Supplementary feeding increases Common Buzzard Buteo buteo productivity but only in poor-quality habitat

Temporal heterogeneity in the effects of food supply during the breeding season on the productivity of the Common Buzzard Buteo buteo was investigated in a supplementary feeding experiment. Pairs were fed artificially (1) before egg-laying, (2) after chicks hatched and (3) continuously throughout the season, and compared with (4) unfed controls. Pairs fed before egg-laying had marginally larger clutches than those not fed, but lay date, egg volume and weight, brood size and hatching success were unaffected. Territorial quality had far greater effects, with pairs nesting in low-quality habitats (bog, scrub and semi-natural grassland) laying later and having lower hatching success, smaller broods and fewer fledglings than those in more productive agricultural landscapes. Supplementary feeding after egg hatching neutralized the negative effect of poor habitat, resulting in fed birds having significantly more fledglings. This study emphasizes the importance of food availability when provisioning chicks in suboptimal habitats and has implications for the success of diversionary feeding in reducing game losses to Buzzards.

Scyphozoan jellyfish provide short-term reproductive habitat for hyperiid amphipods in a temperate near-shore environment

Hyperiid amphipods (Order Amphipoda, Suborder Hyperiidea) are known to infest gelatinous zooplankton. However, the temporal backdrop to these associations is less clear, given that data are often gathered during discrete sampling events rather than over time. In general, hyperiids are considered to be pelagic: however, for individuals associated with metagenic jellyfishes in temperate shallow shelf seas, this may not always be the case, as the majority of their gelatinous hosts are present in the water column from spring to the onset of autumn. Here, we explored the temporal patterns of colonisation and overall duration of the association between Hyperia galba and 3 scyphozoan jellyfish species (Aurelia aurita, Cyanea capillata and C. lamarckii) in a temperate coastal system (Strangford Lough, Northern Ireland) during 2010 and 2012. Concomitantly, we used carbon and nitrogen stable isotope ratios to examine whether hyperiid infestation represented a permanent association with their host or was part of a more complex life history. We found that jellyfish were colonised by H. galba ca. 2 mo after they are first observed in the lough and that H. galba reached 100% prevalence in the different jellyfish species shortly before the medusae of each species disappeared from the water column. It is possible that some jellyfish overwintered in deeper water, prolonging the association between H. galba and their hosts. However, all the medusae sampled during the spring and early summer (whether they were newly emerged or had overwintered from the previous season) were not infected with hyperiids, suggesting that such behaviour was uncommon or that individuals had become dissociated from their host during the winter. Further evidence of temporary association came from stable isotope data, where δ13C and δ15N isotope ratios were indicative of feeding outside of their host prior to jellyfish colonisation. In combination, these findings suggest alternating habitat associations for H. galba, with the amphipods spending the majority of the year outside of the 3 scyphozoan species considered here.

Spatio-temporal Change in Crowned (Propithecus coronatus) and Decken’s Sifaka (Propithecus deckenii) Habitat in the Mahavavy-Kinkony Wetland Complex, Madagascar.

The crowned sifaka (Propithecus coronatus) and Decken’s sifaka (Propithecus deckenii) are Endangered lemurs endemic to west and central Madagascar. Both have suffered habitat loss and fragmentation throughout their ranges. The goal
of this study, conducted in the Mahavavy-Kinkony Wetland Complex (MKWC) in northwestern Madagascar, was to assess the effects of historical change in the species’ habitats, and to model the potential impact of further land-use change on their habitats. The IDRISI Andes Geographical Information System and image-processing software was used for satellite-image classifiation, and the Land Change Modeler was used to compare the natural habitat of the species from 1973 to 2005, and to predict available habitat for 2050. We analyzed two forests in the MKWC occupied by P. coronatus (Antsilaiza and Anjohibe), and three forests occupied by P. deckenii (Tsiombikibo, Marofandroboka and Andohaomby). The two forests occupied by P. coronatus contracted during the period 1949–1973, but then expanded to exceed their 1949 area by 28% in 2005. However, the land change model predicted that they will contract again to match their 1949 area by 2050, and will again lose their corridor connection, meaning that the conservation gains for this species in the complex are at risk of being reversed. The three forests occupied by P. deckenii have declined in area steadily since 1949, losing 20% of their original area by 2005, and are predicted to lose a further 15% of their original area by 2050. Both species are therefore at risk of becoming even more threatened if land-use change continues within the complex. Improved conservation of the remaining forest is recommended to avoid further loss, as well as ecological restoration and reforestation to promote connectivity between the forests. A new strategy for controlling agriculture and forest use is required in order to avoid further destruction of the forest.

