Age at sexual maturity, first parturition and reproductive senescence in wild lowland pacas (Cuniculus paca): Implications for harvest sustainability

© 2019 Elsevier B.V. Generation length (GL) of a mammal, calculated through the age at sexual maturity, first reproduction and reproductive senescence can be used to assess the capacity of a population of a species to withstand differing amounts of hunting pressure by humans without depletion of animal numbers. Due to the lack of reproductive data for wild mammals, the GL is often difficult to determine for most species. In the present study, the GL parameters were assessed for the wild lowland paca (Cuniculus paca) from a sample of 119 female genitalia obtained during a 15-year hunter participatory program in the Amazon. The probability of female pacas being sexually active, with observable ovarian functionality or pregnancy, increased as both body and genitalia masses increased. The average body mass at puberty was 5.46 kg. Puberty was estimated to occur at 4 months of age, from which there was estimation when age at first parturition would occur 9 months after birth. Additionally, there was no indication that there was a decrease in parturition rate at more advanced ages. The estimated age of first reproduction for pacas was much less than previous estimates, most from assessments of captive animals. In addition, because there was no evidence of reproductive senescence, it is suggested that the average age of mature hunted pacas should be used to determine optimal harvesting rates of pacas by humans. The present study highlights the importance of in situ studies on reproduction of animals in their natural habitat because these will yield more accurate reproductive variable estimates than those obtained from captive animals. It is suggested that similar methods be used to accurately assess reproductive parameters of other tropical species that are hunted by humans

Comparative gastrointestinal organ lengths among Amazonian primates (Primates: Platyrrhini)

Objectives: The morphological features of the gastrointestinal tract (GIT) in mammals reflect a species' food niche breadth and dietary adaptations. For many wild mammals, the relationship between the structure of the GIT and diet is still poorly understood, for example, the GIT for frugivorous primates is usually classified as unspecialized and homogeneous. Here, we compare the GIT structure of 13 primate species from the three families of extant platyrrhines (Atelidae, Pitheciidae, and Cebidae) in Amazonia, and discuss possible evolutionary adaptations to different diets and trophic niches. Methods: We measured the length of the esophagus, stomach, small intestine, large intestine, cecum, colon, and rectum of the digestive tracts of 289 primate specimens. We determined the allometric relationships of the different tubular organs with the total length of the GIT as a proxy of specimen body size. Allometric parameters were used to establish the quotients of differentiation of every organ for each primate specimen. Results: There was a high differentiation in structure of the digestive organs among genera. Alouatta specimens clearly separated from the other genera based on dissimilarities in gastric, colonic, and rectal quotients, likely linked to the fermentation of plant contents. In contrast, all cebines (Sapajus, Cebus, and Saimiri) and Cacajao species had similar small intestine quotients, which is expected due to their high rates of animal matter consumed. Conclusions: We show that diverse adaptations in digestive structure exist among frugivorous primates, which in turn reflect different dietary patterns within this group that may enable the geographic coexistence of different primate species

Breeding seasonality in the lowland paca (Cuniculus paca) in Amazonia: interactions with rainfall, fruiting, and sustainable hunting

The resilience of a given species to hunting is conditioned by the effect of potential threats upon the more sensitive periods in its life history, such as when animals are breeding. We investigated the environmental drivers of breeding seasonality in the lowland paca (Cuniculus paca), and the potential impact of hunting on the species. As part of a participative study with hunters in 2 Amazonian sites, we obtained reproductive organs of pacas as well as information on the hunters’ daily wild meat extraction. Using data on rainfall, river water level, and fruiting phenology from the 2 study sites, we applied generalized additive models for location, scale, and shape (GAMLSS) to examine the effect of climatic and environmental factors on paca reproduction. Forest fruiting was directly linked to higher pregnancy rates in pacas, and when lactation and weaning of offspring mostly occurred. Hunting was highly seasonal in all studied years and positively correlated with higher levels of river water. The coincidence between hunting patterns and paca reproductive cycles during the wet season resulted in more pregnant females being harvested. In addition to the known slow reproductive rate of pacas, the disproportionate offtake of pregnant females may affect the long-term sustainability of hunting of this species. Reducing hunting during the flooded season may not be feasible because the lowland paca provides most of the wild meat consumed by thousands of rural Amazonians during this period. However, options to offset the negative effects of killing of pregnant females could include the zoning of hunting areas or encouraging hunters to target primarily males. Our results indicate that strategies for the sustainable harvest of pacas and other heavily hunted Amazonian mammals should consider the interaction between the species’ reproductive cycles and hunting by local people in order to enhance conservation and management efforts

