Caribou, military jets and noise: The interplay of behavioural ecology and evolutionary psychology

Whether a human activity is likely to have a negative impact on a species depends largely on how stimuli from that activity are interpreted and acted upon by individuals, within the context of their behavioural ecology. The interpretations and decisions made by individuals in response to these stimuli are largely governed by neural systems evolved by the species as adaptations to common and recurrent selective pressures. In this paper I will review previous findings concerning the responses of caribou to overflights by military jet aircraft in Labrador/Quebec and Alaska, casting them in an evolutionary psychological framework. One prediction from such an exercise is that identical stimuli (noise from jet overflights) that elicit similar responses (short-distance avoidance) can have quite different population consequences for sedentary (woodland) and migratory (barren-ground) ecotypes. For a female woodland caribou, which shares her calving range with a resident predator population, an increase in movements following disturbance may significantly increase her calf's exposure to predators. Similar movements by a female barren-ground caribou, which has fewer predators to contend with, may have only a negligible impact on her calf's predation risk. Thus woodland caribou may be more vulnerable to negative impacts of military jet noise during calving periods, dependent on predator density

Human impacts on George River Caribou: An Overview

Habitat loss exerts its influence by lowering the carrying capacity of the habitat. Loss of critical habitat, therefore, is of most concern. The fact that calving range is the one "constant" in the caribou's migratory movements, and that summer range appears to be overgrazed at present and may be limiting the population, indicates that protection of habitat in or about calving and summer range is a priority. It is important to monitor human influences of the population, so that changes in the relative magnitudes, at least, of these variables can be detected before their impacts become serious. Until a fuller understanding of the impacts of these various activities is acquired, it may be more appropriate to accept the alternative hypothesis that there is an impact, rather than the null hypothesis that there is none

Double Marking in Arctic Wolves, Canis lupus arctos: Influence of Order on Posture

Double marking by Arctic Wolves (Canis lupus arctos) was recorded by Mech (2006) from a pack on Ellesmere Island, Nunavut, Canada, during 16 summers between 1986 and 2005. Using his data on the frequency of occurrence for each of the four postures used by Wolves for urine marking (males – raised leg and stand urinations; females – flexed leg and squat urinations), the probabilities of occurrence for each of eight possible double mark sequences were determined and compared with observed frequencies. Females were somewhat but not significantly more likely to initiate double mark sequences. There was no evidence for any bias in the posture used to initiate a double mark sequence, but assertive postures by both males and females nearly always completed the sequence, occurring much more often than expected by chance

What does it mean to put caribou knowledge into an ecosystem context?

Ecosystems are envisioned as integrated, complex systems with both living and non-living components, that are linked through processes of energy flow and nutrient cycling (Bowen, 1971; Ricklefs, 1979). The ecosystem approach seeks to describe the components of this system, the pathways through which energy and nutrients move, and the processes that govern that movement. The goal is a better understanding of the role or effect of each component (abiotic or biotic) within the system. Theorerically, the more we know, the better we can predict the future behaviour of the ecosystem and therefore manage the system on whatever sustainable basis we deem appropriate. Caribou (Rangifer tarandus) presently inhabit two ecosystems, tundra (arctic and alpine) and taiga (or boreal forest), both characterized by relatively low productivity and diversity (Bowen, 1971; Bliss, 1981; Bonan, 1992a). As increased anthropogenic impacts are expected in these ecosystems through the next century, our ability to ensure the continued survival of caribou requires that we pay increasing attention to the processes that drive these systems. In this endeavour, an awareness of the effects of both spatial and temporal scale, in both ecosystem processes and our research programs to understand those processes, is critical

AN ANALYSIS OF HOWLING RESPONSE PARAMETERS USEFUL FOR WOLF PACK CENSUSING

Gray wolves (Canis lupus) were studied from April 1972 through April 1974 in National Forest in northeastern Minnesota by radio-tracking and simulated howling. Based during 217 of 456 howling sessions, the following recommendations were derived for using howling as a census technique: (1) the best times of day are dusk and night; (2) July, August, and are the best months; (3) precipitation and winds greater than 12 km/hour should be avoided; (of 5 single howls should be used, alternating flat and breaking howls; (5) trials should 3 times at about 2-minute intervals with the first trial at lower volume; and (6) the trial series repeated on 3 nights as close to each other as possible. Two censuses are described: a saturation and a sampling census

