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Iberodes littoralis subsp. gallaecica (Laínz) M. Serrano, R. Carbajal & S. Ortiz is a small annual plant endemic to dune systems in the north-west Iberian Peninsula. It is categorized as Endangered on the IUCN Red List and is a priority taxon under the EU Habitats Directive. Nevertheless, the only comprehensive census of this subspecies was conducted in 2009. Here we present the results of a new survey conducted in 2023 that adds a new location to its known range. Comparison with the previous census suggests that both the total population and area of occupancy have increased. However, these changes were not uniform across the range of the subspecies, with populations increasing at the northern and southern extremes and populations at central sites remaining stable or decreasing. Spatial differences in climate, anthropogenic pressures, plant performance and/or random fluctuations may explain these interpopulation variabilities. Given that the majority of populations are already located within the EU Natura 2000 network, we recommend that the current level of protection be maintained and that the plant be reintroduced into dune systems from which it has recently disappeared. Despite the increase in the total population, we recommend that the plant be recategorized as Critically Endangered given that its area of occupancy is small. Further censuses over time will be needed to provide information on population dynamics, trends, fluctuations and responses to environmental variables.
Spix’s Macaw Cyanopsitta spixii, extinct in the wild since 2000, was successfully reintroduced in Brazil in 2022, leading to significant progress, including the hatching of wild chicks. However, recent restrictions on further releases by the Brazilian government have put the reintroduction programme into jeopardy. This study updates our 2023 population viability analysis (PVA) to assess the impact of these delayed releases on the wild population. Using six modelled scenarios, we confirm that without annual supplementation of captive-bred birds, the probability of extinction in the wild remains at 100%. Even a one-time release is insufficient to secure population stability. Our results highlight that those annual releases of at least 20 individuals are necessary to ensure long-term viability, with reduced but still essential growth achievable with 10 birds per year. Supplementation of the wild population does not compromise the long-term viability of the well-established captive population. We urge immediate action to resume the release programme in 2024 to prevent the species from once again facing extinction in the wild.
The Secretarybird Sagittarius serpentarius is a charismatic raptor of the grasslands and open savannas of Africa. Evidence of widespread declines across the continent has led to the assessment that the species is at risk of becoming extinct. Southern Africa was identified as a remaining stronghold for the species, but the status of this population requires reassessment. To determine the status of the species in South Africa, Lesotho, and Eswatini, we analysed data from a citizen science project, the Southern African Bird Atlas Project (SABAP). We implemented novel time-to-detection modelling, as well as summarisation of changes in reporting rates, using standard metrics, to determine the trajectory of the population. To cross-validate our findings, we used data from another citizen science project, the Coordinated Avifaunal Roadcounts (CAR) project. While our results were in agreement with previous studies that have reported significant declines when comparing SABAP1 (1987–1992) and SABAP2 (2007 and onwards), all analysis pathways that examined data within the SABAP2 period only, as well as CAR data from this period, failed to show an alarming declining trend over this more recent time period. We did, however, find some evidence for decreases in Secretarybird abundance in urban grid cells. We used random forest models to predict probability of occurrence, as well as probability of abundance (reporting rates) for the assessed region and provided population estimates based on these analysis pathways. Continued monitoring and conservation efforts are required to guard this population stronghold.
Despite thousands of individuals entering the illegal wildlife trade each year, assessments of pangolin populations are largely non-existent, even in areas with high exploitation and limited personnel and field equipment. Although pangolins have unique keratin-based scales, there is no universal scale-marking method for individuals despite some pangolin conservation programmes utilizing marking for reference and cataloguing. Each programme currently establishes and manages its own system, resulting in inconsistencies and limiting data sharing. To facilitate pangolin monitoring and research, we developed a standardized method for assigning individual identification numbers, which we call the Pangolin Universal Notching System. This system is neither resource nor training intensive, which could facilitate its adoption and implementation globally. Its application could help to address knowledge gaps in pangolin ageing, reproduction, survivorship, migration and local trafficking patterns, and could be used in combination with other tagging techniques for research on pangolin biology.
Living plant collections play a crucial role in ex situ conservation, but their conservation value hinges on assessment of their composition, data quality and on strategic planning for optimization of the collection that takes into account species diversity, conservation status and allocation of resources. Cactaceae is one of the most threatened plant families globally and has a broad distribution in Brazil, with two of the seven centres of diversity for this group and a total of 276 known species. Climate change could escalate the threat to cacti, potentially placing 90% of species at risk by 2050. We conducted a case study of Cactaceae in the living Cactarium collection of the Rio de Janeiro Botanic Garden, evaluating the diversity of the collection and recommending strategic actions to enhance its conservation value. In 2022, we inventoried all specimens in the collection and cross-referenced them with the institutional specimen registry system, Jabot. The collection contains 156 cacti species that naturally occur in Brazil (57% of the total), including 43 species categorized as threatened on the Brazilian Red List and 57 categorized as threatened on the IUCN Red List. We recommend research to map cacti species that are threatened but not covered by in situ conservation in the country, list the priority species for acquisition by the collection, and make recommendations that will facilitate improved contribution of the Rio de Janeiro Botanic Garden to the conservation of the Brazilian flora.