The Roosevelt – Rondon expedition marmoset (Mico marcai) : unveiling the conservation status of a data deficient species

The Roosevelt-Rondon Expedition marmoset, Mico marcai, was collected in 1914 and to date, all information on this species comes from three skins brought back by the Expedition and two additional skins collected in the 1990s. It is no surprise then that M.marcai has been classified as Data Deficient (DD). Given that Mico marcai’s suspected range sits on the path of the advancing Brazilian “Arc-of-Deforestation”, it is urgent that relevant data be collected to assess this taxon. Here we present the first comprehensive field data on the distribution, population size and threats on M. marcai with the goal of removing the species from the DD category. From 2012 to 2015, we surveyed for the species in 11 localities, in and around the Marmelos-Aripuanã interfluve, and estimated density using distance sampling on 10 transects. We also used spatial predictive modelling to project the amount of habitat that will be lost within its range in 18 years under different deforestation scenarios. We found marmosets in 14 localities and calculated its Extent of Occurrence to be 31,073 km2. We walked 271 km and detected 30 marmoset groups, allowing us to estimate their density to be 8.31 individuals/km2 and a total population of 258,217.71 individuals. By a “Business as usual” scenario, 20,181 km2 of habitat will be lost in three marmoset generations (~18 years), compromising 33% of the species’ range. Accordingly, M. marcai should be classified as globally Vulnerable under category A3c. Following our study, we propose the Amazonian marmosets, genus Mico, should undergo similar re-assessment as their ranges all fall in the path of the Arc-of-Deforestation. Keywords: Amazonian marmosets, Conservation Status, Data Deficient, Habitat Loss, Southern Amazoni

Involving local communities for effective citizen science: determining game species' reproductive status to assess hunting effects in tropical forests

1. Involving communities in sustainable wildlife management in tropical forests can ensure food security and livelihoods of millions of forest dwellers that depend on wild meat, but also safeguard hunted species. Mathematical models have been developed to assess hunting sustainability; but these require empirical information on reproductive parameters of the prey species, often challenging to obtain. 2. Here, we suggest that if local people can accurately identify the reproductive status of hunted animals in the field, these data could fill the existing knowledge gap regarding species’ life-history traits and enable better assessments of hunting impacts. 3. We first tested whether local people in 15 rural communities in three Amazonian sites could accurately diagnose, before and after training, the pregnancy status of hunted pacas (Cuniculus paca), which we use as our model. We then applied the results from these tests to correct reproductive status data of hunted specimens, voluntarily collected over 17 years (2002-2018) as part of a citizen science project in one of our study sites. We ran generalized additive models to contrast these corrected reproductive rates with those obtained from the direct analysis of genitalia by researchers, and with indices describing game extraction levels (catch-per-unit-effort, CPUE, and age structure of hunted individuals). 4. Before training, interviewees correctly diagnosed pregnancy in 72.5% of tests, but after training, interviewees accurately diagnosed pregnancy in 88.2% of tests, with high improvements especially for earlier pregnancy stages. Monthly pregnancy rates determined by hunters and by researchers were similar. Reported annual pregnancy Page 3 of 45 Confidential Review copy Journal of Applied Ecology 4 rates were negatively correlated with CPUE, and positively correlated with the percentage of immatures in the hunted population, in accordance to an expected densitydependent response to variations in hunting levels. 5. We showed that the voluntary diagnosis of game species’ reproductive status by local people is a feasible method to obtain accurate life-history parameters for hunted tropical species, and to assess hunting effects on game populations. Given that almost half of the protected areas in the world are co-managed by local people, our results confirm the potential of integrating local communities in citizen science initiatives to ensure faster, low-cost, and more accurate data collection for wildlife management

