Lawrence A. Sawchuk

Demography ofMacaca sylvanus of Gibraltar

The demographic structure ofMacaca sylvanus (Gibraltar) is analyzed over a 21 year period in light of human interference on this population. Social behaviour is examined in terms of its influence on the parameters investigated. The findings lead to speculations concerning the nature of homeostatic processes operating in a non-wild group.

Birth Intervals inM. sylvanus of Gibraltar

The length of the birth interval inMacaca sylvanus of Gibraltar was defined and one-year intervals were found to be normative. The effect of infant loss on the interbirth interval was assessed and found to have no influence.Variability in the birth interval in comparable species is noted.

Brief communication: Rethinking the impact of the 1918 influenza pandemic on sex differentials in mortality.

This study will assess the general impact of the 1918 influenza on overall mortality and its impact on mortality attributable to pulmonary tuberculosis in a small-scale population. Using life table and decomposition methodologies, changes in mortality in Gibraltar used a scheme that identified a pre-epidemic period (1904-1917), the epidemic year (1918), and the post-epidemic period (1919-1927). Overall health in both sexes fell significantly in 1918 with a drop in life expectancy at birth, however, health quickly rebounded in the post-epidemic period. In the case of women, there was a significant increase in life expectancy at birth after the epidemic. The impact of influenza on the magnitude of sex differentials in the life expectancy at birth fell during epidemic year but returned to a level comparable to that of the pre-epidemic period. With respect to respiratory tuberculosis deaths, the immediate impact of influenza was restricted to only a significant increase in the rate among women (aged 15-54). In the post-epidemic period, tuberculosis mortality rates returned to the pre-epidemic state in both sexes. The findings from Gibraltar stand in contrast opposition to results reported for experience in the United States during the 1918 flu.

Tuberculosis mortality and recent childbirth: a retrospective case-control study of Gibraltarian women, 1874–1884

Prior to the introduction of effective treatment for pulmonary tuberculosis, there was little consensus on the potential health risk of pregnancy among infected women. While, intuitively, pregnancy was viewed as a risk for tuberculosis disease and mortality, early studies could not establish such a link with any great certainty. Our case study combines the methods of family reconstitution and a case-control approach to explore the possibility that the physiological and social strains of recent childbirth and the early mothering of infants may have been risk factors in adult female tuberculosis mortality in late 19th-century Gibraltar. The study is based on 244 reproductive age women who died between 1874 and 1884; some 55% of these deaths were attributed to tuberculosis. The record linkage indicates that almost 12% of the women who died had given birth within the year preceding their death. Factoring in the effects of age at death, marital status, and religion, the logistic regression results indicate that recent childbirth did not increase the risk of tuberculosis mortality among these women.

A MATTER OF PRIVILEGE: INFANT MORTALITY IN THE GARRISON TOWN OF GIBRALTAR, 1870-1899

The British colony of Gibraltar offers an opportunity to compare the infant mortality rates of the civilian and military populations inhabiting a small-scale urban setting from 1870 to 1899. Both groups shared the same poor-quality housing, the same sanitary infrastructure, and the same environmental inseparability. Sufficient water supply, in particular, proved to be a daily struggle for the families living on the Rock. Privilege for the military meant that service families had preferential access to a pure water supply after the installation of a water-condensing plant as well as to a better quality supply of water and milk. The availability of these privileges to one group, and not the other, is associated with a marked decline in infant mortality in the second half of the study period.

