Dietary niche differentiation among three species of invasive rodents (Rattus rattus, R. exulans, Mus musculus)

The diets of sympatric rodents partially define their realized niches. Identifying items in stomachs of introduced rodents helps determine rodents’ trophic positions and species most at risk of consumption. In the Hawaiian Islands, which lacked rodents prior to human arrival, three rodents (Rattus rattus or black rat, R. exulans or Pacific rat, Mus musculus or house mouse) commonly coexist in native habitats where they consume a wide range of plants and animals. These three rodent species were trapped in montane forest for 2.5 years; their stomach contents were analyzed to determine short-term diets (n = 12–95 indiv. per species), and isotopic fractions of δ¹⁵N and δ¹³C in their bone collagen were analyzed to further estimate their trophic positions (n = 11–20 indiv. per species). For all three species, >75 % of individuals had plants and >90 % had arthropods in their stomachs, and significant differences in mean relative abundances were found for food items in stomachs among all three rodents. Rodents may be dispersing some native and non-native seeds, including the highly invasive Clidemia hirta. Most identifiable arthropods in rodent stomachs were non-native, and no stomachs contained birds, snails, or lizards. The δ¹⁵N and δ¹³C signatures were consistent with trophic feeding differences revealed from stomach contents. Dietary niche differentiation by coexisting rodent species is evident in this forest, with Pacific rats being intermediate between the mostly carnivorous house mouse and the mostly herbivorous black rat; such findings can help forecast rodent impacts and direct management efforts in ecosystems where these invasive animals coexist.     

Patterns and mechanisms of invasive plant impacts on North American birds: a systematic review

Understanding how invasive plants affect biodiversity is a crucial conservation need. Numerous studies examine impacts of invasions on birds, but trends in these effects have not been synthesized. We reviewed 128 studies from North America to quantify the frequency of positive, negative, and neutral (non-significant) effects of invasive plants on avian ecology, and then evaluated support for proposed mechanisms of impacts. Our frequency-based approach enabled us to draw value from the full breadth of available literature, including articles that do not provide information necessary for meta-analyses and articles examining understudied phenomena. Total avian abundance and prevalence of individual bird species were usually unaffected by invasion, with 48.9 and 57.2% of tests showing neutral results, respectively. Avian richness decreased with invasion in 41.3% of tests. Although birds often preferred nesting in invasive vegetation (45.0% of tests), effects on nest survival were typically neutral (57.9%). Multiple metrics (e.g. body condition, fledgling survival) have received scant attention. Some of the patterns we highlight differ across ecological contexts, emphasizing the need to understand impact mechanisms. Several studies have directly linked invasion impacts to altered nest-site availability, habitat heterogeneity, and food supplies. There is mixed evidence that plant architecture impacts nest-site selection and nest predation. Our review highlights the nonuniform consequences of biological invasions. The high frequency of reported neutral effects suggests that invasions often have minimal impacts on birds, but positive and negative impacts certainly can arise. Managers considering eradicating invasive plants for avian conservation should monitor impacts locally to determine whether eradication will be beneficial.     

Weeds,worms, and deer: positive relationships among common forest understory stressors

Biotic global change agents, such as non-native plants (‘weeds’), non-native earthworms (‘worms’), and overabundant herbivores (white-tailed ‘deer’), can be major stressors in the forest understory. The status and relationships among these global change stressors across large spatial extents and under naturally varying conditions are poorly understood. Here, through an observational study using a network of U.S. National Park Service forest health monitoring plots (n = 350) from eight parks in seven northeastern states, we modeled causal pathways among global change stressors through model selection in a structural equation (SEM) framework. Weeds, worms, and, deer were common across all parks in the study—46% of plots had non-native plants, 42% of plots had evidence of earthworms, and all parks had plots with high deer browse damage. All biotic global change stressors were significantly and positively correlated with one another (all Spearman rank correlations ≥ 0.44). Consequently, 28% of plots had a combination of earthworms absent, low deer browse, and no non-native plants, and 29% of plots included earthworms, non-native plants, and moderate or greater browse damage. Through SEM, we found strong support for pathways among global change stressors, e.g., deer browse positively influenced earthworm presence and both deer and earthworms promoted non-native plants. Warmer air temperatures and higher soil pH also facilitated non-natives. This research highlights the tremendous multipronged management challenge for areas already experiencing the combined effects of weeds, worms, and deer and the future vulnerability of other areas as temperatures warm and conditions become more amenable to biotic global change stressors.     