Patterns of extinction risk can vary across taxa, with species of some groups being particularly vulnerable to extinction. Rails (Aves: Rallidae) represent one of the most extreme yet well-documented cases of mass extinction within a modern vertebrate group. Between 54 and 92% of rail species became extinct following waves of human contact during both the Holocene and the Anthropocene eras, and a third of the extant species are currently threatened or near-threatened. Here, we (1) examine extinction filters through consecutive human contacts with rails, investigating the role of intrinsic life-history traits and (2) investigate the drivers of contemporary vulnerability. During the most recent wave of extinction, we found that body size was an important correlate of rail extinctions, with both smaller and larger bodied species more likely to become extinct. Island endemism and small clutch size were the strongest predictors of contemporary vulnerability. Overall, island endemic rails tend to follow the same trajectory as extinct species, suffering mostly from invasive predators and overhunting, but with different traits targeted contemporarily compared to past extinctions. Moreover, modern anthropogenic threats have created the potential for new intricate pathways – or a contemporary ‘field of bullets’ – making future vulnerability potentially less predictable.
The “Critically Endangered” Alagoas Antwren Myrmotherula snowi is found only in the Atlantic Rainforest of north-east Brazil. We surveyed all sites where the species has been recorded, as well as 15 other potential sites. We summarise all observations of the species, focusing on the period from 2016 onwards, and including systematic censuses in three breeding seasons (October–March 2018/19, 2019/20, and 2020/21) at the type locality, Murici, where we also searched for nests of the species. We did not locate any individuals at sites other than Murici. The number of apparent individuals detected declined by 67% over seven years (a decline of 50% over the three years in which standardised systematic counts were made), and only six adults were observed in the most recent breeding season. The global population is now likely to be in single-digit figures. Of five nests found, four failed, through predation by snakes and opossums, and abandonment. We installed protective barriers to protect two of these nests from predators, which may have contributed to the single successful fledging. Such methods offer most hope for now of stalling the decline. Efforts to develop captive breeding methods with model species have been underway since 2019 but face many difficulties. Improving habitat protection and restoration is crucial but will only take effect in the long term.
Understanding the distribution and habitat requirements of species is crucial for designing conservation actions, yet this information is not available for many plant species. We report the first confirmed wild populations of Porroglossum parsonsii, which, because of its horticultural value, is commercialized in national and international markets, from where it was first described to science. Our large-scale survey of 341 10 × 30 m plots spanning Andean forests, paramo habitats and pasturelands in Colombia suggests that P. parsonsii has a restricted geographical distribution in Andean forests with high forest cover (71.4–86.2%), where it occurs in low numbers (5–17 individuals per plot). Because of its market value (USD 18–20 per plant) there is a risk the species could be collected illegally, and therefore the habitat of the species in the Santuario de Fauna y Flora de Iguaque requires appropriate conservation.
The family Syngnathidae contains 52 seahorse species, which inhabit a range of habitats including coral reefs, seagrass beds and coastal estuaries. The seahorse Hippocampus kelloggi is among the most widely distributed species, occurring from Indo-West Pacific to East Africa. This species was included in the IUCN Red List in 2017 and is classified as vulnerable according to A2cd criteria. In this study, three specimens collected from the central coast of Mozambique were investigated and based on morphology and mitochondrial subunit of cytochrome oxidase I (COI) were identified as H. kelloggi. These results confirmed for the first time the extensive range of occurrence of H. kelloggi on the central coast of Mozambique.
Spix’s Macaw Cyanopsitta spixii is one of the most endangered Neotropical Psittacidae species. Extinct in the wild in the year 2000, in June 2022 the first cohort of C. spixii was reintroduced to its original habitat. For a successful reintroduction of the species, it is necessary to examine the viability of the population against natural and external threats and the environmental requirements for success. Thus, this paper presents a “Population Viability Analysis” (PVA) for Spix’s Macaw. It used the Vortex and RangeShiftR software, biological and environmental data from a bibliographic survey, and information provided by the field team responsible for the reintroduction of the species, and who work directly with the species in captivity. We found that the minimum viable population (MVP) for reintroduction of the species is 20 individuals. However, considering the impact of disease, drought, hunting, and illegal trafficking, this population can only persist if the release of individuals from captivity occurs annually over the next 20 years combined with the reforestation of natural habitat to support population growth.
