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1.
Mol Ecol ; 32(20): 5514-5527, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37702122

RESUMO

During the last century, the critically endangered cotton-top tamarin (Saguinus oedipus) has been threatened by multiple anthropogenic factors that drastically affected their habitat and population size. As the genetic impact of these pressures is largely unknown, this study aimed to establish a genetic baseline with the use of temporal sampling to determine the genetic makeup before detrimental anthropogenic impact. Genomes were resequenced from a combination of historical museum samples and modern wild samples at low-medium coverage, to unravel how the cotton-top tamarin population structure and genomic diversity may have changed during this period. Our data suggest two populations can be differentiated, probably separated historically by the mountain ranges of the Paramillo Massif in Colombia. Although this population structure persists in the current populations, modern samples exhibit genomic signals consistent with recent inbreeding, such as long runs of homozygosity and a reduction in genome-wide heterozygosity especially in the greater northeast population. This loss is likely the consequence of the population reduction following the mass exportation of cotton-top tamarins for biomedical research in the 1960s, coupled with the habitat loss this species continues to experience. However, current populations have not experienced an increase in genetic load. We propose that the historical genetic baseline established in this study can be used to provide insight into alteration in the modern population influenced by a drastic reduction in population size as well as providing background information to be used for future conservation decision-making for the species.

2.
Am J Primatol ; : e23525, 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37257913

RESUMO

International laws and conventions have gone a long way in reducing the number of wild primates entering the United States of America (US) for the pet trade. However, breeding primates for sale to private owners in the United States continues, and individual states present a bewildering array of laws and regulations on the holding of primates as pets. As primatologists we can act to decrease the demand for primate pets by (1) speaking out on the inappropriate use of primates in mass media and especially in social media; (2) not posing in photographs in close proximity to primates; (3) continuing to educate about why primates do not make good pets; and (4) contributing to the science that underlies state and federal legislation with the goal of eliminating captive breeding of primates for the pet trade. We encourage primatologists and others in related fields to be cognizant of the persistent commercialization of primates and be willing to take action to deter it.

3.
Am J Primatol ; 85(5): e23431, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36106358

RESUMO

Cotton-top tamarins (Saguinus oedipus) are a critically endangered species found only in Colombia. Their survival is threatened by extensive habitat destruction and the illegal pet trade. Because many people in Colombia have a low level of awareness of cotton-top tamarins and even less understanding of the impacts that the illegal pet trade has on the species and its long-term survival, Proyecto Tití has developed a series of programs for children in rural elementary schools that introduce children to cotton-top tamarins. This study examines Proyecto Titi's efforts to reduce the desire to have a cotton-top tamarin as a pet with outcomes focused specifically on (1) creating an emotional connection between people and cotton-top tamarins, (2) identifying the feelings and understanding the challenges that cotton-top tamarin face when they are kept as pets, and (3) empowering students to make positive choices to help cotton-top tamarins. Both TITI KIDS and TITIRITIANDO programs helped students to (1) increase their knowledge of cotton-top tamarins, (2) understand the damage that the pet trade has on individual animals and the long-term survival of cotton-top tamarins and (3) provide practical actions that they can engage in to protect cotton-top tamarins for the future. Our hope is that students from our programs become advocates for conservation in their communities and assist in the long-term conservation activities to protect cotton-top tamarins in Colombia.


Assuntos
Ecossistema , Saguinus , Animais , Espécies em Perigo de Extinção , Colômbia
4.
Adv Neurobiol ; 27: 213-238, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36169817

RESUMO

Direct care of offspring by the father (sire) is relatively rare in primates. Besides humans, there are a number of species where the male is essential for the survival of offspring: marmosets, tamarins, titis and owl monkeys, some lemurs, and siamangs. All these species show reduced sexual dimorphism, territoriality, and biparental care. However, timing and levels of direct care may vary among these species. Here, relying on both lab and field data, we address the variability found in father's involvement with his infants, the behavioral, neuroendocrine and sensory systems that are a cause and consequence of paternal care, and social bonds between the breeding pair. We integrate studies of laboratory animals (where detailed observations and experimentation are possible) with field studies (which illuminate the ecological and evolutionary functions of paternal care) and discuss the future directions for examining the proximate and ultimate mechanisms of paternal care in nonhuman primates.


