An alternative to dolphin oil as a fish attractant in the Ganges River system: conservation of the Ganges River dolphin

Oil extracted from blubber of the Ganges River dolphin, Platanista gangetica, is used as a fish attractant in India and Bangladesh. This oil fishery is associated with the mortality of hundreds of dolphins every year. Oil from fish scraps was field tested for 121 days during 1997-1999 in the Ganges at Patna and was a very effective alternative to dolphin oil as a fish attractant. Fishing with fish oil resulted in higher catches and greater income per person per hour (Rs. 17.8±12.5) than fishing with dolphin oil (Rs. 11.6±9.3). However, there is no statistically significant difference between the results from fishing with dolphin and fish oil. Oil from fish scraps is inexpensive and can be made readily available to all the fishermen. Its widespread use would help in conserving the endangered Ganges River dolphin.     

Population sizes, site fidelity and residence patterns of Australian snubfin and Indo-Pacific humpback dolphins: Implications for conservation

Very little is known about the ecology of snubfin Orcaella heinsohni and Indo-Pacific humpback dolphins Sousa chinensis in Australian waters. We used photo-identification data collected between 1999 and 2002 in Cleveland Bay, northeast Queensland, to estimate abundance, site fidelity and residence patterns of these species in order to make recommendations for their effective conservation and management. Our abundance estimates indicate that less than a hundred individuals of each species inhabit this coastal area. Even with relatively unbiased and precise abundance estimates population trends will be extremely difficult to detect in less than three years unless changes in population size are very high (>20% p.a.). Though both species are not permanent residents in Cleveland Bay, they both used the area regularly from year to year following a model of emigration and reimmigration. Individuals of both species spend periods of days to a month or more in coastal waters of Cleveland Bay before leaving, and periods of over a month outside the study area before entering the bay again. Because of their small population sizes and movement patterns, snubfin and humpback dolphins are particularly vulnerable to local extinction. Our results illustrate that: (1) detection of population trends should not be a necessary criterion for enacting conservation measures of both species in this region, and (2) efforts to maintain viable populations of both species in Cleveland Bay must include management strategies that integrate anthropogenic activities in surrounding areas.     

To be or not to be—the effect of nature conservation management on flowering of Paeonia mascula (L.) Miller in Israel

Mount Meiron Nature Reserve is the largest Mediterranean reserve in Israel. Since its establishment, goat grazing and woodcutting have been prohibited and dense oak maquis has developed by succession. The succession of vegetation poses the risk of losing species. The peony (Paeonia masculla) is a locally endangered species in Israel, growing only in a small population in the Mount Meiron Nature Reserve with only 5% of plants flowering. We sought a management practice that would increase the flowering percentage of the peonies and secure the future of its population. We found that flowering peonies grew mainly in locations with about 47% direct sun radiation, while most plants grew under heavy shade with only 27% direct radiation. Creation of small gaps increased the flowering to 15-20%. To ensure the future of the peonies in the Mount Meiron Nature Reserve, small gaps must be created—even if this conflicts with broader current management policies.     

Artificial dispersal of endangered epiphytic lichens: a tool for conservation in boreal forest landscapes

Due to increasing fragmentation of the boreal forests of Fennoscandia, a number of epiphytic lichens are now becoming threatened. Since these species typically are limited by a poor ability of dispersal, one possible but largely unexplored strategy for conservation is to disperse lichen material artificially into suitable habitats. Therefore, the objective of this study was to evaluate survival and vitality in lichen fragments from Evernia divaricata (L.) Ach. and Ramalina dilacerata (Hoffm.) Hoffm. after transplantation into three different stand types situated in northern Sweden, using different fragment sizes and modes of transplantation. After one year, survival ranged between 85% and 97.5%, and new growth occurred at all transplantation sites. The study has shown that transplantations of small fragments might constitute a resource-efficient option for establishment of new populations of endangered lichen species, or for enlarging their populations at the present sites of occurrence. In addition, the mode of transplantation was of importance for fragment vitality.     

