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1.
Cell Rep ; 43(4): 114097, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38613783

RESUMO

The rodent medial prefrontal cortex (mPFC) is functionally organized across the dorsoventral axis, where dorsal and ventral subregions promote and suppress fear, respectively. As the ventral-most subregion, the dorsal peduncular cortex (DP) is hypothesized to function in fear suppression. However, this role has not been explicitly tested. Here, we demonstrate that the DP paradoxically functions as a fear-encoding brain region and plays a minimal role in fear suppression. By using multimodal analyses, we demonstrate that DP neurons exhibit fear-learning-related plasticity and acquire cue-associated activity across learning and memory retrieval and that DP neurons activated by fear memory acquisition are preferentially reactivated upon fear memory retrieval. Further, optogenetic activation and silencing of DP fear-related neural ensembles drive the promotion and suppression of freezing, respectively. Overall, our results suggest that the DP plays a role in fear memory encoding. Moreover, our findings redefine our understanding of the functional organization of the rodent mPFC.


Assuntos
Medo , Memória , Córtex Pré-Frontal , Animais , Medo/fisiologia , Memória/fisiologia , Camundongos , Córtex Pré-Frontal/fisiologia , Masculino , Camundongos Endogâmicos C57BL , Neurônios/fisiologia , Optogenética
2.
Int J Parasitol Parasites Wildl ; 24: 100931, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38655449

RESUMO

Forficuloecus pezopori Martin, Keatley & Ash n. sp. from the western ground parrot Pezoporus flaviventris North, 1911 (Psittaculidae) is proposed based on combined evidence from morphology and COI mitochondrial DNA. Phylogenetically, the new species is closest to its two known congeners from Western Australia: F. josephi Price, Johnson & Palma, 2008 from Bourke's parrot Neopsephotus bourkii (Gould, 1841) and the scarlet-chested parrot Neophema splendida (Gould, 1841), and F. palmai Guimarães, 1985 from the Australian ringneck parrot Barnardius zonarius (Shaw, 1805). Morphologically it is distinguishable by abdominal chaetotaxy and characters of the male genitalia, and is most similar to F. josephi and F. greeni Guimarães, 1985; the latter has no representative sequence data. Forficuloecus pezopori is the eleventh species of its genus and the only metazoan parasite known from P. flaviventris, which is among Australia's most endangered vertebrates. The new louse is apparently restricted to P. flaviventris and is therefore co-endangered, facing at least the same likelihood of extinction as its host. We recommend ongoing translocation and field monitoring efforts for P. flaviventris include monitoring but not treatment for lice infestations in otherwise healthy individuals, and that the care management plan for captive P. flaviventris considers that F. pezopori is similarly imperilled.

3.
Conserv Biol ; : e14270, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38628146

RESUMO

International and national conservation policies almost exclusively focus on conserving species in their historic native ranges, thus excluding species that have been introduced by people and some of those that have extended their ranges on their own accord. Given that many of such migrants are threatened in their native ranges, conservation goals that explicitly exclude these populations may overlook opportunities to prevent extinctions and respond dynamically to rapidly changing environmental and climatic conditions. Focusing on terrestrial mammals, we quantified the number of threatened mammals that have established new populations through assisted migration (i.e., introduction). We devised 4 alternative scenarios for the inclusion of assisted-migrant populations in mainstream conservation policy with the aim of preventing global species extinctions. We then used spatial prioritization algorithms to simulate how these scenarios could change global spatial conservation priorities. We found that 22% (70 species out of 265) of all identified assisted-migrant mammals were threatened in their native ranges, mirroring the 25% of all mammals that are threatened. Reassessing global threat statuses by combining native and migrant ranges reduced the threat status of 23 species (∼33% of threatened assisted migrants). Thus, including migrant populations in threat assessments provides a more accurate assessment of actual global extinction risk among species. Spatial prioritization simulations showed that reimagining the role of assisted-migrant populations in preventing species extinction could increase the importance of overlooked landscapes, particularly in central Australia, Europe, and the southwestern United States. Our results indicated that these various and nonexhaustive ways to consider assisted-migrant populations, with due consideration of potential conservation conflicts with resident taxa, may provide unprecedented opportunities to prevent species extinctions.


