark eyes in owls. The specific evolutionary pathway by which iris coloration and activity rhythm coevolve, however, remains to be investigated further as we have found only partial support for the idea that dark irises in birds might be an adaptive feature evolved due to the selective advantage of concealment from undesired visual receptors.

Toxoplasma gondii infection in raptors from Italy: Seroepidemiology and risk factors analysis

Toxoplasma gondii is a zoonotic parasite infecting a wide range of intermediate hosts, including birds. Nevertheless, scant information on the spread of infection in wild bird populations is available to date. With the aim of updating information on T. gondii infection in birds of prey and possible risk factors associated with the infection, a serosurvey was planned on both wild and captive raptors. An overall of 93 raptors from Northern Italy were tested for the presence of anti-T. gondii antibodies with a commercial modified agglutination test (MAT). A T. gondii prevalence of 10.7% was recorded; the highest seroprevalence was observed within the Family Strigidae (12.5%). Only wild animals tested positive; any statistical difference among species, taxonomic family, age, origin, use, migratory behavior and diet composition was not highlighted. Toxoplasmosis in birds of prey, sentinel species for the environmental spread of T. gondii, should always be considered within sanitary programs devoted to avian species protection.

Evolutionary progression of mitochondrial gene rearrangements and phylogenetic relationships in Strigidae (Strigiformes)

The bird mitogenome is generally considered to have a conservative genome size, consistent gene content, and similar gene order. As more mitogenomes are sequenced, mitochondrial (mt) gene rearrangements have been frequently identified among diverse birds. Within two genera (Bubo and Strix) of typical owls (Strigidae, Strigiformes), the rearrangement of the mt gene has been a subject of debate. In the current study, we first sequenced the whole mitogenomes of S. uralensis and B. scandiaca and resequenced the entire mitogenome of B. bubo. By combining our data with previously sequenced mitogenomes in Strigidae, we examined the mt gene rearrangements in the family and attempted to reconstruct the evolutionary progression of these rearrangements. The mitogenomes were then used to review the phylogenies of Strigidae. Most mitogenomes exhibited the ancestral gene order (A) in Strigidae. The ancestral gene order in the previously published mitogenome of B. bubo was found to be incorrect. We determined the mt gene order (the duplicate tRNAThr–CR, B) and discovered two additional mt gene orders (the duplicate tRNAGlu-L–CR and CR, C and D) in the Bubo and Strix genera. Gene order B was likely derived from A by a tandem duplication of the region spanning from tRNAThr to CR. The other two modified gene orders, C and D, were likely derived from B by further degenerations or deletions of one copy of specific duplicated genes. We also preliminarily reconstructed the evolutionary progression of mt gene rearrangements and discussed maintenance of the duplicated CR in the genera. Additionally, the phylogenetic trees based on the mitogenomes supported the division of Strigidae into three subfamilies: Ninoxinae + (Surniinae + Striginae). Within the Striginae clade, the four genera formed a phylogenetic relationship: Otus + (Asio + (Bubo + Strix)). This suggests that Otus firstly diverges in their evolutionary history, and Bubo and Strix show a close relationship. B. bubo, B. blakistoni and B. scandiaca form a clade should be considered members of the same genus. The well–supported topology obtained in our Bayesian inference (BI) and maximum likelihood (ML) analyses of Strigid mitogenomes suggests that these genomes are informative for constructing phylogenetic relationships.

Taphonomy of small mammal bone accumulations generated by the Chaco owl (Strix chacoensis, Strigiformes) from the Monte Desert (Mendoza, Argentina): a contribution to South American archaeological and palaeontological studies

The present study analyses the taphonomic features of recent small mammal bone and teeth accumulations recovered from pellets generated by Strix chacoensis in a Natural Protected Area in the central Monte Desert of Mendoza, Argentina. In order to identify the taphonomic signature of this predator in the formation of zooarchaeological and palaeontological accumulations, taxonomic profiles, relative abundances, bone breakage patterns and digestive corrosion were evaluated. Taphonomic results locate S. chacoensis in modification category 2 (intermediate). Although the general taphonomic patterns detected in the present study were similar to a typical owl pattern, some differences from that pattern were detected. This sample showed lesser relative abundances of skeletal elements, greater loss of teeth and a larger number of incisors modified by digestion than those generated by other strigiforms. The comparison with reported archaeological accumulations suggested that the small mammal remains recovered in some sites from the Monte Desert may correspond to the predatory activity of S. chacoensis. The identification of the action of S. chacoensis in archaeological and palaeontological small mammal bone and teeth accumulations is a promising tool to evaluate the conservation status of native forests in the past.

