DOCSLIB.ORG

Natal and Breeding Dispersal in Barn Owls

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Natal and Breeding Dispersal in Barn Owls THE JOURNAL OF RAPTOR RESEARCH A QUARTERLY PUBLICATION OF THE RAPTOR RESEARCH FOUNDATION, INC. VOL. 33 SEPTEMBER 1999 No. 3 j. RaptorRes. 33(3):181-189 ¸ 1999 The Raptor ResearchFoundation, Inc. NATAL AND BREEDING DISPERSAL IN BARN OWLS CARL D. MARTI 1 Departmentof Zoology,Weber State University, Ogden, UT 84408-2505 U.S.A. ABSTRACT.-•Istudied dispersal of the Barn Owl (Tyt0alba) in northern Utah from 1977-96. Basedon 144 recoveriesof 2085 banded nestlings,the averagedispersal distance was 102.9 km (median = 60 km, range = 0-1267 km), occurredin most compassdirections from natal sites,but wasnot random with mountains,deserts, and the Great Salt Lake altering dispersalroutes. Dispersaldistance was not corre- lated with severityof winter weather nor population density.Among owls banded as nesdingsand re- capturedas breeders,females (N = 48) moved significantlyfarther (i = 61.4 km, median = 57.5 km, range = 0-160 km) than males (N = 34, i = 35.7 km, median = 14.7 km, range = 0.8-120 km, P = 0.015). Turnover of breeders at nest sites resulted mostly from individuals dispersinginto the study area. Only 19 (of at least 500) breedersmoved from one breeding site to another. The mean distance moved between breeding sitesof 2.3 km (median = 2.25 km) was not significantlydifferent between males and females (P -- 0.9), but more females (16) than males (3) made these moves.Eight of the adults that shifted breeding sitesdid so in the same year either after a failed first attempt (2) or to produce a secondbrood (6). The remainder changed nest sitesin subsequentyears. K•Y WOADS: Barn Owl;Tyto alba; breedingdispersa• long-term study; natal dispersal;Utah. Dispersi6nnatal y reproductivade Tytoalba PmSUMEN.--Estudi6la dispersi6nde Tytoalba en el norte de Utah desde 1977-96. Con base en 144 recapturasde 2085 pichonesanillados, encontr6 que la distanciade dispersi6nfue de 102.9 km (media = 60 km, rango = 0-1267 km), ocurridas en todas las direccionesdesde el sitio de nacimiento. Esta situaci6nno ocurri6 al azar en montafias,desiertos y el Great Salt Lake los cualesalteraron las rutas de dispersi6n.La distanciade dispersi6nno estuvocorrelacionada con la severidaddel clima invernal, ni con la densidad poblacional. Entre las lechuzasanilladas como pichonesy recapturadascomo re- productores,las hembras (N = 48) se movilizaronsignificativamente mas lejos (i = 61.4 km, media = 57.5 km, rango = 0-160 km) que los machos(N = 34, i = 35.7 km, media 14.7 km, rango = 0.8-120 km, P = 0.015). E1 regreso de los reproductoresa los sitios de los nidos, fue el resultado de individuos dispersadosdentro del area de estudio. S61o 19 (de por lo menos 500) reproductores se movilizaron de un sitio de reproducci6n a otro. La distanciapromedio recorrida entre los sitiosde reproducci6n fu• de 2.3 km (media = 2.25 km). Esta distanciano fue significativamentediferente entre machosy hembras (P = 0.9). Mas hembras (16) que machos (3) hicieron estosmovimientos. Ocho de los adultos que cambiaron sussitios de reproducci6n lo hicieron en el mismo afio despuesde fracasaren un primer intento (2) o para producir una segunda nidada (6). E1 resto cambi6 el sitio del nido en los aftos subsecuentes. [Traducci6n de C6sar M/trquez] The Barn Owl (Tyto alba) is among the most pects of its biology closely resemble other owls widespreadof land birds, and although some as- (e.g., trophic biology), other attributesare striking- ly different. Among the important disparitiesare • Presentaddress: Boise State University, Raptor Research aspectsof the Barn Owl's reproductivebiology and Center, Boise, ID 83725 U.S.A. life-history (Marti 1997). Here, I show that dis- 181 182 MARTI VOL. 33, No. 3 persal in Barn Owls conformswith the species'r- selected life-history strategy (reproduction at an early age, short reproductive life, high reproduc- tive output, and an ability to find new resources-- sometimesat