Ecological dynamics of extinct species in empty habitat networks. 1. The role of habitat pattern and quantity, stochasticity and dispersal

We examined a remnant host plant (Primula veris L.) habitat network that was last inhabited by the rare butterfly Hamearis lucina L. in north Wales in 1943, to assess the relative contribution of several spatial parameters to its regional extinction. We first examined relationships between P. veris characteristics and H. lucina eggs in surviving H. lucina populations, and used these to predict the suitability and potential carrying capacity of the habitat network in north Wales. This resulted in an estimate of roughly 4500 eggs (ca 227 adults). We developed a discrete space, discrete time metapopulation model to evaluate the relative contribution of dispersal distance, habitat and environmental stochasticity as possible causes of extinction. We simulated the potential persistence of the butterfly in the current network as well as in three artificial (historical and present) habitat networks that differed in the quantity (current and X3) and fragmentation of the habitat (current and aggregated). We identified that reduced habitat quantity and increased isolation would have increased the probability of regional extinction, in conjunction with environmental stochasticity and H. lucina's dispersal distance. This general trend did not change in a qualitative manner when we modified the ability of dispersing females to stay in, and find suitable habitats (by changing the size of the grid cells used in the model). Contrary to most metapopulation model predictions, system persistence declined with increasing migration rate, suggesting that the mortality of migrating individuals in fragmented landscapes may pose significant risks to system-wide persistence. Based on model predictions for the present landscape we argue that a major programme of habitat restoration would be required for a re-established metapopulation to persist for > 100 years.

Ecological dynamics of extinct species in empty habitat networks. 2. The role of host plant dynamics

This paper explores the relative effects of host plant dynamics and butterfly-related parameters on butterfly persistence. It considers an empty habitat network where a rare butterfly (Cupido minimus) became extinct in 1939 in part of its historical range in north Wales, UK. Surviving populations of the butterfly in southern Britain were visited to assess use of its host plant (Anthyllis vulneraria) in order to calibrate habitat suitability and carrying capacity in the empty network in north Wales. These data were used to deduce that only a portion ( similar to 19%) of the host plant network from north Wales was likely to be highly suitable for oviposition. Nonetheless, roughly 65,460 eggs (3273 adult equivalents) could be expected to be laid in north Wales, were the empty network to be populated at the same levels as observed on comparable plants in surviving populations elsewhere. Simulated metapopulations of C. minimus in the empty network revealed that time to extinction and patch occupancy were significantly influenced by carrying capacity, butterfly mean dispersal distance and environmental stochasticity, although for most reasonable parameter values, the model system persisted. Simulation outputs differed greatly when host plant dynamics was incorporated into the modelled butterfly dynamics. Cupido minimus usually went extinct when host plant were at low densities. In these simulations host plant dynamics appeared to be the most important determinant of the butterfly's regional extirpation. Modelling the outcome of a reintroduction programme to C. minimus variation at high quality locations, revealed that 65% of systems survived at least 100 years. Given the current amount of resources of the north Wales landscape, the persistence of C. minimus under a realistic reintroduction programme has a good chance of being successful, if carried out in conjunction with a host plant management programme.

