Modelling the impact of hen harrier management measures on a red grouse population in the UK

Human‐wildlife conflict is one of the greatest barriers to effective conservation. The recovery of the hen harrier Circus cyaneus in the United Kingdom has been limited due to illegal persecution, a consequence of the raptors’ predation on the economically valuable game‐bird, the red grouse Lagopus lagopus scoticus. To improve management of the system it is necessary to understand the interactions between the two species in their broader community context. We therefore developed a multi‐species model in which the life history and interactions of each of the two bird species are described through linked process models. This model was fit to population data using a Bayesian state–space framework and used to investigate the effectiveness of a conflict–mitigation technique known as diversionary feeding, in which harrier nests are provided with food in an attempt to reduce consumption of grouse chicks. To explore the utility of diversionary feeding we specified four scenarios in which 1) harriers were absent from the system, 2) there was no diversionary feeding of harriers, 3) only a portion of the harrier nests were provided with diversionary food and 4) all nests were provided with diversionary food. The results from fitting the model under the different scenarios were used to determine the strength of harriers’ impact on grouse density, as well as the effectiveness of diversionary feeding. Given the lack of information on other grouse predators and only two years of data on supplementary feeding, our results need to be implanted with caution. However, we found theoretical support for the hen harriers’ suppression of grouse cycle amplitude and average density. Furthermore, our results suggest that on grouse estates where diversionary feeding is the only active management, diversionary feeding is only marginally successful and not sufficient to mitigate the consequences of hen harrier predation on red grouse chicks.     

A global view of the OCA2-HERC2 region and pigmentation

Mutations in the gene OCA2 are responsible for oculocutaneous albinism type 2, but polymorphisms in and around OCA2 have also been associated with normal pigment variation. In Europeans, three haplotypes in the region have been shown to be associated with eye pigmentation and a missense SNP (rs1800407) has been associated with green/hazel eyes (Branicki et al. in Ann Hum Genet 73:160-170, 2009). In addition, a missense mutation (rs1800414) is a candidate for light skin pigmentation in East Asia (Yuasa et al. in Biochem Genet 45:535-542, 2007; Anno et al. in Int J Biol Sci 4, 2008). We have genotyped 3,432 individuals from 72 populations for 21 SNPs in the OCA2-HERC2 region including those previously associated with eye or skin pigmentation. We report that the blue-eye associated alleles at all three haplotypes were found at high frequencies in Europe; however, one is restricted to Europe and surrounding regions, while the other two are found at moderate to high frequencies throughout the world. We also observed that the derived allele of rs1800414 is essentially limited to East Asia where it is found at high frequencies. Long-range haplotype tests provide evidence of selection for the blue-eye allele at the three haplotyped systems but not for the green/hazel eye SNP allele. We also saw evidence of selection at the derived allele of rs1800414 in East Asia. Our data suggest that the haplotype restricted to Europe is the strongest marker for blue eyes globally and add further inferential evidence that the derived allele of rs1800414 is an East Asian skin pigmentation allele.     

Biological Control of Crown Gall: Field Measurements and Glasshouse Experiments

S ummary : An ecological study showed that the pathogeniec form of Agrobacterium radiobacter (A.r. var. tumefaciens ), biotype 2 was present in soil near galled almond seedlings, where it formed a significant proportion of the total biotype 2 population; the pathogen was not detected near healthy plants. One nonpathogenic biotype 2 isolate was able, when present in numbers approximately equal to the pathogen, to prevent crown gall induction in tomato and peach seedlings. This isolate gave complete biological control of crown gall in a glasshouse test. Six other nonpathogenic isolates did not significantly inhibit gall induction by equal numbers of the pathogen. In the field, gall induction probably depends on the size of the population of the pathogen (both absolutely and relative to that of the nonpathogen) at a wound site and on the inhibitory efficiency of the nonpathogen.     

An in vivo/in vitro evaluation of the teratogenic action of excess vitamin A

Pregnant rats of CFHB strain were injected 81/2 days postcoitum with a 1% suspension of retinoic acid (RA) in arachis oil to give 20 mg RA per kg body weight. Control rats were injected with arachis oil only. After 26 hours, one uterine horn was removed from each rat and the embryos cultured in serum from untreated rats. The embryos in the other horn were allowed to continue development in vivo. After a further 48 hours the cultures were terminated and the second uterine horn removed from each rat. This provided four groups of embryos for comparison: (1) embryos from RA-treated rats, (2) cultured embryos from RA-treated rats, (3) embryos from control rats, and (4) cultured embryos from control rats. The results showed that the effects of the teratogen on the cultured embryos were similar to those on the embryos allowed to continue development for the same period in the mother. In both groups RA reduced protein synthesis, inhibited somite and limb bud formation, and caused various neural tube defects, particularly microcephaly and abnormalities in the closure of the anterior and posterior neuropores.     

Insect conservation in early succession on islands: lessons from Surtsey, Iceland, and the Krakatau Archipelago, Indonesia

Early successional communities on islands may include specialised aeolian-based pioneer arthropods scavenging on aerial fallout on volcanic lava or ash. Some such species appear to be restricted to such extreme habitats. Persistence of such species may be governed by volcanic activity and their future thus be beyond the control of people. Surveys to determine their presence elsewhere are needed to determine their possible status as refugees in later successional stages, and as a basis for any more informed conservation measures. Insect colonization patterns on Surtsey and Anak Krakatau are briefly reviewed and contrasted to indicate the background to insect community formation on remote islands.     

Impacts of large dams on riparian vegetation: applying global experience to the case of China’s Three Gorges Dam

Dams are widely recognised as having significant negative consequences for the surrounding natural ecosystems and environment. China’s Three Gorges Dam, being one of the largest in the world, stands to inflict more damage than most for numerous reasons. This paper reviews the current knowledge on the impacts of dams and impoundments with regard to reservoir riparian vegetation in order to apply this knowledge to the Three Gorges Project. It also summarises research performed to date on the effects of the Three Gorges Dam on the local riparian zone and vegetation. The known and potential outcomes for local plant communities are examined in terms of their responses to the increased water levels, altered hydrological characteristics and other adverse effects associated with the construction of the dam. Vegetation responses will be diverse and change over time, but will ultimately result in a markedly different landscape and riparian zone within the Three Gorges Reservoir. These changes will take place through a loss of previous vegetation, potential invasion by exotics and result from the significant alteration in hydrological regimes and also erosion and sedimentation processes influencing and creating novel plant communities. Management of the environmental consequences of the Three Gorges Project should take into account factors associated with these processes, in order to facilitate vegetation recovery in the reservoir and to conserve biodiversity of the surrounding ecosystems.