Reproductive biology and conservation implications of three endangered snapdragon species (Antirrhinum, Plantaginaceae)

About 32% of Antirrhinum species are considered to be endangered; however, no field studies have focused on their reproductive biology. In this work, several aspects of the reproductive biology (flowering phenology, floral biology, breeding system) and potential limits on seed quantity and quality (pollen limitation, inbreeding depression) were studied in natural populations of three endangered species of the genus (Antirrhinum charidemi, Antirrhinum subbaeticum, Antirrhinum valentinum). Results disclose that all three species need insect visitors for seed production since fruit set after autonomous self-pollination was lower than under hand cross-pollination. A. charidemi and A. valentinum were mainly self-incompatible, whereas A. subbaeticum was self-compatible but herkogamous. Supplementary pollination in open-pollinated flowers only increased fruit set and seed set relative to controls in a given population of A. valentinum. Preliminary data on inbreeding depression at early life-cycle stages of the self-compatible A. subbaeticum revealed that the cumulative level was low. Despite the three species being closely related and sharing many ecological characteristics, they show different mating systems, and different factors limit seed quantity and quality. Thus, caution should be taken when making a common conservation plan for a group of closely related taxa.     

Distribution, status, and conservation needs of Asian elephants (Elephas maximus) in Lampung Province, Sumatra, Indonesia

In the mid 1980s, Asian elephant (Elephas maximus) populations were believed to persist in 44 populations on the Indonesian island of Sumatra. Twelve of these populations occurred in Lampung Province, but our surveys revealed that only three were extant in 2002. Causal factors underlying this decline include human population growth, changes in land use, and human-elephant conflict. Nevertheless, our surveys in the Province’s two national parks, Bukit Barisan Selatan and Way Kambas, produced population estimates of 498 (95% CI = [373, 666]) and 180 (95% CI = [144, 225]) elephants, respectively. The estimate for Bukit Barisan Selatan is much larger than previous estimates; the estimate for Way Kambas falls between previous estimates. The third population was much smaller and may not be viable. These are the first estimates for Southeast Asian elephant populations based on rigorous sampling-based methods that satisfied the assumptions of the models used, and they suggest that elephant numbers in these parks are of international importance. While our results suggest that Sumatra’s remaining elephant populations may be larger than expected, they also suggest that the future for these animals is bleak. Human-elephant conflict was reported around all three areas in Lampung and their elephant populations are currently threatened by habitat loss and poaching. Local solutions are possible, but will require much greater commitment by all stakeholders.     

Status assessment of the Indus River dolphin, Platanista gangetica minor, March-April 2001

A survey was conducted in March and April 2001, to assess the status of the Indus River dolphin, Platanista gangetica minor, throughout its present range. A total of 1535 km of survey effort was conducted, consisting of 1375 km of the Indus River main channel, 136 km of Indus River secondary channels, and 24 km of the Panjnad River, a tributary of the Indus. The effective range of the Indus dolphin has declined by 80% since 1870. The sum of best group size estimates produced an abundance estimate of 965 dolphins. Extrapolation of encounter rates to un-surveyed channels and application of a correction factor to account for missed dolphins indicates that the metapopulation may number approximately 1200 individuals. Dolphins occur in five subpopulations separated by irrigation barrages. A pronounced increase in dolphin abundance and encounter rate was observed in each subsequent downstream subpopulation (except the last). The three largest subpopulations were between Chashma and Taunsa Barrages (84 dolphins; 0.28/km), Taunsa and Guddu Barrages (259 dolphins; 0.74/km) and Guddu and Sukkur Barrages (602 dolphins; 3.60/km). Reasons suggested for the high encounter rate between Guddu and Sukkur Barrages, include high carrying capacity, low levels of anthropogenic threat, effective conservation, and augmentation of the subpopulation by downstream migration of dolphins from upstream.     

Ecology of the native and introduced crayfishes Austropotamobius pallipes and Procambarus clarkii in southern Spain and implications for conservation of the native species

The former and present distribution of white clawed crayfish (Austropotamobius pallipes) in the province of Granada (southern Spain) is studied. Before 1980 it was widely distributed but at present only 16 populations exist. The decline is related to the presence of the freshwater red-swamp crayfish (Procambarus clarkii), an American species, vector of the aphanomycosis disease, introduced to the Iberian Peninsula in 1974 and now widely distributed in the watercourses and marshes of southern Spain. To establish an appropriate conservation policy for A. pallipes at its southernmost distribution limit, we studied watercourses from two river basins, Genil and Guadiana Menor, (tributaries of the Guadalquivir River). P. clarkii inhabits the medium to lower reaches of these two river basins (with its upper limit at 820 m a.s.l.). The distribution of this species was best explained by the effect of three of the 12 analyzed variables: altitude, water-current and minimum winter temperatures. From our results, the repopulation of the native crayfish is almost impossible in those reaches inhabited by P. clarkii. However, based on the habitat selection study, it is clear that upper reaches are unsuitable for the red-swamp crayfish, where the native white-clawed crayfish may have greater survival possibilities, and these sites can be used for future restocking projects.     

