scholarly journals Population dynamics of the sheep blowfly Lucilia sericata: seasonal patterns and implications for control

2002 ◽  
Vol 39 (3) ◽  
pp. 493-501 ◽  
Author(s):  
Isla Cruickshank ◽  
Richard Wall
Keyword(s):  
Population Dynamics ◽  
Lucilia Sericata ◽  
Seasonal Patterns

Life history and population dynamics of the exotic snail Potamopyrgus antipodarum (Prosobranchia : Hydrobiidae) in Lake Purrumbete, Victoria, Australia

1998 ◽  
Vol 49 (1) ◽  
pp. 73 ◽  
Author(s):  
E. S. G. Schreiber ◽  
A. Glaister ◽  
G. P. Quinn ◽  
P. S. Lake
Keyword(s):  
Population Dynamics ◽  
Reproductive Output ◽  
Size Structure ◽  
Seasonal Pattern ◽  
Potamopyrgus Antipodarum ◽  
Seasonal Patterns ◽  
High Fecundity ◽  
Successful Invader ◽  
Density Population ◽  
Different Levels

The density, population size-structure, and fecundity of the exotic snail Potamopyrgus antipodarum are described, for a period of two years, on two shores subject to different levels of disturbance in Lake Purrumbete. The population dynamics of Potamopyrgus antipodarum showed the same seasonal pattern in the numbers of embryos carried per individual female in both years, but seasonal patterns in density and potential reproductive output of the population differed between shores. Densities of Potamopyrgus antipodarum were high, with a trend for highest densities to occur in spring and summer. The population consisted almost entirely of females, which is indicative of a parthenogenic mode of reproduction. Fecundity was high, with the number of embryos carried per female peaking in spring. In summer, the population was dominated by small individuals, but some small snails were present at all times of the year. Potamopyrgus antipodarum was found to be a very successful invader of Lake Purrumbete, with high densities, high fecundity, parthenogenesis and the presence of embryos throughout the year contributing to this success.

Susceptibility to climate change via effects on food resources: the feeding ecology of the endangered mountain pygmy-possum (Burramys parvus)

2018 ◽  
Vol 45 (6) ◽  
pp. 539 ◽  
Author(s):  
Rebecca K. Gibson ◽  
Linda Broome ◽  
Michael F. Hutchinson
Keyword(s):  
Climate Change ◽  
Population Dynamics ◽  
Food Preferences ◽  
Dietary Lipid ◽  
Food Resources ◽  
Future Climate Change ◽  
Seasonal Patterns ◽  
Climate Change Scenarios ◽  
Climate Data ◽  
Long Distance

Context Climate change is causing changes to seasonal food resources, with critical health and survival impacts for many species. The endangered Burramys parvus (mountain pygmy-possum) predominantly consumes Agrotis infusa (Bogong moth), a long-distance seasonal migrant. Aims We aimed to examine direct and indirect climate-related influences on B. parvus food resources so as to assess the susceptibility of the species to climate change. Methods We analysed a long-term (17-year) data record of B. parvus faecal samples from sites across a climate gradient, in relation to plant-growth indices derived from climate data. We also modelled the population dynamics of A. infusa against climate variables and in relation to the probability of consumption by B. parvus. Key Results The diet of B. parvus was highly variable among sites and years and there were strong seasonal patterns for predominant food resources (A. infusa, other local arthropods, Podocarpus sp. and other local seeds). Seasonal patterns generally diminished with an increasing elevation, which may be due to resource availability or complex interactions with food preferences. Growth conditions across spatially far removed A. infusa breeding grounds influenced their abundance recorded in the Alps in spring, which was reflected in B. parvus diet. Conclusions Strong seasonal and climatic influences on dominant food resources suggest that B. parvus may be susceptible to climate change. Selective foraging for the lipid-rich A. infusa and Podocarpus sp. seed suggests that there may be important health and survival benefits for B. parvus. Implications Given the dependence on cooler, higher-elevation aestivation sites, A. infusa may have reduced survival in a warmer world. Climate change across the vast migratory route of A. infusa is likely to further affect survival and availability for consumption by B. parvus. Predicted increases in fire frequency and severity may reduce availability of the fire-sensitive Podocarpus sp. The health and survival of B. parvus may be compromised as a result of reduced availability of A. infusa and Podocarpus seed and a greater dependence on angiosperm plants (seeds and nectar) and local arthropods because of the consequent change in dietary lipid composition. Integrated predictive modelling of A. infusa and B. parvus population dynamics under future climate-change scenarios is recommended.

