Variability in Grouping in the Eastern Grey Kangaroo, Macropus giganteus II. Dynamics of Group Formation

1984 ◽  
Vol 11 (3) ◽  
pp. 437 ◽  
Author(s):  
CJ Southwell
Keyword(s):  
Population Density ◽  
High Frequency ◽  
Group Formation ◽  
Grey Kangaroo ◽  
Males And Females

The effects of season, population density and habitat on aspects of group formation in the eastern grey kangaroo were examined. The rate at which groups join and split increased exponentially with population density, but did not vary with season or habitat. In general, large males and females with young-at-foot were seen alone more frequently than small males, females with pouch young or females with no young. The high frequency oflone large males may be due to a tendency to move alone from one group to another to check the oestrous condition of females, but females with young-at-foot appear to be relatively solitary. Association among population classes in groups of two or more was highly variable.

The Influence of population density and habitat on grouping in the western grey kangaroo, Macropus fuliginosus

1993 ◽  
Vol 20 (2) ◽  
pp. 151 ◽  
Author(s):  
G Coulson
Keyword(s):  
Population Density ◽  
National Park ◽  
Habitat Structure ◽  
Group Formation ◽  
Lower Range ◽  
Grey Kangaroo ◽  
The Social ◽  
Western Grey Kangaroo ◽  
Western Victoria ◽  
North Western

Population density and habitat structure have been identified as influencing grouping patterns in kangaroos, but the separate contributions of each factor have rarely been distinguished. Grouping was examined in the western grey kangaroo, Macropus fuliginosus, at Hattah-Kulkyne National Park, north-western Victoria, where the population exhibits marked changes in density throughout habitats that provide a range of cover. Group size and population density in each habitat were surveyed at two times of day and at roughly 2-monthly intervals from March 1983 until December 1985. Of the four major habitats, mallee and woodland offered moderate cover, whereas grassland and lake bed gave sparse cover. Visibility of kangaroo groups was highest in the sparse habitats, and was positively related to the size of the group, at least in the lower range of group sizes. At densities up to 40km-2, groups that formed in the sparse habitats were larger than the groups in the two habitats that offered moderate cover. Three habitats (lake bed, grassland and woodland) had more smaller and more larger groups than expected if group formation was a random process. Large males were seen alone more often than expected by chance in lake bed, and less often in moderate cover; females with young-atfoot were over-represented as singletons in all four habitats. The size and composition of groups recorded in this study suggest that the basic components of the social organisation of kangaroos are best discerned in habitats that carry a low population density, but that also provide the most cover.

Effects of population density on female and male burrow characteristics in the fiddler crab, Uca bengali Crane, 1975

Crustaceana ◽  
2015 ◽  
Vol 88 (12-14) ◽  
pp. 1283-1299 ◽  
Author(s):  
Fahmida Wazed Tina ◽  
Mullica Jaroensutasinee ◽  
Krisanadej Jaroensutasinee
Keyword(s):  
Body Size ◽  
Population Density ◽  
Fiddler Crab ◽  
High Density ◽  
The Other ◽  
Low Density ◽  
Density Effects ◽  
Egg Incubation ◽  
Other Hand ◽  
Males And Females

We examined the effects of population density on body size and burrow characteristics ofUca bengaliCrane, 1975. We predicted that (1) males in high-density areas (HD) should be larger in size and build higher quality burrows than males in low-density areas (LD), and (2) HD females should be larger in size, but build lower quality burrows than LD females, as HD females can find higher numbers of good quality male burrows around them for breeding and egg incubation. Our results showed that males and females in HD were larger in size than those in LD. Since HD males were larger in size, they built higher quality burrows than males in LD. On the other hand, even though LD females were smaller in size than HD ones, they built higher quality burrows than HD females. Our results thus indicate that density effects both body size and burrow characteristics.

Variability in Grouping in the Eastern Grey Kangaroo, Macropus giganteus I. Group Density and Group Size

1984 ◽  
Vol 11 (3) ◽  
pp. 423 ◽  
Author(s):  
CJ Southwell
Keyword(s):  
Seasonal Variation ◽  
Population Density ◽  
Group Size ◽  
Spatial Dispersion ◽  
Population Densities ◽  
Forest Habitat ◽  
Open Forest ◽  
Grey Kangaroo ◽  
Group Density ◽  
The Relationship

The effects of season, population density and habitat on group density and group size in the eastern grey kangaroo were examined. In an open forest habitat, both group density and group size increased significantly with population density, but no seasonal variation was detected for either parameter. The relationship with population density was logarithmic for group density and exponential for group size. In a tall shrubland habitat both group density and group size increased with population density, but the range of population densities sampled was too narrow for the nature of the relationships to be determined. Group density was significantly higher, and group size significantly lower, in the tall shrubland than in the open forest. Possible reasons for this difference in spatial dispersion between habitats are discussed.