Assuntos
Pai , Individualidade , Animais , Humanos , Masculino , Primatas , Comportamento Social
5.
Am J Primatol ; 84(2): e23359, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35092063

RESUMO

Seasonal availability of resources can influence the timing and success of reproduction in primates. This study examines the annual pattern of conceptions, mid-term (13 weeks) and full-term (26 weeks) pregnancy losses, births, and infant survivorship of the Critically Endangered cotton-top tamarin (Saguinus oedipus) at Proyecto Tití's long-term field site in Santa Catalina, Colombia. Using 18 years of behavior, physical exam, and fecal steroid data (N = 51 females, 168 conceptions, 121 liters), fecal estrone conjugate (E1 C) and pregnanediol-3-glucuronide (PdG) or progesterone (P4) profiles were examined to investigate the relationships between female reproductive patterns and reproductive success with feeding and climatic data. Cotton-top tamarins demonstrated seasonal patterns of reproduction and pregnancy losses. We found positive correlations between peak conception and nectarivory, births and rainfall, and mid-lactation and frugivory. High body mass mothers reproducing during the peak season were more likely to have infants survive. Overall, these results suggest that tamarins use a "relaxed income-breeder" strategy. Cotton-top tamarins appear to maximize reproductive output at the time of ovulation, and can reduce their investment in the current reproductive effort at many stages. Changes in food availability due to habitat loss and climate change will require the Critically Endangered cotton-top tamarins to alter their reproductive strategies to survive.


Assuntos
Reprodução , Saguinus , Animais , Colômbia , Ecossistema , Estrona , Feminino , Humanos , Masculino , Gravidez
6.
Vet Pathol ; 59(2): 358-370, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34872391

RESUMO

In a retrospective study of a western pygmy marmoset (Cebuella pygmaea) colony, postmortem examination of 1/8 juvenile and 29/47 adult animals identified vascular, cardiac, and renal lesions consistent with systemic hypertension. This included frequent renal arteriolar hypertrophy, hyaline and proliferative arteriolosclerosis, fibrinoid necrosis of arterioles, glomerulosclerosis, and nephrosclerosis. Affected animals ranged from 0.6 to 12 years of age (mean 6 years) and had an observed male predominance. Genealogical relatedness was evident in several breeding pairs and spanned multiple generations. Concurrent cardiac and renal disease was commonly identified, although frequently subclinical, and both were important causes of morbidity and mortality in affected animals. Cardiomegaly and hypertrophy were typical features and were accompanied by left atrial thrombosis in 10 animals. Signs of heart failure included chronic pulmonary edema in 20 cases and body cavity effusions in 17. In the kidneys, 19 cases had glomerular disease and hypertensive vasculopathy, and 26 cases had nephrosclerosis or glomerulosclerosis. Common extrarenal secondary causes of hypertension were excluded by necropsy examination. The pathogenesis is suggested to involve primary hypertension leading to renal and cardiac disease. Elevated sympathetic activity might be an underlying factor in the frequent development of primary systemic hypertension in the pygmy marmoset, as for the owl monkey.


Assuntos
Arteriosclerose , Hipertensão , Nefroesclerose , Animais , Arteriosclerose/veterinária , Callithrix , Callitrichinae , Feminino , Hipertensão/patologia , Hipertensão/veterinária , Hipertrofia/veterinária , Rim/patologia , Masculino , Nefroesclerose/complicações , Nefroesclerose/patologia , Nefroesclerose/veterinária , Estudos Retrospectivos
7.
Zoo Biol ; 40(5): 429-435, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34124807

