TL;DR: Thirteen Mottled Owl nests are described from Tikal National Park, Peten, Guatemala; these were cavities in live trees at a mean height of 12.9 m and each nest contained one egg.
Abstract: -Thirteen Mottled Owl (Ciccaba virgata) nests are described from Tikal National Park, Peten, Guatemala. These were cavities in live trees at a mean height of 12.9 m. Mean clutch size was 2.2 (range 2-3). Nine nests fledged 16 young. Young left the nest at 27-33 days of age. Mean home range size was 20.8 ha (85% harmonic mean) for six radiotagged breeding males, and density was seven breeding adults per km2. Mottled Owls were found to be highly territorial, sedentary, and monogamous. Four nests of the Black-andwhite Owl (C. nigrolineata) are also described. All were in epiphytes in large, live trees. Mean nest height was 20.5 m. Each nest contained one egg. The home range size of a single radio-tagged male was 437.3 ha (85% harmonic mean). One pair studied during three consecutive years was found to be monogamous and completely sedentary. Received 14 Sept. 1993, accepted 11 Feb. 1994. Wood owls of the genus Ciccaba are poorly known, and data have been largely limited to morphological descriptions. Detailed information on natural history has been reported for only one species, the African Wood Owl (C. woodfordii), found only in Africa and the sole Old World representative of the genus (Steyn and Scott 1973; but see Amadon and Bull 1988, who place this species within Strix). New World Ciccaba inhabit Neotropical forests where they are mostly unstudied (Burton 1973). The Mottled Owl (C. virgata) is believed to be the most numerous and widespread wood owl of the neotropics and subtropics; its range extends from Chihuahua and Sonora, Mexico, to northern Argentina and southern Brazil (Peterson and Chalif 1973). It has also been reported from Hidalgo County, Texas (Lasley et al. 1988). The literature contains few references to nests of the Mottled Owl (Belcher and Smooker 1936). Despite being widespread and numerous, virtually nothing is known of its breeding biology. The Black-and-white Owl (C. nigrolineata) inhabits humid lowland and foothill forests from southern Mexico to northwestern Venezuela and northwestern Peru. It is uncommon to rare throughout its range (Peterson and Chalif 1973, Stiles and Skutch 1989). The literature mentioning this species is mostly brief anecdotal descriptions and individual accounts ' Raptor Research Center, Boise State Univ., Boise, Idaho 83725. 2 El Parque Nacional Tikal, El Peten, Guatemala. The Peregrine Fund, Inc., 5666 West Flying Hawk Lane, Boise, Idaho 83709. 4 Present address: 341 NE Chestnut, Madras, Oregon 97128.
TL;DR: A tarsometatarsus has been selected as the type because of completeness of the specimen and the diagnostic features of the element, and the other available elements are discussed as referred material.
Abstract: Upon a recent examination of the owl bones in the Los Angeles Museum collections from Rancho La Brea, certain unusual specimens came to the writer's attention. All are of a size easily to be confused with slender bones of Bubo virginianus and, in fact, were found among the elements which had been so assigned in the first general survey of the collection. The specimens may be separated from those of the Horned Owl, however, on the basis of the same characters which distinguish members of the genus Strix from Bubo. Comparisons were made also with Scotiaptex, Nyctea and Asio of North America and Pulsatrix, Rhinoptynx and Ciccaba from the south.' The fossil, however, most closely accords with Strix, though it is larger than either North American species of that genus. Furthermore, from such information as can be gained from the literature on the subject, and from Dr. Wetmore who has kindly measured Strix rufipes for the writer, it is apparently larger than any other species of that genus or of the genus Ciccaba, which resembles Strix in many characters. Nine of the principal skeletal elements have been identified and are fairly well represented, the number of available specimens totalling fifty-six. With regard to the pelvis, the variation within the genus Strix and the similarities between Strix and Bubo in general characters make difficult a separation of the pelves of these two genera; this fact coupled with the somewhat fragmentary condition of the La Brea specimens has made it impossible to identify this element of the fossil form. This is the case also with the ulna. No furcula, cranium, or lower mandible of the fossil species is available; these elements are but poorly represented and the few specimens of large owl which occur in the collection appear to belong to Bubo. No attempt has been made to identify the radius, vertebrae, ribs or phalanges. In describing the species, a tarsometatarsus has been selected as the type because of completeness of the specimen and the diagnostic features of the element. The other available elements are discussed as referred material. The photographs of the type specimen were made by Mr. H. Wm. Menke.
