Translocations of eight species of burrow-nesting seabirds (genera Pterodroma, Pelecanoides, Pachyptila and Puffinus: Family Procellariidae)

Development of seabird translocation techniques is required to meet species recovery objectives, to improve conservation status, and to restore ecological processes. During 1997-2008 we undertook translocation trials on eight petrel species of four genera within the New Zealand region: common diving petrel (Pelecanoides urinatrix), fairy prion (Pachyptila turtur), grey-faced petrel (Pterodroma macroptera gouldi), Pycroft’s petrel (Pterodroma pycrofti), Chatham petrel (Pterodroma axillaris), Chatham Island taiko (Magenta petrel; Pterodroma magentae), fluttering shearwater (Puffinus gavia), and Hutton’s shearwater (Puffinus huttoni). A total of 1791 chicks within 5 weeks of fledging were moved up to 240 km, placed in artificial burrows and hand-fed until they fledged. Of these, 1546 fledged, and so far at least 68 have returned as adults to the translocation sites. Most birds were crop-fed a puree based on tinned sardines and fresh water. This diet worked well for all species regardless of their typical natural diet (planktonic crustaceans, squid, or fish) with all species fledging above or close to mean natural fledging weights.     

Local perceptions of jaguars (Panthera onca) and pumas (Puma concolor) in the Iguaçu National Park area, south Brazil

Jaguars (Panthera onca) have been killed by local residents within the boundaries and lands surrounding Iguaçu National Park (INP), Brazil. Both jaguars and pumas (Puma concolor) occur in the region, however, livestock predation by pumas has rarely been reported. Our objective was to assess the local perceptions about jaguars and pumas. We identified two major factors that distinguished the perceptions towards the two species: less people feared the puma than the jaguar; and most people believed that jaguars, but not pumas, were released into INP by local authorities. Interestingly, despite those major differences in these perceptions, feelings towards the two species tended to be the same. Perceptions towards jaguars were not influenced by the predation history of the properties, suggesting that the predation impact was not remarkable enough to influence local perceptions towards carnivores. This is apparently the first study on local perceptions towards large carnivores in Brazil.     

Accumulation of specific flavonoids in soybean (Glycine max (L.) Merr.) as a function of the early tripartite symbiosis with arbuscular mycorrhizal fungi and Bradyrhizobium japonicum (Kirchner) Jordan

This study is the first report assessing the effect of soil inoculation on the signalling interaction of Bradyrhizobium japonicum, arbuscular mycorrhizal fungi (AMF) and soybean plants throughout the early stages of colonisation that lead to the tripartite symbiosis. In a study using soil disturbance to produce contrasting indigenous AMF treatments, the flavonoids daidzein, genistein and coumestrol were identified as possible signals for regulating the establishment of the tripartite symbiosis. However, it was unclear whether soil disturbance induced changes in flavonoid root accumulation other than through changing the potential for AMF colonization. In this study, soil treatments comprising all possible combinations of AMF and B. japonicum were established to test whether (1) modifications in root flavonoid accumulation depend on the potential for AMF colonization, and (2) synthesis and accumulation of flavonoids in the roots change over time as a function of the early plant-microbial interactions that lead to the tripartite symbiosis. The study was comprised of two phases. First, maize was grown over 3-week periods to promote the development of the AM fungus Glomus clarum. Second, the interaction between soybean, G. clarum and B. japonicum was evaluated at 6, 10, 14 and 40 days after plant emergence. Root colonization by G. clarum had a positive effect on nodulation 14 days after emergence, producing, 30% more nodules which were 40% heavier than those on roots solely inoculated with B. japonicum. The tripartite symbiosis resulted in 23% more N₂ being fixed than did the simpler symbiosis between soybean and B. japonicum. The presence of both symbionts changed accumulation of flavonoids in roots. Daidzein and coumestrol increased with plant growth. However, development of the tripartite symbiosis caused a decrease in coumestrol; accumulation of daidzein, the most abundant flavonoid, was reduced in the presence of AMF.     

