RESUMO
Decentralized environmental governance has become increasingly common across much of Latin America and in developing countries more generally, yet the impacts of decentralization on wildlife conservation remain unclear. Decentralized environmental governance is thought to improve efficiency, local compliance, and democratic potential of natural resource management. However, wildlife conservation, especially that of large mammals, poses unique challenges in the context of decentralized governance: wildlife conservation is often expensive, requires large expanses of contiguous habitat, and often offers few economic benefits. We analyzed Colombia's decentralized environmental governance and its performance in conserving a contentious and border-crossing wildlife species, the Andean bear (Tremarctos ornatus). We considered both decentralized institutions and nongovernmental organizations (NGOs). This analysis is informed by 67 semi-structured interviews with conservation practitioners in Colombia. We found inconsistent program implementation across the country and little information exchange among institutions. These issues quite likely contribute to exacerbated human-bear conflict and thus more Andean bear deaths suggesting that the successful coordination of large-scale wildlife conservation may yet require the leadership of strong central institutions. A few international NGOs were working to improve Andean bear conservation in Colombia, but we saw little involvement at the national level of Colombian NGOs-some of whom felt they were being unfairly outcompeted by international elites. We recommend a greater engagement with Colombian NGOs (by both donors and international NGOs) as a means through which to ensure the integrity of Andean bear conservation into the future.
Assuntos
Ursidae , Animais , Colômbia , Conservação dos Recursos Naturais , Ecossistema , Política Ambiental , HumanosRESUMO
Whale sharks (Rhincodon typus) - the largest extant fish species - reside in tropical environments, making them an exception to the general rule that animal size increases with latitude. How this largest fish thrives in tropical environments that promote high metabolism but support less robust zooplankton communities has not been sufficiently explained. We used open-source inertial measurement units (IMU) to log 397â h of whale shark behavior in Yucatán, Mexico, at a site of both active feeding and intense wildlife tourism. Here we show that the strategies employed by whale sharks to compensate for the increased drag of an open mouth are similar to ram feeders five orders of magnitude smaller and one order of magnitude larger. Presumed feeding constituted 20% of the total time budget of four sharks, with individual feeding bouts lasting up to 11 consecutive hours. Compared with normal, sub-surface swimming, three sharks increased their stroke rate and amplitude while surface feeding, while one shark that fed at depth did not demonstrate a greatly increased energetic cost. Additionally, based on time-depth budgets, we estimate that aerial surveys of shark populations should consider including a correction factor of 3 to account for the proportion of daylight hours that sharks are not visible at the surface. With foraging bouts generally lasting several hours, interruptions to foraging during critical feeding periods may represent substantial energetic costs to these endangered species, and this study presents baseline data from which management decisions affecting tourist interactions with whale sharks may be made.
Assuntos
Tubarões , Natação , Animais , Espécies em Perigo de Extinção , Masculino , MéxicoRESUMO
This article considers how the global "academic pipeline problem" constrains immigrant, low-income, and ethnic minority students' pathways to higher education, and how some students build pathways to college and career identities. After aligning theories of social capital, alienation/belonging, and challenge and their integration in Bridging Multiple Worlds Theory, we summarize six longitudinal studies based on this theory from a 23-year university-community partnership serving low-income, primarily U.S. Mexican immigrant youth. Spanning from childhood to early adulthood, the studies revealed two overarching findings: First, students built pathways to college and career identities while experiencing capital, alienation/belonging, and challenges across their evolving cultural worlds. Second, by "giving back" to families, peers, schools, and communities, students became cultural brokers and later, institutional agents, transforming institutional cultures. Findings highlight the value of integrating interdisciplinary theories, research evidence, and educational systems serving diverse communities to open individual pathways and academic pipelines in multicultural societies.