Fire mediated patterns of population densities in mountain big sagebrush bird communities

We employed a chronosequence approach to evaluate patterns of bird abundance in relation to post-fire vegetation recovery in mountain big sagebrush (Artemisia tridentata vaseyana). We estimated population density for 12 species of birds within the perimeters of 4 fires that had undergone 8–20 years of vegetation recovery and on adjacent unburned areas in the northwestern Great Basin, USA. Six species showed negative responses to fire persisting up to 20 years. Two species showed positive responses with effects persisting for <20 years. Understory vegetation was similar between burned and unburned areas irrespective of recovery time, and shrub canopy cover was similar between burned and unburned sites after 20 years of recovery. Persistent reductions in bird densities lead us to conclude that shrub canopy cover alone is not a sufficient metric for predicting recovery of songbird abundances following disturbance in mountain big sagebrush. © 2013 The Wildlife Society.     

Effects of Native and Non-Native Grassland Plant Communities on Breeding Passerine Birds: Implications for Restoration of Northwest Bunchgrass Prairie

One common problem encountered when restoring grasslands is the prominence of non-native plant species. It is unclear what effect non-native plants have on habitat quality of grassland passerines, which are among the most imperiled groups of birds. In 2004 and 2005, we compared patterns of avian reproduction and the mechanisms that might influence those patterns across a gradient of 13 grasslands in the Zumwalt Prairie in northeastern Oregon that vary in the degree of non-native plant cover (0.9–53.4%). We monitored the fate of 201 nests of all the breeding species in these pastures and found no association of percent non-native cover with nest densities, clutch size, productivity, nest survival, and nestling size. Regardless of the degree of non-native cover, birds primarily fed on Coleoptera, Orthoptera, and Araneae. But as percent non-native cover in the pastures increased, Orthoptera made up a greater proportion of diet and Coleoptera made up a smaller proportion. These diet switches were not the result of changes in terrestrial invertebrate abundance but may be related to decreases in percent bare ground associated with increasing cover of non-native vegetation. Measures of nest crypticity were not associated with cover of non-native vegetation, suggesting that predation risk may not increase with increased cover of non-native vegetation. Thus, the study results show that increased non-native cover is not associated with reduced food supplies or increased predation risk for nesting birds, supporting the growing body of evidence that grasslands with a mix of native and non-native vegetation can provide suitable habitat for native grassland breeding birds.     

Melatonin mends adverse temporal effects of bright light at night partially independent of its effect on stress responses in captive birds

ABSTRACT

Ecological artificial light at night (ALAN) has been increasingly associated with negative effects on the behavior and ecology of wild birds. However, the impacts of short-term bright ALAN on the temporal biology of companion animals and the underlying mediating mechanism are unknown. We evaluated impacts of 1X60-min/middle night ALAN (200 lux, λ_Dominant = 460 nm) nightly with or without melatonin administration on growth performance, reproductive capacity, food and water intake, and stress responses in Australian budgerigars (Melopsittacus undulatus) under captivity. 36 birds were housed in pairs under natural photoperiod and were equally divided into three groups: control, natural conditions; ALAN, control + ALAN; and melatonin, ALAN + melatonin in the drinking water during the dark period. Birds were regularly monitored for body mass, egg production, and hatchability over four months. Food intake, water consumption, and daily rhythm of fecal corticosterone were also evaluated. ALAN increased mass gain, food intake, water consumption, and drastically decreased reproductive capacity, whereas stress responses were markedly augmented. Melatonin restored food and water intake to control levels but partly reversed mass gain. Melatonin failed to ameliorate the impaired reproductive capacity despite reducing the stress responses to basal levels. These results suggest that the ALAN-induced negative impacts cannot be attributed solely to direct effects of melatonin suppression or/and exacerbated stress responses and the involvement of other photoperiodic pathway components warrant further studies. Finally, the results of our study may be of importance for improving the housing conditions of companion animals at least as concern bright ALAN exposures.     

