Animal Sciences Commons^™

Kinorhynchs From Sandy Coastal Habitats In Turkey, With The Description Of A New Pan-Mediterranean Species Of Echinoderes (Cyclorhagida: Echinoderidae), Martin Vinther Sørensen, Maria Herranz, Fernando Pardos, Furkan Durucan

Turkish Journal of Zoology

Kinorhynchs from eight sandy, shallow water localities along the west and south coasts of Turkey were examined. The study resulted in the finding of six different species: Two species, Echinoderes gerardi and Cephalorhyncha flosculosa were known from Turkey, two species, Echinoderes riedli and Campyloderes vanhoeffeni were known from the Mediterranean, but are new to Turkey, and two species, Echinoderes sp. and E. shahmaranae sp. nov. are new to science. Echinoderes sp. resembles E. charlotteae from the Gulf of Mexico, but differs at some minor points. However, since only a single specimen was available, only diagnostic details, but no formal description, …

Infestation And Effect Of Parasitic Isopod Epipenaeon Ingens Ingens Nobili, 1906 Oncommercial Shrimp Species In The Eastern Mediterranean: A Case Study Of The Populationof Brown Shrimp Penaeus Aztecus Ives, 1891, Mehmet Cengi̇z Deval, Fatma Gonca Koçanci

Turkish Journal of Zoology

Monthly samples of seven species of penaeid shrimps, namely, Penaeus aztecus (Ives, 1891), Penaus hathor (Burkenroad, 1959) Penaus japonicus (Spence Bate,1888), Penaus kerathurus (Forskal,1775), Penaus semisulcatus (De Haan,1844), Metapenaeus monoceros (Fabricus, 1798) and Metapenaeopsis aegyptia (Galil & Golani, 1990) were collected from Antalya Bay in the Eastern Mediterranean Sea from March, 2019 through March, 2020. Except for P. aztecus and P. semisulcatus, no other shrimp species were infected with the parasitic isopod Epipenaeon ingens ingens. Of the 3043 P. aztecus shrimp inspected, 541 individuals were infected (17.8%) with the bopyrid parasite E. ingens ingens. However, the annual infestation rate in …

The Sicilian Rock Partridge: Latest Data On Genetic Integrity From Four Different Relict Areas, Giusi Macaluso, Claudia Manno, Mario Lo Valvo, Marco Tolone, Salvatore Mastrangelo, Roberto Puleio, Guido Ruggero Loria

Turkish Journal of Zoology

Sicily (Italy) hosts a "relict", endemic population of the birds Alectoris graeca whitakeri commonly known as Sicilian Rock Partridge. In the last decades, due to the risk of restocking with other European and Asiatic species for hunting purpose, a study was carried out to investigate the potential risk of hybridisation. The mtDNA control-region and nuclear microsatellites were genotyped. Due to the importance of the species, samples were mainly characterized by feather and stool samples, and rarely by carcasses found in the environment, from year 2011 to 2012. A panel of 7 microsatellite loci was validated. Three multiplexes that allowed the …

Effects Of Temperature And Duration Of Storage On The Hatching Behaviour Ofheterodera Latipons (Nematoda: Heteroderidae), Yi̇ği̇t Ali̇ Tatli, Refi̇k Bozbuğa, Göksel Özer, Fouad Mokrini, Rachid Lahlali, Abdelfattah Dababat, Mustafa İmren

Turkish Journal of Zoology

Mediterranean cereal cyst nematode (CCN) Heterodera latipons is considered as one of the main CCN that causes significant economic losses in the production of intolerant cereal crops in Turkey. Accordingly, this study aimed at evaluating the effect of different storing temperatures and durations on the emergence of second-stage juveniles (J2s) of the nematode populations obtained from the eastern Mediterranean (Adana and Hatay) and south-eastern (Gaziantep and Kilis) regions of Turkey. The obtained results revealed a variation in the J2s hatching profiles of the regional nematode populations. The eastern-Mediterranean and the south-eastern populations hatched at between 5 and 20 °C; however, …

Identification And Characterisation Of Crustacean Hyperglycaemic Hormone (Chh) From Mediterranean Shore Crab Carcinus Aestuarii, Marsilda Qyli, Valbona Aliko, Riccardo Sgarra, Pi̇ero Giulio Giulianini, Chiara Manfrin