great distances--throughnatal dis- persal), but alsofits somepatterns of dispersalthat are widespreadin other birds. Dispersalis a very important but poorly under- stood element of population biology (Begon et al. 1990). Dispersalmay be either natal--the one-way \1 salt movement by an individual from its birthplace to a breeding (or potential breeding) site, or breed- ing--the movement by adults between breeding sites.Natal dispersalusually covers greater distanc- Figure 1. Location and topographic features of es than breeding dispersal (Greenwood and Har- OM study area in northern Utah. vey 1982). Advantagesattributed to natal dispersal include reducing the chance of inbreeding, reduc- ing competition,and extending the range (Green- persal occurred and look for supportthat dispersal wood 1983, Swingland1983). In many bird species, reduces inbreeding. dispersalpatterns differ between adults and juve- niles and between males and females (Greenwood STUDY AREA AND METHODS 1983, Greenwood and Harvey 1982). The studyarea was a narrow(12-25 km wide,500 km2) Relativelyfew studiesof dispersalhave been con- valley lying between the Wasatch Mountains and the ducted on raptors. See for example, Newton Great Salt Lake in Box Elder, Weber, and Davis counties of northcentral Utah (Fig. 1) that is close to the Barn (1979) and referenceswithin, Newton (1986) and Owl's northern range limit in the Intermountain Region Ferrer (1993) for European diurnal raptors, and (Marti 1992). The area was shrubsteppedesert but that Korpimfiki et al. (1987), Korpimfiki (1988), Kor- communityhas been entirely supplantedby irrigated ag- pimfiki and Lagerstr6m(1988), and Colesand Pet- riculture and urban development.Hot dry summersand cold winters characterizethe region; mean temperatures ty (1997) for Europeanowls. In North America,see for July andJanuary are 23.9øcand -3.5øC, respectively. Jacobs (1995), Woodbridgeet a1.(1995), Steenhof Barn Owl nestinghabitat is limited and disjunctin this et al. 1984, and Miller and Smallwood (1997) for area; most Barn Owls nest in lower elevation valleys diurnal raptors,and VanCampand Henny (1975), where irrigated agriculture occurs. Rugged mountains and high elevationvalleys immediately east of the study Adamcik and Keith (1978), Marks (1985), Bull et area were unsuitable Barn Owl habitat, and, likewise, the al. (1988), Belthoff and Ritchison (1989), Ganeyet Great Salt Lake and alkali desertsto the westof the study al. (1998), Gehlbach (1994), and Arsenault et al. area offered little habitat for Barn Owls. See Marti (1994) (1997) for owls. for more details on the studyarea and owl nest sites. Most of the Barn Owls on my studyarea nestedin nest Dispersal in Barn Owls has been studied in boxes (Marti et al. 1979). From 1977-96, I visited these North America (Stewart 1952), Europe (Frylestam nest boxesyear-round at leastonce per month. I made 1972, Sch6nfeld 1974, Glutz von Blotzheim 1979, additional visits as needed to band and color mark nest- Bairlein 1985, Baudvin 1986, Chanson et al. 1988, lings and adults with a standardUSGS aluminum band Taylor 1994, Martinez and L6pez 1995), and to a and a combination of colored plastic bands unique to each bird (two bands per leg) permitting identification very minor extent in Australia (Purchase1972). of individualswithout havingto recapturethem. Few oth- Only Taylor (1994) presenteddata on both the dis- er suitable nest sitesexisted on the study area, but owls persal of nestlings to breeding sites and move- occasionallynested in buildings and hay stacks.These ments of adults between nest sites. were often reported to me by farmers or by ownersof buildings havingvarious problems caused by the nesting Previously,I documented the reproductive pat- owls.Thus, I wasable to document nestingin these sites tern (Marti 1994) and lifetime reproductive suc- as well. cess(Marti 1997) in a Barn Owl population breed- I attempted to capture all breeding owlseach year to determine their identity, age, and movements.Most fe- ing close to the northern