Tehokalastuksen vaikutukset Lappajärvessä : Kalastus elinkeinoksi Lappajärvellä -hankkeen vuosien 2001-2006 seurannan loppuraportti

Lappajärven, Etelä-Pohjanmaan suurimman järven, ekologinen tila on heikentynyt ja se luokitellaan nykyisin tyydyttäväksi. Rehevöityminen, 1990-luvun muikkukato ja yhteiskunnan rakennemuutos ovat vähentäneet kalastajien ja kalansaaliin määrää. Ammattikalastuksen edellytysten parantamiseksi toteutettiin vuosina 2001–2004 ”Kalastus elinkeinoksi Lappajärvellä” – hanke. Hankkeen vaikutuksia kalastoon ja järven ekosysteemiin seurattiin vuosina 2001–2006. Kokonaissaalis vuosina 2001–2004 oli 1655 tonnia (n. 29 kg/ha/vuosi). Vaikka saalistavoitetta (2100 tn) ei täysin saavutettu, oli hankkeella runsaasti myönteisiä, joskin osin vähäisiä tai epävarmoja vaikutuksia järven tilaan ja kalastoon. Kalastajien yksikkösaaliit etenkin kuhan ja isokokoisen ahvenen osalta nousivat hankkeen alussa. Loppuvuosina yksikkösaaliiden kehitys oli osittain ristiriitaista. Ulapan taloudellisesti vähempiarvoinen kalasto, varsinkin kuorekanta harveni selvästi. Muikku puolestaan lisääntyi ja pysyi runsaana. Kuhan ja isokokoisen ahvenen lisääntymistä selittivät pääosin lämpimät kesät ja kuhan onnistuneet istutukset. Petokalat, etenkin kuha, voivat osaltaan säädellä Lappajärven ulapan planktonsyöjäkalojen kantoja ja toisaalta estää särjen siirtymistä ulapalle. Tehokalastuksen loputtua alkoi näkyä merkkejä kalakantojen palautumisesta takaisin kohti lähtötilannetta. Rantavyöhykkeellä hankkeen vaikutukset jäivät selvästi vähäisemmiksi kuin ulapalla. Eläinplankton lisääntyi hieman ylemmissä vesikerroksissa, mutta tilanne alkoi palautua ennalleen hankkeen jälkeen. Sinileväkukinnot vaikuttivat vähentyneen hankkeen aikana, tosin kukintojen voimakas vaihtelu vaikeutti arviointia. Tehokalastus ja vesiensuojelun tehostuminen vähensivät fosforipitoisuuksia, tosin myös vähäsateiset vuodet vaikuttivat vähenemiseen. Pitoisuuksien lasku jatkui hankkeen jälkeen. Hanketta edeltänyt klorofyllipitoisuuksien kasvusuuntaus pysähtyi ja pitoisuustaso vakiintui. Tehokalastus pienensi klorofylli/fosfori-suhdetta ja vähensi sisäistä kuormitusta, mutta vaikutus alkoi heiketä hankkeen loputtua. Typpipitoisuuksiin, veden väriin tai näkösyvyyteen kalastus ei vaikuttanut. Tehokalastuksella voidaan parantaa Lappajärven tilaa, mutta kalastuksen on oltava jatkuvaa. Saalistavoitteeksi voisi riittää n. 20-30 kg/ha vuodessa, mutta samalla on jatkettava ulkoisen kuormituksen vähentämistä. Kalastuksen tulisi kohdistua arvokalojen lisäksi myös vähempiarvoisiin kalalajeihin ja samalla on tuettava petokalakantojen vahvistumista.