RESUMO

Raising insects in a laboratory for release into the wild is a common conservation practice, but maintaining breeding colonies year-round can be limited by seasonal food availability. Food availability is particularly challenging for insects which depend on specific host plants. For example, our early efforts to rear the imperiled Atala hairstreak butterfly (Eumaeus atala Poey) resulted in colony failure during winter due to lack of food. To overcome this barrier, we developed a modified freeze-dried host plant diet to support the colony. The diet consisted of reconstituted freeze-dried leaves and stems from fresh-growth coontie (Zamia integrifolia), the host plant for the Atala butterflies. We fed larvae less than 9 mm on this freeze-dried diet and transferred them to live coontie plants after they were more than 9 mm. We reared a colony of Atala butterflies using these methods for 859 days, resulting in more than 3400 animals released into the wild. Comparing colony counts during that time period to the 548 days we reared them without modified freeze-dried diet showed a clear benefit in using freeze-dried diet. A growth trial (N = 40) of larvae fed on only freeze-dried diet compared to larvae fed on fresh coontie cuttings found no significant difference in larval or pupal development between groups (p = 0.71 and p = 0.47, respectively). We, therefore, conclude that the freeze-dried diet provided an appropriate alternative for Atala colonies when fresh growth from the host plant is unavailable, and we recommend use of this technique for raising other host plant-dependent insect species of conservation concern.


Assuntos
Borboletas , Animais , Animais de Zoológico , Dieta/veterinária , Insetos , Larva
8.
Am J Primatol ; 83(7): e23262, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33899981

RESUMO

Studies of cooperative breeding species have suggested that helpers are needed for infant survival and that helpers gain skills to successfully raise their own offspring. Studies of callitrichids in managed care and early field studies suggested that group size correlated with infant survival and that helpers needed to learn parental skills to be successful breeders. We present infant survival data from a 20-year field study of cotton-top tamarins (Saguinus oedipus) in Colombia involving 126 litters born to 41 females. There was no difference in the survival of male and female offspring to 6 months of age. However, litter size impacted survival, with triplet litters having lower survival and male triplets having lower survival than females. Loss of infants was highest in the first week of life and, of the animals remaining in the group at 6 months of age, 90% of them survived to 1 year. The mean length of time in the natal group was 2.3 years but some young migrated to other groups after 4 months of age. Group size and number of male helpers (>1 year) was not related to infant survival. However, groups with only one male had fewer surviving infants. Primiparous females had lower infant survival, but previous infant care experience by mothers as helpers had no effect on survival. A major cause of infant loss was group disruption due to deaths/evictions/loss of the reproductively active animals, or immigration of pregnant females. Thus, factors that cause a change in the stability of the reproductively active animals can disrupt group cohesion. Capture of individuals for the illegal pet trade, as well as habitat fragmentation, may increase competition between groups for access to territories and breeding opportunities. This may have long-term impacts to infant survival in this critically endangered species.


Assuntos
Ecossistema , Saguinus , Animais , Colômbia , Espécies em Perigo de Extinção , Feminino , Tamanho da Ninhada de Vivíparos , Masculino , Gravidez
9.
Zoo Biol ; 39(5): 304-314, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32644286

RESUMO

Conservation is an important organizational focus for zoos and aquariums. Organizational identity theory predicts a relationship between what is central to organizations, such as their mission statements, and their strategic activities. Based on this theory, we tested how organizational missions relate to their conservation strategies and practices. Tax forms and websites provided data from 173 zoos and 38 aquariums in the Association of Zoos and Aquariums in North America. We analyzed conservation mission strength, organizational characteristics, and project features with dependent variables representing the depth of organizational conservation commitments: amount of grants zoos funded, number of partner organizations, and number of projects per zoo. On tax forms, the average amount of total conservation grants donated to partner organizations per zoo was over $650,000, while the average number of partners reported on the tax forms was two. The content analysis of websites revealed an average of 14 conservation partners and 10 projects per zoo. Negative binomial regression models were significant. The financial analysis revealed that only the number of zoo personnel, as a surrogate for organization size, significantly predicted the amount of zoos' conservation grants. Website analyses found increasing budgets, organizational involvement, and geographic reach of the projects predicted increasing numbers of conservation projects and partnerships. However, our findings did not support the hypothesized relationship-strength of organizational mission did not predict strategy and activities. Zoos could do more to strategically activate their organizational identities and conservation missions to achieve their conservation goals.