limit of its range. Here, malesand somemales were caughtby hand in nestboxes I present dispersalpatterns in the same popula- but, because males were less often found in nest boxes, tion, test whether sex and age differences in dis- I sometimes used nest-box traps to capture them (Sau- SEPTEMBER 1999 BARN OWL DISPERSAL 183 60 2o! Males • 50 E • 40 '0 30 • lO {= 2o Z 10 0 0.40 81-120 161-200 241-260 0.40 81-120 161-200 41-80 121-160 201-240 261+ 41-80 121-160 Dispersal distance, km Dispersal distance, km Figure 2. Dispersaldistances in Barn Owls banded as Figure 3. Comparison of dispersal distancesbetween nestlingsin northern Utah. breeding male and female Barn Owlsbanded asnestlings in northern Utah. rola 1987). For breeding owls not banded as nestlings, age wasdetermined by wing-moltpattern. Barn Owlsdo not molt any primaries until 13 months of age (P. Bloom recovered (either found dead or identified alive) pers. comm., Lenton 1984, Taylor 1993). Thus, in the at an average of 102.9 --- 162.03 (-SD) km from spring,breeding owlswith one generationof primaries their natal sites(median = 60 km, range = 0-1267 are in their first year of life, and those with two genera- km; Fig. 2). Among owls banded as nestlingsand tions of primary feathersare at least 2-yr old. I also in- cluded data from some nestlingowls that I banded on a recaptured as breeders,females (N = 48) moved site similar to my study area located in Cache County, significantlyfarther (i = 61.4 +--52.04 km, median Utah. Similarly,I useddata from severalBarn Owlsband- = 57.5 km, range = 0-160 km) than males (N = ed asnestlings by the Utah Divisionof Wildlife Resources 34, / = 35.7 +--36.61 km, median = 14.7 km, range m Utah County, Utah and recaptured in my study area. = 0.8-120 km; t = 2.48, df = 80, P = 0.015, power Barn Owls were nonmigratory in northern Utah as they appear to be in most if not all other parts of the species' = 0.66; Fig. 3). One female nestedin her natal site range (Schneider1937, Cramp 1985, Taylor1994). and two siblings that dispersedonly 8 km from Statisticalanalyses (t-tests and linear correlation)were their natal site paired and raised young.
Load more

Recommended publications
  • SCIENCE 93 Least Were Found Partly Buried in Loose Soil
    JANUAkRY 24, 1919] SCIENCE 93 least were found partly buried in loose soil. the birds of the Americas, is included in the One, weighing 61 pounds, was found about six introductory mnatter. The present part com- inches in sandy soil where it had fallen and prises 1,265 species and subspecies, represent- broken into several pieces as it struck. Som-le ing 232 genera of the following families: pieces show secondary fusion surfaces, and Bubonidce, Tytonidoe, Psittacida, Steator- some appear to show tertiary fusion surfaces. nit-hidae, Alcedinidae, TodidT., Molnotide, The stone is brittle and most of the pieces are Nyctibiidoe, Caprimulgide, " Cypselidae " (lege broken; however, one fine boloid of twenty Micropodide) and Trochilidie. pounds has beeni founid and several of about Of the higher groups niothing but the names ten pounds weight. is given, but for each genus there are added The writer is preparing a detailed descrip- the authority, the original reference, and a tion of the mieteorite and the phenomena of its citation of the type. 'For each species and fall and would appreciate any data that may subspecies there appear the full technical com- have been gathered by other observers or bination; the common rname; reference to the collectors. original description; the type locality; such TERENCE T. QUIRaE essential synonymy at references (usually DEPARTMENT or GEOLOGY AND MINERAXLOGY, not over half a dozen) to Mr. Ridgway's UNIVERSITY OF MINNESOTA, " Birds of North and AIiddle America," " The MINNEAPOLIS, MINN. Catalogue of Birds of the tritish MAuseum," original descriptionis, revisions of groups, and on March 27, 2016 SCIENTIFIC BOOKS other important papers; a brief statement of geoglaphic range; and a list of specimens Catalogue of Birds of the Americas.