In Chapter 1 it was emphasised that the first cellular life forms to evolve were bacteria, and that photosynthetic bacteria called cyanobacteria released oxygen through photosynthesis and thus set in train the conditions which allowed the many forms of aerobic life to evolve.
The Wood Snipe Gallinago nemoricola is one of the least known shorebird species, and its habitat associations are very poorly understood. Here we provide the first assessment of the habitat use of the Wood Snipe during the breeding season. Between May and July 2021 at a 4-km2 alpine meadow in Sichuan province, China, we conducted population surveys and behavioural observations to identify sites where breeding Wood Snipe occurred and foraged. We quantified the habitat characteristics and food resource availability of these sites and compared them with randomly selected “background” sites. Comparison between 34 occurrence sites and 25 background sites indicated that during the breeding season, Wood Snipes are not distributed evenly across alpine meadow habitats, but preferred habitats in the lower part (3,378–3,624 m) of the alpine meadow with intermediate levels of soil moisture. In addition, comparison between 17 foraging sites and 24 background sites showed that the Wood Snipe tended to forage at sites with higher soil fauna abundance. We found weak evidence for denser vegetation cover at its height and no evidence for other biotic habitat variables such as vegetation composition or other abiotic habitat variables such as slope, soil penetrability, or disturbance level to influence Wood Snipe habitat associations. Our results suggest that the actual distribution range of the Wood Snipe during the breeding season may be smaller than expected from the extent of apparently suitable habitat. We advise caution in evaluating the potential habitat availability and distribution of the Wood Snipe, and call for further research to better understand the ecology of this rare species to inform its conservation.
Grazielanthus is a monotypic, dioecious and microendemic plant genus of the Brazilian Atlantic Forest. Its only species, Grazielanthus arkeocarpus, is categorized as Critically Endangered on the IUCN Red List and comprises only one small population, in the Poço das Antas Biological Reserve, Rio de Janeiro State. Collaborative activities have been developed since 2013 to implement in situ and ex situ conservation actions for this species. Successful in situ planting has increased the number of individuals in its natural population. Ex situ conservation efforts have resulted in the cultivation of the species in two Brazilian living plant collections, and this will soon increase to three collections.
The American crocodile Crocodylus acutus occurs across the Americas, with its northernmost distribution being in South Florida, USA. This species has undergone severe declines across its range and is categorized globally as Vulnerable on the IUCN Red List and as Threatened on the U.S. Federal Endangered Species List. Long-term monitoring studies in the USA have documented a shift in American crocodile nesting activity and an expansion of its range throughout the southern and eastern coasts of South Florida. However, no successful American crocodile nests have been recorded until now on the west coast of South Florida. Here we document the American crocodile nest monitoring conducted during 1997–2021 at Rookery Bay National Estuarine Research Reserve and the first successful nest from the west coast of South Florida for C. acutus. Marco Airport and McIlvane Marsh are the two main American crocodile nesting areas identified at the Reserve, with 92 nests and 3,586 eggs recorded during 1997–2021. We found most nests at Marco Airport (95.7%) and only four nests (4.3%) at McIlvane Marsh. To date, none of the nests found at Marco Airport have produced successful hatchlings. In contrast, hatchlings have been produced at McIlvane Marsh since nests were first documented there in 2020. We discuss the implications of our findings in terms of the future conservation of the species.
Tasmanian devils are endangered due to an infectious clonal cancer that has reduced populations by up to 80 per cent since it first arose in 1996. As part of a management strategy for the species, an island population was established through an assisted colonisation event on Maria Island National Park. The original scope of the Maria Island population was to establish and maintain a disease-free population of devils. The island is now used as a source site for these trial releases of devils to mainland Tasmania populations. The 2012 release cohort to the island had a high degree of relatedness. However, through dedicated management strategies, including contraception and selective harvesting, this situation has been rectified and the Maria Island population now represents a genetically diverse group. Monitoring, using traditional methods of trapping and camera traps, in addition to genetic monitoring, has been essential to the establishment and maintenance of the Maria Island population.
Extensive cattle ranging is an important economic activity in mountains, with diverse effects on native mammal communities. The effects of cattle Bos taurus can be negative, positive or neutral, mostly depending on the stocking rate. We examined the effect of cattle on the diversity and abundance of native mammalian species in the Austral Yungas region of Argentina, considering environmental variables, land protection status, and human influence. Using 12,512 trap-nights from 167 camera-trap stations over 11 years (2009–2019), we calculated a relative abundance index using camera events and used generalized linear models to estimate the effect of cattle on small mammals, large herbivores, species of conservation concern and felids. Cattle had different effects on each group of native mammals. We observed a lower abundance of large native herbivores and the absence of small mammals in areas with high cattle abundance. The tapir Tapirus terrestris, jaguar Panthera onca and white-lipped peccary Tayassu pecari are rare in the Yungas and therefore potentially vulnerable to extinction there. Conservation of small felids and low cattle abundance could be compatible, but felids are threatened by other anthropogenic influences. Native mammalian diversity and richness were related to land protection status. The entire ecoregion is potentially suitable for cattle, suggesting the potential for further threats, and that cattle should be excluded from strictly protected areas. To ensure extensive cattle ranging is compatible with wildlife conservation in areas where exclusion is not possible, we recommend improved management of cattle and moderate stocking rates.