Turkish Journal of Zoology

Crustacean hyperglycaemic hormone (CHH) is a neuropeptide that was originally identified in the X-organ/sinus gland complex of the eyestalks (ESs) in crustaceans. Several CHH isoforms and spliced variants were later identified in other tissues, and their functions have still not been completely unveiled. In this study, the identification and characterisation of the conventional CHH prepropeptide from the ESs of the littoral crab, Carcinus aestuarii, via rapid amplification of cDNA ends was reported. The identified CHH resulted in a coding sequence of 429 bp, an estimatedprotein of 142 aa with a signal peptide of 26 aa, followed by a CHH precursorrelated …

Assessment Of The Zooplankton Community Structure Of The Coastal Uzungöl Lagoon(Kızılırmak Delta, Turkey) Based On Community Indices And Physicochemicalparameters, Ceren Deni̇z Özdemi̇r, Yasemi̇n Saygi, Ertunç Gündüz, Fatma Yildiz Demi̇rkalp, Çağaşan Karacaoğlu

Turkish Journal of Zoology

The objective of this study is to provide information on the zooplankton community and physicochemical properties of Uzungöl Lagoon. Sampling studies were performed at monthly intervals for abiotic factors and community parameters between September 2015 and August 2016. The variations of zooplankton community were estimated using Shannon-Weiner diversity (H'), Pielou evenness (J), species richness (S), frequency, and dominancy indices. The relationship between environmental variables and community parameters were analyzed with Pearson?s correlation test and redundancy analysis (RDA). During the study, 39 species, most of which belonged to Rotifera, were recorded. The quantitative analysis indicated that most important fraction of zooplankton …

Contributions To The Genus Zodarion Walckenaer, 1826 In Turkey, With The Description Ofa New Species (Araneae: Zodariidae), İlhan Coşar, Tarik Danişman, Ersen Aydin Yağmur

Turkish Journal of Zoology

In this paper, two species are newly recognized in Turkey. One is new to science, described as Zodarion kunti sp. n. (♂, ♀) from southeast Anatolian region. The other, Zodarion christae Bosmans, 2009 is found for the first time in Denizli, Antalya, and Muğla provinces.

A Contribution To The Biogeography And Taxonomy Of Two Anatolian Mountain Brooknewts, Neurergus Barani And N. Strauchii (Amphibia: Salamandridae) Using Ecologicalniche Modeling, Muammer Kurnaz, Mehmet Kürşat Şahi̇n

Turkish Journal of Zoology

The Anatolian newt, Neurergus strauchii, is an endemic Anatolian species. Until recently, N. strauchii was represented by three subspecies. It has been discussed within a recent phylogenetic study in which the subspecies N. s. barani is recommended to be evaluated as a cryptic but distinct species. To address this subject, we aimed to discuss the niche differentiation between N. barani and N. strauchii using geographical and bioclimatic aspects. All georeferenced data of N. barani and N. strauchii were used to estimate the potential distributions of these species in the Anatolian Peninsula. To evaluate their ecological niche differentiation, point-based analysis and …

Natural Animal Food Preference Of Chinese Mole Shrew (Anourosorex Squamipes) From An Urban Area: A Laboratory Study, Yun-Chun Ye, Yi Luo, Zhao-Min Zhou

Turkish Journal of Zoology

Most wild animals are urban avoiders, but some others become adapters or exploiters successfully living in urban areas. Often, the latter is assumed to be attracted into cities by readily accessible and digestive anthropogenic food resources. Here, we quantified food preferences of sixteen (eight females and eight males) Chinese mole shrews (Anourosorex squamipes) captured from an urban area for "cafeteria tests" in laboratory. Shrews were presented with twelve foods allocated into three sets (natural animal, natural plant, and anthropogenic food). Once the most two highly consumed food items from each set were determined, six items were pooled together to form …

Contributions To The Turkish Oribatid Mite Fauna (Acari: Oribatida) From Sakarya Andyozgat Provinces, Sedat Per, Kübra Çubukçu, Ayşe Toluk, Nusret Ayyildiz

