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Barn Owl (1 Viewer)

am I missing something? how is that citation wrong? It's pretty common to abbreviate names in references.

Usually, if doing "last name" "first name" there will be a comma separating the two. The lack of that comma makes people read it as the opposite order which people knowing the authors protests.

Niels
 
North America

Machado A.P., Clément L., Uva V., Goudet J. & Roulin A., in press. The Rocky Mountains as a dispersal barrier between Barn Owl (Tyto alba) populations in North America. J. Biogeogr.

Abstract
Aim: Geological barriers within a species range play a key role in shaping patterns of genetic variation by restricting gene flow. Mountain ranges are particularly imposing barriers responsible for creating genetic differentiation across multiple taxa, from small amphibians to large mammals and birds. Here, we examined the population structure of North American barn owls (Tyto alba) and investigated whether the Rocky Mountains influence gene flow and dispersal at the continental scale.
Location: Continental North America.
Methods: We collected 292 museum samples covering the species range, genotyped them at 20 microsatellite markers and sequenced 410 bp of the mitochondrial gene ND6. Population and landscape genetics tools were used to study range-wide patterns of structure and identify gene flow barriers. Ring recapture data were also analysed to investigate individual movement patterns and frequency of exchanges between both sides of the Rocky Mountains.
Results: We found faint overall genetic structure, which is consistent with barn owl’s high mobility across its continuous range. Nonetheless, we identified two distinct genetic groups on the western and eastern regions of the Rocky Mountains with a likely contact point through the narrow southern pass between them and the Sierra Madre Occidental in Mexico. Accordingly, most recaptured barn owls remain on the same side of the mountains. The Rockies appear to significantly isolate the populations in the west, which, as a consequence, display lower genetic diversity than their counterparts to the east.
Main conclusions: The Rocky Mountains appear to constrain barn owl dispersal and gene flow. Our study supports the hypothesis that regional landscape barriers can shape gene flow and population structure even in highly mobile organisms.
 
Systematics and distribution of the living and fossil small barn owls of the West Indies (Aves: Strigiformes: Tytonidae)
WILLIAM SUÁREZ, STORRS L. OLSON

Abstract

After reviewing the systematics and distribution of the living and fossil small West Indian taxa of Tytonidae (Tyto), we reached the following conclusions: (1) Strix tuidara J. E. Gray, 1827, type locality of Brazil, is the earliest available and correct name to be used in a binomen for New World mainland barn owls; (2) the North American mainland subspecies Tyto tuidara pratincola (Bonaparte, 1838), new combination, is resident in the Bahamas (“Tyto perlatus lucayanus” Riley, 1913, is a synonym), where it probably did not colonize until after the European introduction of Rattus Fischer, in Hispaniola (Dominican Republic and Haiti) where it became established in the 20th century, and subsequently in Puerto Rico; (3) Tyto furcata (Temminck, 1827) of Cuba, Jamaica and the Cayman Islands is a different species restricted to its insular distribution, with “T. alba niveicauda” Parkes & Phillips, 1978, of the Isle of Pines (now Isla de la Juventud) as a synonym; (4) the distinct species Tyto glaucops (Kaup, 1852), now endemic to Hispaniola, once occurred in Puerto Rico, as the fossil species “T. cavatica” Wetmore, 1920, is here shown to be a synonym; (5) the smallest taxon Tyto insularis (Pelzeln, 1872) of the southern Lesser Antilles is treated as a separate species, in which the nominate subspecies T. i. insularis (St. Vincent, Grenada, and the Grenadines) differs slightly but consistently in coloration from T. i. nigrescens (Lawrence, 1878) of Dominica; (6) another barn owl, Tyto maniola, new species, of this group of small tytonids from the West Indies inhabited Cuba during part of the Quaternary, and is here named and described.



Keywords

Aves, Tytonidae, Distribution, Fossil Birds, Systematics, Tyto, West Indies


www.biotaxa.org/Zootaxa/article/view/zootaxa.4830.3.4

Tyto furcata and tuidara are not extinct
 
Might be interesting to know whether Tyto maniola occurred until the Late Quarternary (Pleistocene/Holocene border?). So if someone has access to this paper, it would be great to send me a copy.
 