Capture of the vicuña (Vicugna vicugna) for sustainable use: Animal welfare implications

The current program of vicuña conservation includes their live-capture for wool harvest in the Andes Region in northern Chile. Here, we describe studies that assess the impacts on the species of different variables relating to the capture process. The immediate physical and physiological effects on vicuña of contrasting capture methods, chase distances and restraint were measured.Comparisons between two methods of capture showed that cortisol concentrations were higher in animals herded using vehicles alone compared to those herded using a combination of vehicles and local people on foot. Blood glucose levels, heart rate and respiratory rate showed an immediate but ephemeral response to herding into a corral. The range of distances over which animals were herded caused less noticeable changes in blood and physical parameters. The most marked changes were associated with restraint, during which there were significant increases in creatin kinase, packed cell volume and rectal temperature. The implications of changes in these parameters on vicuña welfare and conservation are discussed.     

Hydrolytic enzyme activities in maize (Zea mays) and sorghum (Sorghum bicolor) roots inoculated with Gluconacetobacter diazotrophicus and Glomus intraradices

Two strains of Gluconacetobacter diazotrophicus (Pal 5, UAP5541) and the arbuscular mycorrhizal fungus Glomus intraradices increased both the shoot and root dry weight of sorghum 45 days after inoculation, whereas they had no effect on the shoot and root dry weight of maize. Co-inoculation (Gluconacetobacter diazotrophicus plus Glomus mosseae) did not increase the shoot and root dry weight of either plant. There was a synergistic effect of Gluconacetobacter diazotrophicus on root colonization of maize by Glomus intraradices, whereas an antagonistic interaction was observed in the sorghum root where the number of Gluconacetobacter diazotrophicus and the colonization by Glomus intraradices were reduced. Plant roots inoculated with Gluconacetobacter diazotrophicus and Glomus intraradices, either separately or together, significantly increased root endoglucanase, endopolymethylgalacturonase and endoxyloglucanase activities. The increase varied according to the plant. For example, in comparison with non-inoculated plants, there were higher endoglucanase (+328%), endopolymethylgalacturonase (+180%) and endoxyloglucanase (+125%) activities in 45-day old co-inoculated maize, but not in 45-day old sorghum. The possibility is discussed that hydrolytic enzyme activities were increased as a result of inoculation with Gluconacetobacter diazotrophicus, considering this to be one of the mechanisms by which these bacteria may increase root colonization by AM fungi.     

Commercial honey bees (Apis mellifera) reduce the fecundity of an Australian native bee (Hylaeus alcyoneus)

European honey bees used for commercial honey production represent a potential source of competition for floral resources with native nectar and pollen feeding insects. This study reports the results of an experiment run over two years on the impact of commercial honey bees on the fecundity of a solitary native bee, Hylaeus alcyoneus. Registered apiary sites were used as treatment sites (with honey bees) while control sites (without honey bees) were interspersed between. The fecundity of H. alcyoneus was measured using trap nests. We compared the number of nests produced, number of eggs per nest and emerging progeny mass of H. alcyoneus in sites with and without commercial bee hives. The number of nests produced by H. alcyoneus was 23% less (Wilcoxon’s T) at treatment sites than control sites. Analysis of individual measurement intervals using ANOVA was compromised by a general lack of power. This result highlights that even though honey bees have been present in certain areas for many years, competition with native bees may still be occurring.     

Decomposition processes under Bt (Bacillus thuringiensis) maize: Results of a multi-site experiment

The effects of maize expressing the Bacillus thuringiensis Cry1Ab protein (Bt maize) on decomposition processes under three different European climatic conditions were assessed in the field. Farming practices using Bt maize were compared with conventional farming practices using near-isogenic non-Bt maize lines under realistic agricultural practices. The litter-bag method was used to study litter decomposition and nitrogen mineralization dynamics of wheat straw. After 4 months incubation in the field, decomposition and mineralization were mainly influenced by climatic conditions with no negative effect of the Bt toxin on decomposition processes.     