Prevención de la extinción en una época de migración de especies y cambios planetarios Resumen Las políticas de conservación nacionales e internacionales casi siempre se enfocan en la conservación de las especies dentro de su distribución histórica y nativa, por lo que se excluyen especies que han sido introducidas por el humano y algunas que se han extendido por cuenta propia más allá de su distribución. Ya que muchas de estas especies migrantes están amenazadas dentro de su distribución nativa, los objetivos de conservación que excluyen explícitamente a estas poblaciones pueden ignorar las oportunidades para prevenir extinciones y responder de forma dinámica a las condiciones ambientales y climáticas que cambian con rapidez. Nos enfocamos en los mamíferos terrestres para cuantificar el número de especies amenazadas que han establecido poblaciones nuevas mediante la migración asistida (introducción). Diseñamos cuatro escenarios alternativos para la inclusión de las poblaciones con migración asistida dentro de las políticas de conservación generales con el objetivo de prevenir extinciones globales de especies. Después usamos algoritmos de priorización espacial para simular cómo estos escenarios podrían cambiar las prioridades de conservación espacial en todo el mundo. Descubrimos que el 22% (70 de 765 especies) de todos los mamíferos con migración asistida están amenazados dentro de su distribución nativa, lo que es similar al 25% de especies amenazadas de todas las especies de mamíferos. La reevaluación de los estados mundiales de amenaza mediante la combinación de la distribución nativa y migrante redujo el estado de amenaza de 23 especies (∼33% de los migrantes asistidos amenazados). Por esto, incluir a las poblaciones migrantes en la evaluación de amenazas proporciona una evaluación más certera del riesgo de extinción que existe entre las especies a nivel mundial. Las simulaciones de priorización espacial mostraron que reinventar el papel que tienen las poblaciones con migración asistida en la prevención de la extinción de especies podría incrementar la importancia de los paisajes ignorados, particularmente en Australia central, Europa y el suroeste de los Estados Unidos. Nuestros resultados indican que estas maneras diversas y no exhaustivas de considerar a las poblaciones con migración asistida, con la debida consideración de los potenciales conflictos de conservación con los taxones residentes, puede proporcionar oportunidades sin precedentes para prevenir la extinción de las especies.

4.
Ecol Evol ; 14(4): e11216, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38571791

RESUMO

Maternally-inherited sex ratio distorting microbes (SRDMs) are common among arthropod species. Typically, these microbes cause female-biased sex ratios in host broods, either by; killing male offspring, feminising male offspring, or inducing parthenogenesis. As a result, infected populations can experience drastic ecological and evolutionary change. The mechanism by which SRDMs operate is likely to alter their impact on host evolutionary ecology; despite this, the current literature is heavily biased towards a single mechanism of sex ratio distortion, male-killing. Furthermore, amidst the growing concerns surrounding the loss of arthropod diversity, research into the impact of SRDMs on the viability of arthropod populations is generally lacking. In this study, using a theoretical approach, we model the epidemiology of an understudied mechanism of microbially-induced sex ratio distortion-feminisation-to ask an understudied question-how do SRDMs impact extinction risk in a changing environment? We constructed an individual-based model and measured host population extinction risk under various environmental and epidemiological scenarios. We also used our model to identify the precise mechanism modulating extinction. We find that the presence of feminisers increases host population extinction risk, an effect that is exacerbated in highly variable environments. We also identified transmission rate as the dominant epidemiological trait responsible for driving extinction. Finally, our model shows that sex ratio skew is the mechanism driving extinction. We highlight feminisers and, more broadly, SRDMs as important determinants of the resilience of arthropod populations to environmental change.

