The distribution and conservation status of Carpentarian grasswrens (Amytornis dorotheae), with reference to prevailing fire patterns

2015 ◽  
Vol 21 (4) ◽  
pp. 291 ◽  
Author(s):  
Graham N. Harrington ◽  
Stephen A. Murphy

The Carpentarian grasswren (Amytornis dorotheae) is a small, shy passerine patchily distributed through Triodia systems in the central and southern parts of Australia’s tropical savannas. Population decline has been reported in the Northern Territory, presumably due to mismanaged fire. The species is considered Endangered in the Northern Territory and Near Threatened in Queensland, but it is not listed Federally. Here, we present the results of over 3000 surveys conducted between 2008 and 2013. We show that Carpentarian grasswrens are divided into four populations, although the northernmost one (Borroloola) now appears to be extinct. The Area of Occupancy for the southernmost population appears to have declined by 28%, while only small numbers of isolated birds now occur at the two intervening populations. Our data suggest that the four populations appear to be at different stages on an extinction pathway, from population decline, to fragmentation and isolation, to extinction, and this seems to be related to worsening fire patterns as one moves northwards. We suggest that the Carpentarian grasswren be listed as Vulnerable at the State and Federal level, and that urgent investment in long-term regional fire management using prescribed burning is required to reverse the declines in the extant populations. For the presumed extinct Borroloola population, restoration will probably need to involve translocation coupled with effective fire management.

2007 ◽  
Vol 16 (3) ◽  
pp. 295 ◽  
Author(s):  
Owen F. Price ◽  
Andrew C. Edwards ◽  
Jeremy Russell-Smith

We investigated the efficacy of firebreaks in the prevention of wildfires in the Arnhem Land Plateau, a vast, rugged and sparsely populated region with high biodiversity value and frequent wildfires. A total of 623 events where a fire met a permanent firebreak (cliffs, stream order, tracks and roads) in different fire seasons were compiled. Cliffs were more effective than streams at stopping fires, which were more effective than roads. Larger streams were more effective than small ones. The largest streams stop 75% of early dry season fires, but there are no firebreak types with more than 50% likelihood of stopping a late dry season fire. Geographic Information System (GIS) surfaces of the relative density of the three firebreak features in the landscape were randomly sampled and compared with the total number of fires and late dry season fires using generalised linear modelling. Several of the density variables were weakly but significantly related to fire frequency, and it appears that late dry season fires are influenced by features at a larger scale (16-km radius) than total fires (4 km). The Aerial Prescribed Burning program for 2004 was studied to identify how effective it was at stopping subsequent wildfires by dividing ignition lines into 137 5-km sections. Only 20% of sections achieved a 100% burn and where gaps occurred, a subsequent fire was 88% likely to penetrate the line. Firebreaks are not certain instruments for fire management in this area.


2009 ◽  
Vol 259 (1) ◽  
pp. 132-142 ◽  
Author(s):  
Matthias M. Boer ◽  
Rohan J. Sadler ◽  
Roy S. Wittkuhn ◽  
Lachlan McCaw ◽  
Pauline F. Grierson

2019 ◽  
Vol 46 (6) ◽  
pp. 455
Author(s):  
Jeff Short ◽  
Peter Copley ◽  
Laura Ruykys ◽  
Keith Morris ◽  
John Read ◽  
...  

Abstract Greater stick-nest rats were widely distributed across southern Australia in pre-European times, but only survived as a single population on the Franklin Islands in South Australia. Conservation efforts since 1983 have included survey of the remaining population, establishment of a captive colony and subsequent translocations to both island and mainland sites. Translocations have met with mixed success, with four of 10 (three islands and one mainland site) successful and extant for 19–28 years, five unsuccessful (one island and four mainland sites) and one as yet indeterminate. Overall, the increase in number of populations, area of occupancy and extent of occurrence has been positive, and has resulted in a down-listing of conservation status. There are numerous plausible explanations for the lack of success at some sites, but few data to differentiate among them. These plausible explanations include: the release of stick-nest rats to habitats of poor quality; high levels of predation (perhaps hyperpredation) by native predators (chiefly monitors and predatory birds) in combination, at some sites, with predation by feral cats or foxes; and ineffective release protocols. Most extant populations have undergone substantial fluctuations over time, and some show apparent long-term declines in abundance, likely increasing their probability of local extinction over time. There is a need for regular ongoing monitoring – of stick-nest rats themselves, their habitat and their suite of potential predators – to aid interpretation of outcomes. A more experimental approach to future releases is required to adjudicate among competing explanations for such declines.