scholarly journals Population of Proboscis Monkey (Nasalis lavatus) in Manggar River, Balikpapan City, Indonesia

2021 ◽  
Vol 886 (1) ◽  
pp. 012068
Author(s):  
Ike Mediawati ◽  
Teguh Muslim ◽  
Amir Ma’ruf ◽  
Mukhlisi ◽  
Hery Seputro ◽  
...  
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Anthropogenic Activities ◽  
Proboscis Monkey ◽  
Adult Males ◽  
Conservation Area ◽  
Nasalis Larvatus ◽  
Survey Technique ◽  
Males And Females ◽  
Proboscis Monkeys

Abstract A population estimation of proboscis monkeys (Nasalis larvatus) has been conducted in Manggar River, Balikpapan. In this non-conservation area, the anthropogenic activities threaten the proboscis monkey habitat. Boat survey technique was applied along ± 17 km of the river in the morning and evening. The number of proboscis monkeys in the surveyed area was estimated to range from 57 to 69 individuals with estimated population density of 4.75 individuals/Km2. Moreover, the population of this primates was divided into 4 groups and the sex ratio between adult males and females was 1:2.33. The proboscis monkeys were distributed in the middle of the river to the upstream. The highest population was found in the upstream area with less human activities. Conservation efforts in the Manggar River need to be carried out considering the proboscis monkey habitat in the area has been fragmented and isolated. These efforts could involve local economic communities.

ANALISIS KERAWANAN DAN KERENTANAN BENCANA GEMPABUMI DAN TSUNAMI UNTUK PERENCANAAN WILAYAH DI KABUPATEN MALUKU TENGGARA BARAT

2013 ◽  
Vol 13 (2) ◽  
Author(s):  
Suryana Prawiradisastra
Keyword(s):  
Land Use ◽  
Population Density ◽  
Regional Development ◽  
High Frequency ◽  
Tectonic Plates ◽  
Tsunami Disaster ◽  
Geological Conditions ◽  
The Future ◽  
Prone Area

The District of Maluku Tenggara Barat is situated between: 07º 06’ 13” - 08º 02’ 08” South Latitudes and 131º 03’ 39” - 131º 45’ 09” East Longitudes. The Broad of Territory in the District of Maluku Tenggara ± 325,725 Ha. Maluku Tenggara Barat District was above three tectonic plates, resulting in the formation of the complex geological conditions, therefore the region include earthquake and tsunami prone area. About 30 percent of the tsunami in Indonesia occurred in the Maluku Sea and Banda Sea. Based on record have occurred BMKG station, 31 tsunami events occurred which caused a big earthquake. Looking at a fairly high frequency, it is important to assess potential earthquake and tsunami disaster in the future. The results of the study the potential for disaster if it is associated with population density, infrastructure and land use will be obtained a vulnerability. Vulnerability is needed in preparing the Regional Development.

Home ranges, time budgets and food-tree use in a high-density tropical population of greater gliders, Petauroides volans minor (Pseudocheiridae : Marsupialia)

1996 ◽  
Vol 23 (4) ◽  
pp. 401 ◽  
Author(s):  
SS Comport ◽  
SJ Ward ◽  
WJ Foley
Keyword(s):  
Population Density ◽  
Home Range ◽  
Kernel Method ◽  
Radio Telemetry ◽  
High Population ◽  
Home Ranges ◽  
Time Budgets ◽  
High Population Density ◽  
Mean Values ◽  
Males And Females

The socio-ecology of Petauroides volans has been studied for subtropical and temperate populations, but not for the northern tropical subspecies, Petauroides volans minor. Data on the effects of a high population density on home ranges, time budgets and food-tree use were obtained by means of radio-telemetry. Three techniques were used to estimate home-range area (kernel, MCP and harmonic mean) and the kernel method was preferred. Estimates of home-range area (defined by the 95% kernel) gave mean values of 2.5 and 1.3 ha for males and females, respectively. Broad overlap of home ranges of males was observed, which has not been reported previously for populations of P. volans. Behaviour patterns for males and females were similar to those in previous studies, although the mating system may differ, possibly because of the high population density. Dietary patterns were similar to those previously reported for this species, the most important food items being young leaves and flower buds of particular eucalypt species, notably Eucalyptus acmenoides.

Sex ratios and survival in fluctuating populations of the deer mouse, Peromyscus mamculatus borealis

1970 ◽  
Vol 48 (4) ◽  
pp. 809-811 ◽  
Author(s):  
Raymond P. Canham
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Deer Mouse ◽  
Sex Ratios ◽  
Natural Populations ◽  
In Captivity ◽  
Males And Females ◽  
Young Of The Year ◽  
Fluctuating Populations ◽  
Number Of Males

In litters of the deer mouse, Peromyscus mamculatus borealis, born in captivity there was a significantly greater number of males than females. In natural populations of the same subspecies, an excess of males caused the sex ratio in captured young of the year to differ significantly from 1:1 only in those summers in which population density increased considerably. The sex ratio did not change appreciably during a winter in which density remained stable, but in winters of low survival the proportion of males declined. A difference between males and females in the amplitude of the fluctuations in postnatal survival thus appeared responsible for variations in the sex ratio.