Diets of Kauai’s invasive rose-ringed parakeet (<Emphasis Type="Italic">Psittacula krameri</Emphasis>): evidence of seed predation and dispersal in a human-altered landscape

Rose-ringed parakeets (Psittacula krameri) are the world’s most successful introduced parrots, and > 2000 individuals reside on Kauai, Hawaii. These birds destroy crops, but impacts to other native and non-native species are largely unknown. Our study objectives on Kauai were to determine: (1) diets of rose-ringed parakeets at five sites (n = 9–25 per site), by sex, through crop and gizzard analysis and carbon and nitrogen stable isotope analysis, and (2) whether birds are dispersing or depredating seeds. We found 100% of birds (n = 64) were eating plant material and 80% of their diet was seed; males had more food in their crops and gizzards than did females. Corn (Zea mays) was eaten by 67% of birds and averaged 31% of mass in crops and gizzards. Invasive yellow guava (Psidium guajava) was eaten by 97% of birds and averaged 30% of their diet. Parakeets are potentially dispersing yellow guava seeds, as 66% of birds had intact guava seeds, and each bird had an average of three intact seeds. Diets differed statistically among sites. Parakeets from Lihue Airport did not have any corn, and isotopic carbon values also supported low feeding on corn by birds at Lihue Airport. No seeds of native plants were identified in rose-ringed parakeet diets. Our findings of a diverse plant diet, frequent seed predation, and potential to disperse invasive species’ seeds implies that land managers in agricultural, urban, and natural areas should be concerned with the current expansion of these invasive birds on Kauai and elsewhere.     

Fitness costs of butterfly oviposition on a lethal non-native plant in a mixed native and non-native plant community

Non-native plants may be unpalatable or toxic, but have oviposition cues similar to native plants used by insects. The herbivore will then oviposit on the plant, but the offspring will be unable to develop. While such instances have been described previously, the fitness costs at the population level in the wild due to the presence of the lethal host have not been quantified, for this or other related systems. We quantified the fitness cost in the field for the native butterfly Pieris macdunnoughii in the presence of the non-native crucifer Thlaspi arvense, based on the spatial distributions of host plants, female butterflies and eggs in the habitat and the survival of the larvae in the wild. We found that 2.9 % of eggs were laid on T. arvense on average, with a survival probability of 0, yielding a calculated fitness cost of 3.0 % (95 % confidence interval 1.7–3.6 %) due to the presence of the non-native in the plant community. Survival probability to the pre-pupal stage for eggs laid on two native crucifers averaged 1.6 % over 2 years. The magnitude of the fitness cost will vary temporally and spatially as a function of the relative abundance of the non-native plant. We propose that the fine-scale spatial structure of the plant community relative to the butterflies’ dispersal ability, combined with the females’ broad habitat use, contributes to the fitness costs associated with the non-native plant and the resulting evolutionary trap.     

Point of Care Tuberculosis Sero-Diagnosis Kit for Wild Animals: Combination of Proteins for Improving the Diagnostic Sensitivity and Specificity

