Ecologists have been unable to successfully explain regular population cycles for many decades delayed density dependence may hold the answer . forest insects as well as the population cycles of larger mammals such as moose and wolves.
22.
Ecologists have been unable to successfully explain regular population cycles for many decades delayed density dependence may hold the answer . forest insects as well as the population cycles of larger mammals such as moose and wolves.
23.
Pregnancy rates ranged from 78 to 100 % for females during the period of first litter production, 82 to 100 % for second litters, and for the periods of third and fourth litters pregnancy rates vary with population cycle.
24.
From Gordon Hewitt's 1921 book " The Conservation of the Wildlife of Canada ", Elton noticed the Canadian lynx and snowshoe hare population cycles, and developed a greater understanding of population fluctuations in Arctic vertebrates with the Hudson's Bay Company.
25.
Each population cycles in relative independence of the other populations and eventually goes extinct as a consequence of demographic stochasticity ( fluctuations in population size due to random demographic events ); the smaller the population, the more prone it is to extinction.
26.
Pearson is best known for his work on the role of predation on vole demography and population cycles, and for his piercing contributions to the biology of South American mammals, but his earlier studies on reproductive and physiological ecology are highly regarded as well.
27.
In classical metapopulation theory, each population cycles in relative independence of the other populations and eventually goes extinct as a consequence of demographic stochasticity ( fluctuations in population size due to random demographic events ); the smaller the population, the more chances of inbreeding depression and prone to extinction.
28.
As illustrated in the circulating oscillations in the figure above, the level curves are closed orbits surrounding the fixed point : the levels of the predator and prey populations cycle, and oscillate without damping around the fixed point with period \ omega = \ sqrt { \ alpha \ gamma }.
29.
The distribution of one prey species placed on each of 120 oranges, the impediments to predator movement created by the petroleum jelly divisions between sections of oranges, and the dispersal aid of wooden sticks for the prey species, all worked together to create a spatially heterogeneous environment in which both the predator and prey species survived for three population cycles.
30.
Oscillations occur not only in mechanical systems but also in dynamic systems in virtually every area of science : for example the beating human heart, business cycles in economics, predator prey population cycles in ecology, geothermal geysers in geology, vibrating strings in musical instruments, periodic firing of nerve cells in the brain, and the periodic swelling of Cepheid variable stars in astronomy.
