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1.
Chaos ; 30(9): 093123, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33003939

RESUMO

COVID-19 is an emerging respiratory infectious disease caused by the coronavirus SARS-CoV-2. It was first reported on in early December 2019 in Wuhan, China and within three months spread as a pandemic around the whole globe. Here, we study macro-epidemiological patterns along the time course of the COVID-19 pandemic. We compute the distribution of confirmed COVID-19 cases and deaths for countries worldwide and for counties in the US and show that both distributions follow a truncated power-law over five orders of magnitude. We are able to explain the origin of this scaling behavior as a dual-scale process: the large-scale spread of the virus between countries and the small-scale accumulation of case numbers within each country. Assuming exponential growth on both scales, the critical exponent of the power-law is determined by the ratio of large-scale to small-scale growth rates. We confirm this theory in numerical simulations in a simple meta-population model, describing the epidemic spread in a network of interconnected countries. Our theory gives a mechanistic explanation why most COVID-19 cases occurred within a few epicenters, at least in the initial phase of the outbreak. By combining real world data, modeling, and numerical simulations, we make the case that the distribution of epidemic prevalence might follow universal rules.


Assuntos
Infecções por Coronavirus/epidemiologia , Modelos Teóricos , Pneumonia Viral/epidemiologia , Betacoronavirus , Humanos , Pandemias , Dinâmica Populacional
2.
Nat Commun ; 11(1): 4392, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32873810

RESUMO

The successful mitigation of emerging wildlife diseases may involve controversial host culling. For livestock, 'preemptive host culling' is an accepted practice involving the removal of herds with known contact to infected populations. When applied to wildlife, this proactive approach comes in conflict with biodiversity conservation goals. Here, we present an alternative approach of 'proactive hunting surveillance' with the aim of early disease detection that simultaneously avoids undesirable population decline by targeting demographic groups with (1) a higher likelihood of being infected and (2) a lower reproductive value. We applied this harvesting principle to populations of reindeer to substantiate freedom of chronic wasting disease (CWD) infection. Proactive hunting surveillance reached 99% probability of freedom from infection (<4 reindeer infected) within 3-5 years, in comparison to ~10 years using ordinary harvest surveillance. However, implementation uncertainties linked to social issues appear challenging also with this kind of host culling.


Assuntos
Abate de Animais/métodos , Animais Selvagens , Conservação dos Recursos Naturais/métodos , Monitoramento Epidemiológico/veterinária , Rena , Doença de Emaciação Crônica/diagnóstico , Fatores Etários , Animais , Simulação por Computador , Feminino , Masculino , Modelos Estatísticos , Dinâmica Populacional , Fatores Sexuais , Doença de Emaciação Crônica/prevenção & controle , Doença de Emaciação Crônica/transmissão
3.
MMWR Morb Mortal Wkly Rep ; 69(35): 1198-1203, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32881851

RESUMO

SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), is thought to spread from person to person primarily by the respiratory route and mainly through close contact (1). Community mitigation strategies can lower the risk for disease transmission by limiting or preventing person-to-person interactions (2). U.S. states and territories began implementing various community mitigation policies in March 2020. One widely implemented strategy was the issuance of orders requiring persons to stay home, resulting in decreased population movement in some jurisdictions (3). Each state or territory has authority to enact its own laws and policies to protect the public's health, and jurisdictions varied widely in the type and timing of orders issued related to stay-at-home requirements. To identify the broader impact of these stay-at-home orders, using publicly accessible, anonymized location data from mobile devices, CDC and the Georgia Tech Research Institute analyzed changes in population movement relative to stay-at-home orders issued during March 1-May 31, 2020, by all 50 states, the District of Columbia, and five U.S. territories.* During this period, 42 states and territories issued mandatory stay-at-home orders. When counties subject to mandatory state- and territory-issued stay-at-home orders were stratified along rural-urban categories, movement decreased significantly relative to the preorder baseline in all strata. Mandatory stay-at-home orders can help reduce activities associated with the spread of COVID-19, including population movement and close person-to-person contact outside the household.