5.
Ecol Evol ; 14(4): e11184, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38571803

RESUMO

In recent years, Hooded Vulture populations in West Africa have decreased substantially. However, in some areas within this region, the species is still relatively abundant. To find out more about the situation in West Africa, we assessed the status of Hooded Vultures in Benin, one of the countries where their status is not well known. We conducted road counts on paved and unpaved roads and along small trails over a total of 1451 km. We also conducted interviews with local abattoir watchmen, veterinarians, butchers and foresters to examine potential threats to this species. A total of 52 Hooded Vultures were counted mostly in the departments of Atacora (32) but also in Alibori (10) and Borgou (10). The relative abundance was four Hooded Vultures per 100 km, highlighting the near extirpation of this bird from Benin. A total of 49 interviews revealed that poaching for belief-based use (through shooting and traps) and decreasing food availability remain the most important threats for Hooded Vultures in northern Benin. If these threats are not mitigated, we predict the extirpation of the Hooded Vulture outside protected areas in Benin within the next two decades, possibly even sooner. Conservation measures, including awareness campaigns, and the improvement and enforcement of environmental legislation, must be urgently implemented to improve the protection of this Critically Endangered vulture species.

6.
Curr Biol ; 2024 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-38657609

RESUMO

Reptiles are an important, yet often understudied, taxon in nature conservation. They play a significant role in ecosystems1 and can serve as indicators of environmental health, often responding more rapidly to human pressures than other vertebrate groups.2 At least 21% of reptiles are currently assessed as threatened with extinction by the IUCN.3 However, due to the lack of comprehensive global assessments until recently, they have been omitted from spatial studies addressing conservation or spatial prioritization (e.g., Rosauer et al.,4,5,6,7,8 Fritz and Rahbek,4,5,6,7,8 Farooq et al.,4,5,6,7,8 Meyer et al., 4,5,6,7,8 and Farooq et al.4,5,6,7,8). One important knowledge gap in conservation is the lack of spatially explicit information on the main threats to biodiversity,9 which significantly hampers our ability to respond effectively to the current biodiversity crisis.10,11 In this study, we calculate the probability of a reptile species in a specific location being affected by one of seven biodiversity threats-agriculture, climate change, hunting, invasive species, logging, pollution, and urbanization. We conducted the analysis at a global scale, using a 50 km × 50 km grid, and evaluated the impact of these threats by studying their relationship with the risk of extinction. We find that climate change, logging, pollution, and invasive species are most linked to extinction risk. However, we also show that there is considerable geographical variation in these results. Our study highlights the importance of going beyond measuring the intensity of threats to measuring the impact of these separately for various biogeographical regions of the world, with different historical contingencies, as opposed to a single global analysis treating all regions the same.

7.
Conserv Biol ; : e14283, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38660931

RESUMO

Human behavior is a key driver of the biodiversity crisis, and addressing it requires changing individual choices and actions. Yet, the same processes that imperil biodiversity (e.g., urbanization) also alienate people from the experience of nature, eroding care for the natural world. Although averting this extinction of experience is increasingly recognized as a major contemporary conservation challenge, understanding of what constitutes nature experience remains elusive and few empirical studies have explored it directly. Most researchers have used nature interactions as a stand-in for experience, even though experience extends beyond interactions. We aimed to determine what constitutes the experience of nature and to propose a holistic, empirically derived framework that incorporates the multiple dimensions and components of the experience of nature. Using a mixed-method approach across 3 countries (the United States, Switzerland, and Israel), we conducted a multistage, conceptual content, cognitive mapping (3CM) exercise with 106 participants. This methodology included developing a prompt to capture participants' perceptions of nature experiences and subsequently refining and organizing their input into distinct components and underlying dimensions through an iterative engagement process. Beyond multisensory interactions with nature, experience of nature consisted of 2 dimensions: the circumstances in which interactions occur and the internal responses that encompass various cognitive, affective, and restorative benefits associated with nature interactions. These 3 dimensions had 33 components that occurred consistently across participants in the 3 countries. Frequently mentioned components included seeing animals, landscapes, or scenery; lack of human influence; weather conditions; relaxing, recharging; feeling good; and awe for nature. Fear and nature experienced at home were the least mentioned components. Together, our results showed that nature experience is a combination of nature interactions, circumstances, and internal responses. The emphasized components underscore the significance of offering access to extensive, less human-influenced natural spaces. This in turn can foster a profound nature experience, cultivating feelings of connectedness and care for nature.


