The land of parrots

An increasingly important contributor to the low fertility characteristic of many western societies now experiencing ‘the second demographic transition’ has been the availability of legal pregnancy termination, so much so that national rates of one abortion for every four or five births are not uncommon. Prior to the passage of the 1967 Act legalising abortion in the UK, abortion in Scotland was not actually illegal, but its availability was extremely limited in most areas outside the northeast. Although uptake had increased dramatically in all regions by the mid 1990s, inter‐regional differences in abortion rates remained pronounced. This paper charts regional changes in uptake rates through the period 1974–96 then outlines and tests the effectiveness of ecological models involving socio‐demographic and health‐service related variables in accounting for variations in abortion rates across the thirteen Scottish Health Board regions in 1996. Although deprivation levels, marital and educational status are significantly involved, regional variations in consultant attitudes and professional practice seem also to be important. If the move to free up the availability of the ‘morning‐after pill’ is accepted throughout Scotland such differentials may soon disappear.     

Historical ecology of late Holocene sea otters (Enhydra lutris) from northern British Columbia: isotopic and zooarchaeological perspectives

We examined the isotopic composition (δ¹³C and δ¹⁵N) of sea otter (Enhydra lutris) bone collagen from ten late Holocene (ca. 5200 years BP–AD 1900) archaeological sites in northern British Columbia (BC), Canada. Because sea otters are now extinct from much of this region and have not fully recolonized their former range (e.g. Haida Gwaii and most of northern BC) these data represent an important first step towards better understanding sea otter foraging ecology in BC. The isotopic data suggest a diet composed primarily of benthic invertebrates, with a very low reliance on epibenthic fish. There is very low isotopic and thus inter-individual dietary variability in Holocene BC sea otters during the late Holocene. Furthermore, zooarchaeological abundance data suggest that otters represented a widespread and significant focus of aboriginal hunting practices on the northern BC coast during the mid- to late-Holocene. The consistent reliance on a small number of low-trophic level prey and limited dietary variability in Holocene BC sea otters may reflect top-down impacts on otter populations by aboriginal peoples. As part of our assessment of sea otter diet, we review trophic discrimination factors (Δ¹³C and Δ¹⁵N) for bone collagen from published literature and find marked variability, with mean values of +3.7 ± 1.6 for Δ¹³C (n = 21) and +3.6 ± 1.3 for Δ¹⁵N (n = 15).     

Variation in the taphonomic effect of scavengers in semi‐arid Australia linked to rainfall and the El Niño Southern Oscillation

Scavenging is one of the primary taphonomic processes shaping the final composition of fossil faunal assemblages. The taphonomic effect of scavengers is variable and must be understood in the context of the causes of that variation. In this study, we investigated relationships between the El Niño Southern Oscillation (ENSO), variable rainfall and scavenging on 20–40 kg mammal carcasses in semi‐arid New South Wales over four years. Following periods of above‐average rainfall (coincident with the La Niña phase of the ENSO), there was an increased availability of non‐carrion food and scavenging activity was moderate. Following below‐average rainfall (coincident with the El Niño phase of the ENSO), foraging options diminished, leading to a greater importance of carrion in the diet of scavengers and a resultant increase in carcass disturbance, transport and destruction by scavengers. Feral pigs (Sus scrofa) and red foxes (Vulpes vulpes) were the most taphonomically significant scavengers in the study. Australian ravens (Corvus coronoides) and wedge‐tailed eagles (Aquila audax) were active scavengers throughout the period of the study, but had little impact on bone survival. Lace monitors (Varanus varius) also fed mostly on soft tissue and were only present seasonally. We found that climate variability in the form of short‐term oscillation can result in significant variation in the impact of scavengers on carcasses and may be an important consideration when evaluating site formation scenarios and biases in fossil faunal assemblages. Copyright © 2006 John Wiley & Sons, Ltd.     

Weather variability and conflict forecasts: Dynamic human-environment interactions in Kenya

While conflict prediction has gained considerable attention in recent years, the existing literature has relied mainly upon aggregated data for large administrative areas or even entire countries. Such approaches obscure significant geographic variation of conflict dynamics based on household and individual experiences. Conflicts are highly localized, shaped by social and economic contexts that vary across space and change throughout time. We predict two types of conflict reported by respondents in a 2018 Kenyan population survey (N = 1,400) using an identical survey carried out in 2014 in the same enumeration areas (sample locations). We use a conditional random forest (CRF) machine learning method for forecasting. Due to heavy reliance on agriculture in Kenya, we expect that adding weather variability and vegetation health (“environmental”) predictors to a CRF model with 29 demographic and contextual variables will improve the performance of our baseline forecasts. Against our expectations, adding environmental predictors does not enhance our 2018 predictions. Models with only environmental data have the worst fit. A logical extension of many “climate-conflict” studies is that environmental data should improve our ability to predict the location and timing of conflict, yet we find that they generally do not. We interpret this finding through the lens of human-environment interactions research developed in human geography and political ecology. These studies similarly emphasized that circumstantial and historical political, economic, and social relationships have greater credibility for understanding conflict than the weather.