Inter- and intra-specific interactions of Lumbricus rubellus (Hoffmeister, 1843) and Octolasion lacteum (Örley, 1881) (Lumbricidae) and the implication for C cycling

Earthworms are important engineering species of many terrestrial ecosystems as they play a significant role in regulating C turnover. The effects of earthworms on moderating C decomposition processes differ across species and with interactions between species, which is not fully understood. We carried out an experiment to study the interactions of Lumbricus rubellus and Octolasion lacteum, and their effects on soil respiration. Laboratory mesocosms were set up using tulip poplar (Liriodendron tulipifera) leaf litter and varying densities of earthworms in single and combined species treatments. CO₂ efflux rate was used as an indicator of C decomposition rates, and measured with CO₂ sensors every five days over one month. L. rubellus induced higher leaf consumption rate and higher CO₂ efflux than O. lacteum; meanwhile O. lacteum grew more than L. rubellus. Both litter consumption rate and growth rate of earthworms decreased with increasing earthworm density. Soil CO₂ efflux increased with increasing earthworm density (from ∼1-2 μg CO₂ g⁻¹ hr⁻¹ with no earthworms to ∼ 4 μg CO₂ g⁻¹ hr⁻¹ with 8 earthworms). Combining the two species had a synergistic effect on leaf litter consumption, and neutralizing effects on soil respiration. The data suggest that the strength of intra- and inter-specific interactions among earthworm ecological groups varies at different absolute and relative densities, leading to altered leaf litter decomposition and C cycling.     

Hybridisation with introduced chukars (Alectoris chukar) threatens the gene pool integrity of native rock (A. graeca) and red-legged (A. rufa) partridge populations

The decline of over-hunted red-legged (Alectoris rufa) and rock (A. graeca) partridge populations has been contrasted with massive releases of captive-reared birds, often hybrids with non-indigenous A. chukar. Released interspecific hybrids raise the risks of introgressive hybridisation, and can contribute to further depress the fitness of native populations. Aiming to assess the extent of hybridisation, we genotyped the mtDNA control-region and eight nuclear microsatellites in 671 red-legged, rock and chukar partridges and hybrids, identified by phenotypic traits. Results reveal a diffuse occurrence of hybridisation: (1) 39 samples (6.2%) show mtDNA haplotypes discordant with their phenotypes, indicating red-legged and chukar mtDNA introgression in native rock partridges; (2) admixture analyses of the microsatellite genotypes identified 32 additional rock partridges (5.1%) hybridised mainly with chukars. We analysed also 39 samples collected from a presumed natural red-legged x rock partridge hybrid zone in the French Alps. Surprisingly, 28% birds showed typical chukar mtDNAs, indicating hybridisation with introduced chukars or hybrids. This hybrid zone led to an introgression cline of chukar alleles into neighbouring Alpine rock partridges detectable up to 100 km, which was shorter than expected by neutral genetic theory, and that suggested natural selection against hybrids. These findings indicate that introgressive hybridisation may disrupt local adaptations in natural red-legged partridge and rock partridge populations, and call for strict control of farming and restocking operations.     

The mycorrhizal fungus (Glomus intraradices) affects microbial activity in the rhizosphere of pea plants (Pisum sativum)

Pea plants were grown in γ-irradiated soil in pots with and without addition of the AM fungus Glomus intraradices at sufficient N and limiting P. Depending on the growth phase of the plant presence of AM had negative or positive effect on rhizosphere activity. Before flowering during nutrient acquisition AM decreased rhizosphere respiration and number of protozoa but did not affect bacterial number suggesting top-down regulation of bacterial number by protozoan grazing. In contrast, during flowering and pod formation AM stimulated rhizosphere respiration and the negative effect on protozoa decreased. AM also affected the composition of the rhizosphere bacterial community as revealed from DNA analysis (DGGE). With or without mycorrhiza, rhizosphere respiration was P-limited on very young roots, not nutrient limited at more mature roots and C-limited at withering. This suggests changes in the rhizosphere community during plant growth also supported by changes in the bacteria (DGGE).     

