Costs and benefits of trap-neuter-release and euthanasia for removal of urban cats in Oahu, Hawaii.

Our goal was to determine whether it is more cost-effective to control feral cat abundance with trap-neuter-release programs or trap and euthanize programs. Using STELLA 7, systems modeling software, we modeled changes over 30 years in abundance of cats in a feral colony in response to each management method and the costs and benefits associated with each method . We included costs associated with providing food, veterinary care, and microchips to the colony cats and the cost of euthanasia, wages, and trapping equipment in the model. Due to a lack of data on predation rates and disease transmission by feral cats the only benefits incorporated into the analyses were reduced predation on Wedge-tailed Shearwaters (Puffinus pacificus). When no additional domestic cats were abandoned by owners and the trap and euthanize program removed 30,000 cats in the first year, the colony was extirpated in at least 75% of model simulations within the second year. It took 30 years for trap-neuter-release to extirpate the colony. When the cat population was supplemented with 10% of the initial population size per year, the colony returned to carrying capacity within 6 years and the trap and euthanize program had to be repeated, whereas trap-neuter-release never reduced the number of cats to near zero within the 30-year time frame of the model. The abandonment of domestic cats reduced the cost effectiveness of both trap-neuter-release and trap and euthanize. Trap-neuter-release was approximately twice as expensive to implement as a trap and euthanize program. Results of sensitivity analyses suggested trap-neuter-release programs that employ volunteers are still less cost-effective than trap and euthanize programs that employ paid professionals and that trap-neuter-release was only effective when the total number of colony cats in an area was below 1000. Reducing the rate of abandonment of domestic cats appears to be a more effective solution for reducing the abundance of feral cats.

The construction of a "population problem" in colonial India, 1919-1947.

This article examines the construction of a "population problem" among public health officials in India during the inter-war period. British colonial officials came to focus on India's population through their concern with high Indian infant and maternal mortality rates. They raised the problem of population as one way in which to highlight the importance of dealing with public health at an all-India basis, in a context of constitutional devolution of power to Indians where they feared such matters would be relegated to relative local unimportance. While they failed to significantly shape government policy, their arguments in support of India's 'population problem' nevertheless found a receptive audience in the colonial public sphere among Indian intellectuals, economists, eugenicists, women social reformers and birth controllers. The article contributes to the history of population control by situating its pre-history in British colonial public health and development policy and outside the logic of USA's Cold War strategic planning for Asia.

Socio-cultural aspects of the high masculinity ratio in India.

The paper aims to explicate those factors accountable for the continuing imbalance in the sex ratio and its further masculinization over the whole of the 20th century. Here it is contended that the traditional practice of female infanticide and the current practice of female foeticide in the contemporary period, especially in the north-west and Hindi-speaking states, have significantly contributed to the high masculinity ratio in India. In addition, increasingly higher survival ratios of male children, particularly from the 1951 census onward, have been the prime reason for a declining proportion of females in the Indian population. As the Indian value system has been imbued with a relatively higher preference for sons, improvements in health facilities have benefited males more than females, giving rise to a highly imbalanced sex ratio in the country. This scenario, however, has steadily tended to alter in favour of greater balance in sex ratio.

Allee effect and control of lake system invasion.

We consider the model of invasion prevention in a system of lakes that are connected via traffic of recreational boats. It is shown that in presence of an Allee effect, the general optimal control problem can be reduced to a significantly simpler stationary optimization problem of optimal invasion stopping. We consider possible values of model parameters for zebra mussels. The general N-lake control problem has to be solved numerically, and we show a number of typical features of solutions: distribution of control efforts in space and optimal stopping configurations related with the clusters in lake connection structure.

Considerations for determining optimal mouse caging density.

At the 2006 National Meeting of the American Association of Laboratory Animal Science, a panel discussed the question of what constitutes optimal or acceptable housing density for mice. Though there is a consensus that present guidelines are somewhat arbitrarily defined, scientific research has not yet been able to provide clear recommendations for amending them. Speakers explored the many factors that influence decisions on mouse housing, including regulatory requirements, scientific data and their interpretation, financial considerations and ethical concerns. The panel largely agreed that animal well-being should be the measure of interest in evaluating housing density and that well-being includes not only physical health, but also animals' behavior, productivity and preference.

Impact of a bilingual mobile spay/neuter clinic in a U.S./Mexico border city.

There are between 4 and 10 million dogs and cats killed annually in the United States. Although there are no accurate national estimates of the number of companion animals who are sterilized surgically. Approximately 26,000 companion animals are euthanized annually in El Paso County, Texas, located on the U.S./Mexico border. In an effort to determine if a readily available spay/neuter program would be cost effective and eventually help to lower the county's euthanasia rate, a mobile spay/neuter clinic began operation for a 5-month period in 2004, using a volunteer veterinarian and paid staff. Sterilizations performed totaled 1,108: 959 dogs (372 males and 587 females) and 149 cats (50 males and 99 females). The per companion animal sterilization cost of 15.13 dollars (27.83 dollars had the veterinarian been paid) was considerably cheaper than the rate of 57 dollars per companion animal achieved by a local voucher program contracting with private veterinarians to perform reduced-cost sterilizations.