    [Show full text]
  • Unusual Results from Pellet Analysis of the American Barn Owl, Tyto Alba Pratincola (Bonaparte) Kenneth N
    Journal of the Arkansas Academy of Science Volume 33 Article 38 1979 Unusual Results from Pellet Analysis of the American Barn Owl, Tyto alba pratincola (Bonaparte) Kenneth N. Paige Arkansas State University Chris T. McAllister Arkansas State University C. Renn Tumlison Arkansas State University Follow this and additional works at: http://scholarworks.uark.edu/jaas Part of the Zoology Commons Recommended Citation Paige, Kenneth N.; McAllister, Chris T.; and Tumlison, C. Renn (1979) "Unusual Results from Pellet Analysis of the American Barn Owl, Tyto alba pratincola (Bonaparte)," Journal of the Arkansas Academy of Science: Vol. 33 , Article 38. Available at: http://scholarworks.uark.edu/jaas/vol33/iss1/38 This article is available for use under the Creative Commons license: Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0). Users are able to read, download, copy, print, distribute, search, link to the full texts of these articles, or use them for any other lawful purpose, without asking prior permission from the publisher or the author. This General Note is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Journal of the Arkansas Academy of Science by an authorized editor of ScholarWorks@UARK. For more information, please contact [email protected], [email protected]. Journal of the Arkansas Academy of Science, Vol. 33 [1979], Art. 38 Arkansas Academy of Science Table 2. Teacher evaluations of college courses. had course 5 B3 General Bio] >f-y 1.53 17 91 General Boti iy 1.214 15 63 General Zool >gy i.00 6 33 Cell Bl 1 .'V 1.33 11 78 Genetic 1.29 9 50 General Boo] '*y 1.51 13 72 General Phyi ol igy 1.15 13 72 Human Ana tony 1 ,07 11 61 Human Physiology 1.18 1 5 Human Sexuality i.
    [Show full text]
  • Montana Owl Workshop April 19-24, 2019 © 2018
    MONTANA OWL WORKSHOP APRIL 19-24, 2019 © 2018 High, wide, and handsome, Montana is the country’s fourth largest state, encompassing 145,392 square miles (376,564 square kilometers), and has one of the lowest human densities of all states; about six to seven people per square mile. Its biological diversity and variable climate reflects its immensity. Among its alpine tundra, coniferous forests, plains, intermountain valleys, mountains, marshes, and river breaks, Montana lists 433 species of birds, 109 species of mammals, 13 species of amphibians, and 18 species of reptiles. Montana also maintains about 2,080 species of native plants. Join researchers for four full days of learning how to survey, locate, and observe owls in the field. Montana boasts the largest number of breeding owl species in any state within the United States. Fifteen species of owls occur in Montana, of which 14 species breed: American Barn Owl, Flammulated Owl, Eastern Screech Owl, Western Screech Owl, Great Horned Owl, Barred Owl, Great Gray Owl, Northern Hawk Owl, Northern Pygmy Owl, Burrowing Owl, Boreal Owl, Northern Saw-whet Owl, Long-eared Owl, and Short-eared Owl. Snowy Owls are winter visitors only. Although all species will not be seen, chances are good for five to seven species, and with some luck, eight species are possible. Highlights can include Great Gray Owl, Northern Pygmy Owl, Boreal Owl, and Northern Saw-whet Owl. It’s not often the public has an opportunity to follow wildlife researchers on projects. During this educational workshop, we will meet and observe field researchers of the Owl Research Institute (ORI) who have been conducting long-term studies on several species of owls.