Might be interesting to know whether Tyto maniola occurred until the Late Quarternary (Pleistocene/Holocene border?). So if someone has access to this paper, it would be great to send me a copy.
Sorry, not at the moment - sci-hub is giving 'article not found'. I'll check again in a couple of days (it often happens like this with newly announced papers).
 
Sorry, not at the moment - sci-hub is giving 'article not found'. I'll check again in a couple of days (it often happens like this with newly announced papers).

Fred was so kind and sent me this paper after he've got it from William Suarez.

What I've learned from this paper is that Tyto cavatica is either invalid or a subspecies of Tyto glaucops and that the new species Tyto maniola occurred in the Late Pleistocene.
 
Not really glowing reception by the first couple of comments

Niels
Reading the comments (but not re-reading the papers), I was concerned at the generally dismissive approach to possibly quite deep genetic divergence. How to arrange the taxa is subjective (whether species, subspecies or whatever), but I'd suggest any deep genetic divergence requires explanation.

I also wonder about the importance of vocalisations in barn owls in particular, as I think they're more diurnal than most..?
 
I also cannot find the actual genetic differences published anywhere... the supplemental materials available online don't seem to include them?

Barn Owls are really interesting, and it wouldn't be surprising, to anyone, I don't think, to find that there truly are three species there. There very likely are three species (at least by our human definitions). But it's also fair to say that nothing presently available seems to resolve the issue adequately, even if common sense suggests it's an open-and-shut case. For instance, Colihueque 2015 (link), using mtDNA to study Barn Owl in Chile, found "intraspecific genetic divergence (mean p-distance) was 4.6 to 5.5% for the Common Barn Owl in comparison with specimens from northern Europe and Australasia." However, large mtDNA divergence is to be expected with such a great geographic distance. Large genetic distance
(particularly nuclear) between birds breeding closer together would be a much more incontrovertible argument - but I am not sure any such data has been published?

I also think the question of vocalizations in Barn Owls is interesting. Perhaps, at some point, some more clever computational analysis will uncover patterns that we do not hear - similar to UV plumage details that we do not see.
 
I also cannot find the actual genetic differences published anywhere... the supplemental materials available online don't seem to include them?

Barn Owls are really interesting, and it wouldn't be surprising, to anyone, I don't think, to find that there truly are three species there. There very likely are three species (at least by our human definitions). But it's also fair to say that nothing presently available seems to resolve the issue adequately, even if common sense suggests it's an open-and-shut case. For instance, Colihueque 2015 (link), using mtDNA to study Barn Owl in Chile, found "intraspecific genetic divergence (mean p-distance) was 4.6 to 5.5% for the Common Barn Owl in comparison with specimens from northern Europe and Australasia." However, large mtDNA divergence is to be expected with such a great geographic distance. Large genetic distance
(particularly nuclear) between birds breeding closer together would be a much more incontrovertible argument - but I am not sure any such data has been published?

I also think the question of vocalizations in Barn Owls is interesting. Perhaps, at some point, some more clever computational analysis will uncover patterns that we do not hear - similar to UV plumage details that we do not see.
I'm not sure geographic distance per se should lead to large mtDNA divergence. Yes if there's some physical break in the population when you'll get drift and founder effects but if there's regular dispersal between populations and individuals "freely" interbreed any divergence should be shallow. You might get difference by distance effects but these would be clinal and not great "breaks" in the phylogeny. Deep divergence suggests reproductive isolation to me.

If populations are isolated (islands etc) they will drift away from the parent one and at some point we'd expect them to become biological species (again deep divergence can be our proxy estimate for this)

[Edit: so, without reading Colihueque &c, I'd say 5% would indicate these "intraspecific" things are probably different biological species]
 
I believe it was the printed HBW that recounted an experiment where some Barn Owls of Australian and American origin was released on the same island location. The experiment ended with the birds dying out and there was speculation it was because the two groups did not recognize each other an belonging to same species? (disclaimer, it is a long time since I read this so I might mis-remember something).