Assuntos
Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Dinâmica Populacional/estatística & dados numéricos , Saúde Pública/legislação & jurisprudência , Infecções por Coronavirus/epidemiologia , Humanos , Pneumonia Viral/epidemiologia , Fatores de Tempo , Estados Unidos/epidemiologia
4.
Phys Rev Lett ; 125(9): 098003, 2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32915622

RESUMO

We show that "Malthusian flocks"-i.e., coherently moving collections of self-propelled entities (such as living creatures) which are being "born" and "dying" during their motion-belong to a new universality class in spatial dimensions d>2. We calculate the universal exponents and scaling laws of this new universality class to O(ε) in an ε=4-d expansion, and find these are different from the "canonical" exponents previously conjectured to hold for "immortal" flocks (i.e., those without birth and death) and shown to hold for incompressible flocks in d>2. Our expansion should be quite accurate in d=3, allowing precise quantitative comparisons between our theory, simulations, and experiments.


Assuntos
Modelos Biológicos , Animais , Hidrodinâmica , Movimento (Física) , Movimento , Dinâmica Populacional
5.
Proc Biol Sci ; 287(1935): 20201829, 2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-32933442

RESUMO

Annual migration is common across animal taxa and can dramatically shape the spatial and temporal patterns of infectious disease. Although migration can decrease infection prevalence in some contexts, these energetically costly long-distance movements can also have immunosuppressive effects that may interact with transmission processes in complex ways. Here, we develop a mechanistic model for the reactivation of latent infections driven by physiological changes or energetic costs associated with migration (i.e. 'migratory relapse') and its effects on disease dynamics. We determine conditions under which migratory relapse can amplify or reduce infection prevalence across pathogen and host traits (e.g. infectious periods, virulence, overwinter survival, timing of relapse) and transmission phenologies. We show that relapse at either the start or end of migration can dramatically increase prevalence across the annual cycle and may be crucial for maintaining pathogens with low transmissibility and short infectious periods in migratory populations. Conversely, relapse at the start of migration can reduce the prevalence of highly virulent pathogens by amplifying culling of infected hosts during costly migration, especially for highly transmissible pathogens and those transmitted during migration or the breeding season. Our study provides a mechanistic foundation for understanding the spatio-temporal patterns of relapsing infections in migratory hosts, with implications for zoonotic surveillance and understanding how infection patterns will respond to shifts in migratory propensity associated with environmental change. Further, our work suggests incorporating within-host processes into population-level models of pathogen transmission may be crucial for reconciling the range of migration-infection relationships observed across migratory species.


Assuntos
Migração Animal/fisiologia , Doenças Transmissíveis/epidemiologia , Animais , Dinâmica Populacional , Prevalência
6.
BMC Public Health ; 20(1): 1478, 2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-32993598

RESUMO

BACKGROUND: Four decades of population-based tobacco control strategies have contributed to substantial reduction in smoking prevalence in Australia. However, smoking prevalence is still double in socially disadvantaged groups compared to those that are not. But not all tobacco control strategies successfully used in the general population is effective in specific high-risk population groups. Hence, an effective way to reduce smoking in high risk population groups may include targeting them specifically to identify and support smokers to quit. In this backdrop, we examined whether tobacco control interventions at the population-level are more effective in increasing life expectancy among Australians compared to interventions targeting a high risk group or a combination of the two when smoking prevalence is reduced to 10 and 0% respectively. METHODS: Using the risk percentiles approach, analyses were performed separately for men and women using data from various sources such as the 2014-15 National Health Survey linked to death registry, simulated data for high risk groups, and the Australian population and deaths data from the census. Indigenous status was simulated by preferentially assigning those who are indigenous to lower SES quintiles. The age-sex distribution of mental disorder status was simulated using its distribution from 2016 National Drug Strategy Household Survey with 25.9% of mentally ill being assigned to current smoking category and the rest to non-smoking category. The age-sex distribution of prisoners was simulated based on 2014 ABS Prisoners Australia survey with 74% of prisoners being assigned to current smoker category and the rest to non-smoker category. Homelessness status was simulated according to age, sex and indigenous status for 2011 census with all homeless being allocated to the lowest SES category. The age-sex distribution of total cholesterol level was simulated based on 2011-13 Australian Health Survey. RESULTS: The results showed that the combined approach for reducing smoking is most effective for improving life expectancy of Australians particularly for the socially disadvantaged and mentally ill groups both of which have high fraction of smokers in the population. For those who were mentally ill the gain in ALE due to reduction of smoking to 10% was 0.53 years for males and 0.36 years for females which were around 51 and 42% respectively of the maximal gains in ALE that could be achieved through complete cessation. CONCLUSIONS: Targeting high-risk population groups having substantial fraction of smokers in the population can strongly complement the existing population-based smoking reduction strategies. As population and high risk approaches are both important, the national prevention policies should make judicious use of both to maximize health gain.