    [Show full text]
  • Barn Owls in the Vineyards
    VITICULTURE Barn Owls in the Vineyards Natural Born Killers Story and photos by Christopher Sawyer re you sick of pocket gophers and swoop and strike quickly before the prey can other rodents gnawing away on your react. vines and other costly investments on your property? Well, the answer to this PUTTING BARN OWLS TO WORK Adilemma could be as easy as purchasing a small These impressive attributes caught the atten- box and befriending a feathery creature tion of Mark Browning, a professional 2 with golden wings and a heart animal trainer and field researcher shaped face. for the Pittsburgh Zoo. Brown- Welcome to the kingdom ing’s knowledge of barn owls of the barn owl, the most inspired him to develop a widespread land bird in way to put the predatory the world. bird to work in rodent- Known for its vora- plagued vineyards and cious appetite, mag- farms: the Barn Owl nificent plumage and Box (see sidebar). Con- amazing flying skills, the barn owl is a mem- ber of the Tytonidae family. Highly success- ful in natural breeding Barn owl boxes can and longevity, the mul- help growers reduce tiple subspecies of this populations of gophers Vineyard & Winery Management • May/Jun 2009 www.vwm-online.com bird have spread around the and other rodents in globe. Currently, the two best- vineyards. (Photo by Mark known races are the barn owl of Browning.) Europe, Tyto alba alba, and the North American barn owl, Tyto alba pratincola. At a Glance In terms of living conditions, the barn owl is a hole nester that lives in closed quarters or Rodents like pocket gophers can wreak dark cavities found inside hollow trees, barns, havoc in vineyards, and are difficult to sheds and other outbuildings.
    [Show full text]
  • FEEDBACK 52- AUTUMN 2014 Welcome to the 52Nd Issue of Feedback Containing Our 2013 - 2014 Annual Report
    Issue Number 52 - Autumn 2014 FEEDBACK & the Barn wl Trust Annual Report 2013 - 2014 WATERLEAT, ASHBURTON, DEVON TQ13 7HU - (01364) 653026 - www.barnowltrust.org.uk Reg Charity No: 299 835 2014 is a good year for Barn Owls Conserving the Barn Owl1 and its EnvironmentFEEDBACK 52- AUTUMN 2014 Welcome to the 52nd issue of Feedback containing our 2013 - 2014 Annual Report. Once again we’ve produced these two In this issue ... publications together to reduce our printing and postage costs. It’s great to be able to start this issue by announcing, for the first Welcome to Feedback 2 time in many years, that this has been a good year for Barn Owls! Generally the birds have nested earlier than usual, giving hope of Diary Dates 2 second broods and they’ve had bigger broods than usual. See page BOT News 3 4 for more details of our annual monitoring site visits. More BOT News 4 This is particularly good news in light of last year’s extraordinarily Encouraging Barn Owls 5 poor breeding season. In fact it was so bad we compiled results from groups all over the UK and in April produced a new publication, Winners 6 the ‘State of the UK Barn Owl Population 2013’. Twenty-one groups Nestcam Update 6 provided data for the first edition; by July we’d produced a second run with two more groups included and in August the number of Bird News 7 groups wanting to contribute rose to twenty-six. The full publication In Memoriam 7 is available free-of-charge on our website but we have included a summary and the table of results on pages 18 -19.
