Impact of hydrocarbon extraction on heavy metal concentrations in lowland paca (Cuniculus paca) from the Peruvian Amazon

Oil has been extracted from the Western Amazon since the 1920s, leading to severe environmental contamination due to frequent occurrence oil spills and the dumping of produced water. Local inhabitants, along with environmental and human rights organizations, have reported the adverse effects of oil-related pollution on their livelihoods and the ecosystems they depend on. Here, we study accumulation of oil-related heavy metals in wildlife, and its subsequent incorporation into the trophic chain. We analysed the concentration of 14 heavy metals (Cd, Cr, Hg, As, Ni, V, Ba, Se, Be, Fe, Cu, Zn, Mn, Al) in liver samples from 78 lowland pacas (Cuniculus paca) hunted for subsistence in an oil-polluted area from the northern Peruvian Amazon where oil has been extracted since the 1970s (n = 38), and two control areas, the Yavari-Mirín River basin (n = 20), and the Pucacuro River basin (n = 20). Pacas in the oil-polluted area have significantly higher concentrations of Cd (P < 0.01) and Ba (P < 0.0001) compared to those in control areas, suggesting bioaccumulation of oil-related pollution. Conversely, Se levels were significantly lower in the oil-polluted area (P < 0.0001), likely due to the sequestration of Se by other heavy metals, particularly Cd. Additionally, minor variations in other heavy metals, e.g., Fe and Zn, were observed in pacas from the oil-polluted area, whereas control areas showed higher concentrations of Ni and Cu. Mn and Al levels did not significantly differ between the study areas. These results underscore the impact of oil extraction on the absorption and assimilation of heavy metals in wildlife, point at oil activities as the source of the high and unsafe blood Cd levels reported for the indigenous population of the studied oil extraction area and raise concerns about the long-term health risks from oil extraction posed to local Indigenous People who rely on subsistence hunting.

Use of wild vertebrates for consumption and bushmeat trade in Brazil: a review

BACKGROUND

Bushmeat is a resource exploited by thousands of people around the world, especially in tropical and neotropical regions, constituting an important source of protein and income. But what is known, so far, about the consumption and trade of wild vertebrate meat (hereinafter "bushmeat") in a megadiverse country like Brazil? This question was answered through a systematic survey of publications on the consumption and trade of wild vertebrate meat made in Brazil between 2011 and 2021.

METHODS

We selected 63 scientific articles available on "Google Scholar," "Science Direct," "Scopus," " Web of Science" and "Portal de Periódico da CAPES." The articles were categorized as: exclusive to (1) consumption or (2) bushmeat trade, totals of 54 and three articles, respectively; both (3) consumption and trade bushmeat, totaling six articles. We applied a nonparametric Spearman's correlation analysis to verify the association between the number of papers and the species richness of wild vertebrates cited for consumption by Brazilian state.

RESULTS

The results revealed that the publications were concentrated in the Northeast (36), North (26) and Southeast (1) regions, distributed across 16 states of the federation. These data reinforce the need for more researches in states and other regions of the country. Our research hypothesis was confirmed, since the richness of species cited for meat consumption was positively associated with the amount of work carried out by the states of the federation. We identified a total of 321 species of wild vertebrates mentioned in the categories involving the consumption of bushmeat. We had a greater bird species richness mentioned for consumption (170) to the detriment of mammals (107), reptiles (40) and amphibians (4). Furthermore, in the articles involving the bushmeat trade categories we had 57 species of vertebrates mentioned, with mammals being the most representative in terms of species richness (29), to the detriment of birds (20) and reptiles (8). These data reinforce that birds and mammals have been the groups most used both for consumption and trade in bushmeat in the country's regions, and it is necessary to mitigate the hunting exploitation of these groups. We recorded that socioeconomic, biological, environmental and sociocultural factors were the most cited predictors of the consumption and trade of bushmeat in the articles. We identified that the bushmeat trade chain is dynamic and ramified, made up of several actors, including specialized and diversified hunters, intermediaries, market sellers, market vendors, restaurant owners and final customers. Public markets and open-air fairs were the most cited places for buying and selling wild meat in commerce.

CONCLUSIONS

In general, our results indicate that we have made significant advances in publications on the consumption and trade of bushmeat in Brazil over the last few years. However, we highlight the need to better understand the patterns of consumption and trade of bushmeat in different regions of the country, as well as the factors associated with the dynamics of the trade chain and uses of wildlife by local communities. We emphasized that a multidimensional understanding of hunting activities is important to face socio-ecological problems and improve the conservation of target species which have continually been explored for uses by populations in different regions of the world.

The complete mitochondrial genome of the lowland paca (Cuniculus paca) and its phylogenetic relationship with other New World hystricognath rodents

The lowland paca (Cuniculus paca) is a nocturnal, widespread, and solitary large-sized rodent in the family Cuniculidae, and one of the most frequently hunted mammals in the Neotropical forests of Latin America. We assembled the first complete mitochondrial genome of lowland paca using three closely related hystricognath species as reference sequences. The mitochondrial genome is 16,770 basepairs (bp) in length, with similar characteristics of vertebrate mitochondrial genomes. We performed phylogenetic analyses using 26 mitochondrial genome of hystricognath species based on thirteen protein-coding genes. The result confirms the taxonomical placement among the New World hystricognath rodents with high support. The placement is consistent with previous phylogenetic studies based on individual mitochondrial and nuclear genes. The current study improves the phylogenic resolution of hystricognath rodents.