The Jewish Advantage and Household Security: Life Expectancy among 19th Century Sephardim of Gibraltar

Using the historical population of Gibraltar to examine the pattern of mortality of Jews and Roman Catholics revealed that: (1) the Jews exhibited a significantly better health status as measured by life expectancy at birth (47.66 and 47.56 for Jewish males and females vs. 38.10 and 40.89 for Catholics males and females, respectively), (2) most of the disparity is found in the very young age categories and (3) the significantly lower rates of deaths could be attributed to the diarrheal and nutritional complex. Stage two of the research involved the linkage of deaths over a 7-year period relative to their household context as of 1878. Being Jewish, having a servant, having access to a water well in the tenement and residing in a tenement only with other Jews, were all factors that contributed to a higher life expectancy. Our explanation for the enhanced survivorship among the Jews is grounded in economics as well as in an established welfare system, in religious precepts and in secular knowledge of health. One of the more notable and hitherto unobserved findings is that Roman Catholics residing in the same tenements with Jews enjoyed a distinct health advantage. This suggests that a positive amplification effect arose from their co-residence with the Jews.

Situating mortality: quantifying crisis points and periods of stability.

A wide range of stressors can cause a dramatic and sudden rise in the death rate in populations, typically resulting in what is referred to as crisis mortality. Here we present a method to standardize the assessment of identifying moments of crises. A modification of the mortality Z-score methodology which is combined with time series analysis was used to investigate mortality events over the course of nearly two centuries for two populations: Gibraltar and Malta. A benefit of this method is that it situates the yearly death rate within the prevailing mortality pattern, and by doing so allows the researcher to assess the relative impact of that event against the norm for the period under investigation. A series of threshold values were established to develop levels of mortality to distinguish moments of lower mortality than expected, background mortality, a crisis, and a catastrophe. Our findings suggested that within defined periods, a limited number of events constituted moments of excessive mortality in the range of a crisis or higher. These included epidemics (yellow fever and influenza in Gibraltar only, and cholera) and casualties associated with World War II. Episodes of lower than expected mortality were only detected (although not significant) in the 20th century in Malta, and at the micro level, the harvesting effect appears to have occurred following cholera epidemics in both locations and influenza in Gibraltar. The analysis demonstrates clearly that the impact of epidemics can be highly variable across time and populations.

Alien encounters: The jus soli and reproductive politics in the 19th-century fortress and colony of Gibraltar

In a place where land was scarce and military security paramount, population growth was perceived as Gibraltars most insidious curse. While British law protected the rightful residence of those who were recognized by the early 19th century definition of Gibraltar “native,” colonial authorities realized that the local population was also increasing by other means. The tenet of the jus soli became one of Gibraltars most notable weaknesses in attempting to control local population growth. Laws were enacted in a patchwork fashion, attempting to defeat any loopholes that might encourage large-scale immigration and the birth of alien offspring on the Rock. So far as alien/alien unions were concerned, the laws were straightforward, but problems ultimately arose for those local women and men who married aliens and who intended to remain in Gibraltar. Concerns over alien contributions to population growth seemed to reach crisis proportions in the 1860s and 1870s, but thereafter the burdens and difficulties imposed on that portion of the local population that opted to marry out eased substantially under the authority of a new governor.

THE GENETIC IMPLICATIONS OF EFFECTIVE POPULATION SIZE FOR THE BARBARY MACAQUE IN GIBRALTAR

The structure and dynamics of the present population of Barbary macaques in Gibraltar have already been described in Fa (Chap, 11, this volume). The purpose of this paper is to examine the genetic composition of the population with regard to its health and future conservation.

“Voluntariness of Exposure”: Life in a Convict Station

Convict Stations were commonplace during the 19th century. Despite the fact that thousands of prisoners of the British Empire served out their sentences under deplorable conditions, scant information exists on the health of these men. Using Gibraltar’s Convict Station as a case study, a profile of life of the convicts is documented. An examination of the health profile of the prisoners for the period from 1860 to 1873 suggests that their overall health status was similar to that of the military, another transient group resident on the Rock. However, during the cholera epidemic of 1865, the health of the convicts was severely compromised with significantly higher attack and mortality rates. Factors responsible for the higher rates can be attributed to a cluster of vulnerabilities that were intrinsic to the convict way of life where exposure to a host of risk factors played out during a compressed period of time.