Comparison of granulometric methods and sampling strategies used in marine habitat classification and Ecological Status assessment

Sediment particle size analysis (PSA) is routinely used to support benthic macrofaunal community distribution data in habitat mapping and Ecological Status (ES) assessment. No optimal PSA Method to explain variability in multivariate macrofaunal distribution has been identified nor have the effects of changing sampling strategy been examined. Here, we use benthic macrofaunal and PSA grabs from two embayments in the south of Ireland. Four frequently used PSA Methods and two common sampling strategies are applied. A combination of laser particle sizing and wet/dry sieving without peroxide pre-treatment to remove organics was identified as the optimal Method for explaining macrofaunal distributions. ES classifications and EUNIS sediment classification were robust to changes in PSA Method. Fauna and PSA samples returned from the same grab sample significantly decreased macrofaunal variance explained by PSA and caused ES to be classified as lower. Employing the optimal PSA Method and sampling strategy will improve benthic monitoring. © 2012 Elsevier Ltd.

Behaviour-time budget and functional habitat use of a free-ranging European badger (Meles meles)

Background: The European badger (Melesmeles) is involved in the maintenance of bovine tuberculosis infection and onward spread to cattle. However, little is known about how transmission occurs. One possible route could be through direct contact between infected badgers and cattle. It is also possible that indirect contact between cattle and infected badger excretory products such as faeces or urine may occur either on pasture or within and around farm buildings. A better understanding of behaviour patterns in wild badgers may help to develop biosecurity measures to minimise direct and indirect contact between badgers and cattle. However, monitoring the behaviour of free-ranging badgers can be logistically challenging and labour intensive due to their nocturnal and semi-fossorial nature.We trialled a GPS and tri-axial accelerometer-equipped collar on a free-ranging badger to assess its potential value to elucidate behaviour-time budgets and functional habitat use. Results: During the recording period between 16:00 and 08:00 on a single night, resting was the most commonly identified behaviour (67.4%) followed by walking (20.9%), snuffling (9.5%) and trotting (2.3%).When examining accelerometer data associated with each GPS fix and habitat type (occurring 2 min 30 s before and after), walking was themost common behaviour in woodland (40.3%) and arable habitats (53.8%), while snuffling was themost common behaviour in pasture (61.9%). Several nocturnal resting periods were also observed. The total distance travelled was 2.28 km. Conclusions: In the present report, we demonstrate proof of principle in the application of a combined GPS and accelerometer device to collect detailed quantitative data on wild badger behaviour. Behaviour-time budgets allow us to investigate how badgers allocate energy to different activities and how thismight change with disease status. Such information could be useful in the development of measures to reduce opportunities for onward transmission of bovine tuberculosis from badgers to cattle.

Habitat-species interactions in a carnivore community

Na maioria das area protegidas nacionais existe uma considerável falta de informação científica relativa aos mamíferos carnívoros. A Reserva Natural da Serra da Malcata, localizada no centro-este de Portugal, tem vindo a desenvolver, desde os últimos 20 anos, estudos de ecologia e esta tese pretende dar seguimento a esse esforço de monitorização, através do desenvolvimento de métodos simples e eficientes, de monitorização de carnívoros, que possam servir como percursores de trabalhos a longo-prazo em áreas relevantes para a conservação. Através do uso de armadilhagem fotográfica, foram estudadas relações espécies-habitats para 5 espécies: gato-bravo (Felis silvestris), fuinha (Martes foina), raposa (Vulpes vulpes), gineta (Genetta genetta), e sacarrabos (Herpestes ichneumon). Foram desenvolvidos métodos para se determinar a densidade absoluta de raposa e gineta e a população de gato-bravo foi estudada em detalhe. As principais conclusões do estudo foram: 1) a ocupação de raposas é uniforme e parece ser independente de variáveis ambientais; 2) a ocupação de fuinha encontra-se relacionada com variáveis de habitat, estrutura paisagística e presas; 3) a ocupação de gineta está relacionada com a cobertura de folhosas e distribuição de presas; 4) para o sacarrabos verificase que a ocupação é influenciada pelas extensões de habitat arbustivos, 5) a população de gato-bravo sofreu um forte declínio durante o trabalho e requer urgentes medidas de conservação. Metodologicamente foi demonstrada a importância da modelação das probabilidades de detecção para espécies para as quais este parâmetros apresenta valores baixos ou é muito variável. Esta tese também demonstrou a grande importância da Serra da Malcata para a conservação de carnívoros e a necessidade do desenvolvimento de técnicas de monitorização padronizadas para uma correcta gestão adaptativa das áreas protegidas.