TL;DR: The author will add a further perspective of systematic zoology by proposing a way leading to deeper understanding of owl taxonomy through laboratory experiments, which, however, he has not yet been able to carry out himself.
Abstract: "... speaking here as a taxonomist to taxonomists, I am certainly no less than respectful toward the noble art of classification" (Leon Croizat, 1958, p. 119). In considering a thorough systematic study a necessity before entering into zoogeographical theories, the author feels he may expect the full and sympathetic approval of Professor H. Boschma, to whom this paper is dedicated. Indeed, taxonomy or systematic zoology is one of the corner-stones of a sound building of zoogeography. The present paper, therefore, dealing with the taxonomy of wood owls and subsequent zoogeographical inferences probably is in line with the way of thinking of Boschma as a systematist. The author will add a further perspective of systematic zoology by proposing a way leading to deeper understanding of owl taxonomy through laboratory experiments, which, however, he has not yet been able to carry out himself. James Lee Peters (1940), the latest reviewer of the owls in his "Check-list of birds of the world", volume 4, was confronted with the problem of designing a systematic arrangement of the group of "wood owls", mediumlarge owls with big round heads without ear-tufts and usually dark eyes. In a preliminary paper Peters (1938) turned back to a classification of owls proposed by Sharpe (1875) and more or less strictly followed by Ridgway (1914), using the size and shape of the external ear as a character distinguishing between a "bubonine" and a "strigine" group of owls, ultimately giving these groups subfamily rank.
TL;DR: This review and emended description of Strix brea has provided a clearer picture of this species, and it is found that it is more appropriately placed in a new genus, Oraristrix, whose affinities remain unclear.
Abstract: We review all of the fossil specimens from the upper Pleistocene Rancho La Brea asphalt deposits previously referred to the extinct owl Strix brea, and all newly identified specimens referable to that species. This review and emended description of Strix brea have provided a clearer picture of this species, and we find that it is more appropriately placed in a new genus, Oraristrix, whose affinities remain unclear. We provide a variety of morphometric data and more detailed osteological descriptions of this extinct owl based on 138 specimens from the Rancho La Brea collections in the George C. Page Museum that represent a minimum of 23 individuals. An additional nine specimens of this extinct species were confirmed in collections from the upper Pleistocene asphalt deposits of Carpinteria, California. Oraristrix brea is interpreted as being more terrestrial in habits than forest owls because, compared to available species of the genera Bubo and Strix, it had longer legs relative to its wingspan. Campbell Jr., Kenneth e., & Zbigniew m. boChensKi, 2010. A new genus for the extinct Late Pleistocene owl Strix brea Howard (Aves: Strigiformes) from Rancho La Brea, California. In Proceedings of the VII International Meeting of the Society of Avian Paleontology and Evolution, ed. W.E. Boles and T.H. Worthy. Records of the Australian Museum 62(1): 123–144. A large, extinct owl from the upper Pleistocene asphalt deposits of Rancho La Brea, California was described as Strix brea Howard, 1933. In addition to the holotypic tarsometatarsus, several other elements of the skeleton were briefly described and referred to this species by Howard (1933). However, since its original description, with the exception of being included in faunal lists (e.g., Howard, 1962), this species, which is known as the Brea Owl, has not been revisited. Herein we reevaluate the characters Howard (1933) used to distinguish the species, describe additional characters, illustrate bones not previously illustrated, and add to the list of elements and specimens referable to this extinct species. We offer suggestions as to the size and life habits of the Brea Owl based on its osteology and limb bone proportions. Strix brea is found to be a valid species, but one best placed in a new genus. This study is part of an overall review of all of the fossil owls in the collections from Rancho La Brea maintained at the George