Miehittämättömien ilma-alusten tekninen kehitys 1990-luvulta nykypäivään

Tutkielman päätutkimuskysymys on, miten miehittämättömät ilma-alukset ovat teknisesti kehittyneet 1990-luvulta nykypäivään. Työssä keskitytään Yhdysvaltain asevoimien käyttämiin miehittämättömiin ilma-aluksiin, koska Yhdysvallat ovat edelläkävijä niiden kehittämisessä ja valmistamisessa. Tutkittavat miehittämättömät ilma-alukset ovat Pioneer, Predator, Hunter, Global Hawk ja Shadow. Tutkielman alatutkimuskysymykset ovat, mitä teknisiä muutoksia eri miehittämättömien ilma-alusten versioiden välillä on tapahtunut ja miten miehittämättömien ilma-alusten tekninen kehitys on vaikuttanut niiden suorituskykyyn. Tutkimusmenetelmänä työssä käytetään laadullista aineistoanalyysia eli kirjallisuustutkimusta. Lähdeaineistona hyödynnetään kirjallisuutta, vanhoja tutkielmia, lehtiä, julkaisuja sekä internetlähteitä, mitkä liittyvät miehittämättömiin ilma-aluksiin. Tutkimukseen käytetty materiaali on suurimmaksi osaksi sähköisessä muodossa, koska aihe on niin tuore ja kehittyy edelleen. Tutkielman tuloksena voidaan havaita, että miehittämättömien ilma-alusten tekninen kehitys on ollut nopeaa viime vuosien aikana ja jatkuu edelleen. Niihin on tehty paljon rakenteellisia muutoksia sekä koneiden runkoihin on tuotu uudempia ja tehokkaampia sensorijärjestelmiä. Myös aseistusta on kehitetty osassa koneista. Teknisellä kehityksellä on ollut vaikutusta miehittämättömien ilma-alusten suorituskykyyn etenkin taisteluun tarkoitetuilla koneilla. Melkein kaikissa miehittämättömissä ilma-aluksissa on kyetty kasvattamaan koneen maksiminopeutta ja toimintakorkeutta. Muutoksia on myös tapahtunut joidenkin koneiden toiminta-ajassa. Johtopäätöksenä voidaan todeta, että suurimmat teknisen kehityksen kohteet miehittämättömissä ilma-aluksissa ovat olleet rakenteellisten muutosten ansiosta uusien sensorijärjestelmien tuonti koneisiin sekä niiden aseistaminen. Tekninen kehitys jatkuu edelleen miehittämättömissä ilma-aluksissa ja niillä pyritään yhä enemmän korvaamaan miehitettyjä ilmaaluksia ja niiden tehtäviä. Tällä voidaan välttää inhimillisiä virheitä sekä käyttää ilmaaluksia yhä vaarallisemmissa tehtävissä.

Does the Ingestion of Isoxaflutole Herbicide Affect the Midgut and Salivary Glands of Pentatomidae Predators?

Podisus nigrispinus is a generalist predator naturally occurring in agricultural and forestry systems that effectively contributes to the population balance of phytophagous insects, especially defoliating caterpillars. Histological changes were evaluated in the salivary glands and midgut of P. nigrispinus caused by ingestion of systemic herbicide isoxaflutole. These predator females were fed with leaves of eucalyptus plants, Tenebrio molitor pupae or water, contaminated or not by herbicide. Salivary glands and midguts were dissected, processed and analyzed under a light microscope. Activity level and cell morphology of the salivary glands and midgut showed differences among insects fed on plants, contaminated water or pupae. The epithelia of the salivary gland and midgut of individuals which had no contact with the herbicide showed homogeneous cytoplasm, nucleus with predominance of decondensed chromatin and evident nucleoli, intense cell activity features. As for the insects in contact with contaminated food, they presented undeveloped nucleus and condensed chromatin. The luminal contents of the salivary glands in the contaminated insects had become more acidophilus than in insects without poisoning, as well as having heterogeneous and granular secretion, being more evident in the bioassay in which the insects fed on contaminated water. There was a marked morphological change in the midgut cells in contaminated insects. High degree of apoptosis, disorganization and secretory vacuoles in the epithelial cytoplasm were observed. The apical portion of the midgut cells proved undeveloped, irregular and partially destroyed. It is concluded that isoxaflutole causes morphological changes in the digestive system of the predator P. nigrispinus.

Frugivory on Margaritaria nobilis L.f. (Euphorbiaceae): poor investment and mimetism