Niels
 
Genomic bases of insularity and ecological divergence in barn owls (Tyto alba) of the Canary Islands
Tristan Cumer, Ana Paula Machado, Felipe Siverio, Sidi Imad Cherkaoui, Inês Roque, Rui Lourenço, Motti Charter, Alexandre Roulin, Jérôme Goudet
bioRxiv 2021.12.24.473866; doi: Genomic bases of insularity and ecological divergence in barn owls (Tyto alba) of the Canary Islands


Islands, and the particular organisms that populate them, have long fascinated biologists. Due to their isolation, islands offer unique opportunities to study the effect of neutral and adaptive mechanisms in determining genomic and phenotypical divergence. In the Canary Islands, an archipelago rich in endemics, the barn owl (Tyto alba) is thought to have diverged into a subspecies (T. a. gracilirostris) on the eastern islands, Fuerteventura and Lanzarote. Taking advantage of 40 whole-genomes and modern population genomics tools, we provide the first look at the origin and genetic makeup of barn owls of this archipelago. We show that the Canaries hold diverse, long-standing and monophyletic populations with a neat distinction of gene pools from the different islands. Using new method, less sensitive to structure than classical FST, to detect regions involved in local adaptation to the insular environment, we identified a haplotype-like region likely under positive selection in all Canaries individuals. Genes in this region suggest morphological adaptations to insularity. In the eastern islands, where the subspecies T. a. gracilirostris is present, genomic traces of selection pinpoint signs of locally adapted body proportions and blood pressure, consistent with the smaller size of this population living in a hot arid climate. In turn, genomic regions under selection in the western barn owls from Tenerife showed an enrichment in genes linked to hypoxia, a potential response to inhabiting a small island with a marked altitudinal gradient. Our results illustrate the interplay of neutral and adaptive forces in shaping divergence and early onset speciation.
 
I believe it was the printed HBW that recounted an experiment where some Barn Owls of Australian and American origin was released on the same island location. The experiment ended with the birds dying out and there was speculation it was because the two groups did not recognize each other an belonging to same species? (disclaimer, it is a long time since I read this so I might mis-remember something).
I just looked it up: on Lord Howe, "birds declined to interbreed".
 
Reading the comments (but not re-reading the papers), I was concerned at the generally dismissive approach to possibly quite deep genetic divergence. How to arrange the taxa is subjective (whether species, subspecies or whatever), but I'd suggest any deep genetic divergence requires explanation.

I also wonder about the importance of vocalisations in barn owls in particular, as I think they're more diurnal than most..?

I'm not certain about how they compare as far as diurnal activity, but Barn Owls seem to have good enough night vision that darkness is not an obstacle. Some of the comments in the SACC responses seem ignorant of studies which do indeed suggest that plumage difference can be important - here is one that suggests that males select females based on spotting density:

Roulin, A. (1999). Nonrandom pairing by male Barn Owls (Tyto alba) with respect to a female plumage trait. Behavioral Ecology 10:688-695.
 
Not really glowing reception by the first couple of comments

Niels

Later comments seem to show members "coming around" to a split, but wanting a more complete proposal. I'm guessing that a lot of these were posted after you commented here, Neils. Toward the end:

Comments from Robbins: “”As Van suggested, will hold off for now on voting on this proposal until a new proposal is presented.”
 
Later comments seem to show members "coming around" to a split, but wanting a more complete proposal. I'm guessing that a lot of these were posted after you commented here, Neils. Toward the end:

Comments from Robbins: “”As Van suggested, will hold off for now on voting on this proposal until a new proposal is presented.”
Yes. The question is how long will it take for someone to get around to do what they hope?
Niels
 
Yes. The question is how long will it take for someone to get around to do what they hope?
Niels
SACC does seem decently fast compared to some committees on creating follow-up proposals. Plus there might be greater pressure to get this done if they are attempting to realign checklists, given that I think American Barn Owl is split from the old world taxa by at least IOC.
 

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