    [Show full text]
  • Proposals 2018-C
    AOS Classification Committee – North and Middle America Proposal Set 2018-C 1 March 2018 No. Page Title 01 02 Adopt (a) a revised linear sequence and (b) a subfamily classification for the Accipitridae 02 10 Split Yellow Warbler (Setophaga petechia) into two species 03 25 Revise the classification and linear sequence of the Tyrannoidea (with amendment) 04 39 Split Cory's Shearwater (Calonectris diomedea) into two species 05 42 Split Puffinus boydi from Audubon’s Shearwater P. lherminieri 06 48 (a) Split extralimital Gracula indica from Hill Myna G. religiosa and (b) move G. religiosa from the main list to Appendix 1 07 51 Split Melozone occipitalis from White-eared Ground-Sparrow M. leucotis 08 61 Split White-collared Seedeater (Sporophila torqueola) into two species (with amendment) 09 72 Lump Taiga Bean-Goose Anser fabalis and Tundra Bean-Goose A. serrirostris 10 78 Recognize Mexican Duck Anas diazi as a species 11 87 Transfer Loxigilla portoricensis and L. violacea to Melopyrrha 12 90 Split Gray Nightjar Caprimulgus indicus into three species, recognizing (a) C. jotaka and (b) C. phalaena 13 93 Split Barn Owl (Tyto alba) into three species 14 99 Split LeConte’s Thrasher (Toxostoma lecontei) into two species 15 105 Revise generic assignments of New World “grassland” sparrows 1 2018-C-1 N&MA Classification Committee pp. 87-105 Adopt (a) a revised linear sequence and (b) a subfamily classification for the Accipitridae Background: Our current linear sequence of the Accipitridae, which places all the kites at the beginning, followed by the harpy and sea eagles, accipiters and harriers, buteonines, and finally the booted eagles, follows the revised Peters classification of the group (Stresemann and Amadon 1979).
    [Show full text]
  • Owls on Islands and Mainland Sites
    J. Raptor Res. 21(1):3-7 ¸ 1987 The Raptor Research Foundation, Inc. PREY SELECTION OF COMMON BARN-OWLS ON ISLANDS AND MAINLAND SITES DAVID W. JOHNSTONAND JAMESM. HILL ABSTRACT.--Datafrom the literature and a recentcollection of CommonBarn-Owl (Tyto alba) pellets from Block Island, Rhode Island, were used to assessthe relative numbers of birds and non-avian vertebratestaken by this owl on islandsand mainland sites.Our analysissupports the hypothesisthat barn-owl diets include proportionatelymore birds (both speciesand individuals) on islands than at mainland sites.The percentof bird speciesand individual birds in the diet decreasesfrom the equator to 54øN. Possible causes for island vs. mainland diets and latitudinal trends are discussed. The interaction between the Common Barn-Owl the percentof bird speciesamong all the vertebratespecies (Tyro alba) and its prey is well documented.Pub- captured, and 2) by consideringthe percent of all indi- vidualbirds vs. individuals of all non-avianvertebrate prey. lishedstudies deal with economicaspects (Bendire 1895; Errington 1932; Wallace 1950), population RESULTS AND DISCUSSION ecology(Davis 1959; Otteni et al. 1972; Herrera Prey Selectionon Islands.Most previousdietary and Jaksi• 1980), and range extensionsof mam- studies of barn-owls from mainland sites have shown malian prey (Kirkpatrick and Conway 1947; Stickel and Stickel 1948; Baker 1953; Parmalee 1954). This a preponderanceof mammalianprey. Mammal prey speciesfrom the 50 mainland sites examined here owl is believedto specializeon mammalian prey, constituteda mean of 92.4% (SD = 8.29) of the total butJohnston (1974: 172) reporteda high percentage vertebratediet. Despite this preponderanceof small of bird speciesin barn-owl pelletsfrom Grand Cay- mammal prey species,the mainland barn-owls took man Island, BWI.
    [Show full text]
  • Bringing the Endangered Barn Owl Back to Mclean County, Illinois: Implementing a Local Nest Box Program
    Illinois Wesleyan University Digital Commons @ IWU Outstanding Senior Seminar Papers Environmental Studies 11-2010 Bringing the Endangered Barn Owl Back to McLean County, Illinois: Implementing a Local Nest Box Program Anna Groves '11 Follow this and additional works at: https://digitalcommons.iwu.edu/envstu_seminar Part of the Civic and Community Engagement Commons, and the Environmental Sciences Commons Recommended Citation Groves, Anna '11, "Bringing the Endangered Barn Owl Back to McLean County, Illinois: Implementing a Local Nest Box Program" (2010). Outstanding Senior Seminar Papers. 7. https://digitalcommons.iwu.edu/envstu_seminar/7 This Article is protected by copyright and/or related rights. It has been brought to you by Digital Commons @ IWU with permission from the rights-holder(s). You are free to use this material in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/ or on the work itself. This material has been accepted for inclusion by faculty at Illinois Wesleyan University. For more information, please contact [email protected]. ©Copyright is owned by the author of this document. BRINGING THE ENDANGERED BARN OWL BACK TO MCLEAN COUNTY , ILLINOIS : IMPLEMENTING A LOCAL NEST BOX PROGRAM Shaw Creek Bird Supply 2003. ANNA GROVES RESEARCH REPORT ABSTRACT Barn owls are an endangered species in Illinois, but populations have been known to increase where nest box programs have been implemented. In conjunction with the John Wesley Powell Audubon Society, a barn owl nest box program was established in McLean County and the surrounding area.
