Achieving population goals in a long-lived wildlife species (Equus caballus) with contraception

2008 ◽  
Vol 35 (6) ◽  
pp. 513 ◽  
Author(s):  
Jay F. Kirkpatrick ◽  
Allison Turner
Keyword(s):  
Population Growth ◽  
Population Decline ◽  
Target Population ◽  
Short Term ◽  
Wildlife Species ◽  
Contraceptive Agents ◽  
Contraceptive Vaccine ◽  
Zero Population Growth ◽  
Assateague Island ◽  
Body Condition Scores

The ultimate goal of any wildlife contraceptive effort is some alteration of the target population, either through a slowing of growth, or stabilisation or reduction of the population. Early population models suggested that short-term contraceptive agents applied to long-lived species would not achieve significant population changes. Native porcine zona pellucida antigen (PZP), a short-term contraceptive vaccine, was applied to a herd of wild horses inhabiting Assateague Island National Seashore, MD, USA, over a 13-year period, with an immediate goal of achieving zero population growth, a secondary goal of reducing the population from 175 to 150 and a tertiary goal of reaching 120 individuals, all without the physical removal of animals. Contraceptive efficacy ranged from 92 to 100% on an annual basis (96.28 ± 2.49%), and the percentage of adult females that was treated on any given year ranged from 42 to 76% (67.78 ± 18.21%). The goal of zero population growth was achieved in 2 years, an initial decline in the population became apparent in 8 years and by Year 11, the population declined to 135, a decrease of 22.8%. The lengthy period required for achieving a population decline was caused by increasing body condition scores, reduced mortality and significantly increased longevity among treated females.

scholarly journals Toward a New Cycle: Short-Term Population Dynamics, Gentrification, and Re-Urbanization of Milan (Italy)

2018 ◽  
Vol 10 (9) ◽  
pp. 3014 ◽  
Author(s):  
Margherita Carlucci ◽  
Francesco Chelli ◽  
Luca Salvati
Keyword(s):  
Population Dynamics ◽  
Population Growth ◽  
Population Decline ◽  
Population Expansion ◽  
Local Scale ◽  
City Centre ◽  
Short Term ◽  
Homogeneous Population ◽  
Scale Population ◽  
The City

After sequential cycles of urbanization and suburbanization, European cities underwent a (more or less intense) re-urbanization wave. The present study analyzes short-term population dynamics in the core of a large metropolitan region (Milan, northern Italy), providing evidence of spatially-heterogeneous re-urbanization characterized by spatially-complex population growth (or shrinkage) at a local scale. Population dynamics over 1999–2017 were assessed in 88 urban districts partitioning Milan′s municipal area and projected up to 2036 for the same spatial units. Empirical results identify spatially-complex and temporally non-linear dynamics with expanding or declining districts distributed heterogeneously across the study area. Multivariate analysis outlines a generalized population decline during 1999–2008 and an opposite pattern afterward (2008–2017), with spatially-homogeneous population expansion expected in the near future. Spatial analysis finally highlights that local-scale population growth rates were more clustered in 2008–2017 than in 1999–2008. While the population decreased continuously in the inner districts (<1 km from the city centre), sub-central districts (1–5 km far from the city centre) experienced mixed patterns of population growth and stability. These results confirm the relevance of local-scale policies managing urban renewal and rehabilitation and promoting metropolitan expansion in a spatially-coordinated manner.

Facing Zero Population Growth

1980 ◽  
Vol 13 (2) ◽  
pp. 370
Author(s):  
Jacques Henripin ◽  
Joseph J. Spengler
Keyword(s):  
Population Growth ◽  
Zero Population Growth

Zero Population Growth, Inc.

BioScience ◽  
1971 ◽  
Vol 21 (14) ◽  
pp. 759-765 ◽  
Author(s):  
Larry D. Barnett
Keyword(s):  
Population Growth ◽  
Zero Population Growth

1. Zero Population Growth: What is it?

1970 ◽  
Vol 2 (3) ◽  
pp. 20 ◽  
Author(s):  
Frank W. Notestein
Keyword(s):  
Population Growth ◽  
Zero Population Growth

scholarly journals Market Access and the Concentration of Economic Activity in a System of Declining Cities

REGION ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 97-109
Author(s):  
Luis Eduardo Quintero ◽  
Paula Restrepo
Keyword(s):  
Population Growth ◽  
Market Access ◽  
Population Decline ◽  
Market Potential ◽  
Population Loss ◽  
City Population ◽  
Alternative Measures ◽  
System Of Cities ◽  
The Impact ◽  
The City