Assuntos
Promoção da Saúde/estatística & dados numéricos , Expectativa de Vida/tendências , Fumantes/estatística & dados numéricos , Abandono do Hábito de Fumar/estatística & dados numéricos , Fumar/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Austrália/epidemiologia , Feminino , Comportamentos Relacionados com a Saúde , Pessoas em Situação de Rua/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Dinâmica Populacional , Prevalência , Fatores de Risco , Distribuição por Sexo , Prevenção do Hábito de Fumar
7.
BMC Public Health ; 20(1): 1477, 2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-32993614

RESUMO

BACKGROUND: Many migrants suffer from discrimination and poor health in China. We sought to examine the associations between experiences of discrimination and self-reported health among internal migrants in China, as well as the mediators of social integration and perceived stress. METHODS: The data was obtained from a specific survey of migrants, as a part of the National Health and Family Planning Dynamic Monitoring for Migrants conducted in 2014. A total of 15,999 migrants aged 15 to 59 years were recruited by a stratified, multistage clustered sampling procedure in eight Chinese cities. Structural Equation Modeling (SEM) was conducted. RESULTS: The results indicated that experiences of discrimination were associated with worse self-reported health (ß = - 0.32, P < 0.001), less social integration (ß = - 0.25, P < 0.001), as well as higher perceived stress (ß = 0.21, P < 0.01). Both objectively measured socioeconomic status (ß = 0.21, P < 0.001) and subjective social status (ß = 0.21, P < 0.01) had significantly positive correlations with self-reported health. CONCLUSIONS: The discrimination, social exclusion and perceived stress experienced by migrants have significant implications on their health.


Assuntos
Comportamentos Relacionados com a Saúde , Preconceito/psicologia , Autorrelato , Estresse Psicológico/psicologia , Migrantes/psicologia , Adolescente , Adulto , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dinâmica Populacional , Preconceito/estatística & dados numéricos , Classe Social , Fatores Socioeconômicos , Estresse Psicológico/epidemiologia , Migrantes/estatística & dados numéricos , Adulto Jovem
8.
Environ Monit Assess ; 192(10): 633, 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32902741

RESUMO

The Tarai region of Nepal is regarded as the food bowl of Nepal, and yet urban areas have increased in size at an average annual rate of 12% for the 30 years since 1988/1989, largely at the expense of prime agricultural land. Nepal is recognized internationally as highly sensitive to food security with 40% of its population undernourished. To aid future planning and reduce potential further loss of agricultural land and consequent increased food insecurity, we here investigated the previously unknown factors underlying this rapid urban expansion. We achieved this through analyses of land use and land cover (LULC) data, population, and climatic data, in association with focus group discussions and questionnaire surveys. We found that socioeconomic factors were perceived to have made the highest (62%) contribution to urbanization, particularly migration-led population growth and the economic opportunities offered by urban areas, followed by political factors (14.5%), physical factors (12%), and planning and policy factors (11.5%). In addition, climate and physiographic features make the area attractive for urban development along with favorable government plans and policies. Accelerated urban expansion during this period was particularly driven by mass migration due to political upheaval in the country resulting in rapid population and urban center growth. Of the total 293 urban centers in the country, the Tarai region includes 150 (51.2%) of which 77 (26.3%) are located in province 2 alone and accommodate 17.2% of Nepal's households. This increasing urbanization trend is expected to continue in the future due to current socioeconomic and demographic factors. We hope our results which show what has driven past urbanization will aid future urban planning and management of the Tarai as well as other similar regions elsewhere in the world. We also identified that such rapid urban growth is largely at the cost of populations in rural areas with rural depopulation resulting in agriculture being abandoned in some areas. Given Nepal's sensitivity to food security and lower food production, this will be an increasing problem for the future.


