With rising sea levels at the end of the Pleistocene, land-bridge or continental islands were formed around the world. Many of these islands have been extensively studied from a biogeographical perspective, particularly in terms of impacts of island creation on terrestrial vertebrates. However, a majority of studies rely on contemporary faunal distributions rather than fossil data. Here, we present archaeological findings from the island of Zanzibar (also known as Unguja) off the eastern African coast, to provide a temporal perspective on island biogeography. The site of Kuumbi Cave, excavated by multiple teams since 2005, has revealed the longest cultural and faunal record for any eastern African island. This record extends to the Late Pleistocene, when Zanzibar was part of the mainland, and attests to the extirpation of large mainland mammals in the millennia after the island became separated. We draw on modeling and sedimentary data to examine the process by which Zanzibar was most recently separated from the mainland, providing the first systematic insights into the nature and chronology of this process. We subsequently investigate the cultural and faunal record from Kuumbi Cave, which provides at least five key temporal windows into human activities and faunal presence: two at the end of the Last Glacial Maximum (LGM), one during the period of post-LGM rapid sea level rise and island formation, and two in the late Holocene (Middle Iron Age and Late Iron Age). This record demonstrates the presence of large mammals during the period of island formation, and their severe reduction or disappearance in the Kuumbi Cave sequence by the late Holocene. While various limitations, including discontinuity in the sequence, problematize attempts to clearly attribute defaunation to anthropogenic or island biogeographic processes, Kuumbi Cave offers an unprecedented opportunity to examine post-Pleistocene island formation and its long-term consequences for human and animal communities.
Policymaking is rarely 'evidence-based'. Rather, policy can only be strongly evidence-informed if its advocates act effectively. Policy theories suggest that they can do so by learning the rules of political systems, and by forming relationships and networks with key actors to build up enough knowledge of their environment and trust from their audience. This knowledge allows them to craft effective influencing strategies, such as to tell a persuasive and timely story about an urgent policy problem and its most feasible solution. Empirical case studies help explain when, how, and why such strategies work in context. If analysed carefully, they can provide transferable lessons for researchers and advocates that are seeking to inform or influence policymaking. Oxfam Great Britain has become an experienced and effective advocate of evidence-informed policy change, offering lessons for building effective action. In this article, we combine insights from policy studies with specific case studies of Oxfam campaigns to describe four ways to promote the uptake of research evidence in policy: (1) learn how policymaking works, (2) design evidence to maximise its influence on specific audiences, (3) design and use additional influencing strategies such as insider persuasion or outsider pressure, and adapt the presentation of evidence and influencing strategies to the changing context, and (4) embrace trial and error. The supply of evidence is one important but insufficient part of this story.
. 1997. Cross-shelf processes north of Scotland in relation to the southerly migration of Western mackerel. -ICES Journal of Marine Science, 54: 168-178.A combined acoustic and hydrographic survey was conducted west of Shetland in January 1995. The temperature-salinity structure at the shelf edge north of Scotland was characterised by a narrow (30 km) core of warm, saline water embedded within a broader distribution of Atlantic Water; this would generally mark the area of the shelf-edge current. Current measurements recorded during the period of this survey demonstrated that, uncharacteristically, the core did not mark the area of maximum transport along the shelf break but lay inshore of it. Hence larger scale processes associated with the north-west European shelf edge are important in determining the intermediate scale physical environment encountered by mackerel during their southerly migration to the spawning areas.Acoustic survey data revealed that a large number of the mackerel schools were located in, or close to, this warm saline core at the shelf edge, the remainder being found further inshore. Mackerel school structure varied dramatically between the areas affected by this core and other parts of the survey area. In general, mackerel form large distinct schools in mid-water, and these were seen during the survey in the shelf waters. In the area of the warm core, schools were found deeper, were more diffuse and tended to form elongated thin layers.We present the hypothesis that the change in schooling behaviour reflects whether or not the schools are actively migrating, and that those schools observed in the warm water core were stationary, and those in cooler waters were actively migrating.1997 International Council for the Exploration of the Sea
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.