Diet, prey selection and their energetic relationship tc reproduction in the tropical herring Herklotsichthys quadnmaculatus in Kiribati, Central Pacific

1994 ◽  
Vol 104 ◽  
pp. 239-250
Author(s):  
DA Milton ◽  
SJM Blaber ◽  
NJF Rawlinson
Keyword(s):  
Prey Selection ◽  
Central Pacific

Diet composition and prey selection of vendace Coregonus albula in the mesotrophic, temperate Lake Ostrowite (Northern Poland)

2008 ◽  
Vol 37 (1) ◽  
Author(s):  
Tomasz Kakareko ◽  
Paweł Napiórkowski ◽  
Jacek Kozłowski
Keyword(s):  
Diet Composition ◽  
Prey Selection ◽  
Temperate Lake ◽  
Coregonus Albula ◽  
Northern Poland ◽  
Mesotrophic Lake ◽  
Selection Of

Diet composition and prey selection of vendaceLake Ostrowite is a mesotrophic lake in Northern Poland 280.7 ha in area and 43 m deep at its deepest point. To study vendace (

PATTERNS OF GASTROPOD MOLLUSK PREDATION ON BIVALVE MOLLUSKS ALONG THE UPPER TEXAS GULF COAST

2018 ◽  
Vol 70 (1) ◽  
Author(s):  
Serena J. Randolph ◽  
Alan D. Maccarone
Keyword(s):  
Shell Thickness ◽  
Prey Species ◽  
Gulf Coast ◽  
Prey Selection ◽  
Drill Hole ◽  
The United States ◽  
Hole Diameter ◽  
Bivalve Mollusks ◽  
Collection Site ◽  
Drill Holes

Abstract Predation on bivalve mollusks by gastropod mollusks is common in coastal regions of the United States; however, few previous studies have examined whether drilling gastropods exhibit prey selection. In 2016, shells with small holes drilled by as many as two gastropod predators were collected at three sites separated by 30 km along the Texas Upper Gulf Coast on the Bolivar Peninsula (29° 40′N, 94° 90′W). The likeliest predators in these waters are the southern oyster drill (Stramonita haemastoma Linnaeus 1767) and the moon snail (Neverita duplicate Say 1822). Collected shells were identified to species and measurements were taken to examine statistical relationships between predators and prey species. These measurements included drill-hole diameter, shell thickness, drill-hole completeness, number of drill attempts, and collection site. Across the three locations, 17 different species of shells with drill holes were collected; of these, we focused on the ten most abundant species (n = 277 shells). The sample showed high variation in drill-hole diameter, shell thickness, and drill-hole completeness. Both the total number of holes and mean drill-hole diameter differed significantly among prey species (ANOVA, both P < 0.0001). In addition, drill-hole diameter correlated directly with prey shell thickness (P < 0.0001). Shells whose drill holes were complete were significantly thinner than shells with incomplete holes (P < 0.0001). Mean prey shell thickness, mean drill-hole diameter, and mean number of drill holes all differed significantly by collection site (all P < 0.0001). Ecological and morphological implications related to gastropod predation on mollusks are discussed.

Kalahari Cheetahs

2017 ◽  
Author(s):  
Gus Mills ◽  
Margaret Mills
Keyword(s):  
Reproductive Success ◽  
Spatial Ecology ◽  
Prey Selection ◽  
Arid Ecosystems ◽  
Foraging Success ◽  
Ecological Processes ◽  
Demographic Groups ◽  
Important Prey ◽  
Hunting Behaviour ◽  
The Impact

This book demonstrates how cheetahs are adapted to arid savannahs like the southern Kalahari, and makes comparisons with other areas, especially the Serengeti. Topics dealt with are: demography and genetic status; feeding ecology, i.e. methods used for studying diet, diets of different demographic groups, individual diet specializations of females, prey selection, the impact of cheetah predation on prey populations, activity regimes and distances travelled per day, hunting behaviour, foraging success and energetics; interspecific competition; spatial ecology; reproductive success and the mating system; and conservation. The major findings show that cheetahs are well adapted to arid ecosystems and are water independent. Cheetah density in the study area was stable at 0.7/100 km2 and the population was genetically diverse. Important prey were steenbok and springbok for females with cubs, gemsbok, and adult ostrich for coalition males, and steenbok, springhares, and hares for single animals. Cheetahs had a density-dependent regulatory effect on steenbok and springbok populations. Females with large cubs had the highest overall food intake. Cheetahs, especially males, were often active at night, and competition with other large carnivores, both by exploitation and interference, was slight. Although predation on small cubs was severe, cub survival to adolescence was six times higher than in the Serengeti. There was no difference in reproductive success between single and coalition males. The conservation priority for cheetahs should be to maintain protected areas over a spectrum of landscapes to allow ecological processes, of which the cheetah is an integral part, to proceed unhindered.

Relations of Sociodemographic Variables and Cognitive Ability: A Comparative Analysis of the Cognitive Scores of High School Seniors

1989 ◽  
Vol 69 (3-2) ◽  
pp. 1139-1157
Author(s):  
Hardeo Sahai
Keyword(s):  
High School ◽  
Socioeconomic Status ◽  
White Students ◽  
Mexican Americans ◽  
Minority Groups ◽  
High School Seniors ◽  
Or Education ◽  
Central Pacific ◽  
North Central ◽  
South Central

This paper compares subgroups using cognitive scores from a test battery administered to high school seniors in the base year survey in 1980. The procedures used to select the sample were designed to yield a data base that can be statistically projected to represent the national population of about 3,040,000 high school seniors. Comparisons were performed to examine differences in cognitive scores by age, sex, race/ethnicity, socioeconomic status, and census region. Boys scored higher than girls on mathematics and visualization tests, but lower on the picture-number and mosaic comparison tests. Mean scores of the two sexes on the vocabulary and reading tests differed by less than 0.1 SD. Asian/Pacific Islanders had higher means than white students and other minority groups on the mathematics, mosaic comparisons, and visualization test, but their scores did not differ significantly from those of white students on the other three tests. Means for Hispanics were lower than those for white students but higher than those for black students, except on reading. Mean scores of Cubans exceeded those of Mexican Americans, Puerto Ricans or other Hispanics. A positive correlation 0.40 obtained between test scores and the socioeconomic status or education attained by the examinees’ mothers. Students in New England had the highest means except on visualization for which the highest scores were in the West, followed in order by those in the Middle Atlantic, West North Central, East North Central, Pacific, Mountain, South Atlantic, East South Central, and West South Central regions.

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