Whole Mitochondrial Genome of Blakiston’s Fish Owl Bubo (Ketupa) blakistoni Suggests Its Redescription in the Genus Ketupa

The paper reports the whole mitochondrial genome (approximately 13 kb) sequencing in three individual representatives of the continental population of Blakiston’s fish owl Bubo blakistoni (Seebohm 1884), the IUCN Red List species in the family Strigidae. The analysis revealed extremely low mtDNA genetic diversity, which may be indicative of the critical state of the studied population. The phylogenetic analysis performed on the basis of the whole mitochondrial genome sequencing data showed that Blakiston’s fish owl is more closely related to the Strix genus than to the Bubo genus with the genetic divergence between blakistoni and either of the two genera being statistically significant and close to intergeneric level (p-distance of 0.135 in the case of the Strix genus and p-distance of 0.151 in the case of the Bubo genus). The results obtained in this work do not match the published data on the mitochondrial cytochrome b gene and the nuclear RAG-1 gene, which laid the basis for the assignment of Blackiston’s fish owl to the Bubo genus in the recent taxonomic bulletins, but rather support the earlier taxonomic classification according to which all four Asian forms, blakistoni, flavipes, zeylonensis, and ketupu, constituted a separate Ketupa genus.

Treatment of Traumatic Brain Injury in Morepork Owls: A Review of Diagnostic and Treatment Options

The Morepork (Ninox novaeseelandiae) is a small owl (150–200 g adult weight) of the family Strigidae. It is common throughout most of New Zealand and closely related to the Southern boobook (Ninox boobook) and Tasmanian boobook owls (Ninox leucopsis) found in Australia. Morepork are commonly presented to the Wildbase Hospital at Massey University, New Zealand. The vast majority of admissions are related to traumatic injuries with many showing some degree of neurological dysfunction. This review of case records indicates that only 35% of morepork admitted with a traumatic brain injury (TBI) recovered to the point of release. A failure to return to normal neurological function could be the result of direct trauma to neurological tissues acquired at the time of impact or ongoing damage with altered physiology compounding the initial trauma. While little can be done to treat primary brain insults, treatments that target minimizing secondary brain injury can improve the outcome of TBI. Diagnostic and treatment options for TBI in human and small animal medicine were reviewed for their potential application to avian medicine with the aim of improving treatment of TBI cases in morepork that will increase recovery rates and long term survival of birds returned to the wild.

Predictive modeling for allopatricStrix(Strigiformes: Strigidae) owls in South America: determinants of their distributions and ecological niche-based processes

Fil: Girini, Juan Manuel. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Division Zoologia de Vertebrados. Seccion Ornitologia; Argentina

Context-aware Composition of Semantic Web Services

Service-based systems are usually conceived and executed in highly dynamic environments, characterized by complex and continuously evolving users' requirements and surrounding conditions. To address this dynamicity, these systems should be designed keeping in mind the different execution contexts where they could be used. This typically impacts service discovery and composition with the aim of dynamically forging the system behavior better fitting a given context. This paper proposes a design approach based on a semantic model for context representation. It is an extension of the OWL-S ontology aimed at enriching the expressiveness of each section of a typical OWL-S semantic service description, by means of context conditions and adaptation rules. By having access to continuously updated context information, these descriptions can be exploited by a discovery/composition tool to automatically find the atomic or composite services that can be better-tuned to the requestor's behaviors and to the particular situations of the surrounding environment.

Recurrent Cytomegalovirus Corneal Endotheliitis after Penetrating Keratoplasty

To report a case of recurrent cytomegalovirus (CMV) corneal endotheliitis after penetrating keratoplasty. Penetrating keratoplasty (PK) was performed in a 49-year-old man with bullous keratopathy. Pigmented keratic precipitates (KPs) were found in the corneal endothelium of the graft 13 days after surgery, with the subsequent appearance of coin-shaped lesions. Confocal microscopy was performed on the corneal endothelium. Aqueous humor was analyzed for viral DNA by polymerase chain reaction (PCR). CMV DNA was detected from the excised corneal button, and aqueous humor revealed positive results for CMV and HSV1 by PCR. Confocal microscopy showed large corneal endothelial cells, consistent with the typical owl's eye morphology of CMV endotheliitis. After systemic ganciclovir was administered, the pigmented KPs and coin-shaped lesions gradually decreased. Stress from surgery and corticosteroid usage can revitalize CMV activity. PCR and confocal microscopy are valuable for the diagnosis of CMV corneal endotheliitis.