Tuberculosis is a significant problem globally for domestic animals as well as captive and free ranging wild life. Rapid point of care (POC) serology kits are well suited for the diagnosis of TB in wild animals. However, wild animals are invariably exposed to environmental non-pathogenic mycobacterium species with the development of cross reacting antibodies. In the present study, POC TB diagnosis kit was developed using a combination of pathogenic Mycobacteria specific recombinant antigens and purified protein derivatives of pathogenic and non-pathogenic Mycobacteria. To benchmark the TB antibody detection kit, particularly in respect to specificity which could not be determined in wildlife due to the lack of samples from confirmed uninfected animals, we first tested well-characterized sera from 100 M. bovis infected and 100 uninfected cattle. Then we investigated the kit’s performance using sera samples from wildlife, namely Sloth Bears (n = 74), Elephants (n = 9), Cervidae (n = 14), Felidae (n = 21), Cape buffalo (n = 2), Wild bear (n = 1) and Wild dog (n = 1).In cattle, a sensitivity of 81% and a specificity of 90% were obtained. The diagnostic sensitivity of the kit was 94% when the kit was tested using known TB positive sloth bear sera samples. 47.4% of the in-contact sloth bears turned seropositive using the rapid POC TB diagnostic kit. Seropositivity in other wild animals was 25% when the sera samples were tested using the kit. A point of care TB sero-diagnostic kit with the combination of proteins was developed and the kit was validated using the sera samples of wild animals.     

An overview of biodiversity and conservation status of steppes of the Anatolian Biogeographical Region

The Anatolian Biogeographical Region is unique in the Palearctic realm, with high plant and butterfly species richness and populations of globally threatened birds, mammals and herptiles (amphibians and reptiles). It is a place of diverse land-use practices, dating back to the earliest farming practices in the world. Among 10,930 species of vascular plants, birds, butterflies, mammals and herptiles distributed in Turkey, we identified 1130 living predominantly in steppic environments and being classified either as threatened, near-threatened or data deficient at the national level, if not globally. A total of 28 effective protected areas were present in the region, covering 1.5 % of the 391,597 km² land area. Only 16.2 % of the threatened and near-threatened species (n = 809) were distributed within the protected area network, ranging from 94.1 % for birds to as low as 12.9 % for vascular plants. The total area of steppe and steppe forest vegetation has been reduced by at least 44 % of its former extent due to diverse habitat destructive activities. The most significant threats arise from unsustainable agricultural activities including overgrazing, conversion to croplands and afforestation. To maintain steppe diversity, we propose a “to-do list”, including mainstreaming biodiversity, effective implementation of Turkey’s Rangeland Act, conducting effective environmental impact assessments, establishing an effective site network for steppe biodiversity conservation and filling gaps in scientific knowledge.     

Meiotic behavior and pollen fertility in triploid and tetraploid natural populations of Campuloclinium macrocephalum (Eupatorieae,Asteraceae)

Campuloclinium macrocephalum DC. is a perennial herb widely distributed in the New World and introduced in South Africa, where it is commonly called “pompom weed”. This species is considered one of the most important weeds of Brazil and one of the problematic invasive plants of South Africa. The meiotic system can be studied to assess the ability of a weed to spread, but only few studies on C. macrocephalum have been realized. In this study, we examined the meiotic behavior and pollen fertility of 14 natural populations of C. macrocephalum from Argentina and Uruguay. Meiotic analysis revealed 2 triploid (2n = 3x = 30), 11 tetraploid (2n = 4x = 40) and 1 mixed population (2n = 2x = 20, 2n = 4x = 40). Both, triploid and tetraploid specimens showed a widely variable meiotic behavior with irregular chromosome pairing showing univalents, bivalents, trivalents (in triploids) and tetravalents (in tetraploids) at diacinesis of first meiotic division. Different abnormalities were observed, such as: laggard chromosomes, chromatin bridges, and out of plate chromosomes at metaphase I. During meiosis I (prophase), some cells showed the phenomenon of cytomixis or chromatin transfer between pollen mother cells. The meiotic indexes suggest that only four populations were normally fertile (over 90 % of fertile pollen), indicating meiotically stable plants. The remaining populations share variable pollen fertility, with triploids ranging from 46.64 to 54.83 % and tetraploids varying from 3.54 to 45.30 %. We suggest that polyploidy seems to be recurrent in C. macrocephalum, promoting partial sterility of pollen grains, generating large numbers of individuals by apomixis promoting invasion of crop fields. This study presents the meiotic behavior of this weed, these could be useful for future studies of biological control in areas with no natural enemies.     