Turkish Journal of Zoology

This study deals with the data on Turkish records of oribatid mites that play an important role in decomposition of organic matter, nutrient cycling, and soil formation. Oribatid mites in litter, lichen, moss, and soil collected from Sakarya and Yozgat provinces were sampled between 2014 and 2020. Standard methods were used for extraction, detection, preservation, and preparation of mites from the material collected from study area. Five oribatid mites were for the first time recorded from Turkey, namely Mesotritia (Mesotritia) nuda (Berlese, 1887) (Oribotritiidae), Hoplophorella (Rhacaplacarus) ortizi (Pérez-Íñigo, 1970) (Phthiracaridae), Eremaeus translamellatus Hammer, 1952 (Eremaeidae), Oribatella (Oribatella) foliata Krivolutsky, 1974 …

Ant Fauna (Hymenoptera: Formicidae) Of Central Anatolian Region Of Turkey, Kadri̇ Kiran, Celal Karaman

Turkish Journal of Zoology

The Central Anatolian part of Turkey was investigated with the aim of determining its Formicidae fauna. Specimens were collected by hand sampling and pitfall traps in 24 habitats in 383 different localities in Central Anatolia Region during 2001-2016. As a result, 137 species belonging to 34 genera were determined. Messor incorruptus Kuznetsov-Ugamsky, 1929 and Ponera testacea Emery, 1895 are new records for Turkish ant fauna. We excluded four species, Camponotus sylvaticus (Oliver, 1792), Messor meridionalis (André, 1883), Proformica striaticeps (Forel, 1911) and Tapinoma nigerrimum (Nylander, 1856), from Turkish ant fauna due to recent taxonomic data and distribution pattern. With these …

The Impact Of Chilling On Selected Attributes Of The Blowfly, Calliphora Vicina(Robineau-Desvoidy, 1830) (Diptera: Calliphoridae), Under Laboratory Conditions, Meltem Kökdener, Nevran Eylem Akman Gündüz, Ünal Zeybekoğlu

Turkish Journal of Zoology

The purpose of this study was to evaluate the effects of four different chilling periods, varying from 24 to 120 h, on the mean survival rate, larval and pupal development durations and the pupal and adult weight of Calliphora vicina (Robineau-Desvoidy) (Diptera: Calliphoridae) under laboratory conditions at 4 ºC in 2018 at Ondokuz Mayıs University. Chilling reduced the survival rate of the pupae of all developmental stages. The adult eclosion rate of first instar larvae and pupae was lower, especially after 72 and 120 h chilling periods, but it increased for the second instar, third instar and postfeeding larvae with …

First Report On Mild Insecticide Resistance In Newly Established Aegean Aedes Albopictus Populations Of Turkey, Sare İlknur Yavaşoğlu

Turkish Journal of Zoology

The invasive nature of Aedes albopictus, a competent vector of dengue, zika, yellow fever, and chikungunya viruses, has spread to many parts of the world. To date, there have been no report regarding the insecticide resistance status of Aedes albopictus populations along the Aegean coasts of Turkey. This study aims to confirm the occurrence of Aedes albopictus populations in the Aegean region of Turkey and test their susceptibility against different insecticide classes. Bioassay for susceptibility to Dikloro difenil trikloroetan (DDT) (4%), propoxur (0.1%), fenitrothion (1%), bendiocarb (0.1%), permethrin (0.75%), and deltamethrin (0.05%) of each population was assessed through the World …

Capoeta Kosswigi Karaman, 1969 A Junior Synonym Of Capoeta Damascina(Valenciennes, 1842) (Teleostei: Cyprinidae), Erdoğan Çi̇çek, Soheil Eagderi, Burak Seçer, Sevi̇l Sungur

Turkish Journal of Zoology

Capoeta kosswigi was described from Lake Van basin, Turkey, being close to C. damascina and C. umbla. It is distinguished from them by a pointed snout and a small horseshoe-shaped mouth, and differing from C. damascina by having smaller scales, and from the C. umbla by processing larger scales. In this study, we tested the suggested synonymy hypothesis of C. kosswigi and C. damascina by comparing the morphometric and meristic data. The results revealed that all morphometric and meristic characters of C. kosswigi overlap with those of C. damascina. In line with previous molecular studies that COI, cytb and 16S …

Exploring The Dynamics Of Small Pelagic Fish Catches In The Marmara Sea In Relation Tochanging Environmental And Bio-Optical Parameters, Eki̇n Akoğlu