Assuntos
Emigração e Imigração , Política Pública , Agricultura , Demografia , Países em Desenvolvimento , Monitoramento Ambiental , Nepal , Dinâmica Populacional , População Urbana , Urbanização
9.
Mar Environ Res ; 160: 105014, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32907732

RESUMO

Alexandrium minutum and Alexandrium pacificum are representatives of the dinoflagellate genus that regularly proliferate on the French coasts and other global coastlines. These harmful species may threaten shellfish harvest and human health due to their ability to synthesize neurotoxic alkaloids of the saxitoxin group. However, some dinoflagellates such as A. minutum, and as reported here A. pacificum as well, may also have a beneficial impact on the environment by producing dimethylsulfoniopropionate-DMSP, the precursor of dimethylsulfur-DMS and sulfate aerosols involved in climate balance. However, environmental conditions might influence Alexandrium physiology towards the production of harmful or environmentally friendly compounds. After assessing the influence of two salinity regimes (33 and 38) relative to each species origin (Atlantic French coast and Mediterranean Lagoon respectively), it appears that DMSP and toxin content was variable between the three experimented strains and that higher salinity disadvantages toxin production and tends to favor the production of the osmolytes DMSP and glycine betaine. Hence, this key metabolite production is strain and species-dependent and is influenced by environmental conditions of salinity which in turn, can diversely affect the environment. Widespread coastal blooms of A. minutum and A. pacificum, although being a risk for seafood contamination with toxins, are also a DMSP and DMS source that potentially contribute to the ecosystem structuration and climate. Regarding recent advances in DMSP biosynthesis pathway, 3 dsyB homologs were found in A. minutum but no homolog of the diatom sequence TpMMT.


Assuntos
Diatomáceas , Dinoflagelados , Ecossistema , Proliferação Nociva de Algas , Humanos , Dinâmica Populacional , Salinidade , Frutos do Mar
10.
PLoS One ; 15(9): e0239175, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32941485

RESUMO

The COVID-19 outbreak has forced most of the global population to lock-down and has put in check the health services all over the world. Current predictive models are complex, region-dependent, and might not be generalized to other countries. However, a 150-year old epidemics law promulgated by William Farr might be useful as a simple arithmetical model (percent increase [R1] and acceleration [R2] of new cases and deaths) to provide a first sight of the epidemic behavior and to detect regions with high predicted dynamics. Thus, this study tested Farr's Law assumptions by modeling COVID-19 data of new cases and deaths. COVID-19 data until April 10, 2020, was extracted from available countries, including income, urban index, and population characteristics. Farr's law first (R1) and second ratio (R2) were calculated. We constructed epidemic curves and predictive models for the available countries and performed ecological correlation analysis between R1 and R2 with demographic data. We extracted data from 210 countries, and it was possible to estimate the ratios of 170 of them. Around 42·94% of the countries were in an initial acceleration phase, while 23·5% already crossed the peak. We predicted a reduction close to zero with wide confidence intervals for 56 countries until June 10 (high-income countries from Asia and Oceania, with strict political actions). There was a significant association between high R1 of deaths and high urban index. Farr's law seems to be a useful model to give an overview of COVID-19 pandemic dynamics. The countries with high dynamics are from Africa and Latin America. Thus, this is a call to urgently prioritize actions in those countries to intensify surveillance, to re-allocate resources, and to build healthcare capacities based on multi-nation collaboration to limit onward transmission and to reduce the future impact on these regions in an eventual second wave.