Dehiscent fruits of Euphorbiaceae usually have two stages of seed dispersal, autochory followed by myrmecochory. Two stages of Margaritaria nobilis seed dispersal were described, the first stage autochoric followed by ornithocoric. Their dehiscent fruits are green and after they detached from the tree crown and fall on the ground, they open and expose blue metallic cocas. We studied the seed dispersal system of Margaritaria nobilis in a semi-deciduous forest in Brazil. In 80 h of focal observations, we recorded only 12 visits of frugivores, however the thrush Turdus leucomelas was the only frugivore that swallowed the fruits on the tree crown. Pitylus fuliginosus (Fringilidae) and Pionus maximiliani (Psittacidae) were mainly pulp eaters, dropping the seeds below the tree. On the forest floor, after fruits dehiscence, jays (Cyanocorax chrysops), guans (Penelope superciliaris), doves (Geotrygon montana) and collared-peccaries (Pecari tajacu) were observed eating the blue diaspores of M. nobilis. Experiments in captivity showed that scaly-headed parrots (Pionus maximiliani), toco toucans (Ramphastos toco), jays (Cyanochorax chrysops), and guans (Penelope superciliaris) consumed the fruits and did not prey on the seeds before consumption. The seeds collected from the feces did not germinate in spite of the high viability. The two stages of seed dispersal in M. nobilis resembles the dispersal strategies of some mimetic species. However M. nobilis seeds are associated with an endocarp, it showed low investment in nutrients, and consistent with this hypothesis, M. nobilis shared important characteristics with mimetic fruits, such as bright color display, long seed dormancy and protection by secondary compounds.

Vahinkoeläinsodasta psykologiseen omistajuuteen. Petokonfliktien historiallinen tausta ja nykypäivän hallinta

Suurpetojen kannanhoitoon, ja etenkin suden kannanhoitoon liittyvä monitahoinen konfl ikti esiintyy jännitteinä paikallisyhteisöjen ja keskushallinnon, maaseudun ja kaupunkien sekä maallikoiden ja tutkijoiden välillä. Suurpetopolitiikan legitimiteettikriisi näkyy kansallisen kannanhoidon tavoitteiden ja toimenpiteiden kiistämisenä passiivisin ja aktiivisin toimin. Tällä ajankohtaisella ongelmalla on mittavat historialliset juuret. Luonnon ja ihmisen välinen suhde on ollut jatkuvaa tasapainottelua konfl iktien ja niiden hallinnan kanssa, ja suurpedot ovat väistämättä olleet konfl iktin keskiössä lajityypillisten piirteidensä vuoksi. Tämän tutkimuksen tavoitteena on osoittaa ympäristöhistoriallisen tutkimusotteen kautta suomalaisen vahinkoeläinhistorian keskeiset toimet ja toimijat, sekä ymmärtää vahinkoeläinten kannanhoidon tavoite- ja toimenpideasettelun vaikutukset eläinpopulaatioihin historiallisessa ja ekologisessa kontekstissa. Tutkimuksen toinen tavoite on tuottaa synteesi nykypäivän suurpetojen kannanhoidon tavoite- ja toimenpiteiden tarkoituksenmukaisuudesta ja vaikuttavuudesta historiallisessa kontekstissa ja esittää uudenlainen lähestymismalli sosiaalisesti kestävämmälle suurpetopolitiikalle. Vahinkoeläinhistoriaa käsitellään deduktiivisella ja rekonstruktiivisella tutkimusotteella käyttäen aineistona lakitekstejä, maksettuja tapporahoja, sanomalehtikirjoituksia, sidosryhmien kirjoituksia sekä eläintieteellisiä julkaisuja. Etenkin laeissa ja asetuksissa eri eläimistä asetetut tapporahat ja toisaalta saalistilastojen perusteella maksetut palkkiot on nostettu tässä tutkimuksessa merkittävään rooliin asenteiden tulkinnan välineenä. Tarkastelu ulotetaan nisäkkäiden lisäksi myös lintuihin, jotka ovat edellä mainitun aineiston valossa olleet merkittävä vainottu eläinryhmä. Nykypäivän petokonfl iktin tarkastelussa keskiöön nostetaan suurpetoasenteet, niiden muodostuminen ja vaikutus suurpetopolitiikan tavoitteiden ja toimenpiteiden kiistämisessä. Suurpetopolitiikan legitimiteettikriisiä tarkastellaan paikallisten uhmakkuutena hallintoa kohtaan ja tulkinta keinoista puuttua sosiopoliittiseen rikokseen rakennetaan tätä ajatusta vasten. Suurpetojen salakaatajat toimivat yhteisönsä puolesta ja saavat tukensa toimilleen yhteisöltään. Sosiopoliittinen rikos ei siten ole ainoastaan salakaatajien vaan sen sijaan yhteisön yhteinen. Salakaatajat ja paikallisyhteisö pyrkivät häivyttämään yhteiskunnassa viranomaisten ja sidosryhmien taholta toimintaan liittämää stigmaa ja siten oikeuttamaan tekonsa vallitsevissa olosuhteissa. Arvoristiriitoihin perustuvat konfl iktit ovat haasteellisia hallita ja lähtökohtana on oltava ymmärrys siitä, että etenkin suteen liittyvät jännitteet ja ristiriidat ihmisten välisissä suhteissa ovat väistämättömiä. Tunnistamalla historiallisen aineiston merkittävyys nykypäivän ongelmakeskeisen kannanhoidon ratkaisun tietopohjana on mahdollista rakentaa sosiaalisesti kestävämpää suurpetojen kannanhoitoa. Tässä väitöskirjatyössä painotetaan suurpetoihin liittyen ajatusta, jonka mukaan paikallisilta suurpetoalueilla eläviltä ihmisiltä tai sidosryhmien edustajilta ei edellytetä arvomaailman muuttumista, vaan hyväksytään heidän käsityksensä suurpetojen roolista vahingontekijöinä. Sen sijaan vahvistetaan suurpetojen välineellistä roolia paikallisyhteisöjen resurssina ja oleellisten sidosryhmien roolia yhteisön toimijoina psykologisen omistajuuden rakentamisen kautta. Suurpetojen kestävä kannanhoito vaatii siten riistahallinnon toimintakulttuurin muutosta ja uudenlaista suhdetta yhteiskunnan eri toimijoihin.