Multigenerational outbreeding effects in Chinook salmon (Oncorhynchus tshawytscha)

Outbreeding, mating between genetically divergent individuals, may result in negative fitness consequences for offspring via outbreeding depression. Outbreeding effects are of notable concern in salmonid research as outbreeding can have major implications for salmon aquaculture and conservation management. We therefore quantified outbreeding effects in two generations (F₁ hybrids and F₂ backcrossed hybrids) of Chinook salmon (Oncorhynchus tshawytscha) derived from captively-reared purebred lines that had been selectively bred for differential performance based on disease resistance and growth rate. Parental lines were crossed in 2009 to create purebred and reciprocal hybrid crosses (n = 53 families), and in 2010 parental and hybrid crosses were crossed to create purebred and backcrossed hybrid crosses (n = 66 families). Although we found significant genetic divergence between the parental lines (F_ST = 0.130), reciprocal F₁ hybrids showed no evidence of outbreeding depression (hybrid breakdown) or favorable heterosis for weight, length, condition or survival. The F₂ backcrossed hybrids showed no outbreeding depression for a suite of fitness related traits measured from egg to sexually mature adult life stages. Our study contributes to the current knowledge of outbreeding effects in salmonids and supports the need for more research to better comprehend the mechanisms driving outbreeding depression.     

Maternal Behavior,Posture Change,and Production Performance of Lactating Sows Housed in an Enriched Environment

This study aimed to evaluate whether adding straw to a loose-farrowing house promotes maternal functions and production. Forty-eight sows (Landrace× Large White) were housed in either a farrowing pen without straw (C, n = 24) or with straw (S, n = 24). Behaviors were observed using video recordings and were statistically analyzed. Lateral recumbency was higher and standing was lower in S compared with C (p = .034 and p = .020, respectively), and lateral recumbency to other postures, ventral to lateral recumbency and standing to lying were markedly lower in S than C (p = .014, p = .025 and p = .023, respectively) on Day 1 postpartum. However, except piglet losses during the first three days postpartum (p = .032), piglet weight on Day 21 (p = .037), and piglet weaning weight (p = .020), other production performances were not significantly different between the two groups during the whole experimental period (p ?.05). The results suggest the enrichment of a farrowing pen with straw has important beneficial effects on sow and piglet welfare and improves piglet survival rates.     

Trends in paediatric and adult bloodstream infections at a Ghanaian referral hospital: a retrospective study

Background

Bloodstream infections (BSI) are life-threatening emergencies. Identification of the common pathogens and their susceptibility patterns is necessary for timely empirical intervention.

Methods

We conducted a 4-year retrospective analysis of blood cultures from all patients excluding neonates at the Korle-Bu Teaching hospital, Ghana, from January 2010 through December 2013. Laboratory report data were used to determine BSI, blood culture contamination, pathogen profile, and antimicrobial resistance patterns.

Results

Overall, 3633 (23.16 %) out of 15,683 blood cultures were positive for various organisms. Pathogen-positive cultures accounted for 1451 (9.3 %, 95 % CI 8.5–9.8 %). Infants recorded the highest true blood culture positivity (20.9 %, n = 226/1083), followed by the elderly (13.3 %, n = 80/601), children (8.9 %, n = 708/8000) and adults (7.2 %, n = 437/6000) (p = 0.001 for Marascuilo’s post hoc). Overall occurrence of BSI declined with increasing age-group (p = 0.001) but the type of isolates did not vary with age except for Citrobacter, Escherichia coli, Klebsiella, Salmonella, and Enterococcus species. Gram negative bacteria predominated in our study (59.8 %, n = 867/1451), but the commonest bacterial isolate was Staphylococcus aureus (21.9 %, n = 318/1451)—and this trend run through the various age-groups. From 2010 to 2013, we observed a significant trend of yearly increase in the frequency of BSI caused by cephalosporin-resistant enterobacteria (Chi square for trend, p = 0.001). Meropenem maintained high susceptibility among all Gram-negative organisms ranging from 96 to 100 %. Among Staphylococcus aureus, susceptibility to cloxacillin was 76.6 %.