Un marco de trabajo para entender la experiencia humana de la naturaleza a través del mapeo cognitivo Resumen El comportamiento humano es un factor clave en la crisis de la biodiversidad, por lo que abordarlo requiere cambios en las acciones y elecciones individuales. Aun así, los mismos procesos que ponen en peligro la biodiversidad (p. ej.: la urbanización) también alejan a las personas de experimentar la naturaleza, lo que disminuye el cuidado por la naturaleza. Aunque cada vez se reconoce más que evitar la extinción de las experiencias es un reto importante para la conservación, todavía no está claro qué constituye una experiencia de la naturaleza y pocos estudios empíricos lo han estudiado directamente. La mayoría de los investigadores ha usado las interacciones con la naturaleza como un sustituto para las experiencias, aunque éstas van más allá de las interacciones. Buscamos determinar qué constituye a las experiencias de la naturaleza y proponer un marco holístico y empírico que incorpore las múltiples dimensiones y componentes de la experiencia de la naturaleza. Usamos una estrategia de método mixto en tres países (EUA, Suiza e Israel) para realizar un ejercicio de un mapeo cognitivo de contenido conceptual en varias fases (3CM) con 106 participantes. Esta metodología incluyó el desarrollo de una entrada para capturar la percepción de los participantes con respecto a las experiencias de la naturaleza y con ello refinar y organizar sus contribuciones en diferentes componentes y dimensiones subyacentes por medio de un proceso iterativo de participación. Más allá de las interacciones multisensoriales con la naturaleza, las vivencias de la naturaleza consistieron en dos dimensiones: las circunstancias en las que ocurren las interacciones y las respuestas internas que engloban varios beneficios cognitivos, afectivos y restauradores asociados con las interacciones con la naturaleza. Estas dos dimensiones contaron con 33 componentes que aparecieron constantemente entre los participantes de los tres países. Con frecuencia mencionaron componentes que incluían avistamiento de animales o paisajes; la ausencia de influencia humana; las condiciones del clima; relajarse, recargarse; sentirse bien; y asombro por la naturaleza. El miedo y la naturaleza vivida en casa fueron los componentes menos mencionados. En conjunto, nuestros resultados mostraron que las vivencias de la naturaleza son una combinación de interacciones con la naturaleza, circunstancias y respuestas internas. Los componentes enfatizados resaltan la importancia de ofrecer acceso a los espacios naturales extensos con menos influencia humana. Esto a la vez puede promover una experiencia profunda de la naturaleza, lo que genera sentimientos de conexión y cuidado de la naturaleza.

8.
Pharmacol Biochem Behav ; : 173772, 2024 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-38653345

RESUMO

The limbic system, particularly the NAc, shows a high concentration of metabotropic glutamate receptors (mGluRs). Recent evidence suggests the significant involvement of mGluRs in mental disorders, including substance abuse and addiction. The objective of this study was to examine the involvement of mGlu8 receptors in the NAc in the mechanisms underlying the extinction and reinstatement of conditioned place preference (CPP) induced by morphine. Male Wistar rats underwent surgical implantation of bilateral cannulas in the NAc and were assessed in a CPP protocol. In study 1 at the same time as the extinction phase, the rats were given varying doses of S-3,4-DCPG (0.03, 0.3, and 3 µg/0.5 µl). In study 2, rats that had undergone CPP extinction were given S-3,4-DCPG (0.03, 0.3, and 3 µg/0.5 µl) five minutes prior to receiving a subthreshold dose of morphine (1 mg/kg) in order to reactivate the previously extinguished morphine response. The findings demonstrated that administering S-3,4-DCPG directly into the accumbens nucleus resulted in a decrease in the duration of the CPP extinction phase. Moreover, dose-dependent administration of S-3,4-DCPG into the NAc inhibited CPP reinstatement. The observations imply that microinjection of S-3,4-DCPG as a potent orthosteric agonist with high selectivity for the mGlu8 receptor into the NAc promotes the process of extinction while concurrently exerting inhibitory effects on the reinstatement of morphine-induced CPP. This effect may be associated with the modulation of glutamate engagement within the NAc and the plasticity of reward pathways at the synaptic level.