Phylogeography and conservation of the populations of Zootoca vivipara carniolica

The lizard Zootoca vivipara has both oviparous and viviparous populations which belong to distinct clades. This study aims to elucidate the geographic distribution, phylogeography and conservation priority of the oviparous subspecies, Zootoca vivipara carniolica, that has recently been identified in Slovenia. We studied seven Slovenian populations, two northeastern Italian populations and five northwestern Italian populations. The seven cytochrome b haplotypes that we identified from the Slovenian and Italian oviparous populations form a monophyletic basal clade. The high homogeneity of the Slovenian and northeastern Italian populations (nucleotide diversity π=0.06%) is a striking contrast with the pattern observed in northwest Italy where each of the five populations studied presents a private haplotype (π=1.03%). The results obtained suggest that all the extant lineages of Z. v. carniolica have originated in an Italian refuge. The reproductive and phylogenetic distinctiveness of Z. v. carniolica clearly justifies conservation of its populations, especially in Italy where the highest genetic diversity and the most ancestral haplotype were observed.     

Assessing waterbird conservation objectives: An example for the Burry Inlet, UK

We use an individual-based model to assess the conservation objectives for knot Calidris canutus L. and oystercatcher Haematopus ostralegus L. on the Burry Inlet Special Protection Area (SPA), UK. Population monitoring has identified a decline in oystercatcher numbers, but cannot determine whether this is due to a decline in site quality. Long term data on cockle stocks show that the biomass of the large-sized cockles consumed by oystercatcher declined after 2004, whereas a similar decline was not observed in the smaller cockles consumed by knot. The model postdicts that during the winters of 2005/2006 to 2008/2009 the site was unable to support the number of oystercatcher present at the time it was designated (i.e. the SPA population). Large cockle biomass remained low during 2009/2010, but increases in mussel biomass meant that the model postdicted that the site could support the SPA population of oystercatcher. Knot food supplies remained high during most years, except 2008/2009 during which the model postdicted that the SPA population could not be supported. The model postdicted that the stock reserved for oystercatchers after shellfishing needed to be 2-4 times the amount consumed by the birds in order to support the bird population. We recommend that where necessary, the conservation objectives of waterbirds should be assessed using a combination of thorough population size and behaviour monitoring to identify sites with population declines, and individual-based modelling on these sites to determine whether reduction in site quality may contribute to the site-specific population decline.     

Impacts of sediment loads, tadpole density, and food type on the growth and development of tadpoles of the spotted tree frog Litoria spenceri: an in-stream experiment

The impact of increased-deposited sediment loads on growth and development of tadpoles of the spotted tree frog, Litoria spenceri, in south-eastern Australia was assessed in conjunction with food type and tadpole density. This investigation was conducted in stream enclosures subjected to varying treatments of tadpole density, substrata and deposited-sediment load. Tadpole growth and development were not significantly affected by food type, but there was a trend toward increased performance on periphyton substrata. Tadpole growth and development were significantly reduced by increases in tadpole density and sediment load. These effects were independent, suggesting that increased sediment load reduced food quality rather than quantity. Activities in catchments that increase sediment loads in streams may adversely affect growth and development of tadpoles of L. spenceri. Increased sediment input into streams may therefore reduce tadpole fitness and recruitment to the terrestrial stage. Disturbance processes that increase stream sediment loads, such as forestry activities and associated road construction, may potentially have contributed to the observed declines of L. spenceri and other lotic anurans in south-eastern Australia.     

Current status and conservation of the gray snub-nosed monkey Rhinopithecus brelichi (Colobinae) in Guizhou, China

Gray snub-nosed monkeys Rhinopithecus brelichi (Colobinae), categorized as endangered on the IUCN Red List, are endemic to Guizhou, China. To evaluate the species’ current status we surveyed five sites in the Mt Fanjing area between August 2007 and June 2008. These sites were identified from previous surveys and interviews with local officials and villagers. Four sub-populations, with a total of ca. 750 individuals, were located in mixed deciduous and evergreen broad leaf forest at 800-2200 m asl. Identified threats to the species include (1) accidentally injured or killed by poaching, (2) loss or alteration of habitat through wood extraction, and (3) loss or alteration of habitat through economic activities, such as building projects and illegal mining. We recommend that several actions can be taken to alleviate the anthropogenic pressure on the ecosystem including: (1) designating specific forest reserve for sustainable wood extraction, (2) utilizing biogas to reduce firewood demands, (3) introducing local people to bamboo utilization for generate greater cash income, (4) educating for young people and encouraging them to work in developed areas, and (5) encouraging the villagers to move out the mountain.     