Conclusion

Our study shows a significantly high blood culture positivity in infants as compared to children, adults and the elderly. There was a preponderance of S. aureus and Gram-negative bacteria across all age-groups. Meropenem was the most active antibiotic for Gram-negative bacteria. Cloxacillin remains a very useful anti-staphylococcal agent.

     

Detection of Rickettsia monacensis from Ixodes nipponensis collected from rodents in Gyeonggi and Gangwon Provinces, Republic of Korea

A total of 1,305 ticks were collected from wild rodents captured monthly, except July and August, during 2008 at three US-ROK operated military training sites and three US military installations in Gyeonggi and Gangwon Provinces, the Republic of Korea (ROK). Ixodes nipponensis was the most frequently collected tick (n = 1,299, 99.5 %), followed by Ixodes pomerantzevi (n = 6, 0.5 %). The ticks were pooled (1–15/sample) and tested by nested polymerase chain reaction (nPCR) for spotted fever group (SFG) rickettsiae with primer sets targeting the outer membrane protein B (ompB), citrate synthase (gltA), and 17-kDa antigen gene loci. A total of 115/197 (58.4 %) pools were positive by nPCR for the outer membrane protein ompB. Nucleotide sequence analysis of 105/115 (91.3 %) ompB targeted nPCR positive products showed a high degree of similarity to Rickettsia monacensis (99.3–100 %, n = 87) and R. japonica (99.5–100 %, n = 18). From the 87 positive samples demonstrating a high degree of similarity to R. monacensis, 15 were selected and analyzed by nPCR for gltA and the 17-kDa genes. A total of 12/15 pooled samples were positive for by nPCR for gltA, with amplicons demonstrating a high degree of similarity to R. monacensis (99.3–99.7 %). A total of 13/15 pooled samples were positive by nPCR for the 17-kDa gene, with amplicons demonstrating a high degree of similarity to R. monacensis (99.4–100 %). These findings demonstrate that R. monacensis is distributed throughout Gyeonggi and Gangwon Provinces in the ROK. Furthermore, data suggest a relative high prevalence of R. monacensis in the tick, I. nipponensis.     

Adélie penguin (Pygoscelis adeliae) survival rates and their relationship to environmental indices in the South Shetland Islands,Antarctica

Seabird life history is typified by low fecundity, high adult survival rates, and relatively long lives. Such traits act as buffers, enabling persistence of populations under variable environmental conditions. Numerous studies, however, have suggested strong sensitivity of seabirds to environmental variability. In the Antarctic Peninsula region, for example, Adélie penguin (Pygoscelis adeliae) populations have declined during the last three decades, attributed largely to rapid changes in environmental conditions and food availability. We use 30 years of mark-recapture data from known-age individuals in the South Shetland Islands and capture-mark-recapture models to estimate survival rates with respect to such environmental variation. We investigated specifically whether negative trends in survival rates were evident and whether indices of global, regional, and local environmental conditions considered important for Adélie penguin survival explained the variability in survival rates. Overall, negative trends in juvenile survival were evident, but adult survival rates exhibited high interannual variability. Indices of sea ice extent had the strongest correlations with survival rates, particularly Weddell Sea ice extent during spring among adults (r = 0.62) and during winter for juveniles (r = 0.46). An analysis of deviance, however, suggested that single environmental covariates explained <30 % of the observed variation in the full mark-recapture models. Despite positive effects of sea ice extent on survival rates of Adélie penguins, limited explanatory power of several environmental conditions previously identified as important for Adélie penguin survival underscores the difficulty of predicting future population responses in this region of rapid environmental change.     

Alien grass disrupts reproduction and post-settlement recruitment of co-occurring native vegetation: a mechanism for diversity decline in invaded forest?