9.
Neurobiol Learn Mem ; 211: 107927, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38582295

RESUMO

Two online experiments evaluated the relationship between long-term stress, as measured with the Perceived Stress Scale-10, and the Renewal Effect. In the first experiment renewal was assessed with a behavioral suppression task in a science-fiction based video game. Participants learned to suppress mouse clicking during a signal for an upcoming attack to avoid losing points. The signal was first paired with an attack in Context A and extinguished in Context B and tested back in Context A. The contexts were different space galaxies where the gameplay took place. Experiment 2 used a food/illness predictive-learning paradigm. Two food items were paired with stomachache in one restaurant (A) and extinguished in Context B prior to testing in both contexts without feedback. Positive correlations were obtained between renewal and stress in each experiment. Unlike acute stress (Drexler et al., 2017), long term stress was associated with greater renewal. The effects of stress, both chronic and punctual, on renewal are discussed.

10.
Curr Biol ; 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38614080

RESUMO

Low genomic diversity is generally indicative of small population size and is considered detrimental by decreasing long-term adaptability.1,2,3,4,5,6 Moreover, small population size may promote gene flow with congeners and outbreeding depression.7,8,9,10,11,12,13 Here, we examine the connection between habitat availability, effective population size (Ne), and extinction by generating a 40× nuclear genome from the extinct blue antelope (Hippotragus leucophaeus). Historically endemic to the relatively small Cape Floristic Region in southernmost Africa,14,15 populations were thought to have expanded and contracted across glacial-interglacial cycles, tracking suitable habitat.16,17,18 However, we found long-term low Ne, unaffected by glacial cycles, suggesting persistence with low genomic diversity for many millennia prior to extinction in ∼AD 1800. A lack of inbreeding, alongside high levels of genetic purging, suggests adaptation to this long-term low Ne and that human impacts during the colonial era (e.g., hunting and landscape transformation), rather than longer-term ecological processes, were central to its extinction. Phylogenomic analyses uncovered gene flow between roan (H. equinus) and blue antelope, as well as between roan and sable antelope (H. niger), approximately at the time of divergence of blue and sable antelope (∼1.9 Ma). Finally, we identified the LYST and ASIP genes as candidates for the eponymous bluish pelt color of the blue antelope. Our results revise numerous aspects of our understanding of the interplay between genomic diversity and evolutionary history and provide the resources for uncovering the genetic basis of this extinct species' unique traits.

11.
Phys Med Biol ; 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38631364

RESUMO

Cortical bone is characterized by a dense solid matrix permeated by fluid-filled pores. Ultrasound scattering has potential for the non-invasive evaluation of changes in bone porosity. However, there is an incomplete understanding of the impact of ultrasonic absorption in the solid matrix on ultrasound scattering. In this study, maps were derived from scanning acoustic microscopy images of human femur cross-sections. Finite-difference time domain ultrasound scatter simulations were conducted on these maps. Pore density, diameter distribution of the pores, and nominal absorption values in the solid and fluid matrices were controlled. Ultrasound pulses with a central frequency of 8.2 MHz were propagated, both in through-transmission and backscattering configurations. From these data, the scattering, bone matrix absorption, and attenuation extinction lengths were calculated. The results demonstrated that as absorption in the solid matrix was varied, the scattering, absorption, and attenuation extinction lengths were significantly impacted. It was shown that for lower values of absorption in the solid matrix (less than 2 dB/mm), attenuation due to scattering dominates, whereas at higher values of absorption (more than 2 dB/mm), attenuation due to absorption dominates. This will impact how ultrasound attenuation and scattering parameters can be used to extract quantitative information on bone microstructure.

12.
Brain Topogr ; 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38635017

RESUMO

The post-retrieval extinction paradigm, rooted in reconsolidation theory, holds promise for enhancing extinction learning and addressing anxiety and trauma-related disorders. This study investigates the impact of two reminder types, mild US-reminder (US-R) and CS-reminder (CS-R), along with a no-reminder extinction, on fear recovery prevention in a categorical fear conditioning paradigm. Scalp EEG recordings during reminder and extinction processes were conducted in a three-day design. Results show that the US-R group exhibits a distinctive extinction learning pattern, characterized by a slowed-down yet successful process and pronounced theta-alpha desynchronization (source-located in the prefrontal cortex) during CS processing, followed by enhanced synchronization (source-located in the anterior cingulate) after shock cancellation in extinction trials. These neural dynamics correlate with the subtle advantage of US-R in the Day 3 recovery test, presenting faster spontaneous recovery fading and generally lower fear reinstatement responses. Conversely, the CS reminder elicits CS-specific effects in later episodic tests. The unique neural features of the US-R group suggest a larger prediction error and subsequent effortful conflict learning processes, warranting further exploration.