Hunting practices in southwestern Amazonia: a comparative study of techniques, modalities, and baits among urban and rural hunters

BACKGROUND

Hunting is a vital means of obtaining animal in various human populations. Hunters rely on their knowledge of species ecology and behavior to develop and employ hunting techniques and increase their chances of success. The comparison of the hunting practices of different human societies can shed light on the sustainability of hunting and the impact it has on species' populations. In this study, we examine and compare the techniques, modalities, and baits used by urban and rural hunters in Rondônia, a state in southwestern Amazonia, Brazil. We expected that rural hunters would use these elements and have greater knowledge when compared to urban hunters. We also expect that the use of specific hunting techniques and modalities will have greater selectivity and specificity of capture for rural hunters and that this knowledge will differ between groups.

METHODS

We conducted 106 semi-structured interviews with rural and urban hunters from October 2018 to February 2020. We analyzed the data using PERMANOVA and Network analyses to compare and contrast the hunting practices of each group.

RESULTS

We recorded four main hunting techniques divided into ten modalities with three techniques and seven modalities being the preferred choices among hunters. Waiting for at a Fruit Tree was cited as the primary technique employed by hunters living in urban and rural areas indicated. While the techniques and modalities were similar among hunters, the composition of species targeted and baits used differed between groups. Our network approach showed that modularity in urban areas was numerically lower than in rural areas. All species had one to more techniques associated with their capture.

CONCLUSIONS

Hunters living in urban and rural environments showed high similarity in their practices, probably due to sharing similar environments to hunt containing similar species, as well as targeting preferably the same species.

Rural–urban mobility influences wildmeat access and consumption in the Brazilian Amazon

Research demonstrates substantial urban consumption of wildmeat and the existence of trade networks in the Brazilian Amazon. Yet rural–urban mobility persists in this urbanized region, with the circulation of people, goods and ideas, blurring boundaries between rural and urban lives. Here we examined the relationships between rural–urban mobility and wildmeat access in highly forested areas of central Brazilian Amazonia. We surveyed 798 urban households in four towns and 311 rural households in 63 riverine communities. Rural–urban mobility was common amongst urban households: 49.7% maintained rural livelihoods and 57.3% were headed by rural in-migrants. Although many urban consumers purchased wildmeat, gifting was equally important. Urban households with greater rural–urban mobility consumed more wildmeat and were less likely to purchase it. Buying wildmeat was rare in rural areas but emergent in larger rural communities. Rural consumption was greater in remote areas, non-floodplain communities and during the high-water season. Urban populations placed particular pressure on three preferred species: the lowland paca Cuniculus paca, tapir Tapirus terrestris and white-lipped peccary Tayassu pecari. Rural consumption was more diverse, and per-capita wildmeat consumption was four times greater in rural than urban households (21 vs 5 kg/person/year). Total estimated annual wildmeat consumption was 3,732 t across 43 riverine urban centres compared to 11,351 t in surrounding rural areas. Because of poverty in these towns and socially mediated wildmeat acquisition, it is debatable whether urban consumers should or could be denied access to wildmeat. Nonetheless, the probable future increase in urban demand and related risks to sustainable, equitable resource use necessitate the monitoring and management of rural–urban wildmeat flows.

Postweaning Performance of the Agouti (Dasyprocta leporina): A Neotropical Rodent with Potential for Domestication

This project aimed to observe the effect of different weaning times on the weight gain in agouti (Dasyprocta leporina). The goal was to acquire an appropriate weaning time for offsprings. The experiment was performed at the University of the West Indies Field Station Farm (UFS) where animals were divided into four treatment groups, with each treatment group consisted of four animals. Treatment 1 offsprings were weaned at four weeks, treatment 2 offsprings were weaned at three weeks, treatment 3 offsprings were weaned at two weeks, and treatment 4 offsprings were weaned at one week. The offsprings were raised experimentally for their first seven weeks. There was no significant difference (p > 0.05) recorded in offsprings live weight and average daily gain (ADG) for treatments 1, 2, and 3. However, offsprings reared in treatment 4 had significantly (p < 0.05) less live weight and weight gain in comparison to the other groups at seven weeks. Offsprings in treatment 4 also experienced 50% mortality (2/4 animals died), one animal removed from the experiment due to progressive weight loss, and one offspring remained in the experiment for its duration. The other treatment experienced no loss (0% mortality). Based on the results of the experiment, agouti offsprings should not be weaned at one week due to high mortality and low live weight at the end of seven weeks. Animals can be weaned between 2 and 4 weeks of age with no detrimental effects. Dependent on the level of production, animals can be weaned at 2 or 4 weeks depending on the operators desired litters per year.