The karyotypes of thirty-one birds

The karyotypes of thirty-one bird species are presented and some general aspects of bird chromosomes and the use of the karyotypes in the systematic classification of birds are discussed. It is important to take into consideration all the chromosomes and not just a few of the largest pairs. There is nothing that indicates that the small chromosomes should have a different function than the large ones. It is also important to define the sex chromosomes, since closely related species often have a Z chromosome that is similar in size and arm ratio. Differences between closely related species in some cases are due to a centric-fusion mechanism. In these cases it is more useful to compare the autosomes with the Z chromosome than to compare the other chromosomes with chromosome no. 1. The chromosome number is at least in some cases a little lower in species with putative centric fusion than in related species without it, as in the family Strigidae. The relative length of the chromosome may be more important when identifying corresponding chromosomes in different species, as in the family Anatidae. Two different arm ratios have been observed for a special chromosome within a species. In Vanellus vanellus both chromosomes no. 1 and no. 2 and in Chloris chloris chromosome no. 1 may have either of two arm ratios.

Characterization of the cytopathic effect in human bronchial epithelial cell after Human Bocavirus Infection (HBoV)

In this study, human bronchial epithelial cells were inoculated with positive sputum specimens of HBoV. After four days' infection, cytopathic effects (CPE) were observed by inverted microscopy. These viruses all cause typical cell damages such as rounded and shrivelled, fusion and fallout. These damages got quick following increased future degenerations. The other assay result of CPE within the infected cells were observed by inverted microscopy, have typical "owl's eye" plaque and above 90 percent hemadsorption within the infected cells by erythrocytes for hemadsorption technique. The typical fluorescence lump of nucleus within the infected cells was found by indirect immunofluorescence technique. Isolation and identification of HBoV could be done in the human bronchial epithelial cell, and we found some characterizing CPE in the human bronchial epithelial cell after HBoV infection. The above studies pave a way for studying pathogenicity of human bocavirus.

Sex Identification of Owls (Family Strigidae) Using Oligonucleotide Microarrays

Molecular sexing of the diversified avian family Strigidae is difficult. Sex identification using the intron length difference between W and Z chromosomal CHD1 genes, as visualized by agarose gel electrophoreses, often produces ambiguous results. Here we describe a simple method for sexing a variety of Strigidae species using oligonucleotide microarrays, on which several sex-specific probes operated complementarily or in concert. The sex of 8 owl species was identified clearly on the microarrays through sequence recognition. This sequence-directed method can be easily applied to a wider range of Strigidae species.

Micromammal taphonomy of el-Wad Terrace, Mount Carmel, Israel: distinguishing cultural from natural depositional agents in the Late Natufian

A taphonomic analysis of micromammal remains from the Late Natufian deposits of el-Wad Terrace, Mount Carmel, Israel, was conducted in order to test the long-standing premise of owl deposition as the primary accumulating agent. The inferred taphonomic sequence was modeled within an actualistic (recent) comparative framework incorporating a locally derived barn owl pellet collection and an off-site control assemblage of micromammal remains from the cliff overhanging the terrace. The sequence was reconstructed based on multiple types of recorded taphonomic data, comprising skeletal modifications (breakage, digestion, weathering, gnawing, and charring) and age structure. Evidence for post-depositional processes including fluvial transport, trampling, and weathering was isolated and consequently the typical owl imprints were traced through the two actualistic and the archaeological assemblages. Based on the extent of breakage and patterning in skeletal element frequencies it was also possible to scale the preservation potential of primary data in el-Wad Terrace as a discrete site type, intermediate between true cave and open-air depositional environments. Verifying the role of owls as principal agents of accumulation of the el-Wad Terrace micromammal remains enabled the detection of two minor superimposed cultural patterns: consumption of mole rats (Spalax sp.) by the Natufians and commensalism of mice (Mus spp.).

Error rate of axons at the owl's optic chiasm

Background: In owls, the visual pathways from the retina are totally crossed. Attempts to find ganglion cells with uncrossed axons have failed consistently, when retrogade labeling with HRP is used for their identification. In the present investigation we have used retrograde fluorescent tracers of complementary colour in each optic tectum to demonstrate a tiny population of ipsilaterally‐projecting retinal ganglion cells in the owl. Methods: We studied two species, one from each of the two important owl families: the Southern boobook owl, Ninox boobook: (Family Strigidae); and the Barn Owl, Tyto alba: (Family Tytonidae). Results: The small numbers, random distribution and heterogeneity of the mis‐projecting ganglion cells, taken together, argue against a functional role for them. Instead, they appear to be the result of developmental errors in the specification of laterality. At a number of different eccentricities and ganglion cell densities, the error rate was roughly a constant fraction of the neurons involved, at around 10‐4 for the tytonid owl (lacking a fovea) and around 10‐5 for the strigid owl (which has a fovea and a higher overall density of ganglion cells). Conclusions: These values are close to the error rates of replicating enzymes, such as nucleic acid polymerases. The evolution of a higher retinal ganglion cell density and a fovea in the Strigidae appears to be accompanied by an improvement in the error rate.