13.
Elife ; 132024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38619041

RESUMO

Gradually reducing a source of fear during extinction treatments may weaken negative memories in the long term.


Assuntos
Extinção Psicológica , Medo
14.
BMC Plant Biol ; 24(1): 277, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38605351

RESUMO

BACKGROUND: The "woody clade" in Saxifragales (WCS), encompassing four woody families (Altingiaceae, Cercidiphyllaceae, Daphniphyllaceae, and Hamamelidaceae), is a phylogenetically recalcitrant node in the angiosperm tree of life, as the interfamilial relationships of the WCS remain contentious. Based on a comprehensive sampling of WCS genera, this study aims to recover a robust maternal backbone phylogeny of the WCS by analyzing plastid genome (plastome) sequence data using Bayesian inference (BI), maximum likelihood (ML), and maximum parsimony (MP) methods, and to explore the possible causes of the phylogenetic recalcitrance with respect to deep relationships within the WCS, in combination with molecular and fossil evidence. RESULTS: Although the four WCS families were identically resolved as monophyletic, the MP analysis recovered different tree topologies for the relationships among Altingiaceae, Cercidiphyllaceae, and Daphniphyllaceae from the ML and BI phylogenies. The fossil-calibrated plastome phylogeny showed that the WCS underwent a rapid divergence of crown groups in the early Cretaceous (between 104.79 and 100.23 Ma), leading to the origin of the stem lineage ancestors of Altingiaceae, Cercidiphyllaceae, Daphniphyllaceae, and Hamamelidaceae within a very short time span (∼4.56 Ma). Compared with the tree topology recovered in a previous study based on nuclear genome data, cytonuclear discordance regarding the interfamilial relationships of the WCS was detected. CONCLUSIONS: Molecular and fossil evidence imply that the early divergence of the WCS might have experienced radiative diversification of crown groups, extensive extinctions at the genus and species levels around the Cretaceous/Paleocene boundary, and ancient hybridization. Such evolutionarily complex events may introduce biases in topological estimations within the WCS due to incomplete lineage sorting, cytonuclear discordance, and long-branch attraction, potentially impacting the accurate reconstruction of deep relationships.


Assuntos
Genomas de Plastídeos , Saxifragales , Humanos , Filogenia , Saxifragales/genética , Fósseis , Teorema de Bayes , Plastídeos/genética
15.
Glob Chang Biol ; 30(4): e17278, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38655695

RESUMO

The increasing frequency and severity of human-caused fires likely have deleterious effects on species distribution and persistence. In 2020, megafires in the Brazilian Pantanal burned 43% of the biome's unburned area and resulted in mass mortality of wildlife. We investigated changes in habitat use or occupancy for an assemblage of eight mammal species in Serra do Amolar, Brazil, following the 2020 fires using a pre- and post-fire camera trap dataset. Additionally, we estimated the density for two naturally marked species, jaguars Panthera onca and ocelots Leopardus pardalis. Of the eight species, six (ocelots, collared peccaries Dicotyles tajacu, giant armadillos Priodontes maximus, Azara's agouti Dasyprocta azarae, red brocket deer Mazama americana, and tapirs Tapirus terrestris) had declining occupancy following fires, and one had stable habitat use (pumas Puma concolor). Giant armadillo experienced the most precipitous decline in occupancy from 0.431 ± 0.171 to 0.077 ± 0.044 after the fires. Jaguars were the only species with increasing habitat use, from 0.393 ± 0.127 to 0.753 ± 0.085. Jaguar density remained stable across years (2.8 ± 1.3, 3.7 ± 1.3, 2.6 ± 0.85/100 km2), while ocelot density increased from 13.9 ± 3.2 to 16.1 ± 5.2/100 km2. However, the low number of both jaguars and ocelots recaptured after the fire period suggests that immigration may have sustained the population. Our results indicate that the megafires will have significant consequences for species occupancy and fitness in fire-affected areas. The scale of megafires may inhibit successful recolonization, thus wider studies are needed to investigate population trends.