The biochemical transformation of oak (Quercus robur) leaf litter consumed by the pill millipede (Glomeris marginata)

Soil macrofauna play an essential role in the initial comminution and degradation of organic matter entering the soil environment and yet the chemical effects of digestion on leaf litter are poorly understood at the molecular level. This study was undertaken to assess the selective chemical transformations that saprophagous soil invertebrates mediate in consumed leaf litter. A number of pill millipedes (Glomeris marginata) were fed oak leaves (Quercus robur) after which the biomolecular compositions (lipids and macromolecular components) of the leaves and millipede faeces were compared using a series of wet chemical techniques and subsequent analysis by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS). It was found that the concentrations of short chain (<C₂₀) n-alkanoic acids, sterols and triacylglycerols reduced dramatically in the millipede faeces relative to the leaf litter. Hydrolysable carbohydrates and proteins both decreased in concentration in the faeces, whereas similar yields of phenolic components were observed for the cupric oxidation products of lignin, although the oxygenated functionalities were affected by passage through the millipede gut, yielding a more highly condensed state for lignin. This shows that the chemical composition of fresh organic matter entering the soil is directly controlled by invertebrates feeding upon the leaf litter and as such that they are key contributors to the early stages of diagenesis in terrestrial soils.     

Nutrient release from decomposing leaf mulches of karité (Vitellaria paradoxa) and néré (Parkia biglobosa) under semi-arid conditions in Burkina Faso, West Africa

Information on decomposition and nutrient release from leaf litter of trees in agroforestry parkland systems in Sub-Saharan Africa is scarce despite the significant role of these trees on soil fertility improvement and maintenance. Decomposition and nutrient release patterns from pruned leaves of the two most common species of parklands of the semi-arid zone of West Africa: Vitellaria paradoxa C.F. Gaertn (known locally as karité) and Parkia biglobosa (Jacq.) Benth. (known locally as néré), were investigated by a litter-tube study in Burkina Faso. Litter quality, methods of leaf exposure to the soil and combination with fertilizers were the factors studied. Leaves of néré had a higher nutrient content (C, N, P, Ca) and contained more ash and lignin than leaves of karité. Karité leaves had a greater content of K, cellulose and polyphenols. The pruned leaves of karité and néré showed two distinct decomposition patterns. Néré leaves decomposed more rapidly, with less than 32% of the initial weight remaining after the rainy season (4 months) while karité leaves decomposed more slowly with 43% of the leaf litter remaining after the rainy season. Addition of urea and compost did not significantly affect the rate of decomposition. Significant interaction was observed between species and method of leaf exposure for the first sampling date. Leaf litter of néré buried in soil gave the highest weight loss (34% of the initial mass in 1 month) compared with exposed leaf litter of néré and karité, and buried leaf litter of karité. Except for N, nutrient release patterns were similar for both species but the nutrient release rates were higher for néré leaves compared with karité leaves. N was immobilised in karité leaves most likely due to low N and high phenolic content. The rate of nutrient release from karité leaves followed the general trend K>P>N.     

Cattle depredation by puma (Puma concolor) and jaguar (Panthera onca) in central-western Brazil

In this study, data on cattle depredation by puma (Puma concolor) and jaguar (Panthera onca) were recorded for six years (1998-2003) in a cattle ranch in central-western Brazil. Depredation represented 18.9% of the overall cattle mortality, being predominant on calves. In biomass, kills represented 0.4% (63.8 kg/km²) of the ranch’s annual stock. In economic loss, kills represented 0.3% of the cattle stock value. Depredation was mainly associated with cattle’s age class and location along with the time of birth of calves. The proportion of pastures next to forest with depredation (n = 33, 48.5%) was not distinguished to the proportion of pastures not bordering forest with depredation (n = 35, 51.5%). However, the proportion of pastures next to forest with depredation represented 54% (n = 33) of the 61 total pastures that were at least partially surrounded by forest patches or riparian forests that comprised eight continuum blocks of forest fragments of different sizes in the ranch and adjacent areas. No kills occurred in the central portion (main house) of the farm, close to the headquarters where the pastures not bordering forest. The distances of the kills in relation to areas of native forest was 1317.48 ± 941.03 m. In order to reduce depredation, calves should be kept as far as possible from forest areas and concentrated cattle breeding and calving seasons should be encouraged.     