Assuntos
Betacoronavirus , Infecções por Coronavirus/prevenção & controle , Modelos Biológicos , Pandemias/legislação & jurisprudência , Pneumonia Viral/prevenção & controle , África/epidemiologia , Ásia/epidemiologia , Infecções por Coronavirus/epidemiologia , Previsões , Geografia Médica , Humanos , Incidência , América Latina/epidemiologia , Morbidade/tendências , Mortalidade/tendências , Pandemias/prevenção & controle , Pneumonia Viral/epidemiologia , Dinâmica Populacional , Saúde da População Urbana
12.
Nat Commun ; 11(1): 4394, 2020 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-32879314

RESUMO

The Earth's biota is changing over time in complex ways. A critical challenge is to test whether specific biomes, taxa or types of species benefit or suffer in a time of accelerating global change. We analysed nearly 10,000 abundance time series from over 2000 vertebrate species part of the Living Planet Database. We integrated abundance data with information on geographic range, habitat preference, taxonomic and phylogenetic relationships, and IUCN Red List Categories and threats. We find that 15% of populations declined, 18% increased, and 67% showed no net changes over time. Against a backdrop of no biogeographic and phylogenetic patterning in population change, we uncover a distinct taxonomic signal. Amphibians were the only taxa that experienced net declines in the analysed data, while birds, mammals and reptiles experienced net increases. Population trends were poorly captured by species' rarity and global-scale threats. Incorporation of the full spectrum of population change will improve conservation efforts to protect global biodiversity.


Assuntos
Biodiversidade , Vertebrados , Anfíbios , Animais , Mudança Climática , Conservação dos Recursos Naturais , Ecossistema , Extinção Biológica , Dinâmica Populacional/tendências
14.
Phys Rev Lett ; 125(4): 048105, 2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32794803

RESUMO

Environmental changes greatly influence the evolution of populations. Here, we study the dynamics of a population of two strains, one growing slightly faster than the other, competing for resources in a time-varying binary environment modeled by a carrying capacity switching either randomly or periodically between states of abundance and scarcity. The population dynamics is characterized by demographic noise (birth and death events) coupled to a varying environment. We elucidate the similarities and differences of the evolution subject to a stochastically and periodically varying environment. Importantly, the population size distribution is generally found to be broader under intermediate and fast random switching than under periodic variations, which results in markedly different asymptotic behaviors between the fixation probability of random and periodic switching. We also determine the detailed conditions under which the fixation probability of the slow strain is maximal.


Assuntos
Meio Ambiente , Modelos Biológicos , Dinâmica Populacional , Evolução Biológica , Cadeias de Markov , Processos Estocásticos
15.
Phys Rev Lett ; 125(4): 048102, 2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32794821

RESUMO

In exponentially proliferating populations of microbes, the population doubles at a rate less than the average doubling time of a single-cell due to variability at the single-cell level. It is known that the distribution of generation times obtained from a single lineage is, in general, insufficient to determine a population's growth rate. Is there an explicit relationship between observables obtained from a single lineage and the population growth rate? We show that a population's growth rate can be represented in terms of averages over isolated lineages. This lineage representation is related to a large deviation principle that is a generic feature of exponentially proliferating populations. Due to the large deviation structure of growing populations, the number of lineages needed to obtain an accurate estimate of the growth rate depends exponentially on the duration of the lineages, leading to a nonmonotonic convergence of the estimate, which we verify in both synthetic and experimental data sets.


Assuntos
Microbiota/fisiologia , Modelos Biológicos , Fenômenos Microbiológicos , Dinâmica Populacional
16.
Phys Rev Lett ; 125(4): 048101, 2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32794828

RESUMO

The competitive exclusion principle asserts that coexisting species must occupy distinct ecological niches (i.e., the number of surviving species cannot exceed the number of resources). An open question is to understand if and how different resource dynamics affect this bound. Here, we analyze a generalized consumer resource model with externally supplied resources and show that-in contrast to self-renewing resources-species can occupy only half of all available environmental niches. This motivates us to construct a new schema for classifying ecosystems based on species packing properties.


