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Vernes, Karl
- PublicationThe Ecology of the Bhutan takin Budorcas whitei in Jigme Dorji National Park, Bhutan(2019-02-11)
;Sangay, Tiger; The Bhutan takin Budorcas whitei, a large gregarious forest-dwelling ungulate, is endemic to Bhutan and categorized as 'vulnerable' by the IUCN Red List of Threatened Species. The word 'takin' is used hereafter to denote both singular and plural. Prior to my work, there had been only one study on this species which investigated its diet within its summer habitat. Prior to beginning my field research on takin, I assessed its current distribution and conservation status in Bhutan from information gathered through publications, field surveys, interviews and unpublished reports. The assessment resulted in documenting some interesting facts such as establishing the Bhutan takin as endemic to Bhutan; the takin's site fidelity to hot spring and salt lick areas, and their distribution along the river valleys which are important landscape features for habitat selection. I identified additional threats to the takin like anthropogenic disturbance and disruption to migration routes, threats posed by domestic livestock including dogs, and the risk of zoonoses disease transmission.
I examined takin migratory movement between their winter and summer habitat, and their summer habitat use in the Tsharijathang Valley of Jigme Dorji National Park, Bhutan, from 2013-2015 using GPS collars. Bhutan takins are seasonal migrants from warm broad-leaved forest to alpine meadow within the altitude range of 1500 m to 5550 m asl (meter above sea level, hereafter using 'm' instead of 'm asl'). GPS-collars were placed on 13 adult takins (7 males and 6 females) to document these seasonal movements. Because of animal welfare concerns, sub-adult animals could not be collared. Takin, on average, travelled about 4 km per 24-hour period, about a third of which occurred at night. There was high site fidelity and overlap of habitat in their summer range that led to short distance travel which ultimately resulted in a smaller summer home range. The Minimum Convex Polygon (MCP) home range estimate for takin in the summer habitat at a 95% isopleth ranged between 3.35 - 14.21 km2, while the kernel utilization distribution (KUD) estimate ranged between 7.55 to 27.4 km2. A male takin (TM2724) collared on 8 July 2013 provided partial data on takin migration from its summer range to its winter range before the GPS collar ran out of memory on 27 September 2013. However, this inaugural migration data showed that the animal travelled 26.68 km in the rugged mountainous terrain in three days, and part of which was along a ridgeline between 5007 to 5374 m. The male migrated to the area around Zomling, Lingzhi and Barshong, Naro of Thimphu district.
Habitat use by the Bhutan takin in their summer (alpine meadows) and winter (broadleaf forest) habitats was examined by comparing floristic composition in the areas that were used by takin compared to those that were not used. A collective total of 58 plots were laid in the summer habitat (30 plots, 15 each in the used and unused area) and in the winter habitat (28 plots, 14 each in the used and unused area). Principal component analysis (PCA) showed that the first three principal components explained about 70 percent of the total variance between used and unused sites. PC1 had significant loadings from variables like altitude, herb count and herb mean height, PC2's significant variables were tree count and tree mean DBH while PC3 had significant loadings from shrub mean height. Analysis of variance using distance matrices showed that there were significant differences between the used and unused plots in both habitats (summer F 1, 28 = 69.36, p < 0.01; winter F 1, 26 = 3.89, p < 0.01). The analysis of data from the summer habitat showed significant difference between used and unused plots that was driven by differences in plant species and diversity, with used plots having significantly more trees and shrubs which the takin prefers as cover and for rest during midday.
Local knowledge and perceptions by people towards the takin was assessed by conducting facetoface semi-structured interviews on 169 residents of Jigme Dorji National Park from the Laya Geog (takin summer habitat; 91 residents) and Khatey and Khamey Geogs (takin winter habitat; 78 residents). Most respondents knew the takin was the national animal and a significantly higher proportion also knew its protected status. There was a significant difference in knowledge based upon respondents' residence whereby residents in the takin's summer habitat possessed more knowledge on the vulnerable status of takin. The summer habitat has affluent residents that benefit from collection of the prized medicinal Chinese caterpillar fungus or 'Cordyceps' Ophiocordyceps sinensis; this in turn allows them better access to media (e.g. television and radio) that expose them to pertinent information and campaigns surrounding the takin. Most respondents expressed positive feelings towards the takin and supported its protection.
