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

Farming non-typical sentient species: ethical framework requires passing a high bar

More widespread farming of species not typically used as livestock may be part of a sustainable approach for promoting human health and economic prosperity in a world with an increasing population; a current example is peccary farming in the Neotropics. Others have argued that species that are local to a region and which are usually not farmed should be considered for use as livestock. They may have a more desirable nutrient profile than species that are presently used as livestock. It may also reduce the pressure from hunting on other wild species, and cause less environmental damage than exotic species. We propose a sentiocentric utilitarian framework that could be used to decide whether species that are local, but generally not used as livestock, should be farmed. To illustrate the use of our decision-making framework, we employ two contrasting neotropical case studies: the Spotted Paca (Cuniculus paca) and the Capybara (Hydrochoerus hydrochaeris). We argue that it may be acceptable to use non-sentient species that are typically not farmed as livestock. However, research should determine whether farming them offers human, environmental or sustainability benefits. In addition, we recommend that if invertebrate species are considered for farming, research should be conducted to determine the likelihood that they are sentient. Finally, given the ethical failings of current livestock farming practices, we argue that a high bar must be met if 'new' species that are sentient are to be farmed.

The sustainable development goals in two sustainable development reserves in central amazon: achievements and challenges

The 2030 Agenda was set in 2015 by the United Nations, with 17 Sustainable Development Goals. The Amazonian riverine people are recognized as traditional communities that have their own culture and use the local natural resources of their territories in an ancestral and traditional way. The Sustainable Development Reserve is a Brazilian protected area category which aims to ensure the protection of the natural environment while allowing the residence and the use of these lands by traditional populations. This article reports and discusses the achievements and challenges of the Sustainable Development Goals in two sustainable development reserves in Central Amazonia. The goals were evaluated in the Mamirauá and Amanã Sustainable Development Reserves, due to the large research programs developed in those areas along the past 20 years. The 17 Sustainable Development Goals have a clear connection with the mission of these sustainable development reserves in Central Amazon. Despite the many achievements conquered over the years, there are many challenges yet to overcome; and while striving to achieve the goals from the 2030 Agenda, new challenges will emerge. The current main challenges to reach the Sustainable Development Goals in the Mamirauá and Amanã Sustainable Development Reserves, in Central Amazon, are connecting to the reality of rural areas.

Temperament, Plasticity, and Emotions in Defensive Behaviour of Paca (Mammalia, Hystricognatha)

Simple Summary

The paca (Cuniculus paca), a Neotropical caviomorph rodent, provides the most sought-after game meat in all its range, and it therefore faces high hunting pressure and consequent poor welfare. The species is categorised as having a conservation status of “least concern” and appears resilient to over-hunting by humans, which may be related to individuals’ behavioural characteristics. To investigate this, we submitted captive pacas to temperament (personality) tests designed to assess individual responses to short challenges and to evaluate individuals’ emotional states. Our results showed that paca with a “restless” temperament performed more abnormal behaviour and less exploratory behaviour in a test of defensive behaviour, which elevations in faecal glucocorticoid metabolites indicated to be stressful. Plasticity in defensive behaviour was inferred from changes in behavioural responses and apparently rapid adaptation to different levels of risk. Our results suggest that individual differences and consistency of behavioural responses displayed by paca toward challenges may reflect a generally flexible and successful defensive behavioural response that underpins the paca’s survival, despite the threat of overhunting throughout its range.

Abstract

Within a species, some individuals are better able to cope with threatening environments than others. Paca (Cuniculus paca) appear resilient to over-hunting by humans, which may be related to the behavioural plasticity shown by this species. To investigate this, we submitted captive pacas to temperament tests designed to assess individual responses to short challenges and judgement bias tests (JBT) to evaluate individuals’ affective states. Results indicated across-time and context stability in closely correlated “agitated”, “fearful” and “tense” responses; this temperament dimension was labelled “restless”. Individual “restless” scores predicted responses to novelty, although not to simulated chasing and capture by humans in a separate modified defence test battery (MDTB). Restless animals were more likely to show a greater proportion of positive responses to an ambiguous cue during JBT after the MDTB. Plasticity in defensive behaviour was inferred from changes in behavioural responses and apparently rapid adaptation to challenge in the different phases of the MDTB. The results indicate that both temperament and behavioural plasticity may play a role in influencing paca responses to risky situations. Therefore, our study highlights the importance of understanding the role of individual temperament traits and behavioural plasticity in order to better interpret the animals’ conservation status and vulnerabilities.