    [Show full text]
  • Non-Tropical Northern Hemisphere Owls
    Bijdragen tot de Dierkunde, 60 (3/4) 163-170 (1990) SPB Academie Publishing bv, The Hague Species boundaries in non-tropical Northern Hemisphere Owls K.H. Voous Institute of Taxonomie Zoology, University of Amsterdam, P.O. Box 4766, 1009 AT Amsterdam, The Netherlands Keywords: Northern Hemisphere Owls, species boundary, species concept will be made based North- Abstract attempt on non-tropical ern Hemisphere owls on which a comprehensive in non- book has been 1988). A survey is presented of the status of species boundaries published recently (Voous, Northern Hemisphere owls in order to investigate the restricted to discussion of tropical The survey will be a reality of the biological and geographicalspecies concept applied stages in the evolution of owl-species without mak- to these owls in current handbooks. At the same time the prac- ing special reference to expressions of doubt which ticability ofevolutionary systematics as opposed to phylogenetic in recent years have been raised against the objec- synthesis is elaborated on. of the tivity of the concept geographically polytypic species. Résumé 2. On passe en revue la situation des limites entre espèces chez les Monotypic genera Hiboux non-tropicaux du hémisphère Nord, afin d’examiner la réalité du et de concept biologique géographique l’espèce ap- Nyctea scandiaca - Snowy Owl - circumpolar arctic circulation pliqué à ces oiseaux dans les traités en courante. tundra D’autre on insiste sur la de la part, praticabilité systématique Surnia ulula - Northern Hawk Owl - circum- à la évolutive, en tant qu’approcheopposée synthèse phylogéné- global boreal forest tique. Micrathene whitneyi - Elf Owl - Sonoran Saguaro desert “Speotyto” cunicularia — Burrowing Owl - American grass- lands and semi-deserts 1.
    [Show full text]
  • Small Mammals in the Diet of Barn Owls
    ISSN 1519-6984 (Print) ISSN 1678-4375 (Online) THE INTERNATIONAL JOURNAL ON NEOTROPICAL BIOLOGY THE INTERNATIONAL JOURNAL ON GLOBAL BIODIVERSITY AND ENVIRONMENT Original Article Small mammals in the diet of Barn Owls (Tyto furcata) in an urban area in Rio de Janeiro state, Brazil, with a new record of the dwarf mouse opossum (Cryptonanus) Pequenos mamíferos na dieta da coruja-suindara (Tyto furcata) em uma região urbana do estado do Rio de Janeiro, Brasil, com um novo registro da catita do gênero Cryptonanus A. J. Almeidaa* , R. R. Ribeiroa , J. A. Maia-Júniorb , V. C. Silvac , I. C. V. Borgesc , P. R. Gonçalvesc , K. S. Rangela , H. V. R. Diasa and A. B. F. R. Godinhoa a Universidade Estadual do Norte Fluminense Darcy Ribeiro – UENF, Centro de Ciências e Tecnologias Agropecuárias, Campos dos Goytacazes, RJ, Brasil b Prefeitura Municipal de Macaé, Centro de Controle de Zoonoses, Macaé, RJ, Brasil c Universidade Federal do Rio de Janeiro – UFRJ, Núcleo em Ecologia e Desenvolvimento Socioambiental de Macaé, Macaé, RJ, Brasil Abstract Several studies emphasize the use of owl pellets in small mammal inventories in natural areas harboring high richness of rare species, but few Brazilian Atlantic forest localities have been surveyed by this method. The present study documents the species composition and abundance of small mammals in the diet of Tyto furcata in an urban area of the municipality of Campos dos Goytacazes, Rio de Janeiro, Brazil, remarking on a new record of the dwarf mouse opossum genus Cryptonanus in the Atlantic forest. We analyzed 265 pellets regurgitated by a pair of T.