Turkish Journal of Zoology

The Marmara Sea has a large drainage basin that includes cities with heavy industrialisation and agricultural land use. Therefore, it is under the influence of significant anthropogenic activities that adversely affect the well-being of its ecosystem. The Marmara Sea is also an important fishing ground with many commercially important fish species. These fish species are also under the influence of the adverse impacts of anthropogenic activities. Fisheries catches in the Marmara Sea had experienced severe fluctuations since the onset of the 2000s. In this study, possible underlying reasons for these fluctuations were investigated between 2000 and 2019 using remotelysensed environmental …

Population Genetics Of A Reintroduced Fisher (Pekania Pennanti) Population In West Virginia, Caroline E. Harms

Graduate Theses, Dissertations, and Problem Reports (ETD)

Fishers (Pekania pennanti) were reintroduced in West Virginia in 1969 with no population wide genetic analysis ever having been conducted. Genetic analysis of reintroduced populations is vital to assess genetic diversity as an indicative of population viability. My objective was to collect fisher samples throughout West Virginia, nearby states where fisher may be migrating (PA and NY), and the New Hampshire source population to provide a full genetic interpretation of the reintroduced West Virginia population. Genetic analysis was used to measure genetic diversity, admixture or delineation of subpopulations, and effective population size. Sample location and genetic data were …

Effect Of Diet, Age, And Genetics On Rainbow Trout Growth And Fillet Quality, Bahareh Adami

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this study, analyses were conducted to compare fillet quality attributes of 4 rainbow trout families (40, 102, 159, and 187) fed fish meal (FM) and a fishmeal free diet (FMF), to two age endpoints, 9 and 11 months.

Previous studies with rainbow trout have evaluated the effect of age, diet, and family on growth performance and fillet quality. However, a comprehensive analysis of variables is lacking for rainbow trout, one of the main aquatic foods for domestic and international consumers.

Separable muscle as a percent whole body weight was not affected by diet, family, age, and the interaction of …

Age, Growth, And Mortality Of Atlantic Tripletail In The North-Central Gulf Of Mexico, Amanda E. Jefferson, Matthew B. Jargowsky, Meagan N. Schrandt, Pearce T. Cooper, Sean P. Powers, John Dindo, J. Marcus Drymon

University Faculty and Staff Publications

In the southeastern USA and the Gulf of Mexico (GOM), Atlantic Tripletail Lobotes surinamensis are increasingly targeted by recreational anglers, indicating that stock status should be assessed. A critical need for such assessments is age-specific data; however, previous studies have drawn conflicting conclusions regarding the most appropriate structure for aging. Moreover, growth parameters and mortality rates for GOM Atlantic Tripletail are unknown. Therefore, the goals of this study were to (1) evaluate sagittal otoliths and first dorsal spines as aging structures; (2) model combined and sex-specific growth; and (3) estimate mortality rates for GOM Atlantic Tripletail. From 2012 to 2019, …

Documentation Of Atlantic Tarpon (Megalops Atlanticus) Space Use And Move Persistence In The Northern Gulf Of Mexico Facilitated By Angler Advocates, J. Marcus Drymon, Matthew B. Jargowsky, Michael A. Dance, Mitchell Lovell, Crystal L. Hightower, Amanda E. Jefferson, Andrea M. Kroetz, Sean P. Powers

University Faculty and Staff Publications

Atlantic tarpon (Megalops atlanticus, hereafter tarpon) are facing a multitude of stressors and are considered Vulnerable by the IUCN; however, significant gaps remain in our understanding of tarpon space use and movement. From 2018 to 2019, citizen scientists facilitated tagging of 23 tarpon with SPOT tags to examine space use and movement across the northern Gulf of Mexico. Movement-based kernel densities were used to estimate simplified biased random bridge-based utilization distributions and a joint move persistence model was used to estimate a behavioral index for each fish. Tarpon showed consistent east–west movement from the Alabama/Florida border to Louisiana, and utilization …

Effects Of Human-Animal Interactions On Affect And Cognition, Elise L. Thayer, Jeffrey R. Stevens

Jeffrey Stevens Publications

Human-animal interaction has clear positive effects on people’s affect and stress. But less is known about how animal interactions influence cognition. We draw parallels between animal interactions and exposure to natural environments, a research area that shows clear improvements in cognitive performance. The aim of this study is to investigate whether interacting with animals similarly enhances cognitive performance, specifically executive functioning. To test this, we conducted two experiments in which we had participants self-report their affect and complete a series of cognitive tasks (long-term memory, attentional control, and working memory) before and after either a brief interaction with a dog …

