Population Regulation in Deer Mice: The Role of Females

10.2307/4796 ◽  
1987 ◽  
Vol 56 (1) ◽  
pp. 11 ◽  
Author(s):  
Carlos Galindo ◽  
Charles J. Krebs
Keyword(s):  
Population Regulation ◽  
Deer Mice

Hyperbenthic and pelagic predators regulate alternate key planktonic copepods in shallow temperate estuaries

2014 ◽  
Vol 65 (9) ◽  
pp. 791 ◽  
Author(s):  
R. J. Wasserman ◽  
T. J. F. Vink ◽  
R. Kramer ◽  
P. W. Froneman
Keyword(s):  
Population Regulation ◽  
Zooplankton Community ◽  
Copepod Species ◽  
Benthic Fish ◽  
Predator Diversity ◽  
Predatory Impact ◽  
Experimental Treatments ◽  
Zooplankton Communities ◽  
Predatory Pressure

Although predation has been identified as an important community driver, the role of predator diversity in structuring estuarine zooplankton has not been assessed. As such, we investigated the effects of two different zooplanktivorous fish species on the estuarine zooplankton community during a 12-day mesocosm study. Three experimental treatments were established, whereby natural zooplankton communities were subject to either (1) no predatory pressure, (2) predation by a pelagic predator (Monodactylus falciformis) or (3) predation by a hyper-benthic predator (Glossogobius callidus). The pelagic feeding M. falciformis fed largely on the numerically dominant mid-water copepod species, Paracartia longipatella. In contrast, the hyper-benthic fish had a greater predatory impact on the less numerically dominant copepod, Pseudodiaptomus hessei, which demonstrates strong diel vertical migration. Variations in prey-population regulation are ascribed to the distinct behavioural differences of the predators, and mediated by the differences in behaviour of the copepod species.

Foraging range in mice and voles: the role of risk

1986 ◽  
Vol 64 (12) ◽  
pp. 2645-2653 ◽  
Author(s):  
Paul K. Anderson
Keyword(s):  
Risk Assessment ◽  
Deer Mice ◽  
Lake Surface ◽  
Supplementary Food ◽  
Foraging Range ◽  
Time Minimization ◽  
Energy Maximization ◽  
Fourth Experiment ◽  
Foraging Ranges

The significance of risk assessment in determining the boundaries of foraging ranges of deer mice and voles was examined by comparing the distances to which resident animals were willing to follow shifting feeding stations providing equal rewards beyond their previous foraging ranges in an area with abundant cover (forest), and in one where cover was lacking (frozen lake surface). Previous foraging ranges were estimated on the basis of livetrapping and the "rediscovery distances" for the moving stations. In three experiments the distance at which animals stopped visiting the stations ("giving-up distance") averaged 3.3 times farther where cover was abundant (forest) than where it was absent (lake). In a fourth experiment, reduction of supplementary food available within the original ranges extended the giving-up distance where cover was present but had relatively little effect on giving-up distance and almost no effect on rediscovery distance where cover was absent. Supplying cover more than tripled giving-up distances on the lake. The distance at which boxes were visited was affected by snowfall, ambient temperature, food supply, and availability of cover. Results emphasize the importance of risk assessment in defining foraging range, and suggest that hoarding permits choice among energy maximization and time minimization strategies.

POPULATION REGULATION IN AN AQUATIC INSECT: THE ROLE OF DISEASE

Ecology ◽  
2001 ◽  
Vol 82 (8) ◽  
pp. 2294-2305 ◽  
Author(s):  
Steven L. Kohler ◽  
Wade K. Hoiland
Keyword(s):  
Population Regulation ◽  
Aquatic Insect

Experimental Analysis of the Role of Emigration in Population Regulation of Desert Pupfish

Ecology ◽  
1988 ◽  
Vol 69 (6) ◽  
pp. 1871-1883 ◽  
Author(s):  
Thomas E. McMahon ◽  
Jerry C. Tash
Keyword(s):  
Experimental Analysis ◽  
Population Regulation ◽  
Desert Pupfish
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