A crescente frequência e gravidade dos incêndios causados pelo homem provavelmente terão efeitos deletérios na distribuição e persistência das espécies. Em 2020, mega incêndios no Pantanal brasileiro queimaram 43% do bioma e resultaram na mortalidade em massa da vida selvagem. Nós investigamos mudanças no uso ou ocupação do habitat para uma comunidade de oito espécies de mamíferos na Serra do Amolar, Brasil, após os incêndios de 2020, usando um conjunto de dados de armadilhas fotográficas instaladas no período pré e pós­fogo. Além disso, estimamos a densidade de duas espécies naturalmente marcadas, a onça­pintada Panthera onca e a jaguatirica Leopardus pardalis. Das oito espécies, seis (a jaguatirica, o cateto Dicotyles tajacu, o tatu­canastra Priodontes maximus, a cutia Dasyprocta azarae, o veado mateiro Mazama americana e a anta Tapirus terrestris) tiveram ocupação reduzida após os incêndios, e uma teve uso de habitat estável (a onça­parda, Puma concolor). O tatu­canastra apresentou o declínio mais acentuado na ocupação após os incêndios de 0,431 ± 0,171 para 0,077 ± 0,044. A onça­pintada foi a única espécie com uso crescente de habitat, de 0,393 ± 0,127 para 0,753 ± 0,085. A densidade da onça­pintada permaneceu estável ao longo dos anos (2,8 ± 1,3, 3,7 ± 1,3, 2,6 ± 0,85/100 km2), enquanto a densidade da jaguatirica aumentou de 13,9 ± 3,2 para 16,1 ± 5,2/100 km2. No entanto, o baixo número de onças­pintadas e jaguatiricas recapturadas após o período do fogo sugere que a imigração pode ter sustentado as populações. Nossos resultados indicam que os mega incêndios terão consequências significativas para a ocupação e resiliência das espécies nas áreas afetadas pelo fogo. A escala dos mega incêndios pode inibir uma recolonização bem­sucedida, pelo que são necessários estudos mais amplos para investigar as tendências populacionais.


Assuntos
Ecossistema , Animais , Brasil , Mamíferos/fisiologia , Dinâmica Populacional , Incêndios , Densidade Demográfica , Incêndios Florestais
16.
Math Biosci ; 372: 109201, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38636925

RESUMO

We investigated a system of ordinary differential equations that describes the dynamics of prey and predator populations, taking into account the Allee effect affecting the reproduction of the predator population, and mutual interference amongst predators, which is modeled with the Bazykin-Crowley-Martin (BCM) trophic function. Bifurcation analysis revealed a rich spectrum of bifurcations occurring in the system. In particular, analytical conditions for the saddle-node, Hopf, cusp, and Bogdanov-Takens bifurcations were derived for the model parameters, quantifying the strength of the predator interference, the Allee effect, and the predation efficiency. Numerical simulations verify and illustrate the analytical findings. The main purpose of the study was to test whether the mutual interference in the model with BCM trophic function provides a stabilizing or destabilizing effect on the system dynamics. The obtained results suggest that the model demonstrates qualitatively the same pattern concerning varying the interference strength as other predator-dependent models: both low and very high interference levels increase the risk of predator extinction, while moderate interference has a favorable effect on the stability and resilience of the prey-predator system.

17.
J Gerontol Soc Work ; : 1-17, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38600774

RESUMO

This study combined ecological, environmental, nature-based, and epistemic interpretations of older adulthood to gain a previously unresearched look at how older adults feel that their relations with nature are treated by others. Sixty older adults were interviewed in-depth, and data was analyzed using the Eco-Appreciation framework and Thematic Content Analysis. The results indicate the concurrence of processes of withdrawal of older adults from spaces of nature and discourse about nature. These processes obstruct older adults' wellbeing; entail the infliction of existential epistemic injustices and "eco-ageism" toward them; and emphasize the crucial role social work can play in responding thereto.