Short-Term Impacts of Low-Level Jet Fighter Training on Caribou in Labrador

The short-term impacts on caribou (Rangifer tarandus) of low-level jet fighter training activity at Canadian Forces Base Goose Bay (Labrador) were investigated during the 1986-88 training seasons (April-October). Visual observations of low-level (30 m agl) jet overpasses indicated an initial startle response but otherwise brief overt reaction by woodland caribou on late-winter alpine tundra habitat. Between 1986 and 1988, daily effects of jet overflights were monitored on 10 caribou equipped with satellite-tracked radiocollars, which provided daily indices of activity and movement. Half the animals were exposed to jet overflights; the other 5 caribou were avoided during training exercises and therefore served as control animals. In 1988, the control caribou were from a population that had never been overflown. Level of exposure to low-level flying within the exposed population did not significantly affect daily activity levels or distance travelled, although comparison with the unexposed population did suggest potential effects. The results indicate that significant impacts of low-level overflights can be minimized through a program of avoidance.Key words: caribou (Rangifer tarandus), low-level flying, jet aircraft, helicopters, disturbance, activity, movements, LabradorMots clés: caribou (Rangifer tarandus), vol à basse altitude, avion à réaction, hélicoptères, perturbation, activité, déplacement, Labrador

Calving Success of Woodland Caribou Exposed to Low-Level Jet Fighter Overflights

Effects on woodland caribou (Rangifer tarandus caribou) of low-level military jet training at Canadian Forces Base - Goose Bay (Labrador) were studied during the 1986-88 training seasons. Calf survival was periodically monitored during 1987 and 1988 in a sample of 15 females wearing satellite-tracked radiocollars. During 1987, each female's exposure to low-level overflights was experimentally manipulated on a daily basis. In 1988, daily exposure was determined by analyzing jet flight tracks following the low-level flying season. Calf survival was monitored by survey flights every 3-4 weeks. A calf survival index, the number of survey periods (maximum = 4) that a cow was accompanied by a calf, was negatively correlated with the female's exposure to low-level jet overflights during the calving and immediate post-calving period and again during the period of insect harassment during summer. No significant relationship between calf survival and exposure to low-level flying was seen during the pre-calving period, during the late post-calving period prior to insect harassment, and during fall. In view of the continued depression of population growth in the woodland caribou population within the low-level training area, jets should avoid overflying woodland caribou calving range at least during the last week of May and the first three weeks of June.Key words: caribou, Rangifer tarandus caribou, calf survival, low-level flying, jet aircraft, disturbance, LabradorRÉSUMÉ. Au cours des saisons d’entraînement de 1986 à 1988, à la base des Forces années canadiennes de Goose Bay au Labrador, on a étudié les retombées sur le caribou des bois (Rangifer tarandus caribou) de l’entraînement à basse altitude sur des avions militaires à réaction. En 1987 et 1988, on a observé périodiquement la survie des veaux dans un échantillon de 15 femelles équipées de colliers émetteurs suivis par satellite. En 1987, on a manipulé quotidiennement de façon expérimentale l’exposition de chaque femelle à des survols à basse altitude. En 1988, on a déterminé l’exposition quotidienne en analysant le parcours des avions à réaction après la saison de vol à basse altitude. On a observé la survie des veaux en effectuant des relevés en vol toutes les 3 ou 4 semaines. Un index de survie des veaux - le nombre de fois (maximum = 4) durant les relevés où une femelle était accompagnée d’un petit - a été corrélé négativement à l’exposition de la femelle au survol à basse altitude des avions à réaction au cours de la mise bas et de la période lui faisant immédiatement suite, ainsi que durant la saison estivale de harcèlement par les insectes. On n’a observé aucun lien significatif entre la survie des veaux et l’exposition aux vols à basse altitude au cours de la période précédant la mise bas, au cours de la période tardive suivant lamise bas et précédant celle du harcèlement par les insectes, ainsi que durant l’automne. Vu la baisse continue de la croissance de population du caribou des bois à l’intérieur de la zone d’entraînement à basse altitude, les avions à réaction devraient éviter de survoler le territoire de mise bas du caribou des bois au moins durant la dernière semaine de mai et les trois premières semaines de juin.Mots clés: caribou, Rangifer tarandus caribou, survie des veaux, vol à basse altitude, avion à réaction, perturbation, Labrado