Nutritive Value and Physical Properties of Neo-Tropical Rodent Meat-with Emphasis on the Capybara (Hydrochoerus hydrochaeris)

This review will focus on the nutritive characteristics of meat from neo-tropical rodents which have not yet been domesticated. These rodents include the capybara (Hydrochoerus hydrochaeris), agouti (Dasyprocta leporina), and the lappe (Agouti paca). Information about the meat characteristics of these rodents were obtained from peer reviewed journal articles. Literature was obtained using search engines such as Google Scholar, Uwi linc, and Pub Med Central. Keywords used in the searches were "capybara", "Hydrochoerus hydrochaeris", "agouti", "Dasyprocta leporina", "Agouti paca/Cuniculus paca", lappe", and "meat proximate analysis". Over four decades of literature was searched, spanning from the 1970s to 2020. There is a vast amount of information on the meats of the capybara, but limited information on the lappe, and there is a dearth of information on the agouti. Capybara meat is considered to be highly nutritious, with high levels of polyunsaturated fatty acids (PUFA), low levels of saturated fatty acids (SFA), low levels of fats and cholesterol. The animals that were reared in conditions which were similar to their habitat had lower levels of SFA. Diet, age, confinement, and sex had an effect on the chemical composition of the meat of the capybara. On average, capybara meat had a moisture content of 75%, protein 22%, ash 1.5%, and lipid 1%. During the authors' search of the literature, no information was found on the proximate composition of the lappe or agouti meat. Information regarding the fatty acid profile of lappe meat was found, as well as a description of the physical characteristics of agouti and lappe meat. The physical parameter shows that the lappe has the most tender meat of the three rodent species, while the agouti has the least tender meat, and the capybara being intermediary. Neo-tropical rodent meat is highly nutritious, and is an excellent protein alternative for the growing population of the world. These animals are adapted to challenging environments and can grow well using locally available feed resources. However, further research needs to be conducted on the proximate analysis on lappe and agouti meat to fully inform consumers about its nutrient value.

Fetal bone development in the lowland paca (Cuniculus paca, Rodentia, Cuniculidae) determined using ultrasonography

Studying the timing of the main events of embryonic and fetal development may clarify the strategies adopted by species to maximize neonatal survival and the consequences of these events for their life history. This study describes bone development during the fetal phase of the lowland paca (Cuniculus paca), comparing it with other precocial or altricial species, and its relationship with the species' adaptive strategies. A total of 102 embryos/fetuses obtained over the course of 17 years through collaboration with local subsistence hunters in the Amazon were analyzed. Measurements of mineralization of the axial and appendicular skeletons were performed by ultrasonography using a 10-18-MHz linear transducer. The chronological order of occurrence of mineralization in relation to the total dorsal length (TDL) was: skull (TDL = 4.1 cm); vertebral bodies (TDL = 4.6 cm); scapula, humerus, radius, ulna, ilium, ischium, femur, tibia, and fibula (TDL = 6.7 cm); ribs (TDL = 7.8 cm); clavicle (TDL = 8.5 cm); metacarpi/metatarsi (TDL = 11 cm); phalanges (TDL = 15 cm); tarsus (TDL = 18 cm); patella (TDL = 23 cm); and carpus (TDL = 27.2 cm). Secondary ossification centers first appeared in the femoral distal epiphysis (TDL = 16.6 cm) and tibial proximal epiphysis (TDL = 18.4 cm). Advanced fetuses (TDL > 30 cm, 97% gestational period) presented mineralization in all primary and most secondary centers. Compared to other species, paca neonates have a well-developed skeletal system at birth, which is important for their independent postnatal locomotion. Our results may contribute to the monitoring of bone development in other wild species, helping us to understand their life history, and serving as parameters for comparisons between precocial and altricial mammals.

Effects of age on foraging behavior in two closely related albatross species

BACKGROUND

Foraging performance is widely hypothesized to play a key role in shaping age-specific demographic rates in wild populations, yet the underlying behavioral changes are poorly understood. Seabirds are among the longest-lived vertebrates, and demonstrate extensive age-related variation in survival, breeding frequency and success. The breeding season is a particularly critical phase during the annual cycle, but it remains unclear whether differences in experience or physiological condition related to age interact with the changing degree of the central-place constraint in shaping foraging patterns in time and space.

METHODS

Here we analyze tracking data collected over two decades from congeneric black-browed (BBA) and grey-headed (GHA) albatrosses, Thalassarche melanophris and T. chrysostoma, breeding at South Georgia. We compare the foraging trip parameters, at-sea activity (flights and landings) and habitat preferences of individuals aged 10-45 years and contrast these patterns between the incubation and early chick-rearing stages.

RESULTS

Young breeders of both species showed improvements in foraging competency with age, reducing foraging trip duration until age 26. Thereafter, there were signs of foraging senescence; older adults took gradually longer trips, narrowed their habitat preference (foraging within a smaller range of sea surface temperatures) (GHA), made fewer landings and rested on the water for longer (BBA). Some age-specific effects were apparent for each species only in certain breeding stages, highlighting the complex interaction between intrinsic drivers in determining individual foraging strategies.

CONCLUSIONS

Using cross-sectional data, this study highlighted clear age-related patterns in foraging behavior at the population-level for two species of albatrosses. These trends are likely to have important consequences for the population dynamics of these threatened seabirds, as young or old individuals may be more vulnerable to worsening environmental conditions.