18.
Neurobiol Learn Mem ; 211: 107926, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38579897

RESUMO

Learning to stop responding is a fundamental process in instrumental learning. Animals may learn to stop responding under a variety of conditions that include punishment-where the response earns an aversive stimulus in addition to a reinforcer-and extinction-where a reinforced response now earns nothing at all. Recent research suggests that punishment and extinction may be related manifestations of a common retroactive interference process. In both paradigms, animals learn to stop performing a specific response in a specific context, suggesting direct inhibition of the response by the context. This process may depend on the infralimbic cortex (IL), which has been implicated in a variety of interference-based learning paradigms including extinction and habit learning. Despite the behavioral parallels between extinction and punishment, a corresponding role for IL in punishment has not been identified. Here we report that, in a simple arrangement where either punishment or extinction was conducted in a context that differed from the context in which the behavior was first acquired, IL inactivation reduced response suppression in the inhibitory context, but not responding when it "renewed" in the original context. In a more complex arrangement in which two responses were first trained in different contexts and then extinguished or punished in the opposite one, IL inactivation had no effect. The results advance our understanding of the effects of IL in retroactive interference and the behavioral mechanisms that can produce suppression of a response.

19.
Philos Trans R Soc Lond B Biol Sci ; 379(1902): 20230013, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38583472

RESUMO

Species respond dynamically to climate change and exhibit time lags. Consequently, species may not occupy their full climatic niche during range shifting. Here, we assessed climate niche tracking during recent range shifts of European and United States (US) birds. Using data from two European bird atlases and from the North American Breeding Bird Survey between the 1980s and 2010s, we analysed range overlap and climate niche overlap based on kernel density estimation. Phylogenetic multiple regression was used to assess the effect of species morphological, ecological and biogeographic traits on range and niche metrics. European birds shifted their ranges north and north-eastwards, US birds westwards. Range unfilling was lower than expected by null models, and niche expansion was more common than niche unfilling. Also, climate niche tracking was generally lower in US birds and poorly explained by species traits. Overall, our results suggest that dispersal limitations were minor in range shifting birds in Europe and the USA while delayed extinctions from unfavourable areas seem more important. Regional differences could be related to differences in land use history and monitoring schemes. Comparative analyses of range and niche shifts provide a useful screening approach for identifying the importance of transient dynamics and time-lagged responses to climate change. This article is part of the theme issue 'Ecological novelty and planetary stewardship: biodiversity dynamics in a transforming biosphere'.


Assuntos
Biodiversidade , Aves , Animais , Estados Unidos , Filogenia , Aves/fisiologia , Mudança Climática , América do Norte , Ecossistema
20.
PeerJ ; 12: e16893, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38426143

RESUMO

The ongoing destruction of habitats in the tropics accelerates the current rate of species extinction. Range-restricted species are exceptionally vulnerable, yet we have insufficient knowledge about their protection. Species' current distributions, range sizes, and protection gaps are crucial to determining conservation priorities. Here, we identified priority range-restricted bird species and their conservation hotspots in the Northern Andes. We employed maps of the Area of Habitat (AOH), that better reflect their current distributions than existing maps. AOH provides unprecedented resolution and maps a species in the detail essential for practical conservation actions. We estimated protection within each species' AOH and for the cumulative distribution of all 335 forest-dependent range-restricted birds across the Northern Andes. For the latter, we also calculated protection across the elevational gradient. We estimated how much additional protection community lands (Indigenous and Afro-Latin American lands) would contribute if they were conservation-focused. AOHs ranged from 8 to 141,000 km2. We identified four conservation priorities based on cumulative species richness: the number of AOHs stacked per unit area. These priorities are high-resolution mapped representations of Endemic Bird Areas for the Tropical Andes that we consider critically important. Protected areas cover only 31% of the cumulative AOH, but community lands could add 19% more protection. Sixty-two per cent of the 335 species have ranges smaller than their published estimates, yet IUCN designates only 23% of these as Threatened. We identified 50 species as top conservation priorities. Most of these concentrate in areas of low protection near community lands and at middle elevations where, on average, only 34% of the land is protected. We highlight the importance of collaborative efforts among stakeholders: governments should support private and community-based conservation practices to protect the region with the most range-restricted birds worldwide.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Animais , Ecossistema , Florestas , Aves
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