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41.
Over-exploitation of wildlife is a significant threat to global biodiversity, but addressing the sustainability of harvests can be difficult when trade is conducted illegally. The wildlife trade is driven chiefly by consumer demand, largely in developed nations (but increasingly in Asia), and more species are traded to meet international demand for pets than for any other purpose. We surveyed traders of amphibians and reptiles in the Indonesian provinces of Maluku, West Papua and Papua between September 2010 and April 2011. We recorded 5,370 individuals representing 52 species collected solely for the pet trade. At least 44?% were either fully protected or had not been allocated a harvest quota, making their harvest and trade illegal. Approximately half were listed within the Convention on International Trade in Endangered Species of Wild Fauna and Flora. Trade operates via a complex chain, with hunters receiving little income compared to middlemen and exporters. Examination of Indonesian harvest quotas for amphibians and reptiles suggests limited knowledge of species distributions, with quotas often set for species in provinces where they do not occur. Illegal trade is due, partly, to an inadequate understanding of the species being traded and is facilitated by poor monitoring and enforcement at key trade hubs. As a first step to combatting illegal trade, and to better understand the effects of harvest on wild populations, we recommend the need for increased monitoring and enforcement, improving the knowledge base of species traded and educating consumers about the effects their demand for pets has on these species. 相似文献
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The economic viability of the wildlife based enterprises (bee-keeping and caterpillar utilization) in Malawi is discussed in relation to conventional agricultural enterprises (maize, beans and ground-nuts). A strong incentive emerges for rural people to adopt wildlife management as an adjunct to subsistence agriculture, and therefore, to promote conservation of natural ecosystems and wildlife habitats in the face of growing human population and demand for land. Dependence on agriculture has depleted the wildlife resource outside protected areas and has been less effective in improving the wealth and living standards of most rural people. This study illustrates that the Malawi Department of National Parks and Wildlife needs to introduce economic incentives that integrate biological conservation with economic development for the rural people. The management programme involves the adoption of a rotation burning policy that promotes vegetation coppicing, eases harvesting and promotes high caterpillar yields. 相似文献
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Daniel M. Wetzel Ursula L. Haerter Darcy B. Kelley 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1985,157(6):749-761
Vocalizations of South African clawed frogs are produced by contractions of laryngeal muscles innervated by motor neurons of the caudal medulla (within cranial nerve nucleus IX-X). We have traced afferents to laryngeal motor neurons in male and female frogs using retrograde axonal transport of horseradish peroxidase conjugated to wheat germ agglutinin (HRP-WGA). After iontophoretic injection of HRP-WGA into n. IX-X, retrogradely labelled neurons were seen in the contralateral n. IX-X, in rhombencephalic reticular nuclei, and in the pre-trigeminal nucleus of the dorsal tegmental area (DTAM) of both males and females. 相似文献
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Ca2+ is an important intracellular messenger affecting many diverse processes. In eukaryotic cells, Ca2+ storage is achieved within specific intracellular organelles, especially the endoplasmic/sarcoplasmic reticulum, in which Ca2+ is buffered by specific proteins known as Ca2+ buffers. Ca2+ buffers are a diverse group of proteins, varying in their affinities and capacities for Ca2+, but they typically also carry out other functions within the cell. The wide range of organelles containing Ca2+ and the evidence supporting cross-talk between these organelles suggest the existence of a dynamic network of organellar Ca2+ signaling, mediated by a variety of organellar Ca2+ buffers. 相似文献
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1. Host plant phenotypic traits affect the structure of the associated consumer community and mediate species interactions. Intraspecific variation in host traits is well documented, although a functional understanding of variable traits that drive herbivore community response is lacking. We address this gap by modelling the trait-environment relationship using insect traits and host plant traits in a multilevel model. 2. We compare herbivore assemblages from the canopy of the phenotypically variable tree Metrosideros polymorpha on Hawai‘i Island. Multiple distinct varieties of M. polymorpha frequently co-occur, with variation in morphological traits. Using this system, we identify host and insect traits that underlie patterns of herbivore abundance and quantify the strength of host-insect trait interactions. 3. This work examines plant-insect interactions at a community scale, across 36 herbivore species in three orders. We find that co-occurring trees of varying phenotype support distinct communities. Leaf traits, including specific leaf area, trichome presence, and leaf nutrients, explain 46% of variation in insect communities. We find that feeding guild and nymphal life history are correlated with host plant traits, and we show that model predictions are improved by including the host and insect trait interaction. 4. This study demonstrates how insect herbivores traits influence community response to morphologically variable hosts. Environmental heterogeneity indirectly affected herbivore community structure via intraspecific variation in host plants, providing an important source of variation for maintaining diversity in the broader community. 相似文献