Assuntos
Criação de Animais Domésticos/normas , Bem-Estar do Animal/normas , Animais de Zoológico , Conservação dos Recursos Naturais/economia , Conservação dos Recursos Naturais/métodos , Criação de Animais Domésticos/economia , Criação de Animais Domésticos/métodos , Bem-Estar do Animal/economia , Animais , Emprego/economia , Emprego/estatística & dados numéricos , Humanos , América do Norte , Impostos
10.
Forensic Sci Int ; 312: 110310, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32446139

RESUMO

The stomach has long been recognised as a depot for postmortem diffusion. A better understanding of the phenomena of postmortem diffusion would aid forensic practitioners in their interpretation of toxicological results. A limitation of previous stomach diffusion studies was the lack of ability to visualise postmortem diffusion in real time, the use of µX-ray Computed Tomography (CT) could overcome this problem. We utilised CT to track the diffusion of the contrast medium caesium ions (Cs+) (administered by oral gavage) from the rat stomach over 6 days. We investigated the influence of temperature (4°C and 20°C) and body position (horizontal and vertical). The results show that the a) diffusion of Cs+ from the stomach can be visualised over 6 days, over which a significant amount (∼50%) of the diffusion occurs in the first 24h following administration; b) storing the rat at 4°C reduces the distance of diffusion from the stomach by ∼66%; c) body position influences the route of diffusion and d) in 2 of the 16 rats studied Cs+ was found in the right lobe of the liver. Overall these results show that CT using Cs+ is a good model to visualise postmortem diffusion and that bodies show significant variation in postmortem diffusion. It is also clear that bodies should be refrigerated and postmortem samples should be taken as soon as possible to minimise the influences of postmortem diffusion from the stomach.


Assuntos
Césio/química , Cloretos/química , Meios de Contraste/química , Difusão , Conteúdo Gastrointestinal/diagnóstico por imagem , Mudanças Depois da Morte , Tomografia Computadorizada por Raios X , Animais , Toxicologia Forense/métodos , Modelos Animais , Postura , Ratos Wistar , Estômago/diagnóstico por imagem , Temperatura
11.
Sci Justice ; 60(2): 151-159, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32111288

RESUMO

Firearm offences in the UK, though not as high as in the USA, are increasing year upon year within both countries (Office for National Statistics, 2018 & Mervosh, 2018). This preliminary study looked into using Micro-CT scanning as a method to visualise impact damage and spray patterns caused by 12 test firings of both round and flat nosed bullets to porcine bone (shoulder and leg) suspended in ballistic gelatine and left with no covering, covered with a skin substitute, or covered with fabric (cotton or denim). Micro-CT scanning alongside VG Studio Max showed that overall, in the case of the shoulder bones the round nosed produced longer spray patterns (35.37 mm) within the gelatine blocks compared to the flat nosed bullet (27.33 mm); while with the leg bones the spray patterns were shorter, round nosed bullet (15.64 mm) and the flat nosed bullet (20.78 mm). These initial results showed that both bullet types produced considerable damage, from splitting to full penetration, which in turn illustrates how Micro-CT scanning has benefits within forensic ballistics, which should be further investigated.


Assuntos
Osso e Ossos/diagnóstico por imagem , Osso e Ossos/lesões , Balística Forense , Lesões dos Tecidos Moles/diagnóstico por imagem , Ferimentos por Arma de Fogo/diagnóstico por imagem , Microtomografia por Raio-X , Animais , Humanos , Modelos Biológicos , Dados Preliminares , Suínos , Têxteis
12.
Sci Justice ; 59(5): 486-497, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31472793

RESUMO

This study consisted of three parts to evaluate the performance of Lumicyano™ on a variety of fabrics. One part assessed the impact of dye percentage (8%, 9% and 10%) on visualisation of fingermark detail and luminescent brightness in split grab marks. A 9% dye produced the highest quality detail of grab impressions with least interference from background fluorescence. The second part investigated the optimal relative humidity (RH, 75-84%) for certain fabric types using Lumicyano on split, six-series depletion fingermarks. It was concluded that the recommended RH of 80% remained the ideal cyanoacrylate fuming environment. The final and third part of this study determined the impact of sequential addition of Basic Yellow 40 (BY40) on Lumicyano compared to traditional cyanoacrylate (CA) followed with BY40 application. Results from this study demonstrated that Lumicyano on its own developed fingermarks with superior quality to Lumicyano with sequential addition of BY40 or traditional cyanoacrylate followed by BY40. Inclusion of more fabrics, donors and longer ageing periods should be explored in future studies to determine what frameworks are best for certain types of fabrics.