A modelling framework for predicting the optimal balance between control and surveillance effort in the local eradication of tuberculosis in New Zealand wildlife.

Bovine tuberculosis (TB) impacts livestock farming in New Zealand, where the introduced marsupial brushtail possum (Trichosurus vulpecula) is the wildlife maintenance host for Mycobacterium bovis. New Zealand has implemented a campaign to control TB using a co-ordinated programme of livestock diagnostic testing and large-scale culling of possums, with the long-term aim of TB eradication. For management of the disease in wildlife, methods that can optimise the balance between control and surveillance effort will facilitate the objective of eradication on a fixed or limited budget. We modelled and compared management options to optimise the balance between the two activities necessary to achieve and verify eradication of TB from New Zealand wildlife: the number of lethal population control operations required to halt the M. bovis infection cycle in possums, and the subsequent surveillance effort needed to confidently declare TB freedom post-control. The approach considered the costs of control and surveillance, as well as the potential costs of re-control resulting from false declaration of TB freedom. The required years of surveillance decreased with increasing numbers of possum lethal control operations but the overall time to declare TB freedom depended on additional factors, such as the probability of freedom from disease after control and the probability of success of mop-up control, i.e. retroactive culling following detection of persistent disease in the residual possum population. The total expected cost was also dependent on a number of factors, many of which had wide cost ranges, suggesting that an optimal strategy is unlikely to be singular and fixed, but will likely vary for each different area being considered. Our approach provides a simple framework that considers the known and potential costs of possum control and TB surveillance, enabling managers to optimise the balance between these two activities to achieve and prove eradication of a wildlife disease, or the pest species that transmits it, in the most expedient and economic way. This cost- and risk-evaluation approach may be applicable to other wildlife disease problems where limited management funds exist.

An economic analysis of Chinese fertility behavior.

This paper is the first to present a Chinese general fertility model that simultaneously controls for the endogeneity of infant mortality and per capita income determination at county level. Using the 1982 Chinese population census data, comprising 2305 observational units, this analysis improves on existing studies in several ways. First, since all the underlying variables are measured at the Chinese county level, we treat both the per capita income and infant mortality rates as endogenous, as opposed to exogenous as assumed in most previous studies on Chinese fertility. Our testing results strongly reject the null hypothesis of the exogeneity of both infant mortality and income determination within our model. Secondly, concerning the hypothesis of nonlinear income effect on fertility behavior, we examine both the variable income-elasticity and constant income-elasticity models. Strong evidence is obtained in support of the variable income elasticity model, predicting a U-shaped income effect on Chinese general fertility. This suggests that a more equitable income distribution leads to a reduction in the Chinese fertility rates. Thirdly, employing the two stage least squares procedure, we find a much stronger positive replacement effect on infant mortality when the endogeneity of infant mortality and income are both controlled for simultaneously. Our results indicate that Chinese general fertility may well be shaped by optimizing behavior.

Carrots and sticks: fertility effects of China's population policies.

For 20 years following 1949, average total fertility per woman in China hovered just above six children. The year 1970 marked the beginning of persistent fertility declines. By 1980, the rate had dropped to 2.75, and since 1992 it has remained under 2. While some of this transition can be accounted for by broad socioeconomic developments, the extent to which it is attributable to China's unique population policies remains controversial. This paper analyzes household data from the 1992 Household Economy and Fertility Survey (HEFS) to provide the first direct microeconomic empirical evidence on the efficacy of these policies.

Time and financial costs of programs for live trapping feral cats.

OBJECTIVE: To determine the time and financial costs of programs for live trapping feral cats and determine whether allowing cats to become acclimated to the traps improved trapping effectiveness. DESIGN: Prospective cohort study. ANIMALS: 107 feral cats in 9 colonies. PROCEDURE: 15 traps were set at each colony for 5 consecutive nights, and 5 traps were then set per night until trapping was complete. In 4 colonies, traps were immediately baited and set; in the remaining 5 colonies, traps were left open and cats were fed in the traps for 3 days prior to the initiation of trapping. Costs for bait and labor were calculated, and trapping effort and efficiency were assessed. RESULTS: Mean +/- SD overall trapping effort (ie, number of trap-nights until at least 90% of the cats in the colony had been captured or until no more than 1 cat remained untrapped) was 8.9 +/- 3.9 trap-nights per cat captured. Mean overall trapping efficiency (ie, percentage of cats captured per colony) was 98.0 +/- 4.0%. There were no significant differences in trapping effort or efficiency between colonies that were provided an acclimation period and colonies that were not. Overall trapping costs were significantly higher for colonies provided an acclimation period. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that these live-trapping protocols were effective. Feeding cats their regular diets in the traps for 3 days prior to the initiation of trapping did not have a significant effect on trapping effort or efficiency in the present study but was associated with significant increases in trapping costs.