Conservation action in the Galàpagos: feral pig (Sus scrofa) eradication from Santiago Island

Introduced mammals are major drivers of extinction and ecosystem change. As omnivores, feral pigs (Sus scrofa) are responsible for wholesale adverse effects on islands. Here, we report on the eradication of feral pigs from Santiago Island in the Galápagos Archipelago, Ecuador, which is the largest insular pig removal to date. Using a combination of ground hunting and poisoning, over 18,000 pigs were removed during this 30-year eradication campaign. A sustained effort, an effective poisoning campaign concurrent with the hunting program, access to animals by cutting more trails, and an intensive monitoring program all proved critical to the successful eradication. While low and fluctuating control efforts may help protect select native species, current eradication methods, limited conservation funds, and the potential negative non-target impacts of sustained control efforts all favor an intense eradication effort, rather than a sustained control program. The successful removal of pigs from Santiago Island sets a new precedent, nearly doubling the current size of a successful eradication, and is leading to more ambitious projects. However, now we must turn toward increasing eradication efficiency. Given limited conservation funds, we can no longer afford to spend decades removing introduced mammals from islands.     

Decomposer animals (Lumbricidae, Collembola) and organic matter distribution affect the performance of Lolium perenne (Poaceae) and Trifolium repens (Fabaceae)

Decomposer animals stimulate plant growth by indirect effects such as increasing nutrient availability or by modifying microbial communities in the rhizosphere. In grasslands, the spatial distribution of organic matter (OM) rich in nutrients depends on agricultural practice and the bioturbation activities of large detritivores, such as earthworms. We hypothesized that plants of different functional groups with contrasting nutrient uptake and resource allocation strategies differentially benefit from sites in soil with OM accumulation and the presence of decomposer animals. In a greenhouse experiment we investigated effects of spatial distribution of ¹⁵N-labelled grass litter, earthworms and collembola on a simple grassland community consisting of Lolium perenne (grass) and Trifolium repens (legume). Litter aggregates (compared to homogeneous litter distribution) increased total shoot biomass, root biomass and ¹⁵N uptake by the plants. Earthworms and collembola did not affect total N uptake of T. repens; however, the presence of both increased ¹⁵N uptake by T. repens and L. perenne. Earthworms increased shoot biomass of T. repens 1.11-fold and that of L. perenne 2.50 fold. Biomass of L. perenne was at a maximum in the presence of earthworms, collembola and with litter concentrated in a single aggregate. Shoot biomass of T. repens increased in the presence of collembola, with L. perenne generally responding opposingly. The results indicate that the composition of the decomposer community and the distribution of OM in soil affect plant competition and therefore plant community composition.     

Plasmodium blood parasite found in endangered Galapagos penguins (Spheniscus mendiculus)

This is the first report of a Plasmodium blood parasite found in the Galapagos Archipelago. Phylogenetic analyses place this parasite, recovered from endangered Galapagos penguins (Spheniscus mendiculus), within the genus Plasmodium, and suggest a close relationship to some of the most dangerous lineages of Plasmodium that have been known to cause severe mortality and morbidity in captive penguin populations. Infectious disease is an increasingly important cause of global species extinctions, and extinctions due to avian pox and avian malaria (Plasmodium relictum) have been well documented in Hawaiian avifauna. Plasmodium blood parasites had not been detected in Galapagos birds until now, despite previous microscopic and molecular screening of many of the species, including the Galapagos penguin. While penguin populations now appear healthy, it is unclear whether this parasite will have an obvious impact on their survival and reproduction, particularly during El Niño events, which cause stress due to reduced food availability. It is possible that this parasite arrived with or shortly after the recent arrival of an introduced mosquito, Culex quinquefasciatus, known elsewhere as a competent vector of Plasmodium blood parasites.     