Urban wild meat consumption and trade in Central Amazonia

The switch from hunting wild meat for home consumption to supplying more lucrative city marketsin Amazonia can adversely affect some game species. Despite this, information on the amounts of wild meateaten in Amazonian cities is still limited. We estimated wild meat consumption rates in 5 cities in the State ofAmazonas in Brazil through 1046 door-to-door household interviews conducted from 2004 to 2012. With thesedata, we modeled the relationship between wild meat use and a selection of socioeconomic indices. We thenscaled up our model to determine the amounts of wild meat likely to be consumed annually in the 62 urbancenters in central Amazonia. A total of 80.3% of all interviewees reported consuming wild meat during an averageof 29.3 (CI 11.6) days per year. Most wild meat was reported as bought in local markets (80.1%) or hunted by afamily member (14.9%). Twenty-one taxa were cited as consumed, mostly mammals (71.6%), followed by reptiles(23.2%) and then birds (5.2%). The declared frequency of wild meat consumption was positively correlated withthe proportion of rural population as well as with the per capita gross domestic product of the municipality(administrative divisions) where the cities were seated. We estimated that as much as 10,691 t of wild meat mightbe consumed annually in the 62 urban centers within central Amazonia, the equivalent of 6.49 kg per person peryear. In monetary terms, this amounts to US$21.72 per person per year or US$35.1 million overall, the latter figureis comparable to fish and timber production in the region. Given this magnitude of wild meat trade in centralAmazonia, it is fundamental to integrate this activity into the formal economy and actively develop policies thatallow the trade of more resilient taxa and restrict trade in species sensitive to hunting

LED flashlight technology facilitates wild meat extraction across the tropics

Hunting for wild meat in the tropics provides subsistence and income for millions 29 of people. Methods have remained relatively unchanged since the introduction of 30 shotguns and battery-powered incandescent flashlights, but due to the short life of batteries in such flashlights, nocturnal hunting has been limited. However, brighter, 32 more efficient light-emitting diode (LED) flashlights, have recently been adopted by 33 hunters. Brighter spotlights increase the freezing response of many species, and 34 greater battery life allows hunters to pursue game for longer and more frequently. 35 Hunters interviewed in African and South American forests, disclosed that LEDs 36 increase the frequency and efficiency of nocturnal hunting, and the number of kills 37 made. These changes were reflected in harvest data in Brazil. The drastic change in 38 efficiency brought about by LEDs, well known to hunters around the world, poses a 39 significant threat to wildlife. We consider the implications for communities, governments, 40 wildlife managers and conservationist

Social Correlates of and Reasons for Primate Meat Consumption in Central Amazonia

Traditionally, humans have consumed nonhuman primates in many places, including throughout the Amazon region. However, primate consumption rates are changing with rising urbanization and market access. We characterize primate consumption in central Amazonia using 192 qualitative interviews with inhabitants in three rural villages and in the city of Tefé. We used a generalized linear model to investigate how individual consumer characteristics, such as age and gender, and livelihoods affected primate consumption. We also used principal coordinate analysis (PCoA), and word clouds and network text analyses, to describe reasons people gave for eating or avoiding primates. Our results show that men were more likely to say that they eat primates than women, and that the probability that a person said that they eat primates correlated positively with the percentage of their life lived in rural areas. People gave sentiment and ethical reasons not to eat primates. Custom influenced whether people said they eat primates both positively and negatively, while taste positively influenced whether people said they eat primates. A preference for other wild meats in rural areas, and for domestic meats in cities negatively influenced whether people said they eat primates. People also cited the perceptions that primates have a human-like appearance and that primate meat is unhealthy as reasons not to eat primates. People in urban areas also cited conservation attitudes as reasons for not eating primates. Our findings provide an understanding of factors influencing primate consumption in our study area and will be useful for designing tailored conservation initiatives by reducing hunting pressure on primates in rural settings and increasing the effectiveness of outreach campaigns in urban centers

Life history, distribution and abundance of the giant earthworm Rhinodrilus alatus RIGHI 1971: conservation and management implications

Rhinodrilus alatus is an endemic giant earthworm of the Brazilian Cerrado hotspot used as live bait for about 80 years. The goal of this study was to gather ecological data about this species, which will support the establishment of management strategies. The life history, distribution and abundance of R. alatus were investigated in Cerrado, pastures and Eucalyptus plantation areas following the harvesting activities of the local extractors of this species. We found that this earthworm is abundant in all of the sampled areas, showing its resilience to land-use conversion. The Capture Per Unit Effort was 4.4 ± 5 individuals per 100 metres of transect and 5.6 ± 3 individuals per hour. The earthworm's annual cycle is markedly seasonal, with an aestivation period throughout the driest and coldest season of the year. Significant differences in the length and diameter of the body and in the diameter and depth of the aestivation chambers were found between the juveniles and adults. The distribution range of the species was expanded from two to 17 counties. The life history, abundance, distribution and resilience of R. alatus to certain perturbations are key elements to be considered in conservation and management strategies for this species