Origin and timing of New Zealand’s earliest domestic chickens: Polynesian commensals or European introductions?

Human settlers transported chickens (Gallus gallus domesticus) to most East Polynesian archipelagos between AD 1000 and 1300; however, it has long been assumed that New Zealand was an exception. Despite the fact that chicken bones have been recovered from localities of early archaeological middens in New Zealand, their age and genetic relationships have never been critically assessed. Here, we test the assumption that chickens were not introduced to New Zealand during prehistory through ancient DNA and radiocarbon analyses of chicken bones from sites of Māori middens containing prehistoric material. The chickens belong to the widespread mitochondrial control region haplogroup E. Radiocarbon dating reveals that the bones are not prehistoric, but are still the earliest chicken remains known from New Zealand. Two of the bones pre-date permanent European settlement (ca 1803s onwards) but overlap with the arrival of James Cook's second voyage (1773-1774), and, therefore, they are likely to be chickens, or progeny thereof, liberated during that voyage. Our results support the idea that chickens were first introduced to New Zealand by Europeans, and provide new insights into Māori uptake and integration of resources introduced during the early post-European period.Jamie R. Wood, Michael J.B. Herrera, R. Paul Scofield and Janet M. Wilmshurs

High-resolution coproecology: Using coprolites to reconstruct the habits and habitats of New Zealand’s extinct upland Moa (Megalapteryx didinus)

Knowledge about the diet and ecology of extinct herbivores has important implications for understanding the evolution of plant defence structures, establishing the influences of herbivory on past plant community structure and composition, and identifying pollination and seed dispersal syndromes. The flightless ratite moa (Aves: Dinornithiformes) were New Zealand's largest herbivores prior to their extinction soon after initial human settlement. Here we contribute to the knowledge of moa diet and ecology by reporting the results of a multidisciplinary study of 35 coprolites from a subalpine cave (Euphrates Cave) on the South Island of New Zealand. Ancient DNA analysis and radiocarbon dating revealed the coprolites were deposited by the extinct upland moa (Megalapteryx didinus), and span from at least 6,368±31 until 694±30 ¹⁴C years BP; the approximate time of their extinction. Using pollen, plant macrofossil, and ancient DNA analyses, we identified at least 67 plant taxa from the coprolites, including the first evidence that moa fed on the nectar-rich flowers of New Zealand flax (Phormium) and tree fuchsia (Fuchsia excorticata). The plant assemblage from the coprolites reflects a highly-generalist feeding ecology for upland moa, including browsing and grazing across the full range of locally available habitats (spanning southern beech (Nothofagus) forest to tussock (Chionochloa) grassland). Intact seeds in the coprolites indicate that upland moa may have been important dispersal agents for several plant taxa. Plant taxa with putative anti-browse adaptations were also identified in the coprolites. Clusters of coprolites (based on pollen assemblages, moa haplotypes, and radiocarbon dates), probably reflect specimens deposited at the same time by individual birds, and reveal the necessity of suitably large sample sizes in coprolite studies to overcome potential biases in diet interpretation

Grassland heterogeneity under grazing and protection management regimes in the mixed prairie ecosystem

Non-Peer ReviewedGrassland heterogeneity, in terms of spatial pattern, vertical structure, and species composition, is an important indicator of wildlife habitat. Aimed to restore ecological integrity of native prairie, the Grasslands National Park newly approved management plan consists of reintroducing large animals at moderate and intensive grazing densities into the park. Park managers are eager to have a fast and cost effective way to monitor the effects of the new management practices after the park has been under complete protection for over 15 years. This study was proposed to investigate the potential use of remotely sensed data for this purpose. As an ongoing project, a solid conclusion couldn’t be made at this moment. With preliminary results, a new framework was discussed for further analysis

Application of Radarsat imagery on grassland heterogeneity assessment

Non-Peer ReviewedHeterogeneity, the degree of dissimilarity, is one of the most important and widely applicable concepts in ecology. It is highly related to ecosystem condition and wildlife habitat. In this study, the feasibility of applying Radarsat-1 HH polarization Synthetic Aperture Radar (SAR) image on heterogeneity study is tested on the Grasslands National Park (GNP) and surrounding pastures. GNP is located in southern Saskatchewan along the international boundary of Canada and the United States, which represents northern mixed grasslands. Fieldwork was conducted at GNP and surrounding pastures from June to July, 2003. Biophysical variables including species composition, cover, biomass, and canopy height were collected from 10 sites. Height heterogeneity index, Shannon’s index, and standard deviation were calculated based on field data. One standard mode Radarsat-1 HH image acquired on August 1, 2003 was used for this study. Parameters from texture analysis and standard deviation of the backscatters are correlated with biophysical parameters to measure grasslands heterogeneity. Results showed that different parameters had various abilities to detect field heterogeneity. Correlation showed the highest ability to explain variation of bareground cover (79%). Mean and contrast can also be utilized to explain the variation of grass biomass and standing dead cover (59% and 56% respectively)