WOLF HOWLING AND ITS ROLE IN TERRITORY MAINTENANCE

The wolf (Canis lupus) is a wide-ranging social carnivore with a complex spatial organization (MECH, 1972; 1973). The precise manner in which this organization is maintained is unknown, but territory advertisement using olfactory and acoustic modes seems to be involved. The acoustic mode includes primarily howling. Within a wolf pack, howling may be useful to reassemble separated members (MECH, 1966; THEBERGE & FALLS, 1967), and may communicate information on individual identity, location, and other behavioral and environmental contingencies (THEBERGE & FALLS, 1967). Between packs, however, howling may serve to advertise territory, communicating the locations of packs and thus minimizing contact between them (JOSLIN, 1967). The objective of the present study was to determine the possible role of howling in territorial maintenance by investigating the responses of wolves in northeastern Minnesota to simulated wolf howling

Equilibrium and nonequilibrium properties associated with the chiral phase transition at finite density in the Gross-Neveu Model

We study the dynamics of the chiral phase transition at finite density in the Gross-Neveu (GN) model in the leading order in large-N approximation. The phase structure of the GN model in this approximation has the property that there is a tricritical point at a fixed temperature and chemical potential separating regions where the chiral transition is first order from that where it is second order. We consider evolutions starting in local thermal and chemical equilibrium in the massless unbroken phase for conditions pertaining to traversing a first or second order phase transition. We assume boost invariant kinematics and determine the evolution of the order parameter $\sigma$, the energy density and pressure as well as the effective temperature, chemical potential and interpolating number densities as a function of the proper time $\tau$. We find that before the phase transition, the system behaves as if it were an ideal fluid in local thermal equilibrium with equation of state $p=\epsilon$. After the phase transition, the system quickly reaches its true broken symmetry vacuum value for the fermion mass and for the energy density. The single particle distribution functions for Fermions and anti-Fermions go far out of equilibrium as soon as the plasma traverses the chiral phase transition. We have also determined the spatial dependence of the "pion" Green's function $<\bar{\psi}(x) \gamma_5 \psi(x) \bar{\psi}(0) \gamma_5 \psi(0)>$ as a function of the proper time.Comment: 39 pages, 23 figure

Skeeter Buster: A Stochastic, Spatially Explicit Modeling Tool for Studying Aedes aegypti Population Replacement and Population Suppression Strategies

Dengue is a viral disease that affects approximately 50 million people annually, and is estimated to result in 12,500 fatalities. Dengue viruses are vectored by mosquitoes, predominantly by the species Aedes aegypti. Because there is currently no vaccine or specific treatment, the only available strategy to reduce dengue transmission is to control the populations of these mosquitoes. This can be achieved by traditional approaches such as insecticides, or by recently developed genetic methods that propose the release of mosquitoes genetically engineered to be unable to transmit dengue viruses. The expected outcome of different control strategies can be compared by simulating the population dynamics and genetics of mosquitoes at a given location. Development of optimal control strategies can then be guided by the modeling approach. To that end, we introduce a new modeling tool called Skeeter Buster. This model describes the dynamics and the genetics of Ae. aegypti populations at a very fine scale, simulating the contents of individual houses, and even the individual water-holding containers in which mosquito larvae reside. Skeeter Buster can be used to compare the predicted outcomes of multiple control strategies, traditional or genetic, making it an important tool in the fight against dengue