Assuntos
Ecossistema , Modelos Biológicos , Animais , Comportamento Competitivo , Microbiota , Plantas , Dinâmica Populacional
17.
PLoS One ; 15(8): e0230985, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32845879

RESUMO

Spearfishing is currently the primary approach for removing invasive lionfish (Pterois volitans/miles) to mitigate their impacts on western Atlantic marine ecosystems, but a substantial portion of lionfish spawning biomass is beyond the depth limits of SCUBA divers. Innovative technologies may offer a means to target deepwater populations and allow for the development of a lionfish trap fishery, but the removal efficiency and potential environmental impacts of lionfish traps have not been evaluated. We tested a collapsible, non-containment trap (the 'Gittings trap') near artificial reefs in the northern Gulf of Mexico. A total of 327 lionfish and 28 native fish (four were species protected with regulations) recruited (i.e., were observed within the trap footprint at the time of retrieval) to traps during 82 trap sets, catching 144 lionfish and 29 native fish (one more than recruited, indicating detection error). Lionfish recruitment was highest for single (versus paired) traps deployed <15 m from reefs with a 1-day soak time, for which mean lionfish and native fish recruitment per trap were approximately 5 and 0.1, respectively. Lionfish from traps were an average of 19 mm or 62 grams larger than those caught spearfishing. Community impacts from Gittings traps appeared minimal given that recruitment rates were >10X higher for lionfish than native fishes and that traps did not move on the bottom during two major storm events, although further testing will be necessary to test trap movement with surface floats. Additional research should also focus on design and operational modifications to improve Gittings trap deployment success (68% successfully opened on the seabed) and reduce lionfish escapement (56% escaped from traps upon retrieval). While removal efficiency for lionfish demonstrated by traps (12-24%) was far below that of spearfishing, Gittings traps appear suitable for future development and testing on deepwater natural reefs, which constitute >90% of the region's reef habitat.


Assuntos
Conservação dos Recursos Naturais/métodos , Recuperação e Remediação Ambiental/métodos , Espécies Introduzidas/tendências , Animais , Biomassa , Recifes de Corais , Ecossistema , Peixes/crescimento & desenvolvimento , Golfo do México , Perciformes/crescimento & desenvolvimento , Densidade Demográfica , Dinâmica Populacional , Comportamento Predatório
18.
PLoS One ; 15(8): e0236146, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760084

RESUMO

The smalltail shark, Carcharhinus porosus, was the most abundant elasmobranch species in fisheries off Brazil's northern coast (BNC) in the 1980s, but its population has been declining since the 1990s. For this reason, a demographic analysis is necessary to determine the extent of this decline and the fishing effect on the BNC's population. Therefore, we performed a stochastic demographic analysis of the population in the BNC, and considered its global center of abundance. Smalltail shark specimens (n = 937) were collected with gillnets in Maranhão state, eastern BNC, in the 1980s with sizes ranging between 29.6 and 120.0 cm total length. Most of the individuals (90.6%) caught were juveniles (< 6 years-old), and the mortality and exploitation rates showed that the species was overexploited (92.3% above the fishing mortality corresponding to the population equilibrium threshold). The smalltail shark's biological characteristics, such as slow growth and low fecundity, demonstrate that it is one of the least resilient species among similar sized coastal sharks in the region. All these factors yielded an annual decrease of 28% in the intrinsic population growth rate, resulting in a population decline of more than 90% in only 10 years, and much higher for the current period. This set of features comprising fishing recruitment occurring upon juveniles, overfishing, and intrinsically low resilience make the population unable to sustain fishing pressure and severely hamper biological recruitment, thus causing this drastic population decline. Furthermore, several local extinctions for this species in the northeastern and southeastern regions of Brazil highlight its concerning conservation scenario. Therefore, since similar fisheries characteristics occur throughout its distribution range, C. porosus fits the criteria E of the IUCN Red List for a critically endangered species and urgent conservation measures are needed to prevent its extinction in the near future.