Habitat use and diel vertical migration of bigeye thresher shark: overlap with pelagic longline fishing gear

Pelagic longliners targeting swordfish and tunas in oceanic waters regularly capture sharks as bycatch, including currently protected species as the bigeye thresher, Alopias superciliosus. Fifteen bigeye threshers were tagged with pop-up satellite archival tags (PSATs) in 2012-2014 in the tropical northeast Atlantic, with successful transmissions received from 12 tags for a total of 907 tracking days. Marked diel vertical movements were recorded on all specimens, with most of the daytime spent in deeper colder water (mean depth = 353 m, SD = 73; mean temperature = 10.7 °C, SD = 1.8) and nighttime spent in warmer water closer to the surface (mean depth = 72 m, SD = 54; mean temperature = 21.9 °C, SD = 3.7). The operating depth of the pelagic longline gear was measured with Minilog Temperature and Depth Recorders (TDRs), and the overlap with habitat utilization was calculated. Overlap is taking place mainly during the night and is higher for juveniles. The results presented herein can be used as inputs for Ecological Risk Assessments for bigeye threshers captured in oceanic tuna fisheries, and serve as a basis for efficient management and conservation of this vulnerable shark species.

Modeling the suitable habitat of a structural red gorgonian species in the Mediterranean/east Atlantic regions predicts a wider distribution than previously known

Dissertação de mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Univerdade do Algarve, 2015

Identifying the Influence of Channel Morphology on Physical Habitat Availability for Native Fish: Application to the Two-spined Blackfish (Gadopsis bispinosus) in the Cotter River, Australia.

The impact of channel morphology and flow on physical habitat availability for the two-spined blackfish (Gadopsis bispinosus) was assessed in the Cotter River, ACT, Australia. Physical habitat requirements for three life stages were identified based on previous field sampling in the Cotter River. Two sites were selected with contrasting channel morphology: Spur Hole, with a moderate gradient and runs and glides, and Vanity’s Crossing, with a steeper gradient, rapids, and fast-flowing pools. Physical Habitat Simulation System (PHABSIM) was used to simulate the flow v. physical habitat availability relationship for each life stage at both sites. Clear differences were apparent between sites, with Spur Hole characterised by increasing habitat with increasing flow and Vanity’s Crossing showing the opposite relationship. The nature of the channel morphology determined this difference, with Spur Hole characterised by marginal zones becoming inundated at higher flows and providing additional suitable physical habitat as discharge increases. Vanity’s Crossing does not contain similar marginal zones. Further analysis demonstrated that high water velocity was the most important factor limiting physical habitat availability at both sites. This approach demonstrates the importance of channel morphology in determining physical habitat availability and an alternative use of PHABSIM to highlight limiting factors for target species.

Analysis of zooplankton species composition and depth-based habitat preference in Nootka Sound, B.C., Canada

Senior thesis written for Oceanography 445

The trade specialization of SANE: evidence from manufacturing industries

This paper studies the evolution of the foreign trade specialization in manufacturing sectors of South Africa, Algeria, Nigeria and Egypt. These four countries, the so-called SANE, have recently been viewed as Africa’s best chance of producing an economic bloc whose role for Africa might be comparable to that of the BRIC economies of Brazil, Russia, India and China for the world economy. Using data on trade flows since mid-1970s, the results show that the SANE group has experienced few changes in its trade structure, which is still based on low-technology and slow-growth world demand sectors. The degree of persistence in the specialization model is higher in the case of Algeria and Nigeria, where the dependence on products based on natural resources is stronger.