Market access has been widely used as a measure of agglomeration spillovers in models that seek to explain productivity, economic or population growth at the city level. Most results have shown that having higher market access is beneficial to these outcomes. These results, both theoretical and empirical, have been obtained in a context of population growth. This article examines the impact that market access has on a system of cities that has suffered a negative population shock. An extended version of the Brezis and Krugman (1997) model of life cycle of cities predicts that a system of cities experiencing population loss will see a relative reorganization of its population from small to larger cities, and that higher market potential will make this movement stronger. We test these predictions with a comprehensive sample of cities in Eastern Europe and Central Asia. We find that having higher market access - when operating in an environment of population decline - is detrimental to city population growth. This result is robust to different measures of market access that use population. Alternative measures that use economic size rather population are tested, and the result weaker. A possible explanation is that using NLs restricts the sample to only using larger cities. 

Testing the potential for supplementary water to support the recovery and reintroduction of the black-footed rock-wallaby

2017 ◽  
Vol 44 (3) ◽  
pp. 269 ◽  
Author(s):  
Rebecca West ◽  
Matthew J. Ward ◽  
Wendy K. Foster ◽  
David A. Taggart
Keyword(s):  
Population Growth ◽  
Threatened Species ◽  
Population Decline ◽  
South Australia ◽  
Camera Traps ◽  
Limiting Factor ◽  
Population Growth Rates ◽  
Introduced Predators ◽  
Predation Effects

Context Supplementary resource provision is increasingly used by conservation managers to manipulate habitat conditions that limit population growth of threatened species. These methods are popular in reintroduction programs because they can assist released individuals to adapt to novel environments. In situ management and reintroductions are being used to recover warru (black-footed rock-wallaby, Petrogale lateralis MacDonnell Ranges race) on the arid Anangu Pitjantjatjara Yankunytjatjara (APY) Lands of South Australia. Direct predation by introduced predators is thought to be the main cause of population decline, but indirect predation effects reducing access to water resources has also been proposed as a limiting factor. Aims To determine whether warru would use supplementary water and so provide a tool to alleviate resource pressure for in situ (wild) and reintroduced warru populations. Methods We provided supplementary water to a wild and reintroduced warru population across 12 months. Drinking rates were calculated by monitoring water points with camera traps and modelled against plant moisture content and total rainfall. We also examined whether number of visits to water points by warru predators and competitors was significantly different to control points (no water present). Key results Wild and reintroduced warru used water points within 0–10 days of installation. No significant increase in visits by predators or competitors was observed at water points. Drinking rates were significantly higher during dry winter months (March–October) for both wild and re-introduced populations. Conclusions Supplementary water is readily utilised by warru. Water could be provided in this manner to warru populations where predators are present, particularly during drier months (generally March–October on the APY Lands), periods of drought or after fire, when food resources will have a lower water content and/or be less abundant. This may increase breeding rates and recruitment of young, and improve the probability of persistence for populations of this threatened species, and should be further investigated. Implications Supplementary water provision may be a useful tool to increase population growth rates for threatened mammalian herbivores in arid habitats. Experimental trials of the uptake of supplementary water and effects on population dynamics will provide important data for implementing adaptive management frameworks for conservation.

Are We Justified in Conducting Invasive Research on Captive Apes for Their Wild Counterparts?

2018 ◽  
Vol 26 (6) ◽  
pp. 598-615
Author(s):  
Katlin Kraska
Keyword(s):  
Animal Rights ◽  
Power Relations ◽  
Wild Population ◽  
Population Decline ◽  
Conservation Policy ◽  
Wild Animals ◽  
Wildlife Species ◽  
Asymmetrical Power ◽  
Species Membership ◽  
The Individual

Abstract Wildlife species are threatened for a variety of reasons; research on captive individuals of the same species can, in some circumstances, prevent wild population decline. Such decisions pit conservationists and animal rights advocates against one another—the former are interested in survival of the species and the latter in individual rights. I argue that invasive research on captive animals for the sake of wild animals is justifiable in cases of emergency only if it is the lesser of two evils. This requires that the individual chimpanzee be compensated for harms incurred. I then argue this logic generally does not apply to human beneficiaries of invasive research conducted on chimpanzees. This is not because species membership is morally significant, but because asymmetrical power relations characterized by dependency and vulnerability will always exist between the groups if human interests are at stake. The argument focuses on federal chimpanzee conservation policy.

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