Conserving marginal populations of the food plant (Impatiens noli-tangere) of an endangered moth (Eustroma reticulatum) in a changing climate

Impatiens noli-tangere is scarce in the UK and probably only native to the Lake District and Wales. It is the sole food plant for the endangered moth Eustroma reticulatum. Significant annual fluctuations in the size of I. noli-tangere populations endanger the continued presence of E. reticulatum in the UK. In this study, variation in population size was monitored across native populations of I. noli-tangere in the English Lake District and Wales. In 1998, there was a crash in the population size of all metapopulations in the Lake District but not of those found in Wales. A molecular survey of the genetic affinities of samples in 1999 from both regions and a reference population from Switzerland was performed using AFLP and ISSR analyses. The consensus UPGMA dendrogram and a PCO scatter plot revealed clear differentiation between the populations of I. noli-tangere in Wales and those in the Lake District. Most of the genetic variation in the UK (H_T=0.064) was partitioned between (G_ST=0.455) rather than within (H_S=0.034) regions, inferring little gene flow occurs between regions. There was similar bias towards differentiation between metapopulations in Wales, again consistent with low levels of interpopulation gene flow. This contrasts with far lower levels of differentiation in the Lake District which suggests modest rates of gene flow may occur between populations. It is concluded that in the event of local extinction of sites or populations, reintroductions should be restricted to samples collected from the same region. We then surveyed climatic variables to identify those most likely to cause local extinctions. Climatic correlates of population size were sought from two Lake District metapopulations situated close to a meteorological station. A combination of three climatic variables common to both sites explained 81-84% of the variation in plant number between 1990 and 2001. Projected trends for these climatic variables were used in a Monte Carlo simulation which suggested an increased risk of I. noli-tangere population crashes by 2050 at Coniston Water, but not at Derwentwater. Implications of these findings for practical conservation strategies are explored.     

Population viability of the narrow endemic Helianthemum juliae (CISTACEAE) in relation to climate variability

Narrow endemic plants are highly vulnerable to extinction as a result of human disturbance and climate change. We investigated the factors affecting the population viability of Helianthemum juliae, a perennial plant endemic to the Teide National Park on Tenerife, Canary Islands. One population was demographically monitored from 1992 to 2001 and analysed using matrix projection models to determine finite rates of increase and critical stages in the life cycle. Lambda values varied between 0.697 and 1.740, and were highly positively correlated with annual precipitation, but not with temperature. Survival of adults had the highest elasticity, and summed elasticities of the growth and fecundity transitions correlated positively with lambda and precipitation. Most of the mortality in the population seemed drought-related, and no other threats were identified. Deterministic simulations showed population increase, but introducing environmental stochasticity by modelling variation in precipitation from existing data of the past 85 years revealed high extinction probabilities (0.74-0.83 in the next 100 years). This plant is likely to be at risk under scenarios of global warming. Our simulations suggest that augmenting the population would only delay extinction. A more viable option for long-term conservation seems to be the introduction of populations at more humid locations within the Teide caldera.     

Changes in status of the frog (Rana temporaria) and the toad (Bufo bufo) on part of the East Anglian Fenland in Britain

An attempt has been made to determine fluctuations in status of the frog (Rana temporaria) and the toad (Bufo bufo) on parts of the Fens (10 km squares TL38, 39, 48 and 49). Information from Fenland workers indicated that both species were common from at least as far back as 1900 up until the 1930s. Severe declines occured in the 1940s, 1950s and 1960s, and by the 1970s both species were very rare. Improved drainage and the marked change from pasture to arable, with associated loss of suitable wet and damp habitat, are believed to have been responsible for the early decreases. Again, loss of habitat was likely to be the main factor causing the later declines, but pesticides probably also contributed. At present, about half of the dykes containing water at a depth which frogs in other areas normally select for spawning dry out before tadpole metamorphosis would be completed.     

Effect of strains of Rhizobium trifolii on the establishment of oversown white clover (Trifolium repens)

Strains of Rhizobium trifolii incorporated into commercial peat inoculants were compared for their effect on the establishment and growth of oversown white clover (Trifolium repens) on soils devoid of infective rhizobia.There were marked differences in numbers of seedlings establishing and clover dry matter production per hectare with the various strains. However, when adjusted to a constant number of established seedlings, dry matter production from all strains, apart from one strain at one site, were similar indicating that the strains did not appear to influence the growth of individual clover plants.The marked differences in establishment of clover inoculated with the various strains could not be accounted for by differences in the number of rhizobia in the peat inoculant.Selecting strains of rhizobia for ability to increase establishment is considered important where clover is oversown onto soils devoid of rhizobia.