Contraceptive vaccines for the humane control of community cat populations.

Free-roaming unowned stray and feral cats exist throughout the world, creating concerns regarding their welfare as well as their impact on the environment and on public health. Millions of healthy cats are culled each year in an attempt to control their numbers. Surgical sterilization followed by return to the environment is an effective non-lethal population control method but is limited in scope because of expense and logistical impediments. Immunocontraception has the potential to be a more practical and cost-effective method of control. This is a review of current research in immunocontraception in domestic cats. Functional characteristics of an ideal immunocontraceptive for community cats would include a wide margin of safety for target animals and the environment, rapid onset and long duration of activity following a single treatment in males and females of all ages, and sex hormone inhibition. In addition, product characteristics should include stability and ease of use under field conditions, efficient manufacturing process, and low cost to the user. Two reproductive antigens, zona pellucida and GnRH, have been identified as possible targets for fertility control in cats. Zona pellucida, which is used successfully in multiple wildlife species, has achieved little success in cats. In contrast, immunization against GnRH has resulted in long-term contraception in both male and female cats following a single dose. GnRH is an ideal contraceptive target because it regulates pituitary and gonadal hormone responses in both males and females, thus suppressing nuisance behaviors associated with sex hormones in addition to preventing pregnancy. The responsiveness of cats to fertility control via GnRH suppression should encourage researchers and cat control stakeholders to continue efforts to optimize vaccines that induce multiyear contraception following a single dose in a high proportion of treated cats.

Contraceptive vaccines for wildlife: a review.

Wildlife, free-ranging and captive, poses and causes serious population problems not unlike those encountered with human overpopulation. Traditional lethal control programs, however, are not always legal, wise, safe, or publicly acceptable; thus, alternative approaches are necessary. Immunocontraception of free-ranging wildlife has reached the management level, with success across a large variety of species. Thus far, the immunocontraceptive research and management applications emphasis have been centered on porcine zona pellucida and gonadotropin-releasing hormone vaccines. Contraceptive success has been achieved in more than 85 different wildlife species, at the level of both the individual animal and the population. At the population management level with free-ranging species, the primary focus has been on wild horses, urban deer, bison, and African elephants. The challenges in the development and application of vaccine-based wildlife contraceptives are diverse and include differences in efficacy across species, safety of vaccines during pregnancy, the development of novel delivery systems for wild and wary free-ranging animals, and the constraints of certain non-contraceptive effects, such as effects on behavior. Beyond the constraints imposed by the public and a host of regulatory concerns, there exists a real limitation for funding of well-designed programs that apply this type of fertility control.

Contraceptive vaccines based on the zona pellucida glycoproteins for dogs and other wildlife population management.

Zona pellucida (ZP) glycoproteins, by virtue of their critical role in fertilization, have been proposed as candidate antigens for the development of contraceptive vaccines. In this review, the potential of a ZP-based contraceptive vaccine for the management of wildlife population, with special reference to street dogs, is discussed. Immunization of various animal species, including female dogs, with native porcine ZP led to inhibition of fertility, which was associated with the ovarian dysfunction. Immunization of female dogs with Escherichia coli-expressed recombinant dog ZP glycoprotein-3 (ZP3) either coupled to diphtheria toxoid or expressed as fusion protein with 'promiscuous' T non-B-cell epitope of tetanus toxoid also led to inhibition of fertility. To improve the contraceptive efficacy of ZP-based contraceptive vaccine, various groups are working on improving the immunogen, use of DNA vaccine as prime-boost strategy, and delivering the zona proteins/peptides presented on either virus-like particles or entrapped in microsphere. Host-specific live vectors such as ectromelia virus and cytomegalovirus have also been used to deliver mouse ZP3 in mice. Various studies show the enormous potential of the ZP-based vaccine for the management of wildlife population, where permanent sterilization may be desirable.

The limits of scientific planning: Doxiadis and the Tehran Action Plan.

Tehran after the Second World War experienced a modernization drive and rapid population growth. In 1972, the Greek planner, Constantinos Doxiadis, who had already undertaken major housing and planning projects in Iran, was invited to prepare an action plan for the city, to guide the future investment for easing the city's problems. Doxiadis saw cities as nightmares, but advocated that a holistic scientific analysis and a naturalist approach to urban growth management could address their problems. In applying his ideas to Tehran, however, the limits of his ideas of scientific planning became evident, not only through contextual pressures, such as lack of time and data, but also through the planning consultant's approach, in which commercial considerations and the application of readymade solutions could shape the outcome. Rather than working with the context, Doxiadis followed the modernist tenet of breaking with the past, proposing the creation of West Tehran, an alternative to the city where all future growth should take place on a utopian basis. The radical nature of his proposals, his death, and a turbulent revolution aborted the impact of his action plan on Tehran, while faith in modernist scientific planning was widely being abandoned.