Effects of marine reef National Parks on fishery CPUE in coastal Kenya

The role of marine protected areas in conserving fish stocks and their potential influence on adjacent fisheries was studied at Malindi and Watamu Marine National Parks, Kenya (established in 1968). For most species catch per unit effort (CPUE) in traditional Dema traps fished across park boundaries was higher within the parks (up to an order of magnitude). However, a few species (e.g., the seagrass parrotfish, Leptoscarus vaigensis and the whitespotted rabbitfish, Siganus sutor, WSR) had higher seasonal CPUE outside the parks. Potential spillover of fishes from the parks to adjacent fished areas was tested with a logistic “decay” model of density gradients (CPUE) across park borders from fringing and patch reefs. A steep decay in CPUE off the Malindi patch reef suggested little spillover of most species. However, greater spillover was suggested off fringing reefs. Species differences were evident. The two most important commercial species showed different density gradients. Species diversity declined more abruptly off the fringing reefs. We conclude that although spillover of most species from the parks is limited, the most important commercial species exhibits significant spillover to adjacent fisheries and the Parks likely comprise important nursery and growth areas for other species.     

Seasonal movements in the Sumatran orangutan (Pongo pygmaeus abelii) and consequences for conservation

Preservation of orangutan habitat can only be effective when their range requirements are taken into consideration. Here, the effect of the variation in fruit supply at different altitudes on the seasonal movements of orangutans is investigated. Transects were surveyed every 2 months from 1998 to 2000, at different altitudinal zones in the larger Ketambe area, Indonesia. The density of orangutan and sources of ripe fruit with soft pulp were determined along these transects. Both orangutan density and the availability of fruit varied considerably throughout the survey period at different altitudinal zones. The peaks in fruit production at different altitudes occurred in successive periods. For each altitudinal zone a significant correlation was found between orangutan density and the number of fruit sources, which shows that orangutans follow the production of fruit between these altitudinal zones within the boundaries of their home range. Orangutans with core areas in intermediate and highland areas depend seasonally on fruit production of lowland areas, and vice versa. Thus, conservation of large tracts of primary forest with a range of different altitudes is necessary to preserve the remaining orangutan population.     

A nine-year study of successful breeding in a Bonelli’s eagle population in southeast Spain: a basis for conservation

We analyse the factors influencing breeding success in a healthy population of Bonelli’s eagle (Hieraaetus fasciatus) from south-east Spain, a raptor that has suffered a serious decline in Europe. Between 18 and 33 pairs were annually monitored during the period 1994-2002. Several factors that may affect four breeding parameters were studied, namely human presence, vegetation, relief, climatic factors, intra- and inter-specific relationships, diet, prey abundance, nest building, adult mortality and age of reproduction. A consistently high breeding success was registered during the study period (productivity=1.43, SD=0.11), which was probably the result of high adult survival, adequate prey availability and mild weather conditions. However, a certain vulnerability to the presence of golden eagles (Aquila chrysaetos) and to human disturbance was observed. One interesting result was the reduced survival of young chicks on north-facing cliffs owing to colder conditions, which may partially explain the decline of the Bonelli’s eagle populations along its European distribution limits. We discuss the role of this healthy subpopulation in an Iberian metapopulation context, and propose that the potential interference of golden eagles should be taken into account when designing management strategies for Bonelli’s eagles. Finally, we pinpoint some conservation priorities and the importance of reducing the main causes of adult mortality (i.e. shooting and electrocution) to assure successful reproduction and survival of this species.     