Invasive plants significantly threaten native plant biodiversity, yet the mechanisms by which they drive species losses and maintain their own dominance are poorly known. We examined the effects of alien grass invasion (Stenotaphrum secundatum) on (1) abundance and frequency of occurrence, (2) reproductive effort (flowering) and output (fruit production) and (3) soil seed banks for three focal native plants that are characteristic of endangered coastal forest of south-eastern Australia. First, we sampled and compared the foliage cover abundance and frequency (proportion of sites occupied) of the focal natives across invaded and non-invaded (reference) sites (n = 20). We then intensively sampled reproductive effort and output (range of 5–9 sites per species), and density of propagules within the soil (using a standard glasshouse ‘emergence’ method; n = 26) for each species. Invasion was associated with reduced population sizes of all species within the standing vegetation but did not affect population frequency (i.e. proportion of sites where each species was present). Reproductive effort and output were about 75 % lower at invaded than native sites for all species. However, invasion had no effect on propagule densities of the focal natives within the seed bank, despite the substantial reduction in their reproduction. This indicates that the ultimate driver of population declines across invaded landscapes is post-settlement recruitment limitation from the seed bank (e.g. low rates of germination and seedling survival) rather than a reduction in the arrival and storage of propagules at invaded sites. Removal of Stenotaphrum alone might thus be sufficient to stimulate the recovery of native populations from the seed bank.     

L-carnitine counteracts prepubertal exposure to cisplatin induced impaired sperm in adult rats by preventing germ cell apoptosis

We investigated the possible protective effects of L-carnitine on cisplatin induced prepubertal gonadotoxicity and on adult sperm. Prepubertal 30-day-old male rats were divided randomly into three groups: control (n = 12), cisplatin exposed (n = 16) and carnitine treated after cisplatin exposure (n = 16). Rats in the experimental groups were injected with a single dose of cisplatin. L-carnitine was injected 1 h before cisplatin administration and for the following 3 days for the cisplatin + carnitine group. The rats were sacrificed at 31 or 90 days old and their testes were harvested for morphometric and histopathological analysis. Testes of 31-day-old prepubertal rats were examined for germ cell apoptosis using the TUNEL method and for proliferation using PCNA immunostaining. The morphology, motility, quantity and vitality of sperm in epididymal fluid samples of adult 90-day-old rats also were evaluated. L-carnitine treatment reduced testicular damage and the number of TUNEL positive cells significantly, while the number of PCNA positive cells in the cisplatin + carnitine group increased compared to the cisplatin group. During the adult period, epididymal sperm count and viability were improved in rats treated with L-carnitine before prepubertal cisplatin injection. L-carnitine may reduce late testicular and spermatic damage caused by cisplatin administration to prepubertal rats by inducing germ cell proliferation and preventing apoptosis.     

Vegetation response to removal of non-native feral pigs from Hawaiian tropical montane wet forest

Globally, non-native ungulates threaten native biodiversity, alter biotic and abiotic factors regulating ecological processes, and incur significant economic costs via herbivory, rooting, and trampling. Removal of non-native ungulates is an increasingly common and crucial first step in conserving and restoring native forests. However, removal is often controversial and there is currently little information on plant community responses to this management action. Here, we examine the response of native and non-native understory vegetation in paired sites inside and outside of exclosures across a 6.5–18.5 year chronosequence of feral pig (Sus scrofa) removal from canopy-intact Hawaiian tropical montane wet forest. Stem density and cover of native plants, species richness of ground-rooted native woody plants, and abundance of native plants of conservation interest were all significantly higher where feral pigs had been removed. Similarly, the area of exposed soil was substantially lower and cover of litter and bryophytes was greater with feral pig removal. Spatial patterns of recruitment were also strongly affected. Whereas epiphytic establishment was similar between treatments, the density of ground-rooted woody plants was four times higher with feral pig removal. Abundance of invasive non-native plants also increased at sites where they had established prior to feral pig removal. We found no patterns in any of the measured variables with time, suggesting that commonly occurring species recover within 6.5 years of feral pig removal. Recovery of species of conservation interest, however, was highly site specific and limited to areas that possessed remnant populations at the time of removal, indicating that some species take much longer (>18.5 years) to recover. Feral pig removal is the first and most crucial step for conservation of native forests in this area, but subsequent management should also include control of non-native invasive plants and outplanting native species of conservation interest that fail to recruit naturally.