Assuntos
Distribuição Animal , Espécies em Perigo de Extinção/estatística & dados numéricos , Pesqueiros/estatística & dados numéricos , Dinâmica Populacional/estatística & dados numéricos , Tubarões/fisiologia , Fatores Etários , Animais , Brasil , Monitorização de Parâmetros Ecológicos/estatística & dados numéricos , Espécies em Perigo de Extinção/tendências , Fertilidade/fisiologia , Pesqueiros/tendências , Dinâmica Populacional/tendências , Maturidade Sexual/fisiologia
19.
PLoS One ; 15(8): e0236144, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785217

RESUMO

Habitat loss caused by deforestation is a global driver of predator population declines. However, few studies have focussed on these effects for mesopredator populations, particularly the cryptic and elusive species inhabiting tropical rainforests. We conducted camera trapping from 2009-11 and 2014-16, and used occupancy modelling to understand trends of Sumatran mesopredator occupancy in response to forest loss and in the absence of threats from poaching. By comparing the two survey periods we quantify the trend of occupancy for three sympatric felid species in the tropical rainforest landscape of Kerinci Seblat National Park. Between 2000 and 2014, forest loss across four study sites ranged from 2.6% to 8.4%. Of three threatened felid species, overall occupancy by Sunda clouded leopard (Neofelis diardi) and Asiatic golden cat (Catopuma temminckii) remained stable across all four areas between the two survey periods, whilst marbled cat (Pardofelis marmorata) occupancy increased. In general occupancy estimates for the three species were: lower in lowland forest and increased to attain their highest values in hill forest, where they declined thereafter; increased further from the forest edge; positively correlated with distance to river, except for golden cat in the second survey where the relationship was negative; and, increased further from active deforestation, especially for clouded leopard in the second survey, but this was some 10-15km away. Our study offers fresh insights into these little known mesopredators in Sumatra and raises the practically important question of how far-reaching is the shadow of the encroachment and road development that typified this deforestation.


Assuntos
Distribuição Animal , Conservação dos Recursos Naturais , Espécies em Perigo de Extinção/estatística & dados numéricos , Felidae , Parques Recreativos/estatística & dados numéricos , Animais , Monitorização de Parâmetros Ecológicos/estatística & dados numéricos , Espécies em Perigo de Extinção/tendências , Geografia , Indonésia , Parques Recreativos/tendências , Dinâmica Populacional/estatística & dados numéricos , Dinâmica Populacional/tendências , Comportamento Predatório , Floresta Úmida , Gravação em Vídeo/estatística & dados numéricos
20.
PLoS One ; 15(8): e0227163, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32822346

RESUMO

Illegal hunting is a persistent problem in many protected areas, but an overview of the extent of this problem and its impact on wildlife is lacking. We reviewed 40 years (1980-2020) of global research to examine the spatial distribution of research and socio-ecological factors influencing population decline within protected areas under illegal hunting pressure. From 81 papers reporting 988 species/site combinations, 294 mammal species were reported to have been illegally hunted from 155 protected areas across 48 countries. Research in illegal hunting has increased substantially during the review period and showed biases towards strictly protected areas and the African continent. Population declines were most frequent in countries with a low human development index, particularly in strict protected areas and for species with a body mass over 100 kg. Our results provide evidence that illegal hunting is most likely to cause declines of large-bodied species in protected areas of resource-poor countries regardless of protected area conservation status. Given the growing pressures of illegal hunting, increased investments in people's development and additional conservation efforts such as improving anti-poaching strategies and conservation resources in terms of improving funding and personnel directed at this problem are a growing priority.


Assuntos
Conservação dos Recursos Naturais/legislação & jurisprudência , Internacionalidade , Mamíferos , Animais , Dinâmica Populacional
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