Diets Of Double-Crested Cormorants In The Lake Winnebago System, Wisconsin, Ryan P. Koenigs, Daniel J. Dembkowski, Charles D. Lovell, Daniel A. Isermann, Adam D. Nickel

United States Department of Agriculture Wildlife Services: Staff Publications

Double-crested cormorant Phalacrocorox auritus Lesson (cormorant) populations have increased throughout the Great Lakes region of North America causing concern related to the impact of cormorant predation on fish communities. A recent decline in yellow perch Perca flavescens (Mitchill) abundance within the Lake Winnebago System, Wisconsin, USA, prompted an assessment of cormorant diets to evaluate potential effects of cormorant predation on the sportfish community. Diets were collected from 883 cormorants (417 from Lake Winnebago and 466 from Lake Butte des Morts) between 2015 and 2017. Cormorant diets on both waterbodies consisted mostly of freshwater drum Aplodinotus grunniens Rafinesque and gizzard shad …

Records Of Hippoboscidae From Mongolian Birds Of Prey With Checklist, Update, Matthias Jentzsch, Benjamin Meissner, Nayamsuren Batsaikhan, Annegret Stubbe, Michael Stubbe

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

The hippoboscid species Ornithophila gestroi has been rediscovered from Mongolia. It is the easternmost of all the known occurrences. Specimens were collected from Amur Falcon Falco amurensis, Saker Falcon Falco cherrug, Lesser Kestrel Falco naumanni, Eurasian Hobby, Falco subbuteo, Common Kestrel Falco tinnunculus Linnaeus, 1758 and Black Kite Milvus migrans in a breeding area located in southern Mongolia. Amur Falcon, Eurasian Hobby and Black Kite were identified as hosts of O. gestroi for the first time.

Jaguars And Pumas Exhibit Distinct Spatiotemporal Responses To Human Disturbances In Colombia’S Most Imperiled Ecoregion, Joe J. Figel, Sebastián Botero-Cañola, Juan David Sánchez-Londoño, Javier Racero-Casarrubia

University of Nebraska State Museum: Mammalogy Papers

Abstract

Coexistence of sympatric felids is facilitated by mutual avoidance and the partitioning of habitats, prey, and time. Anthropogenic disturbances disrupt this coexistence in fragmented landscapes, potentially triggering cascading influences in ecological communities. We used photographic data from 8,717 trap nights (November 2014–June 2016) at 87 camera trap sites in Colombia’s middle Magdalena River basin to compare spatiotemporal overlap among jaguars (Panthera onca), pumas (Puma concolor), their prey, and humans, at sites of high and low disturbance, as determined by the human influence index. Human disturbance events (e.g. domestic dogs, livestock, and humans, including armed hunters) …

Evidence On The Effectiveness Of Small Unmanned Aircraft Systems (Suas) As A Survey Tool For North American Terrestrial, Vertebrate Animals: A Systematic Map Protocol, Jared A. Elmore, Michael F. Curran, Kristine O. Evans, Sathishkumar Samiappan, Meilun Zhou, Morgan B. Pfeiffer, Bradley F. Blackwell, Raymond B. Iglay

United States Department of Agriculture Wildlife Services: Staff Publications

Background: Small unmanned aircraft systems (sUAS) are replacing or supplementing manned aircraft and groundbased surveys in many animal monitoring situations due to better coverage at finer spatial and temporal resolutions, access, cost, bias, impacts, safety, efficiency, and logistical benefits. Various sUAS models and sensors are available with varying features and usefulness depending on survey goals. However, justification for selection of sUAS and sensors are not typically offered in published literature and existing reviews do not adequately cover past and current sUAS applications for animal monitoring nor their associated sUAS model and sensor technologies, taxonomic and geographic scope, flight conditions and …

Recolonizing Carnivores: Is Cougar Predation Behaviorally Mediated By Bears?, Kristin N. Engebretsen, Jon P. Beckmann, Carl W. Lackey, Alyson M. Andreasen, Cody Schroeder, Pat Jackson, Julie K. Young