2020 ◽  
Vol 29 (5) ◽  
pp. 339 ◽  
Author(s):  
Jeremy Russell-Smith ◽  
Andrew C. Edwards ◽  
Kamaljit K. Sangha ◽  
Cameron P. Yates ◽  
Mark R. Gardener

Northern Australia comprises by far the most fire-prone-half of a fiery continent, where fire frequencies range from annual in the tropical savannas to periodic very-extensive fire events following above-rainfall conditions in the central Australian rangelands. As illustration of the challenges facing effective fire management in Australia’s 5.7×106km2 rangelands, we examine the status of contemporary prescribed burning activities in the Northern Territory, a 1.4×106km2, very sparsely settled (0.18 persons km−2) jurisdiction characterised by vast flammable landscapes, few barriers to fire-spread, predominantly anthropogenic ignitions, and limited institutional resources and capacity. Unsurprisingly, prescribed-fire management is shown to be restricted to specific locales. For more effective, landscape-scale fire management, potential solutions include engagement with dispersed remote communities and incorporation of Indigenous Ranger Groups into the fire-management network, and building on the success of savanna-burning greenhouse gas emission projects as an example for incentivising landscape fire and emergency management services generally. Recently, significant steps have been taken towards implementing formal regional fire-management planning processes involving inclusive community-stakeholder engagement, and the setting of clearly defined time-constrained objectives and targets.


2020 ◽  
Vol 105 (3) ◽  
pp. 281-299
Author(s):  
Javier Carreño-Barrera ◽  
Luis Alberto Núñez-Avellaneda ◽  
Maria José Sanín ◽  
Artur Campos D. Maia

Solitary, dioecious, and mostly endemic to Andean cloud forests, wax palms (Ceroxylon Bonpl. ex DC. spp.) are currently under worrisome conservation status. The establishment of management plans for their dwindling populations rely on detailed biological data, including their reproductive ecology. As in the case of numerous other Neotropical palm taxa, small beetles are assumed to be selective pollinators of wax palms, but their identity and relevance in successful fruit yield were unknown. During three consecutive reproductive seasons we collected data on population phenology and reproductive and floral biology of three syntopic species of wax palms native to the Colombian Andes. We also determined the composition of the associated flower-visiting entomofauna, quantifying the extent of the role of individual species as effective pollinators through standardized value indexes that take into consideration abundance, constancy, and pollen transport efficiency. The studied populations of C. parvifrons (Engel) H. Wendl., C. ventricosum Burret, and C. vogelianum (Engel) H. Wendl. exhibit seasonal reproductive cycles with marked temporal patterns of flower and fruit production. The composition of the associated flower-visiting entomofauna, comprised by ca. 50 morphotypes, was constant across flowering seasons and differed only marginally among species. Nonetheless, a fraction of the insect species associated with pistillate inflorescences actually carried pollen, and calculated pollinator importance indexes demonstrated that one insect species alone, Mystrops rotundula Sharp, accounted for 94%–99% of the effective pollination services for all three species of wax palms. The sequential asynchronous flowering of C. parvifrons, C. ventricosum, and C. vogelianum provides an abundant and constant supply of pollen, pivotal for the maintenance of large populations of their shared pollinators, a cooperative strategy proven effective by high fruit yield rates (up to 79%). Reproductive success might be compromised for all species by the population decline of one of them, as it would tamper with the temporal orchestration of pollen offer.


Oryx ◽  
2020 ◽  
pp. 1-6
Author(s):  
María M. Torres-Martínez ◽  
Héctor E. Ramírez-Chaves ◽  
Elkin A. Noguera-Urbano ◽  
Fernando C. Passos

Abstract The brown hairy dwarf porcupine Coendou vestitus is a poorly studied Andean species endemic to Colombia. Its current Red List category is contradictory: globally it is categorized as Data Deficient but in Colombia it is categorized as Vulnerable. This contradiction has limited the implementation of conservation programmes. We evaluate the level of rarity of the species and provide consolidated information for a new assessment of its Red List status. We reviewed literature, photographs, and voucher specimens in natural history collections. Using the confirmed records, we estimated the extent of occurrence (EOO) based on the minimum convex polygon and the area of occupancy (AOO) summing the area of grid squares occupied by the species. We found that C. vestitus is very rare, with a small range, low estimated population density, occurrence in only one habitat type and small body size. The species has an EOO of 3,323 km2 and an AOO of 24 km2, based on six confirmed localities, all on the western slopes of the Eastern Cordillera, in the central Andean region of Colombia. Based on the species' rarity, restricted distribution, and threats to its natural habitat, we recommend its categorization as Endangered on the IUCN Red List. This will help delineate research and conservation efforts for this porcupine, which has a highly restricted range and inhabits the threatened Andean forest.


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1540
Author(s):  
Bence Fülöp ◽  
Bálint Pacsai ◽  
Judit Bódis

Semi-natural grasslands were previously established through traditional land use and maintained by active management, but their extension nowadays is declining rapidly, particularly in areas that also have tourism potential. In parallel, the conservation value of the remaining areas is increasing. The shore of Lake Balaton is a particularly good example, as Lake Balaton is an area highly affected by tourism, yet there have been valuable habitats able to survive and provide refuge for many vulnerable, protected species. Fortunately, we have reliable information about the vegetation of the area from two decades ago. Comparing these data with our recent surveys we investigated the changes in habitats and the distribution of protected plant species in connection with the active conservation treatments such as grazing or cutting. Our results show that in areas where treatments are still ongoing, protected plant species are more likely to survive, or even other species can appear, which is in clear contrast with conditions experienced in abandoned areas, where at least seven protected species have disappeared. According to our results, minor, but appropriately chosen and well-executed management interventions, can help in the long-term maintenance of species-rich habitats and improving the conservation status of threatened species.


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