Experimental simulation: using generative modeling and palaeoecological data to understand human-environment interactions

The amount of palaeoecological information available continues to grow rapidly, supporting improved descriptions of the dynamics of past ecosystems and enabling them to be seen from new perspectives. At the same time, there has been concern over whether palaeoecological enquiry needs to move beyond descriptive inference to a more hypothesis-focussed, or experimental approach. However, the extent to which conventional hypothesis-driven scientific frameworks can be applied to historical contexts (i.e., the past) is the subject of ongoing debate. In other disciplines concerned with human-environment interactions, including physical geography and archaeology, there has been growing use of generative simulation models, typified by agent-based approaches. Generative modeling encourages counter-factual questioning (“what if…?,”) a mode of argument that is particularly important in systems and time-periods, such as the Holocene, and now the Anthropocene, where the effects of humans and other biophysical processes are deeply intertwined. However, palaeoecologically focused simulation of the dynamics of the ecosystems of the past either seems to be conducted to assess the applicability of some model to the future or treats humans simplistically as external forcing factors. In this review we consider how generative simulation-modeling approaches could contribute to our understanding of past human-environment interactions. We consider two key issues: the need for null models for understanding past dynamics and the need to be able learn more from pattern-based analysis. In this light, we argue that there is considerable scope for palaeoecology to benefit from developments in generative models and their evaluation. We discuss the view that simulation is a form of experiment and by using case studies, consider how the many patterns available to palaeoecologists can support model evaluation in a way that moves beyond simplistic pattern-matching and how such models might also inform us about the data themselves and the processes generating them. Our emphasis is on how generative simulation might complement traditional palaeoecological methods and proxies rather than on a detailed overview of the modeling methods themselves

On the Scale Dependence of Foraging in Terrestrial Herbivores

Meaningful modeling of the spatial and trophic dynamics of terrestrial herbivores demands understanding of the constraints and fitness objectives that presumably underlie behavior. This is complex in terrestrial herbivores, because of scale-dependent constraints on nutrient or energy gain. Mechanistic processes of forage cropping, forage mastication, movements between feeding stations, and forage digestion each have unique constraints that apply on different time, size, and spatial scales. Moreover, competing activities are rarely taken into account. Experimental testing of foraging objectives is therefore clouded by uncertainty regarding which time scale is most relevant from the animal’s perspective, leading to confusion and misrepresentation in the foraging literature. We illustrate these arguments from both theoretical and empirical points of view, based on our work with wild ungulates as well as the contemporary literature

Tuberous sclerosis complex in the Western Cape, South Africa: The clinical presentation features

Tuberous sclerosis complex (TSC) is a genetic neurocutaneous condition, which affects multiple organ systems. This study aimed to determine the presenting features of children with TSC in Cape Town, South Africa. A cross-sectional study was conducted at a TSC clinic, and clinical features at presentation were prospectively collected. Thirty-nine children (23 boys; median age 10 (range 1 - 26) years; median diagnosis age 16 (0 - 153) months) were recruited. Twenty-one (54%) children presented with focal seizures. Seven (18%) children had epileptic spasms. Skin manifestations led to a diagnosis in 13 (33%) and neuroimaging in 22 (56%) children. Antenatal screening detected cardiac rhabdomyomas in 3 children. One child had a positive family history. In the paediatric service, TSC diagnosis usually followed neuroimaging, whereas at the neurology service skin manifestations indicated TSC. In conclusion, most children with TSC presented as emergency cases with seizures. Health practitioner awareness of the common TSC clinical signs was lacking, with the diagnosis often delayed

The African Hospitalist Fellowship

The African Paediatric Fellowship Programme is rolling out a training course for newly qualified paediatricians to equip them with the leadership skills to function in complex general paediatric settings. The care of children in Africa carries its own unique demands, from the layering effects of multiple conditions through to establishing and sustaining services under severe resource constraints. This novel training concept aims to strengthen confidence and knowledge in areas that are not priorities during standard general paediatric training. The skills gained are considered of great relevance in assisting general paediatricians to achieve their full potential in their careers