Assuntos
Escolha da Profissão , Emigrantes e Imigrantes/psicologia , Americanos Mexicanos/psicologia , Alienação Social/psicologia , Capital Social , Identificação Social , Estudantes/psicologia , Universidades , Adolescente , Adulto , Criança , Humanos , México/etnologia , Estados Unidos/etnologia , Adulto JovemRESUMO
BACKGROUND: Species of Schellackia Reichenow, 1919 have been described from the blood of reptiles distributed worldwide. Recently, Schellackia spp. detected in European and Asian lizards have been molecularly characterised. However, parasites detected in American lizard hosts remain uncharacterised. Thus, phylogenetic affinities between the Old and New World parasite species are unknown. METHODS: In the present study, we characterised morphologically and molecularly the hemococcidian parasites (sporozoites) that infect three lizard hosts from North America and two from South America. RESULTS: In total, we generated 12 new 18S rRNA gene sequences of hemococcidian parasites infecting New World lizard hosts. By the microscopic examination of the smears we identified Schellackia golvani Rogier & Landau, 1975 (ex Anolis carolinensis Voigt) and Schellackia occidentalis Bonorris & Ball, 1955 (ex Uta stansburiana Baird & Girard and Sceloporus occidentalis Baird & Girard) in some samples, but the phylogenetic analysis indicated that all 18S rDNA sequences are distant from Schellackia species found in Old World lizards. In fact, the hemococcidian parasites detected in the New World lizards (including S. occidentalis and S. golvani) were closely related to the genus Lankesterella Labbé, 1899. Consequently, we suggest these two species to be included within the genus Lankesterella. CONCLUSIONS: Life history traits of hemococcidian parasites such as the type of host blood cells infected, host species or number of refractile bodies are not valid diagnostic characteristics to differentiate the parasites between the genera Schellackia and Lankesterella. Indeed, lankesterellid parasites with a different number of refractile bodies had a close phylogenetic origin. Based on the phylogenetic results we provide a systematic revision of the North American hemococcidians. Our recommendation is to include the species formerly described in the genus Schellackia that infect American lizards into Lankesterella (Lankesterellidae) as Lankesterella golvani (Rogier & Landau, 1975) n. comb and L. occidentalis (Bonorris & Ball, 1955) n. comb.
Assuntos
Apicomplexa/classificação , Apicomplexa/genética , Lagartos/parasitologia , Filogenia , Infecções Protozoárias em Animais/epidemiologia , Animais , DNA Ribossômico/genética , Eucoccidiida/parasitologia , Especificidade de Hospedeiro , América do Norte/epidemiologia , Infecções Protozoárias em Animais/sangue , Infecções Protozoárias em Animais/parasitologia , RNA Ribossômico 18S/genética , Análise de Sequência de DNA , América do Sul/epidemiologia , Estados Unidos/epidemiologiaRESUMO
Coffee agroforestry systems and secondary forests have been shown to support similar bird communities but comparing these habitat types are challenged by potential biases due to differences in detectability between habitats. Furthermore, seasonal dynamics may influence bird communities differently in different habitat types and therefore seasonal effects should be considered in comparisons. To address these issues, we incorporated seasonal effects and factors potentially affecting bird detectability into models to compare avian community composition and dynamics between coffee agroforests and secondary forest fragments. In particular, we modeled community composition and community dynamics of bird functional groups based on habitat type (coffee agroforest vs. secondary forest) and season while accounting for variation in capture probability (i.e. detectability). The models we used estimated capture probability to be similar between habitat types for each dietary guild, but omnivores had a lower capture probability than frugivores and insectivores. Although apparent species richness was higher in coffee agroforest than secondary forest, model results indicated that omnivores and insectivores were more common in secondary forest when accounting for heterogeneity in capture probability. Our results largely support the notion that shade-coffee can serve as a surrogate habitat for secondary forest with respect to avian communities. Small coffee agroforests embedded within the typical tropical countryside matrix of secondary forest patches and small-scale agriculture, therefore, may host avian communities that resemble those of surrounding secondary forest, and may serve as viable corridors linking patches of forest within these landscapes. This information is an important step toward effective landscape-scale conservation in Neotropical agricultural landscapes.