United States Department of Agriculture Wildlife Services: Staff Publications

Conservation and management efforts have resulted in population increases and range expansions for some apex predators, potentially changing trophic cascades and foraging behavior. Changes in sympatric carnivore and dominant scavenger populations provide opportunities to assess how carnivores affect one another. Cougars (Puma concolor) were the apex predator in the Great Basin of Nevada, USA, for over 80 years. Black bears (Ursus americanus) have recently recolonized the area and are known to heavily scavenge on cougar kills. To evaluate the impacts of sympatric, recolonizing bears on cougar foraging behavior in the Great Basin, we investigated kill sites of 31 cougars between …

Assessing Pace-Of-Life: Comparing Metabolism And Behavior In Tarantulas, Haley Vanscoyoc

Master's Theses and Doctoral Dissertations

Pace-of-Life Syndrome (PoLS) links physiology, behavior, and life history to understand how an organism lives and is under-researched in many invertebrate groups. In this study I used five tarantula species to assess if they follow the predictions of PoLS. I compared individual species as well as Old- and New-World lineages and solitary and sub-social species. I predicted that Old- World and sub-social species would have higher resting metabolic rates (RMRs) and activity levels compared to New-World and solitary species. RMRs were measured using an open-flow respirometry system, and a classic open-arena test was used to assess activity level. Spearman’s correlation …

Text Mining To Identify The Origin Of Chronic Wasting Disease, G. Webb

Faculty Research, Scholarly, and Creative Activity

Chronic wasting  disease (CWD)  is  a 100  percent  fatal,  prion  disease of  deer  that  has  the potential  to decimate  the  deer  population and  jump to  the  human  population.   A  simple  Google  search on  the  “origin of  chronic wasting  disease” yielded  a total  of  56  relevant  articles.   Of  these,  75  percent  report  that  the origin  is  unknown,  19.6  percent  report  that  the  disease  may  have  originated  in  a  Fort  Collins,  Colorado, government  research facility, and 5.4 percent  report  other  possible  origins.  Government  sources  reported the  Fort  Collins  theory  4.3 percent  of  the  time  while  non-governmental  sources,  such  as news articles, reported …

Scaling The Effects Of Ocean Acidification On Coral Growth And Coral-Coral Competition On Coral Community Recovery, Nicolas R. Evensen, Yves-Marie Bozec, Peter J. Edmunds, Peter J. Mumby

Biological Sciences Faculty Publications

Ocean acidification (OA) is negatively affecting calcification in a wide variety of marine organisms. These effects are acute for many tropical scleractinian corals under short-term experimental conditions, but it is unclear how these effects interact with ecological processes, such as competition for space, to impact coral communities over multiple years. This study sought to test the use of individual-based models (IBMs) as a tool to scale up the effects of OA recorded in short-term studies to community-scale impacts, combining data from field surveys and mesocosm experiments to parameterize an IBM of coral community recovery on the fore reef of Moorea, …

Global Extinction Risk For Seahorses, Pipefishes And Their Near Relatives (Syngnathiformes), Riley A. Pollom, Gina M. Ralph, Caroline M. Pollock, Amanda C.J. Vincent

Biological Sciences Faculty Publications

Few marine taxa have been comprehensively assessed for their conservation status, despite heavy pressures from fishing, habitat degradation and climate change. Here we report on the first global assessment of extinction risk for 300 species of syngnathiform fishes known as of 2017, using the IUCN Red List criteria. This order of bony teleosts is dominated by seahorses, pipefishes and seadragons (family Syngnathidae). It also includes trumpetfishes (Aulostomidae), shrimpfishes (Centriscidae), cornetfishes (Fistulariidae) and ghost pipefishes (Solenostomidae). At least 6% are threatened, but data suggest a mid-point estimate of 7.9% and an upper bound of 38%. Most of the threatened species are …

Effects Of Weather On Foraging Success And Hunting Frequency In Winter-Irruptive Snowy Owls (Bubo Scandiacus) In Upstate New York, Russell E. Winter, William M. Shields

Biological Sciences Faculty Publications

The effects of weather on an individual can often alter the population dynamics of a species. Knowledge of how weather influences individual behavior is therefore essential in understanding its full impact in the context of population ecology. Snowy Owls (Bubo scandiacus) exhibit expensive long-distance migrations in winters following population irruptions. During irruptive movements, many owls migrate past the southernmost extent of their traditional wintering grounds, the mechanism for which is still debated. We propose and test the “milder climate” hypothesis; Snowy Owls wintering in lower latitudes are better able to meet their metabolic demands due to higher temperatures …