Asian colobines make up close to half of all non-human primate species found in Asia. These monkeys have specialized dietary and habitat needs and are found in a wide range of habitat at different latitudinal and altitudinal zones. About two-thirds of Asian colobines are endemic to only one country, with the largest number of threatened species found in Indonesia, Vietnam and China. The highest percentage of colobine species are found in tropical rain forest and tropical moist deciduous forest that have correspondingly less areas remaining. Species that are found in specific habitats like karst limestones, flooded forests and highland forest are also particularly threatened. Expansion of agriculture, aquaculture and biological resource use, through hunting and trade are the current top threats to colobines. The successful conservation of these species would require that species-specific protection needs are met, as well as collaborative approaches to ensure better protection across their distribution ranges.
Knowledge of where a threatened species occurs in a landscape is crucial for determining its habitat requirements and informing its conservation planning and management. We conducted the first broad-scale survey of the Endangered Alligator Rivers Yellow Chat Epthianura crocea tunneyi across much of its known range on drying coastal floodplains in northern Australia. Presence-absence records from 257 sites surveyed in the late dry season (August–December) of 2018 and 2019 were modelled using occupancy/detectability models. Occupancy was estimated to be 0.10 ± 0.04 with a high detection probability (0.89 ± 0.07). Modelling of 13 site-level environmental covariates found that chats were more likely to be detected at sites where the native shrub Sesbania sesban was present, were close to hydrogeological features such as depressions or channels, were long unburnt (5+ years) and/or with topsoil damage caused by feral pigs. Our estimates of chat occupancy, detectability, and the covariates that influence their occupancy, have improved our understanding of the role that fire and feral animals have on chat distribution and habitat selection, and can be used as a baseline for future monitoring. We also provide recommendations on how to design and implement future monitoring of this subspecies.
Two introduced carnivores, the European red fox Vulpes vulpes and domestic cat Felis catus, have had extensive impacts on Australian biodiversity. In this study, we collate information on consumption of Australian birds by the fox, paralleling a recent study reporting on birds consumed by cats. We found records of consumption by foxes on 128 native bird species (18% of the non-vagrant bird fauna and 25% of those species within the fox’s range), a smaller tally than for cats (343 species, including 297 within the fox’s Australian range, a subset of that of the cat). Most (81%) bird species eaten by foxes are also eaten by cats, suggesting that predation impacts are compounded. As with consumption by cats, birds that nest or forage on the ground are most likely to be consumed by foxes. However, there is also some partitioning, with records of consumption by foxes but not cats for 25 bird species, indicating that impacts of the two predators may also be complementary. Bird species ≥3.4 kg were more likely to be eaten by foxes, and those <3.4 kg by cats. Our compilation provides an inventory and describes characteristics of Australian bird species known to be consumed by foxes, but we acknowledge that records of predation do not imply population-level impacts. Nonetheless, there is sufficient information from other studies to demonstrate that fox predation has significant impacts on the population viability of some Australian birds, especially larger birds, and those that nest or forage on the ground.
Free-ranging domestic dogs Canis familiaris threaten wildlife species through predation, hybridization, competition for resources, and by contributing to the transmission of pathogens. The impacts of predation may be problematic, but in many regions the interactions of free-ranging dogs and wildlife are poorly studied. To determine the extent of the impacts of attacks by free-ranging dogs on Iranian mammals, we reviewed nearly 2 decades of social and traditional media reports and the scientific literature to gather data from across the country. We identified 160 free-ranging dog attacks (79 from academic articles, 14 from social media, and 67 from a variety of news websites) from 22 of the country's 31 provinces. Attacks by dogs were reported on 17 species, including nine Carnivora, six Artiodactyla, one Rodentia, and one Lagomorpha species. Most of the reported attacks on carnivores were on felids, including the Asiatic cheetah Acinonyx jubatus (n = 19), Eurasian lynx Lynx lynx (n = 18), caracal Caracal caracal (n = 10) and Pallas's cat Otocolobus manul (n = 8). Attacks on Artiodactyla were primarily reported for goitered gazelle Gazella subgutturosa (n = 47). Most of these attacks occurred within or adjacent to protected areas (n = 116, 73%), suggesting that free-ranging dogs are one of the most important human-associated threats to wildlife species even in protected landscapes. The impact of free-ranging dogs may be hampering conservation, and therefore we suggest some practical policy guidance for managing the impacts of free-ranging dogs on threatened species.