Life History Phenomena in Two Populations of the Lizard Sceloporus undulatus in Southwestern New Mexico

1975 ◽  
Vol 93 (2) ◽  
pp. 388 ◽  
Author(s):  
Marian B. Vinegar
Keyword(s):  
Life History ◽  
New Mexico ◽  
Sceloporus Undulatus ◽  
Two Populations

Demography of Xenosaurus platyceps (Squamata: Xenosauridae): a comparison between tropical and temperate populations

2008 ◽  
Vol 29 (2) ◽  
pp. 245-256 ◽  
Author(s):  
Carissa Jones ◽  
Isaac Rojas-González ◽  
Julio Lemos-Espinal ◽  
Jaime Zúñiga-Vega
Keyword(s):  
Life History ◽  
Population Growth ◽  
Adult Mortality ◽  
Life History Strategies ◽  
Relative Importance ◽  
Theoretical Frameworks ◽  
Population Growth Rates ◽  
Relative Contribution ◽  
Two Populations ◽  
Average Fitness

Abstract There appears to be variation in life-history strategies even between populations of the same species. For ectothermic organisms such as lizards, it has been predicted that demographic and life-history traits should differ consistently between temperate and tropical populations. This study compares the demographic strategies of a temperate and a tropical population of the lizard Xenosaurus platyceps. Population growth rates in both types of environments indicated populations in numerical equilibrium. Of the two populations, we found that the temperate population experiences lower adult mortality. The relative importance (estimated as the relative contribution to population growth rate) of permanence and of the adult/reproductive size classes is higher in the temperate population. In contrast, the relative importance for average fitness of fecundity and growth is higher in the tropical population. These results are consistent with the theoretical frameworks about life-historical differences among tropical and temperate lizard populations.

Sceloporus Undulatus: Comparative Life History and Regulation of a Kansas Population

Ecology ◽  
1980 ◽  
Vol 61 (2) ◽  
pp. 313-322 ◽  
Author(s):  
Gary W. Ferguson ◽  
Charles H. Bohlen ◽  
H. Patrick Woolley
Keyword(s):  
Life History ◽  
Sceloporus Undulatus

Life history and taxonomy of two populations of ligulate Desmarestia (Phaeophyceae) from Chile

1986 ◽  
Vol 64 (12) ◽  
pp. 2948-2954 ◽  
Author(s):  
M. E. Ramirez ◽  
D. G. Müller ◽  
A. F. Peters
Keyword(s):  
South Africa ◽  
Life History ◽  
Chromosome Numbers ◽  
Taxonomic Status ◽  
Southern Chile ◽  
Northeast Pacific ◽  
Laboratory Cultures ◽  
Monoecious Population ◽  
Two Populations

Two populations of broad-bladed (ligulate) Desmarestia from central and southern Chile were studied in laboratory cultures. They differ in sporophyte morphology and gametophyte characters (monoecism versus dioecism). The dioecious population is found to be related to D. firma from South Africa and D. munda from the northeast Pacific, while the taxonomic status of the broad-bladed monoecious population is left undetermined. In both populations sporophytes originate after fertilization as well as by apomixis. Chromosome numbers alternate between ca. 23 and ca. 46. Evidence is presented that spermatozoids of the dioecious Desmarestia can develop into sporophytes (androgenesis or ephebogenesis).

scholarly journals Hospital Readmissions Among the Homeless Population in Albuquerque, New Mexico

2016 ◽  
Vol 8 (1) ◽  
Author(s):  
Victoria F. Dirmyer
Keyword(s):  
New Mexico ◽  
Hospital Readmissions ◽  
The United States ◽  
Demographic Characteristics ◽  
Homeless Population ◽  
Health Care Needs ◽  
Care Needs ◽  
Time Period ◽  
Families With Children ◽  
Two Populations

It is estimated that there are 1.7 million homeless individuals in the United States; 36% are families with children under the age of 18. Due to lack of resources, homeless individuals frequent emergency departments for immediate health care needs. The aim of this study was to examine a homeless population who visited an Albuquerque area hospital at any time during a 3-year time period. A comparison of demographic characteristics as well as visit/hospitalization characteristics between two populations was analyzed; homeless individuals who had a 30-day readmission compared to those that did not have a 30-day readmission.

LIFE HISTORY PARAMETERS IN MELANOPLUS SANGUINIPES (F.) IN TWO CRESTED WHEATGRASS PASTURES

1988 ◽  
Vol 120 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Norma E. Sanchez ◽  
Jerome A. Onsager
Keyword(s):  
Life History ◽  
Survival Rates ◽  
Adult Longevity ◽  
Melanoplus Sanguinipes ◽  
Crested Wheatgrass ◽  
Life History Parameters ◽  
Preoviposition Period ◽  
Point Estimates ◽  
Two Populations ◽  
Net Replacement

AbstractA combination of published techniques provided point estimates of life history parameters for two natural field populations of Melanoplus sanguinipes (F.) in crested wheatgrass pastures. Stage-specific survival rates averaged 0.4798, 0.2261, 0.7628, and 0.6903 for egg, instars I–III combined, instar IV, and instar V, respectively. Daily survival rates of adults averaged 0.9702, but were slightly lower for females than for males. Estimated duration of nymphal instars averaged 8.4 days, the adult preoviposition period averaged 13.3 days, and adult longevity averaged 26.7 and 36.3 days in the two populations. Oviposition rates were estimated for up to four successive ovipositions, and net replacement rates of populations also were estimated. Neither population replaced itself, indicating that potential capacities for increase were not approached under conditions of these studies.

scholarly journals Individual variability in life-history traits drives population size stability

2012 ◽  
Vol 58 (2) ◽  
pp. 358-362 ◽  
Author(s):  
Ned A. Dochtermann ◽  
C. M. Gienger
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Individual Variability ◽  
Population Variation ◽  
Sceloporus Undulatus ◽  
Natural Systems ◽  
Size Stability ◽  
Population Sizes ◽  
The Individual ◽  
Dynamics Of Populations

Abstract Understanding how population sizes vary over time is a key aspect of ecological research. Unfortunately, our understanding of population dynamics has historically been based on an assumption that individuals are identical with homogenous life-history properties. This assumption is certainly false for most natural systems, raising the question of what role individual variation plays in the dynamics of populations. While there has been an increase of interest regarding the effects of within population variation on the dynamics of single populations, there has been little study of the effects of differences in within population variation on patterns observed across populations. We found that life-history differences (clutch size) among individuals explained the majority of the variation observed in the degree to which population sizes of eastern fence lizards Sceloporus undulatus fluctuated. This finding suggests that differences across populations cannot be understood without an examination of differences at the level of a system rather than at the level of the individual [Current Zoology 58 (2): 358–362, 2012].

Divergent patterns of impact of environmental conditions on life history traits in two populations of a long-distance migratory bird

Oecologia ◽  
2009 ◽  
Vol 159 (4) ◽  
pp. 859-872 ◽  
Author(s):  
Javier Balbontín ◽  
Anders P. Møller ◽  
Ignacio G. Hermosell ◽  
Alfonso Marzal ◽  
Maribel Reviriego ◽  
...  
Keyword(s):  
Life History ◽  
Environmental Conditions ◽  
Life History Traits ◽  
Migratory Bird ◽  
Long Distance ◽  
Two Populations
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