13.
Stat Med ; 38(8): 1421-1441, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30488481

RESUMO

Diagnosis and prognosis of cancer are informed by the architecture inherent in cancer patient tissue sections. This architecture is typically identified by pathologists, yet advances in computational image analysis facilitate quantitative assessment of this structure. In this article, we develop a spatial point process approach to describe patterns in cell distribution within tissue samples taken from colorectal cancer (CRC) patients. In particular, our approach is centered on the Palm intensity function. This leads to taking an approximate-likelihood technique in fitting point processes models. We consider two Neyman-Scott point processes and a void process, fitting these point process models to the CRC patient data. We find that the parameter estimates of these models may be used to quantify the spatial arrangement of cells. Importantly, we observe characteristic differences in the spatial arrangement of cells between patients who died from CRC and those alive at follow up.


Assuntos
Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/patologia , Algoritmos , Interpretação Estatística de Dados , Humanos , Prognóstico
14.
Forensic Sci Int ; 294: 124-131, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30553124

RESUMO

The Widmark equation is commonly used when blood alcohol calculations are required in forensic and legal medicine, such as in road-traffic cases and alcohol-related deaths. An important biological variable in this connection is the volume of distribution (Vd) of ethanol, which is commonly referred to as the rho-factor. Although a person's Vd can be determined empirically through controlled drinking experiments, this approach is not very practical in reality. For this reason, a number of anthropometric equations have been developed that utilize sex, age, height and weight to estimate the person's total body water (TBW) and hence Vd of ethanol. To date, there are not any studies that compare Vd derived from anthropometric data with robust values measured empirically. From the literature we compiled information about the Vd of ethanol from drinking studies with 173 Caucasian males and 63 Caucasian females from Western Europe. These empirically derived values of Vd were then compared with estimates derived from various anthropometric equations. In males the Watson, Watson and Batt regression equation involving age, height and weight gave the most accurate results (bias was 0.00L/kg) and 95% range ±0.13L/kg. The equation derived by Forrest, which took into consideration a person's body mass index (BMI), gave the best estimates of Vd for females; mean bias -0.01L/kg and range ±0.15L/kg.


Assuntos
Antropometria , Concentração Alcoólica no Sangue , Etanol/farmacocinética , Modelos Estatísticos , Adolescente , Adulto , Idoso , Água Corporal , Depressores do Sistema Nervoso Central/farmacocinética , Feminino , Toxicologia Forense/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Distribuição Tecidual , Adulto Jovem
15.
Insects ; 9(4)2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-30513660

RESUMO

Climate change has caused many ecological changes around the world. Altered phenology is among the most commonly observed effects of climate change, and the list of species interactions affected by altered phenology is growing. Although many studies on altered phenology focus on single species or on pairwise species interactions, most ecological communities are comprised of numerous, ecologically similar species within trophic groups. Using a 12-year butterfly monitoring citizen science data set, we aimed to assess the degree to which butterfly communities may be changing over time. Specifically, we wanted to assess the degree to which phenological sensitivities to temperature could affect temporal overlap among species within communities, independent of changes in abundance, species richness, and evenness. We found that warming winter temperatures may be associated with some butterfly species making use of the coldest months of the year to fly as adults, thus changing temporal co-occurrence with other butterfly species. Our results suggest that changing temperatures could cause immediate restructuring of communities without requiring changes in overall abundance or diversity. Such changes could have fitness consequences for individuals within trophic levels by altering competition for resources, as well as indirect effects mediated by species interactions across trophic levels.