scholarly journals Lepeophtheirus salmonis (Copepoda: Caligidae) on farmed salmon in Ireland

2000 ◽  
Vol 69 (1-2) ◽  
pp. 71-77 ◽  
Author(s):  
David Jackson ◽  
Daniel Hassett ◽  
Sandra Deady ◽  
Yvonne Leahy
Keyword(s):  
Population Dynamics ◽  
Seasonal Variations ◽  
Seasonal Patterns ◽  
Lepeophtheirus Salmonis ◽  
Farmed Fish ◽  
Site Specific ◽  
Farmed Salmon ◽  
Annual Variations ◽  
Parasite Infestation ◽  
Non Destructive

The investigation of specific characteristics of Lepeophtheirus salmonis populations on farmed salmon was made possible by the examination of the parasite infestation parameters of regular non destructive samples taken for up to six years in five bays. Perennial persistence of seasonal patterns of infestation as exhibited by intensity, prevalence and abundance was examined. Site specific characteristics were detected which appeared to be independent of inter-annual variations. Seasonal variations in individual lice size and fecundity, and temporal variation in population dynamics on the farmed fish in the five bays are considered in the context of the not inconsiderable changes in husbandry and lice control practices which have been introduced in the industry over the six year period.

Population Dynamics of Chewing Lice (Phthiraptera) Infesting Birds (Aves)

2021 ◽  
Vol 66 (1) ◽  
pp. 209-224
Author(s):  
Terry D. Galloway ◽  
Robert J. Lamb
Keyword(s):  
Population Dynamics ◽  
Rare Species ◽  
Social System ◽  
Seasonal Patterns ◽  
Spatial Partitioning ◽  
Small Communities ◽  
Chewing Lice ◽  
The Past ◽  
Louse Species ◽  
Species Specific

In the past 25 years, studies on interactions between chewing lice and their bird hosts have increased notably. This body of work reveals that sampling of live avian hosts, collection of the lice, and the aggregated distributions of louse infestations pose challenges for assessing louse populations. The number of lice on a bird varies among host taxa, often with host size and social system. Host preening behavior limits louse abundance, depending on bill shape. The small communities of lice (typically one–four species) that live on individual birds show species-specific patterns of abundance, with consistently common and rare species, and lower year-to-year population variability than other groups of insects. Most species of lice appear to breed continuously on their hosts, with seasonal patterns of abundance sometimes related to host reproduction and molting. Competition may have led to spatial partitioning of the host by louse species, but seldom contributes to current patterns of abundance.

Seasonal Variation of Suicide in the City of São Paulo, Brazil, 1996–2010

Crisis ◽  
2014 ◽  
Vol 35 (1) ◽  
pp. 5-9 ◽  
Author(s):  
Daniel Hideki Bando ◽  
Fernando Madalena Volpe
Keyword(s):  
Seasonal Pattern ◽  
Total Sample ◽  
Sao Paulo ◽  
Seasonal Patterns ◽  
São Paulo ◽  
Health Statistics ◽  
Males And Females ◽  
June July ◽  
The City ◽  
Over Time

Background: In light of the few reports from intertropical latitudes and their conflicting results, we aimed to replicate and update the investigation of seasonal patterns of suicide occurrences in the city of São Paulo, Brazil. Methods: Data relating to male and female suicides were extracted from the Mortality Information Enhancement Program (PRO-AIM), the official health statistics of the municipality of São Paulo. Seasonality was assessed by studying distribution of suicides over time using cosinor analyses. Results: There were 6,916 registered suicides (76.7% men), with an average of 39.0 ± 7.0 observed suicides per month. For the total sample and for both sexes, cosinor analysis estimated a significant seasonal pattern. For the total sample and for males suicide peaked in November (late spring) with a trough in May–June (late autumn). For females, the estimated peak occurred in January, and the trough in June–July. Conclusions: A seasonal pattern of suicides was found for both males and females, peaking in spring/summer and dipping in fall/winter. The scarcity of reports from intertropical latitudes warrants promoting more studies in this area.

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