Differential behavioral outcomes of 3,4-methylenedioxymethamphetamine (MDMA-ecstasy) in anxiety-like responses in mice

Anxiolytic and anxiogenic-like behavioral outcomes have been reported for methylenedioxymethamphetamine (MDMA or ecstasy) in rodents. In the present experiment, we attempted to identify behavioral, hormonal and neurochemical outcomes of MDMA treatment to clarify its effects on anxiety-related responses in 2-month-old Balb/c male mice (25-35 g; N = 7-10 mice/group). The behavioral tests used were open field, elevated plus maze, hole board, and defensive behavior against predator odor. Moreover, we also determined striatal dopamine and dopamine turnover, and serum corticosterone levels. MDMA was injected ip at 0.2, 1.0, 5.0, 8.0, 10, or 20 mg/kg. MDMA at 10 mg/kg induced the following significant (P < 0.05) effects: a) a dose-dependent increase in the distance traveled and in the time spent moving in the open field; b) decreased exploratory activity in the hole board as measured by number of head dips and time spent in head dipping; c) increased number of open arm entries and increased time spent in open arm exploration in the elevated plus maze; d) increased time spent away from an aversive stimulus and decreased number of risk assessments in an aversive odor chamber; e) increased serum corticosterone levels, and f) increased striatal dopamine level and turnover. Taken together, these data suggest an anxiogenic-like effect of acute MDMA treatment, despite the fact that behavioral anxiety expression was impaired in some of the behavioral tests used as a consequence of the motor stimulating effects of MDMA.

Effects of chronic corticosterone and imipramine administration on panic and anxiety-related responses

It is known that chronic high levels of corticosterone (CORT) enhance aversive responses such as avoidance and contextual freezing. In contrast, chronic CORT does not alter defensive behavior induced by the exposure to a predator odor. Since different defense-related responses have been associated with specific anxiety disorders found in clinical settings, the observation that chronic CORT alters some defensive behaviors but not others might be relevant to the understanding of the neurobiology of anxiety. In the present study, we investigated the effects of chronic CORT administration (through surgical implantation of a 21-day release 200 mg pellet) on avoidance acquisition and escape expression by male Wistar rats (200 g in weight at the beginning of the experiments, N = 6-10/group) tested in the elevated T-maze (ETM). These defensive behaviors have been associated with generalized anxiety and panic disorder, respectively. Since the tricyclic antidepressant imipramine is successfully used to treat both conditions, the effects of combined treatment with chronic imipramine (15 mg, ip) and CORT were also investigated. Results showed that chronic CORT facilitated avoidance performance, an anxiogenic-like effect (P < 0.05), without changing escape responses. Imipramine significantly reversed the anxiogenic effect of CORT (P < 0.05), although the drug did not exhibit anxiolytic effects by itself. Confirming previous observations, imipramine inhibited escape responses, a panicolytic-like effect. Unlike chronic CORT, imipramine also decreased locomotor activity in an open field. These data suggest that chronic CORT specifically altered ETM avoidance, a fact that should be relevant to a better understanding of the physiopathology of generalized anxiety and panic disorder.