This strong positive attitude and awareness by residents is promising but it is strongly recommended that the park develops diverse education programs targeting different age groups and learning capabilities in continuing to maintain local support and stewardship. Conservation of the takin, however, is not without its challenges and requires a commitment to reduce anthropogenic disturbance such as land use change from road construction, infrastructure for power transmission lines, unregulated harvesting of natural resources notably the prized cordyceps, competition for foraging resources from domestic livestock, and most critically, the spread of zoonotic disease transmission from domestic livestock. Understanding habitat use by takin and associated preferred habitat variables amidst various anthropogenic threats is integral towards ameliorating damage to takin habitat and preventing further loss. Furthermore, the Jigme Dorji National Park management should reinforce the implementation of the tripartite Tsharijathang Agreement whereby domestic livestock are not grazed in the Tsharijathang Valley a month prior to the takin's arrival. The valley needs urgent protection as a declared takin sanctuary to provide a safe habitat for takin during their breeding season. This valley attracts different congregating herds from several wintering habitats around Thimphu, Paro, Gasa and Punakha, and it is crucial to facilitate the current genetic exchange to increase population vigor for the long-term survival of the takin, Bhutan's national animal.
- PublicationPopulation density of the Northern Bettong 'Bettongia Tropica' in northeastern QueenslandThe population density of the northern bettong ('Bettongia tropica'), an endangered potoroid restricted to northeastern Australia, was estimated using minimum known-to-be-alive (MKTBA) and Jolly-Seber estimates derived from mark-recapture data. At Davies Creek in the north of the bettong's current range, bettong population densities were significantly lower in 'Allocasuarina' forest (1.5 bettongs km⁻²) that in 'Eucalyptus' woodland (3.7 - 7.5 bettongs km⁻²). At 'Eucalyptus' woodland sites south and west of Davies Creek, population density was up to twice as great as it was at Davies Creek, while at sites north of Davies Creek, population densities were very low. Capture success was variable, ranging between 5 and 21%. Our data support previous research that suggested 'B. tropica' density on the Lamb Range was correlated with latitude and moisture. Despite the restricted distribution of the northern bettong, our data indicate that populations on the Lamb Range, the species' stronghold, are generally healthy.
- PublicationManaging Wetlands for Waterbirds on a Coastal Floodplain of New South Wales, Australia(2011)
;Smith, Adam Noel; Ford, HughKey to the conservation of waterbirds on coastal floodplains in Australia is improved management of their wetland habitats. Waterbirds and wetlands of the Clarence River floodplain, in north-east New South Wales, were studied from 2005 to 2007 to gather ecological information about the waterbird species that use the floodplain and the physical properties of the constituent wetlands. The work contained in this PhD consisted of a review of historical accounts, including oral history, appraisals of the wetland types and waterbird species present, monitoring of selected wetlands for waterbirds and water quality, particularly salinity, and bathymetric mapping of selected wetlands. Also, the grazing habits of one species (Black Swan 'Cygnus atratus') were studied, and an assessment of the value of drains as waterbird habitat was undertaken. Finally, wetland management on the floodplain was reviewed to contextualise how this would most favour waterbirds. - PublicationEffects of season and fire on the diversity of hypogeous fungi consumed by a tropical mycophagous marsupial1. Despite the importance of fire in many natural systems, knowledge of how fire affects the relationship between hypogeous fungi and mycophagous mammals in fire-prone environments is limited. Using experimental fires, we examined consumption of hypogeous ectomycorrhizal fruit-bodies by an endangered tropical mycophagist, the northern bettong Bettongia tropica Wakefield, in north-eastern Australia. 2. Fungus was the major dietary component (56%) throughout all seasons, both before and after fire. At least 35 hypogeous taxa were consumed. Number of taxa consumed during different seasons was similar, but was significantly higher on unburnt sites than on burnt sites. Similarly, diversity of taxa per faecal sample was significantly greater on unburnt sites, but also increased irrespective of fire from wet season to dry season. 3. Cluster and principal component analyses were used to examine patterns in consumption of fungal taxa. The greatest differences in dietary composition were between the period immediately after fire on burnt sites (early wet season) and all other season and treatment combinations. This difference was due to increased consumption of taxa in the fire-adapted family Mesophelliaceae and reduced consumption of the genus Elaphomyces. Principal component analysis revealed two major gradients in consumption. The first accounted for 32% of total variance and described change in consumption of taxa with season. The second accounted for 24% of total variance and described change in consumption of taxa before and after fire. 4. Despite taxon-specific changes in consumption of hypogeous fungi, the body condition of bettongs did not change significantly between seasons or in relation to fire, suggesting that bettongs were never compromised in their optimal fungal intake. 5. Our data show that the northern bettong has a flexible response to fire and could be best thought of as a fire-adapted marsupial. We therefore propose a precautionary approach to fire management of bettong habitat; at the present time this would include maintaining the recent fire regime of low to moderately intense fires every 3-4 years.