Thresholds or Comparisons: Mate Choice Criteria And Sexual Selection in a Periodical Cicada, Magicicada Septendecim (Hemiptera: Cicadidae)

Behaviour ◽  
2004 ◽  
Vol 141 (6) ◽  
pp. 647-673 ◽  
Author(s):  
David Marshall ◽  
John Cooley
Keyword(s):  
Mate Choice ◽  
High Frequency ◽  
Mating Systems ◽  
Random Mating ◽  
Lek Mating ◽  
Periodical Cicadas ◽  
Fixed Threshold ◽  
Males And Females ◽  
Periodical Cicada ◽  
Rule Out

AbstractMany insects possess life history characteristics that make them unlikely to use the kinds of relative mate choice criteria implicit in theoretical discussions of leks; thus, many insect mating aggregations are treated differently, as 'swarms' or 'choruses.' Yet periodical cicadas (Magicicada spp.) seem strong candidates for participating in lek mating systems. We present a series of observations and experiments designed to reveal whether there are mating biases in periodical cicadas and whether any biases are most consistent with flexible ('best-of-N 'choice) or fixed (threshold choice) mating criteria. We rule out postcopulatory choice by demonstrating that most females mate once, after which they become sexually unreceptive. In our study, patterns of mating success among actively chorusing males are indistinguishable from random mating, and we uncover no consistent differences between unmated and mated males on the basis of size and song pitch, two criteria that have been associated with Magicicada mating biases in other contexts. Because our results are most consistent with a fixed-threshold choice mechanism, we suggest that Magicicada mating aggregations do not function in a manner similar to vertebrate leks even though they fulfill Bradbury's (1981) lek criteria. Instead, features of Magicicada behavior suggesting female selectivity may arise incidentally from males' and females' unequal tendencies to mate multiply, the resulting superabundance of sexually receptive males, and the high frequency at which females are courted at the onset of mating readiness.

scholarly journals Frecuencia de Obesidad y Sobrepeso en una Institución de Salud de la Ciudad de Barranquilla

2013 ◽  
Author(s):  
Mirary Mantilla Morr
Keyword(s):  
Public Health ◽  
High Frequency ◽  
Public Health Problem ◽  
Demographic Variables ◽  
Overweight And Obesity ◽  
The People ◽  
Obesity And Overweight ◽  
Factores De Riesgo ◽  
Males And Females ◽  
Las Mujeres

Introducción: Por su relación con la alta frecuencia de enfermedades crónicas no transmisibles, el sobrepeso y la obesidad se han convertido en un problema emergente de salud pública. Objetivo: Determinar la prevalencia de sobrepeso y obesidad en los sujetos afiliados a una institución de salud en la ciudad de Barranquilla. Materiales y métodos: Se realizó un estudio transversal en 245 personas que asisten a una institución de salud de primer nivel, ubicada en la ciudad de Barranquilla. Como indicador de sobrepeso y obesidad, se utilizó el índice de masa corporal (IMC), definido mediante la medición individual de peso y talla. Además, se aplicó una encuesta para identificar las variables sociodemográficas de los sujetos de estudio. Resultados: La frecuencia de sobrepeso fue del 77,9% para mujeres, y 22,1% para los hombres. La de obesidad fue de un 82,8% para las mujeres, y 17,2% para los hombres. La frecuencia de sobrepeso y obesidad aumentó específicamente con la edad tanto en varones como en mujeres, observándose las proporciones del IMC más elevadas en los mayores de 55 años, así: 35,1% en sobrepeso, y 23,7% en obesidad. Conclusión: El sobrepeso y la obesidad son factores de riesgo cardiovascular presentes en la población estudiada y su proporción varía según el sexo y edad de las personas.ABSTRACTIntroduction: Obesity and overweight have become an emerging public health problem, by its relationship with the high frequency of chronic non-communicable diseases. Objective: To determine the prevalence of overweight and obesity in subjects affiliated with an institution of health in Barranquilla. Materials and methods: study of 245 people who attend an institution of first level health located in Barranquilla. (BMI) body mass index, defined by individual measuring weight and height, is used as an indicator of obesity. In addition a survey was applied to identify the socio-demographic variables of the study subjects. Results: the frequency of overweight was 77.9% for women and 22.1% for men and obesity was 82.8% for women and 17.2% for men. Overweight and obesity increased specifically with age in males and females, noting the proportions of BMI higher in people over 55 years, 35.1% overweight, 23.7% in obesity. Conclusions: overweight and obesity are cardiovascular risk factors present in the studied population, and their proportion varies according to sex and age of the people.

Sign in / Sign up

Export Citation Format

Share Document