16.
Sci Justice ; 58(2): 109-120, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29526262

RESUMO

Bows and arrows are used more for recreation, sport and hunting in the Western world and tend not to be as popular a weapon as firearms or knives. Yet there are still injuries and fatalities caused by these low-velocity weapons due to their availability to the public and that a licence is not required to own them. This study aimed to highlight the penetration capabilities of aluminium arrows into soft tissue and bones in the presence of clothing. Further from that, how the type and fit of clothing as well as arrowhead type contribute to penetration capacity. In this study ballistic gelatine blocks (non-clothed and loose fit or tight fit clothed) were shot using a 24lb weight draw recurve bow and aluminium arrows accompanied by four different arrowheads (bullet, judo, blunt and broadhead). The penetration capability of aluminium arrows was examined, and the depth of penetration was found to be dependent on the type of arrowhead used as well as by the type and fit or lack thereof of the clothing covering the block. Loose fit clothing reduced penetration with half of the samples, reducing penetration capacity by percentages between 0% and 98.33%, at a range of 10m. While the remaining half of the samples covered with tight clothing led to reductions in penetration of between 14.06% and 94.12%. The damage to the clothing and the gelatine (puncturing, cutting and tearing) was affected by the shape of the arrowhead, with the least damaged caused by the blunt arrowheads and the most by the broadhead arrows. Clothing fibres were also at times found within the projectile tract within the gelatine showing potential for subsequent infection of an individual with an arrow wound. Ribs, femur bones and spinal columns encased in some of the gelatine blocks all showed varying levels of damage, with the most and obvious damage being exhibited by the ribs and spinal column. The information gleaned from the damage to clothing, gelatine blocks and bones could potentially be useful for forensic investigators, for example, when a body has been discovered with no weapons or gunshot residue present.


Assuntos
Osso e Ossos/lesões , Vestuário , Armas , Ferimentos Penetrantes/patologia , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/patologia , Desenho de Equipamento , Medicina Legal , Gelatina , Humanos , Imageamento Tridimensional , Modelos Biológicos , Ferimentos Penetrantes/diagnóstico por imagem , Microtomografia por Raio-X
17.
PLoS One ; 11(12): e0168324, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28030570

RESUMO

Numerous animals have declining populations due to habitat loss, illegal wildlife trade, and climate change. The cotton-top tamarin (Saguinus oedipus) is a Critically Endangered primate species, endemic to northwest Colombia, threatened by deforestation and illegal trade. In order to assess the current state of this species, we analyzed changes in the population of cotton-top tamarins and its habitat from 2005 to 2012. We used a tailor-made "lure strip transect" method to survey 43 accessible forest parcels that represent 30% of the species' range. Estimated population size in the surveyed region was approximately 2,050 in 2005 and 1,900 in 2012, with a coefficient of variation of approximately 10%. The estimated population change between surveys was -7% (a decline of approximately 1.3% per year) suggesting a relatively stable population. If densities of inaccessible forest parcels are similar to those of surveyed samples, the estimated population of cotton-top tamarins in the wild in 2012 was 6,946 individuals. We also recorded little change in the amount of suitable habitat for cotton-top tamarins between sample periods: in 2005, 18% of surveyed forest was preferred habitat for cotton-top tamarins, while in 2012, 17% percent was preferred. We attribute the relatively stable population of this Critically Endangered species to increased conservation efforts of Proyecto Tití, conservation NGOs, and the Colombian government. Due to continued threats to cotton-top tamarins and their habitat such as agriculture and urban expansion, ongoing conservation efforts are needed to ensure the long-term survival of cotton-top tamarins in Colombia.


Assuntos
Mudança Climática , Conservação dos Recursos Naturais , Ecossistema , Animais , Colômbia , Espécies em Perigo de Extinção , Feminino , Masculino , Densidade Demográfica , Saguinus
18.
Am Nat ; 188 Suppl 1: S28-40, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27513909