- PublicationDiet of mala ('Lagorchestes hirsutus') at Ulu-r̲u-Kata Tju-t̲a National Park and comparison with that of historic free-ranging mala in the Tanami Desert: Implications for management and future reintroductionsLack of information regarding the ecology of threatened species may compromise conservation efforts. Mala, a small macropod that historically inhabited a vast area of arid Australia, became extinct in the wild in 1991. Although dietary studies were completed before their disappearance from the Tanami Desert, no such work was conducted in the southern Northern Territory before mala became extinct in this part of its former range. The reintroduction of mala to Uluru-Kata Tjuta National Park provided an opportunity for dietary analysis of faecal pellets. Results show that mala foraged a wide variety of plant species, although grasses and supplementary food comprised the bulk of the diet. Neither the average percentage of Poaceae, 'Triodia' in particular, nor supplementary food found in pellet samples was correlated with rainfall. Niche breadth analysis showed a narrow dietary range for both the Tanami and Uluru studies. Mala at both locations selected similar types of plants, plant parts, and several of the same species. Results suggest that food species 'Aristida holathera' and 'Eragrostis eriopoda' should be monitored to assist in determining the carrying capacity of the Uluru enclosure. A botanically diverse reintroduction site supporting 'Eragrostis', 'Aristida' and 'Triodia' appears to be most suitable for mala.
- PublicationThe northern flying squirrel ('Glaucomys sabrinus') as a vector for inoculation of red spruce ('Picea rubens') seedlings with extomycorrhizal fungiMycophagous mammals excavate and ingest fruiting bodies (ascomata) of hypogeous ectomycorrhizal fungi and produce faeces containing numerous spores. To evaluate the significance of mycophagy to plant hosts we compared inoculation rate and degree of fungal development on red spruce (Picea rubens) seedlings treated with (1) faeces of the northern flying squirrel (Glaucomys sabrinus) against seedlings treated with (2) ascospores of Elaphomyces granulatus, and (3) those grown in natural forest soil or (4) forest soil that had been rendered sterile. No seedlings grown in sterilised soil showed fungal colonization. Significantly more seedlings were colonized in natural forest soil (97.5 %) than in sterile soil treated with squirrel faeces (69.2 %) or fruiting body spores (27.5 %). Treatment with squirrel faeces produced significantly more colonization than treatment with fruiting body spores. Fungal development was significantly greater on seedlings grown in forest soil compared with other treatments, but did not differ significantly between squirrel faeces and fruiting body treatments. These results demonstrate that passage through the digestive tract of flying squirrels may enhance germination and inoculation potential of fruiting body spores, although actively growing mycelium in forest soil may be the primary and most effective means by which seedlings develop mycorrhizae under natural conditions.
- Publication'Cort short on a mountaintop' - Eight new species of sequestrate 'Cortinarius' from sub-alpine Australia and affinities to sections within the genusDuring the course of research on mammal mycophagy and movement in the Northern Tablelands of New South Wales, Australia, extensive collections of sequestrate fungi were made, including numerous cortinarioid taxa. Historically any novel taxa would have been described in the cortinarioid sequestrate genera 'Descomyces', 'Hymenogaster', 'Protoglossum', 'Quadrispora', 'Thaxterogaster' or 'Timgrovea' based on broad morphological similarities of the sporocarps and spore ornamentation. However, consistent with other recent analyses of nuclear DNA regions, taxa from sequestrate genera were found to have affinities with 'Cortinarius' and 'Descolea' or 'Hebeloma', and to be scattered across many sections within 'Cortinarius'. None of the historical sequestrate cortinarioid genera are monophyletic in our analyses. In particular, the gastroid genus 'Hymenogaster' is paraphyletic, with one clade including two species of 'Protoglossum' in 'Cortinarius', and a second clade sister to Hebeloma. Eight new species of sequestrate Cortinarius are described and illustrated, and discussion of their affinities with various sections provided: 'C. argyronius', 'C. caesibulga' and 'C. cinereoroseolus' in section 'Purpurascentes', 'C. maculobulga' in section 'Rozites', 'C. sinapivelus' in section 'Splendidi', 'C. kaputarensis' in a mixed section 'Phlegmacium/Myxacium' within a broader section 'Dermocybe', 'C. basorapulus' in section 'Percomes' and 'C. nebulobrunneus' in section 'Pseudotriumphantes'. Keys to genera of the 'Bolbitiaceae' and 'Cortinariaceae' containing sequestrate taxa and to currently known Australian species of sequestrate 'Cortinarius' and 'Protoglossum' are provided. As with the related agaricoid taxa, macroscopic characters such as colour and texture of basidioma, degree of loculisation of the hymenophore, and stipe-columella development and form remain useful for distinguishing species, but are generally not so useful at the sectional level within 'Cortinarius'. Microscopic characters such as spore shape, size, and ornamentation, and pileipellis structure (simplex vs duplex and size of hyphal elements) are essential for determining species, and also appear to follow sectional boundaries.