What ethologically based models have taught us about the neural systems underlying fear and anxiety

Classical Pavlovian fear conditioning to painful stimuli has provided the generally accepted view of a core system centered in the central amygdala to organize fear responses. Ethologically based models using other sources of threat likely to be expected in a natural environment, such as predators or aggressive dominant conspecifics, have challenged this concept of a unitary core circuit for fear processing. We discuss here what the ethologically based models have told us about the neural systems organizing fear responses. We explored the concept that parallel paths process different classes of threats, and that these different paths influence distinct regions in the periaqueductal gray - a critical element for the organization of all kinds of fear responses. Despite this parallel processing of different kinds of threats, we have discussed an interesting emerging view that common cortical-hippocampal-amygdalar paths seem to be engaged in fear conditioning to painful stimuli, to predators and, perhaps, to aggressive dominant conspecifics as well. Overall, the aim of this review is to bring into focus a more global and comprehensive view of the systems organizing fear responses.

Foraging ecology and parental behaviour in the common tern (Sterna hirundo)

One component of successful parenting is related to efficiency in foraging behaviour. The relationships among chick feeding, the size and type of food package, and length of parental foraging trips has not been well studied in seabirds. In addition, relatively few data have been collected on the activities of seabirds when foraging away from the nest site. The objectives of this study were: (1) to contrast productivity, feeding rate, and attendance patterns of individuals carrying a novel transmitter with a control group of birds; (2) to use radio-telemetry to assess the variability in foraging locations within and between individual male Common Terns; (3) to determine the seasonal variation in chick diet; (4) to determine for each transmittered bird, the relationships among the foraging patterns, parental behaviour, and seasonal reproductive success. The study took place over two years (1990-91) on a concrete breakwater 1 km offshore on Lake Erie near Port Colbome, Ontario. Ten pairs of terns in 1990 and 12 pairs in 1991 were radio-tracked by boat or car during the chick rearing stage. Concurrent behavioural observations documented the time each sex spent foraging or at the nest. The frequency and prey species composition of feeds to chicks were also recorded. The transmitters had negligible effects on the feeding frequency and brood attendance patterns of transmitter carrying birds. Peak nesting transmittered birds in 1990 and 1991 exhibited some inter-individual variability in foraging locations, however intraindividual variability was low. Birds foraged primarily to the west and northwest of the colony. Late nesters exhibited greater inter-individual variability, however intra-individual variability remained low for most birds. Neither group demonstrated sufficient variability to support the regular use of this colony as an "information centre". Individual transmittered birds had unique and predictable foraging patterns, and corresponding differences in feeding frequencies and brood attendance patterns, yet productivity was essentially equal between nests due to the impact and importance of stochastic events. Individuals that were recaptured in 1991 exhibited very similar foraging patterns to 1990, suggesting littie variability between years. Conservation of foraging patterns between years may have potential implications for mate choice decisions in future breeding seasons. Prey species delivered to chicks differed between morning and evening for peak and late nesters in 1990, but not 1991. Peak nesters in 1990 fed significantiy more Rainbow Smelt fOsmerus mordM) than Emerald Shiner (Notropis atherinoidesV this trend was reversed for late nesters who also fed large numbers of unidentified larval fish. No significant differences were found in 1991. Seasonal changes in prey species delivered to chicks is believed to be attributable to the temperature tolerances of the smelt and shiners, and the presence of large schools of larval fish during the late nesting season.

Behavioural, mensural, and ecological correlates of polygyny in the eastern meadowlark (Sturnella magna)