    [Show full text]
  • BARN OWLS (Tyto Alba) in PENNSYLVANIA
    CONSERVATION POTENTIAL OF BARN OWLS (Tyto alba) IN PENNSYLVANIA by Alicia Burtner Dr. Curt Richardson, advisor May 2010 Masters project proposal submitted in partial fulfillment of the requirements for the Master of Environmental Management degree in the Nicholas School of the Environment of Duke University 2010 ________________________________ Dr. Curtis Richard, MP advisor ABSTRACT Though once prolific, the barn owl (Tyto alba) is now considered vulnerable in Pennsylvania and vulnerable-to-critically imperiled in all surrounding states. Barn owls are charismatic animals. They are wide-ranging generalists, so they are seldom the target of species-specific conservation efforts. Barn owls thrive in open habitats, so their North American extent expanded extensively in the early 1900 with the increased deforestation brought by intensified farming. Farming practices in the northern range of the Unites States subspecies (T. alba pratincola) are changing, and barn owl populations appear to be responding. Across Pennsylvania, open pastures are being replaced by smaller, row crop fields that have the decrease barn owl hunting habitat. With the exception of a several nesting box companies, few people are actively working towards conservation of barn owls. Statistically accurate descriptions of their specific habitat requirements are rare as a result of their wide range and general disinterest in studying the species. Radio-transmitted data from 16 barn owl fledglings released from Pittsburgh, Pennsylvania, was used to determine preferred habitat and climatic conditions. Owl dispersal paths spanned the eastern United States. Dispersal patterns consisted of bursts of rapid dispersal as well as heavy use of home ranges of 320 km2. The most heavily used point within each established home range used by a successful owl was compared to locations of mortalities using envelope, generalized linear, and classification and regression tree spatial models.
    [Show full text]
  • Draft National Recovery Plan for the Barn Owl and Its Habitat
    DRAFT NATIONAL RECOVERY PLAN FOR THE BARN OWL AND ITS HABITAT (Tyto alba) Ontario Population Prepared by Bernt D. Solymár, EarthTramper Consulting Inc. And Jon D. McCracken, Bird Studies Canada ON BEHALF OF THE Ontario Barn Owl Recovery Team FOR THE Recovery of Nationally Endangered Wildlife (RENEW) Committee December 2002 Disclaimer This document is the National Recovery Plan for the Barn Owl (Tyto alba) - Ontario population. It has been prepared on behalf of the Ontario Barn Owl Recovery Team (OBORT) by Bernt Solymár of EarthTramper Consulting Inc. and Jon McCracken of Bird Studies Canada, with the advise and input from Recovery Team members, to define recovery actions necessary to protect and recover the species and its habitat. It does not necessarily represent official positions of agencies and/or the views of individuals involved in the development of the plan. The goals, objectives, and recovery actions identified in this recovery document are subject to the priorities and budgetary constraints of participating jurisdictions and organizations, as well as modifications to accommodate new objectives or findings. Acknowledgements We thank Heide Isaacs, Habitat Haldimand; Debbie Badzinski, Bird Studies Canada; Dave Reid, Norfolk Stewardship Council; Mary Gartshore, Norfolk Field Naturalists; and Dave Richards, Ron Gould and Hal Shraeder of the Ontario Ministry of Natural Resources for critical review of the draft recovery plan. Also thanks to Bruce Colvin, Colvin Consulting Services in Massachusetts, Dave Scott of the Ohio Division
    [Show full text]