- PublicationFire-related changes in biomass of hypogeous sporocarps at foraging points used by a tropical mycophagous marsupialChanges in pre- and post-fire biomass of hypogeous fungal sporocarps remaining at locations where an endangered mycophagous marsupial, the northern bettong ('Bettongia tropica'), had foraged, were assessed in fire-prone sclerophyll forest in northeastern Australia. Low to medium intensity experimental fires were set during the late dry season in 1995 and 1996 and post-foraging biomass of sporocarps (expressed as biomass of sporocarps remaining at recent 'B. tropica' diggings) was measured at unburnt and burnt sites at approximately six-week intervals for a period of 14 months. Post-foraging biomass was significantly higher at burnt sites immediately following fire compared with control sites, solely due to increased biomass of hypogeous species belonging to the family 'Mesophelliaceae'. Several months after fire, post-foraging biomass was significantly higher on unburnt sites compared with very low biomass on burnt sites. Twelve months after fire, the biomass on burnt and unburnt sites was not significantly different, having returned to biomass observed pre-fire. All evidence points toward mesophellioid fungi being greatly more available to bettongs on recently burnt ground, but fire may make several other sporocarp taxa considerably less available several months following fire.
- PublicationHypogeous fungi in the diet of the red-legged pademelon 'Thylogale stigmatica' from a rainforestopen forest interface in northeastern AustraliaThe diet of the Red-legged Pademelon 'Thylogale stigmatica' has previously been described as comprising a range of dicotyledonous and monocotyledonous plants, rainforest fruits, seeds, and some fungi. We collected T stigmatica faecal samples from a rainforest-open forest ecotone in northeastern Australia and analysed them for the presence of fungal spores. Of the 20 samples collected, 12 contained spores of several types of hypogeous fungi, with the number of spore types per sample ranging from 1-7, with a mean of 5.Twenty fungal spore types were recognised in total; seven of these could be attributed to hypogeous ('truffle-like') ectomycorrhizal genera, and most others had spore morphologies suggestive of a hypogeous habit. This is the first report of consumption of ectomycorrhizal hypogeous fungi by the genus 'Thylogale', and as such, adds important new information on the role these forest-dwelling wallabies might play in dispersing hypogeous fungi across the dynamic interface between rainforest and open forest in eastern Australia.
- PublicationEffects of landscape composition and configuration on northern flying squirrels in a forest mosaicHabitat loss and sometimes habitat fragmentation per se affect species survival, reproduction, dispersal, abundance and distribution. However, understanding the independent effects of fragmentation (i.e., landscape configuration) has been limited because it is frequently confounded with landscape composition (i.e., habitat amount). We assess the independent effects of landscape composition and configuration on the occurrence of northern flying squirrels ('Glaucomys sabrinus') in New Brunswick, Canada after controlling for local site conditions. We measured landscape structure using an "organism-based" approach; landscape structure was characterized quantitatively using a spatially explicit local scale distribution model for northern flying squirrels. Flying squirrels occurred more frequently in old forest, at sites with mixed coniferous–deciduous microhabitat composition and greater amounts of habitat cover at the neighbourhood (within homerange) scale. Squirrels were less likely to occur at sites surrounded by greater proportions of non-habitat matrix (non-treed or early seral open areas). The occurrence of flying squirrels was not strongly correlated with patch size or edge contrast. We detected no interaction between the effects of patch size and habitat composition. Landscape composition was clearly a more important predictor of flying squirrel distribution than configuration. We conclude that management practices that maximize the amount of old forest cover,maintain diverse tree species composition and minimize the creation of open areas should enhance the conservation value of landscapes for northern flying squirrels. Manipulating landscape pattern though forest management likely has limited use in mitigating the negative influence of habitat loss on this species.
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