RESUMO

New discoveries from direct tracking of temperate-breeding passerines show that intratropical migration (ITM) occurs in a growing number of species, which has important implications for understanding their evolution of migration, population dynamics, and conservation needs. Our large sample size ([Formula: see text]) for purple martins (Progne subis subis) tracked with geolocators to winter sites in Brazil, combined with geolocator deployments at breeding colonies across North America, allowed us to test hypotheses for ITM, something which has not yet been possible to do for other species. ITM in purple martins was not obligate; only 44% of individuals exhibited ITM, and movements were not coordinated in time or space. We found no evidence to support the resource hypothesis; rainfall and temperature experienced by individual birds during their last 2 weeks at their first roost site were similar to conditions at their second roost site after ITM. Birds generally migrated away from the heavily forested northwestern Amazon to less forested regions to the south and east. ITM in this aerial insectivore appears to support the competition-avoidance hypothesis and may be triggered by increasing local density in the core wintering region. Full life cycle models and migratory networks will need to incorporate ITM to properly address seasonal carryover effects and identify which wintering regions are most important for conservation.


Assuntos
Migração Animal , Aves , Cruzamento , Animais , Brasil , Ecologia , América do Norte , Estações do Ano
19.
PLoS One ; 9(2): e89403, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24586753

RESUMO

The Samburu pastoralists of Northern Kenya co-exist with African elephants, Loxodonta africana, and compete over resources such as watering holes. Audio playback experiments demonstrate that African elephants produce alarm calls in response to the voices of Samburu tribesmen. When exposed to adult male Samburu voices, listening elephants exhibited vigilance behavior, flight behavior, and produced vocalizations (rumbles, roars and trumpets). Rumble vocalizations were most common and were characterized by increased and more variable fundamental frequencies, and an upward shift in the first [F1] and second [F2] formant locations, compared to control rumbles. When exposed to a sequence of these recorded rumbles, roars and trumpets, listening elephants also exhibited vigilance and flight behavior. The same behavior was observed, in lesser degrees, both when the roars and trumpets were removed, and when the second formants were artificially lowered to levels typical of control rumbles. The "Samburu alarm rumble" is acoustically distinct from the previously described "bee alarm rumble." The bee alarm rumbles exhibited increased F2, while Samburu alarm rumbles exhibited increased F1 and F2, compared to controls. Moreover, the behavioral reactions to the two threats were different. Elephants exhibited vigilance and flight behavior in response to Samburu and bee stimuli and to both alarm calls, but headshaking behavior only occurred in response to bee sounds and bee alarm calls. In general, increasingly threatening stimuli elicited alarm calls with increases in F0 and in formant locations, and increasing numbers of these acoustic cues in vocal stimuli elicited increased vigilance and flight behavior in listening elephants. These results show that African elephant alarm calls differentiate between two types of threat and reflect the level of urgency of threats.


Assuntos
Comunicação Animal , Abelhas , Elefantes/fisiologia , Animais , Humanos
20.
Appl Ergon ; 44(2): 297-302, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23021630

RESUMO

Touch technology is becoming more prevalent as functionality improves and cost decreases. Therefore, it is important that this technology is accessible to users with diverse abilities. The objective of this study was to investigate the effects of button and gap size on performance by individuals with varied motor abilities. Participants with (n = 38) and without (n = 15) a motor control disability completed a digit entry task. Button size ranged from 10 to 30 mm and gap size was either 1 or 3 mm. Results indicated that as button size increased, there was a decrease in misses, errors, and time to complete tasks. Performance for the non-disabled group plateaued at button size 20 mm, with minimal, if any gains observed with larger button sizes. In comparison, the disabled group's performance continued to improve as button size increased. Gap size did not affect user performance. These results may help to improve accessibility of touch technology.


Assuntos
Transtornos dos Movimentos/psicologia , Análise e Desempenho de Tarefas , Tato , Interface Usuário-Computador , Adulto , Paralisia Cerebral/fisiopatologia , Paralisia Cerebral/psicologia , Desenho de Equipamento/psicologia , Tremor Essencial/fisiopatologia , Tremor Essencial/psicologia , Feminino , Humanos , Doença de Huntington/fisiopatologia , Doença de Huntington/psicologia , Masculino , Pessoa de Meia-Idade , Transtornos dos Movimentos/fisiopatologia , Esclerose Múltipla/fisiopatologia , Esclerose Múltipla/psicologia , Doença de Parkinson/fisiopatologia , Doença de Parkinson/psicologia , Preferência do Paciente , Fatores de Tempo
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