Using habitat models to determine conservation priorities for pond-breeding amphibians in a privately-owned landscape of northern Idaho, USA

As rural landscapes experience increasing levels of residential development, the persistence of species that rely on them will depend on informed planning and management decisions. An understanding of habitat requirements is essential for setting priorities and developing landscape-level plans for the survival of these species. In many temperate rural landscapes, artificially created ponds may be the only wetlands available for aquatic reproduction by amphibians. The introduction of non-native fish into these ponds reduces survival and prohibits successful reproduction of many native pond-breeding amphibians. We surveyed 105 randomly selected wetlands in a primarily privately-owned, rural landscape in north Idaho, USA, for pond-breeding amphibian larvae in 2004 and 2005. We used an information theoretic multimodel inference and an algorithmic (random forests) approach to model habitat for each species based on local and landscape characteristics. We also used a mail survey to quantify how landowners value fish in their wetlands and their plans for future wetland development and fish stocking. Sixty-seven percent of pond owners reported that fishing in their pond was at least slightly important to them and 36% of owners indicated that they were at least 50% likely to add fish to their ponds in the next 5-10 years. Landscape change predictions for this area indicate that forests will become more open due to thinning; habitat models indicated that this is likely to be detrimental to long-toed salamanders and beneficial to Pacific treefrogs. Habitat models also indicate that Columbia spotted frog breeding sites consist of wetlands on flat ground with high solar insolation and that this species is sensitive to nearby development, indicating that as this landscape becomes further developed, this species may require habitat protection for persistence.     

Anthropogenic and natural disturbance lead to differing patterns of gene flow in the Rocky Mountain tailed frog, Ascaphus montanus

Understanding the influence of habitat alteration on population structure and persistence is critical for effective conservation strategies. Timber harvest and wildfire are two of the most prevalent disturbances across temperate forests, yet the long-term effects of these two forces on population connectivity have rarely been studied. We studied populations of the Rocky Mountain tailed frog (Ascaphus montanus) across landscapes that have experienced either timber harvest or broad scale fires. Rocky Mountain tailed frogs generally require forested habitat, and are a species of concern in managed forests. We used landscape genetic techniques to test the explanatory power of alternative paths of connectivity across both burned and harvested forests and identified topographical and climatic variables that significantly influenced gene flow. We found that timber harvest and fire led to different patterns of genetic connectivity. Widespread terrestrial gene flow was maintained across previously burned areas and connectivity was primarily limited by solar radiation. In contrast, gene flow among populations in managed forests followed riparian corridors, presumably to avoid the loss of cover due to timber harvest. Gene flow along riparian corridors in Rocky Mountain tailed frogs differs from a population of the closely related coastal tailed frog (Ascaphus truei), for which gene flow appears to occur primarily over land. These results suggest management of Rocky Mountain tailed frogs should focus on maintaining riparian buffer zones, which may be less effective for the coastal species. Thus, consideration of landscape differences is essential even for conservation of closely related, morphologically similar species.     

Intensive beach management as an improved sea turtle conservation strategy in Mexico

We evaluate the role of intensive beach management, meaning intense patrolling and nest reburial to a central hatchery, as a strategy for improving the success of sea turtle conservation at nesting sites in Mexico. We report the results of an experimental program at Playa Cuixmala, Jalisco, western Mexico. Sea turtle conservation efforts in Mexico have, in general, poor results because of lack of funds, which leads to insufficient beach protection and severe negative effects of nest removal on hatching success and sex ratios. Alternative strategies are needed to optimize limited resources. We predicted that intensive beach management, which included intense patrolling and careful nest reburial, could be an effective way to maximize nest survival and hatchling release under limited financial and human resources. The results of our 9-year study were very positive. Survival rate increased several fold during the study period. Hatching success and sex ratios were not significantly different between in-situ and removed nests. Survival in removed nests was, however, much higher that in-situ nests, because of predation and beach erosion. In total, the small (3 km length) Playa Cuixmala became the second most productive sea turtle nesting beach in the region because of these concentrated efforts. Intense beach management can be an important technique for sea turtle conservation, and can be properly applied to small beaches or the most productive sections of large beaches.     

Relationship between population size and genetic diversity in endangered populations of the European bullhead (Cottus gobio): implications for conservation

This study investigated the relationship between the current size of endangered bullhead (Cottus gobio) populations and microsatellite genetic variability. Additionally, the microsatellite data were used to evaluate whether a genetic test for population bottlenecks was able to provide evidence of recent severe population declines. Finally, our results were used to develop conservation priorities and measures. Population size appears to be a crucial parameter in determining the amount of genetic diversity that can be preserved in bullheads, since a significant positive correlation was observed between both variables. Furthermore, in some populations we were able to detect genetic signatures of the documented decline in population size. We suggest that the most immediate goal for bullhead conservation should be to increase the size and the range of the populations, and in doing so minimise or even reverse further genetic erosion. Potential management actions like habitat quality improvement, reduction of river fragmentation and supplementation programmes (translocation, supportive breeding) are discussed.