C. Page Museum by the Natural History Museum of Los Angeles County (LACM). At least nine species of owls are represented in the collections by a total of over 7500 specimens. In the course of this review we found that the post-cranial elements of the genera of owls could be fairly easily distinguished by osteological characters, at least for the 124 Records of the Australian Museum (2010) Vol. 62 several genera represented in the Rancho La Brea collection. This finding is contrary to that of Olson & James (1991), who, citing an unpublished work by Ford (1967), suggested that post-cranial differences between the various subgroups and genera of owls are very slight or non-existent. Materials and methods The fossil specimens were compared in detail with specimens of modern Bubo virginianus (20+) and all of the numerous fossil specimens of B. virginianus from Rancho La Brea, B. bubo (4), B. africanus (1), Strix occidentalis (8), S. varia (7), S. nebulosa (9), and S. aluco (3). The numbers reflect the largest sample sizes of each species available for comparison. Points on scatter diagrams are often less numerous because of incomplete modern comparative specimens. The genera Ketupa and Nyctea are considered by some (Amadon & Bull, 1988; Wink & Heidrich, 1999; Wink et al., 2008) as properly being included within Bubo, so these genera were included in our study. Nyctea, for the most part, agrees with Bubo as far as the osteological characters useful for distinguishing the Brea Owl from Bubo and Strix are concerned. Ketupa [K. ketupa (1), K. zeylonensis (3)], on the other hand, varies considerably from Bubo osteologically, and we find it to be easily distinguished from both Bubo and the Brea Owl. In our opinion, based on its osteological features, we agree with Sibley & Monroe (1990) that Ketupa is a valid genus separate from Bubo. However, we were unable to compare the species of Ketupa with those Asian species of Bubo that Wink & Heidrich (1999) and Wink et al. (2008) suggested were closest to Ketupa based on molecular studies. Similarly, the genus Ciccaba is considered by some as properly being included within Strix (e.g., Sibley & Monroe, 1990; Wink & Heidrich, 1999; Wink et al., 2008), and we found that two species referred to Ciccaba [C. virgata (1) and C. nigrolineata (1)] agree with Strix as far as most of the osteological characters we detail below are concerned. Based on the osteology of available specimens, we accept that Nyctea belongs within Bubo and Ciccaba within Strix. Comparisons were also made with the genera Tyto, Otus, Megascops, Lophostrix, Pulsatrix, Surnia, Glaucidium, Athene, Aegolius, Micrathene, Ninox, and Asio. Each of these genera can be readily distinguished from Bubo, Strix, and the Brea Owl using osteological characters. In molecular studies, Strix and Bubo appear as closely related taxa (Wink & Heidrich, 1999; Wink et al., 2008), which is reflected in the many osteological characters they share that differ significantly from those of the other genera examined. Therefore, because this study was not intended as a comparative osteological review of all genera of owls we limit our detailed comparisons to species of Bubo and Strix, the genera that most closely resemble the Brea Owl osteologically. Measurements were taken using digital calipers accurate to 0.01 mm, and all data were captured directly to computer. The measurements were stored, and the basic statistics, including minimum, maximum, arithmetic mean, and standard deviations, were computed in Microsoft Excel. For illustrations as to how the measurements were taken, see Appendix 2. All bones were checked for ratios useful for differentiating the species, and scatter diagrams of the ratios were prepared using Microsoft Excel and Corel PhotoPaint. Osteological terminology is primarily from Baumel & Witmer (1993). Abbreviations used: Cond. = condylus; Fac. artic. = facies articularis; Lig. coll. = ligamentum collaterale; Proc. = processus; Tub. = tuberulum Figure 1. Holotypic tarsometatarsus of Oraristrix brea (LACM RLB E9379) in (A) anterior, (B) lateral, (C) posterior, (D) medial, (E) proximal, and (F) distal views. Lateral view (G) of distal tarsometatarsus of O. brea (LACM RLB K9623) illustrates the straight posterior edge of the lateral condyle of Trochlea III. Scale bar = 20 mm. Campbell & Bochenski: New genus of extinct Late Pleistocene owl 125