During 1982 and 1983 I studied male attributes and attributes of the territory of male Eastern Meadowlarks (Sturnella magna) in order to determine whether there was a correlation between any of the attributes investigated and the number of females attracted by a male. Seventeen males, nine of which were polygynous and eight monogamous, were studied in 1982 and sixteen males.of which .. seven were polygynous and nine ~onogamous, were studied in 1983. The study was conducted in Short Hills Park, 10 km southwest of St. Catharines, Ontario and was designed to compare two hypotheses: the "sexy son" hypothesis (Weatherhead and Robertson,1977) and the polygyny threshold model (Verner and Willson,1966, Orians, 1969). Male attributes investigated were male size and song behaviour. Six measures of male size were taken: weight, flattened and natural wing chord length, culmen length, bill depth and length of the tarsometatarsus. In 1983 song repertoire size and song versatility measures were investigated. Attributes of the territory studied were: territory size, density of plant stems, percentage plant cover and measures of vegetation structure. In 1983 Arthropods were collected from each territory and sorted according to taxonomic group and size. During 1983, territory attributes were sampled twice, once early and once later in the nesting season. Analysis of data involved univariate comparisons between monogamous and polygynous males using T-tests and multivariate comparisons were made using discriminant function analysis (DFA) and principle components analysis (PCA).No correlations were found between the number of females attracted with, .ny measure of male size or with me, .sures of song versatili or size of song repertoire. Also no correlation was found between terri size and the number of females nesting on a terri . Some attributes of the male's terri id distinguish between monog,mous and po s males of thistudy. Analysis of Arthropod numbers showed that e~ .eran counts were significantly great~r on polygynous territories, a1 the total numb~rs of Arthropods collected showed no s fico .nt differences between territories of monogamous and po males. DFA chose ear teran and Hymenopteran counts as multivariate discriminators; both variables we' e more vegetation revealed that there were no univariate differences between the two groups of males fOT 1982 stem densities, but ~ spp. and Solidago spp. were chosen DFA as multivariate discriminators. The total number of plant stems and of Vicia spp. stems were s ficantly the early 1983 ing on monogamous territories for however DFA found no multivariate discriminators" Variables concerned with the overall aspects of vegetation structure showed significant differences between territories of monogamous and polygynous males. DFA of the 1982 sampling of vegetation structure showed significantly greater mat depth and vegetation height on polygynous territories, a finding which was not supported, however, by peA. For the early 1983 sampling period, plant height was greater on polygynous territories. Multivariate analysis identified greater green cover on polygynous territories, greater ground cover on monogamous territories, and greater depth of mat material on monogamous territories as discriminators between territories of monogamous and polygynous males. A DFA on the major variables of the study showed no significant difference between the territories of monogamous and polygynous male Meadowlarks. Of the correlations found, some were for non-prey Arthr~ods, for cover plants with very small samples sizes, or for variables which were greater for monogamous males during one sampling period and polygynous males during the next. While multivariate discriminators were found, peA showed no grouping of monogamous or polygynous males according to any of the variables investigated. On the basis of the univariate and multivariate analysis of major variables, I concluded that there were no correlations between the number of females attracted with male attributes and no unambiguous correlation with attributes of the territory. My study does not unequivocally support either the "sexy son" or the polygyny threshold hypothesis.

Demographic and genetic attributes of dispersing and resident individuals of an enclosed Microtus pennsylvanicus population

A dispersal polymorphism may exist in emigrants from cyclic populations of Microtus '~nnsylvanicus biasing trap-revealed movements of unenclosed animals in favour of sedentary or colonizing individuals. The dispersal tendency of emigrants from an enclosed population was investigated by releasing animals via tubes into one of two adjacent enclosures, one vacant and one inhabited. Individuals from the enclosed population were monitored for age, sex, weight and electrophoretically detectable serum transferrin genotype in an intensive live-trapping program. In 1973 the minimum number alive in the introduced enclosed study population reached approximately l67/ha when breeding stopped in October. In 1974 intensive breeding increased the population density to 333/ha by mid-July when a long decline in numbers and breeding intensity began without an intervening plateau. An adjacent unenclosed area had a much lower density and longer breeding season in 1974. The growth rate of young males in the enclosed population tended to be lowest during the decline period in 1974. Survival of the enclosed population was high throughout but was lowest during the decline phase in both sexes, especially males. Low transferrin heterozygote survival during the decline coincided with a significant heterozygote deficiency in females whereas in males genotype frequencies did not depart from Hardy-Weinberg equilibrium values throughout th.e study. Twenty-nine suitable ani.mals were released during the decline in five periods from July to November 1974. The proportions of males and transferrin heterozygotes in the released graun were generally greater than in the source population~ In the test enclosures 21% of the released animals continued their movement through the vacant area while 41% (no significant difference) moved through the inhabited enclosure. In the vacant test area, females had a greater tendency than males to continue dispersal whereas no difference was noted in the inhabited area. Low frequency of captures in the tubes, predator disturbances and cold weather forced the termination of the study. The role of dispersal as a population regulating mechanism was further substantiated. The genetic differences between emigrant and resident animals lend support to Howard's hypothesis that a genetic polymorphism influences the tendency to disperse. Support is also given to Myers' and Krebs' contention that among dispersers an additional density dependent polymorphism influences the distance dispersed.

Foraging ecology and parental care of common terns (Sterna hirundo) nesting in Windermere Basin, Lake Ontario

The relationships among chick feeding, size and type of prey item, and foraging time away from the brood have not been well studied in seabirds. This study investigated spatial and temporal patterns of foraging and chick-provisioning among 23 radio-tagged male common terns nesting at Hamilton Harbour, Lake Ontario during 1991 and 1992. Telemetry data were collected concurrently with behavioural observations from an elevated blind. Terns fitted with transmitters did not differ from controls with respect to either brood attendance, patterns of chick mortality, species and size distributions of prey delivered to offspring, or chick-provisioning rates. There was a clear separation of parental roles: males were primarily responsible for feeding chicks while females allocated more time to brood attendance. The prey species most commonly delivered to chicks by adults were rainbow smelt (Osmerus mordax) and alewife (A/osa pseudoharengus), followed in importance by larval fish, emerald shiner (Notropis antherinoides), salmonids, and fathead minnows (Pimepha/es prome/as). The relative proportions of various fish speCies delivered to chicks by males differed over the course of each breeding season, and there was also much variability in species composition of prey between years. Sizes of prey delivered to chicks also differed between sampling periods. The modal size of fish brought to chicks during Peak 1991 was 1.5 bill lengths, while the majority of prey in Late 1991 were small larval fish. The reverse trend occurred in 1992 when small fish were delivered to chicks predominantly during the Peak nesting period. During periods when predominantly small fish were delivered to chicks, the foraging activity of radio-tagged males was concentrated within a two kilometer radius of the colony. The observed variation in prey composition and foraging locations during the study likely reflects temporal variation in the availability of prey in the vicinity of the colony. Males delivered fish to chicks at a constant rate, while females 4 increased their feeding frequency over the first six to ten brood days. The mean length of fish delivered to chicks by adults increased significantly with increasing chick age. As a group, within each nesting period, transmittered males either foraged predominantly in the same directional bearing (north during Peak 1991, south during Late 1992), or concentrated foraging activity in the immediate vicinity of the colony (Late 1991, Peak 1992). However, individual radio-tagged males exhibited unique and predictable foraging patterns, often favouring specific locations within these areas and differing in their secondary foraging patterns. Overall, the Lake Ontario shoreline between NCB Bay" (3.5 km south of colony) and the lift bridge canal (4 km north of colony) was the foraging area used most frequently by radiotagged males during the chick-rearing period. Foraging patterns of transmittered males at Windermere Basin are similar to patterns of peak-nesting common terns, but differ from those of late-nesters, at a nearby colony (Port Colborne, Lake Erie). Differences between the foraging patterns of late-nesting terns at these colonies likely reflect differences in annual patterns of fish availability between the two locations. No relationship was found between foraging proficiency of adults and survival of offspring. Stochastic factors, such as predation by black-crowned nightherons (Nycticorax nycticorax) and adverse weather conditions during the early stages of chick rearing, may be more important determinants of common tern breeding success than parental quality or fish availability.

Characterizing the impact of multiple potential enemies (predators and parasites) on the behaviour of ranid tadpoles

In order to fully understand an organism's behaviours the interactions between multiple enemies or selective pressures need to be considered, as these interactions are usually far more complex than the simple addition of their effects in isolation. In this thesis, I consider the impact of multiple enemies (fish predators and parasites) on the behaviour of three larval anurans (Lithobates sylvaticus, L. clamitans and L. catesbeianus). I also determine whether species that differ in life-histories and habitat preferences possess different antipredator mechanisms and how this affects species responses to multiple enemies. I show that the three Ranid larvae respond differently to the trade-off imposed by the presence of both fish predators and trematode parasites within the environment. The two more permanent pond breeders (L. clamitans and L. catesbeianus) increased activity when in the combined presence of predators and parasites. In contrast, the temporary pond breeder (L. sylvaticus) decreased activity in the combined presence of predator and parasites, in the same manner as they responded to fish alone. Further, the presence of fish along with parasites increased the susceptibility of both L. sylvaticus and L. clamitans to trematode infection, whereas parasite infection in L. catesbeianus was unaffected by the presence of fish. A second experiment to assess palatability of the three anuran species to fish, revealed a range of palatabilities, with L. catesbeianus being least palatable, L. clamitans being somewhat unpalatable, and L. sylvaticus being highly palatable. This result helps to explain the species differences in tthe observed behaviour to the combined presence of fish and parasites. In conclusion, the results from this study highlight the importance of considering multiple selective pressures faced by organisms and how this shapes their behaviour.

An investigation of the psychopathy construct and its (novel) correlates in non-clinical samples

A substantial research literature exists regarding the psychopathy construct in forensic populations, but more recently, the construct has been extended to non-clinical populations. The purpose of the present dissertation was to investigate the content and the correlates of the psychopathy construct, with a particular focus on addressing gaps and controversies in the literature. In Study 1, the role of low anxiety in psychopathy was investigated, as some authors have proposed that low anxiety is integral to the psychopathy construct. Participants (n = 346) responded to two self-report psychopathy scales, the SRP-III and the PPI-R, as well as measures of temperament, personality, and antisociality. Of particular interest was the PPI-R Stress Immunity sub scale, which represents low anxiety content. I t was found that Stress Immunity was not correlated with SRP-III psychopathy, nor did it share common personality or temperament correlates or contribute to the prediction of anti sociality. From Study 1, it was concluded that it was unlikely that low anxiety is a central feature of the psychopathy construct. In Study 2, the relationship between SRP-III psychopathy and Ability Emotional Intelligence (Le., Emotional Intelligence measured as an ability, rather than as a self-report personality trait-like characteristic) was investigated, to determine whether psychopathy is be s t seen as a syndrome characterized by emotional deficits or by the ability to skillfully manipulate and prey upon the others' emotions. A negative correlation between the two constructs was found, suggesting that psychopathy is best characterized by deficits in perceiving, facilitating, managing, and understanding emotions. In Study 3, sex differences in the sexual behavior (i.e., promiscuity, age of first sexual behaviors, extradyadic sexual relations) and appearance-related esteem (i.e., body shame,appearance anxiety, self-esteem) correlates of SRP-III psychopathy were investigated. The sexual behavior correlates of psychopathy were quite similar for men and women, but the esteem correlates were very different, such that high psychopathy in men was related to high esteem, whereas high psychopathy in women was generally related to low esteem. This sex difference was difficult to interpret in that it was not mediated by sexual behavior, suggesting that further exploration of this topic is warranted. Together, these three studies contribute to our understanding of non-clinical psychopathy, indicating that low anxiety is likely not part of the construct, that psychopathy is related to low levels of ability in Emotional Intelligence, and that psychopathy is an important predictor of behavior, ability, and beliefs and feelings about the self

Interactions between the cholinergic and dopaminergic systems during the production of ultrasonic vocalizations in rats

Rats produce ultrasonic vocalizations that can be categorized into two types of ultrasonic calls based on their sonographic structure. One group contains 22-kHz ultrasonic vocalization (USVs), characterized by relatively constant (flat) frequency with peak frequency ranging from 19 to 28-kHz, and a call duration ranging between 100 – 3000 ms. These vocalization can be induced by cholinomimetic agents injected into the ascending mesolimbic cholinergic system that terminates in the anterior hypothalamic-preoptic area (AH-MPO) and lateral septum (LS). The other group of USVs contains 50-kHz USVs, characterized by high peak frequency, ranging from 39 to 90-kHz, short duration ranging from 10-90 ms, and varying frequency and complex sonographic morphology. These vocalizations can be induced by dopaminergic agents injected into the nucleus accumbens, the target area for the mesolimbic dopaminergic system. 22-kHz USVs are emitted in situations that are highly aversive, such as proximity of a predator or anticipation of a foot shock, while 50 kHz USVs are emitted in rewarding and appetitive situations, such as juvenile play behaviour or anticipation of rewarding electrical brain stimulation. The activities of these two mesolimbic systems were postulated to be antagonistic to each other. The current thesis is focused on the interaction of these systems indexed by emission of relevant USVs. It was hypothesized that emission of 22 kHz USVs will be antagonized by prior activation of the dopaminergic system while emission of 50 kHz will be antagonized by prior activation of the cholinergic system. It was found that injection of apomorphine into the shell of the nucleus accumbens significantly decreased the number of carbachol-induced 22 kHz USVs from both AH-MPO and LS. Injection of carbachol into the LS significantly decreased the number of apomorphine-induced 50 kHz USVs from the shell of the nucleus accumbens. The results of the study supported the main hypotheses that the mesolimbic dopaminergic and cholinergic systems function in antagonism to each other.