Low Reproductive Rates Research Articles

Conservation Letter: Raptors and Anticoagulant Rodenticides

Conservation Letter: Raptors and Anticoagulant Rodenticides

Spatial and Temporal Variation in Annual versus Biennial Reproductive Cycles in Eastern Bering Sea Snow Crab Chionoecetes opilio

AbstractThe stock assessment model currently used for the management of the fishery for snow crab Chionoecetes opilio in the eastern Bering Sea assumes an annual reproductive cycle. However, temperatures below 1°C can extend the snow crab reproductive cycle to 2 years, which could depress the total reproductive potential of the stock. Our objective was to determine the prevalence of snow crab in the eastern Bering Sea on a biennial reproductive cycle, relative to latitudinal and thermal gradients, and evaluate whether available bottom temperature data could be used to predict the proportions of biennial spawners. Mature female snow crab were collected on the annual National Marine Fisheries Service eastern Bering Sea bottom trawl survey during 2014–2018. Bimodality in the frequency distribution of oocyte area suggests that oocyte area can likely be used to distinguish annual and year‐1 biennial spawners from year‐2 spawners. In 2014, the highest rates of biennial reproduction were found in northern, colder areas in the eastern Bering Sea. In 2015–2018, very low rates of biennial reproduction coincided with warm temperatures across the eastern Bering Sea. This work could help in the estimation of female reproductive potential and allow the development of female‐based reference points for the eastern Bering Sea snow crab fishery.

Does Social Complexity Drive Vocal Complexity? Insights from the Two African Elephant Species.

Simple SummaryThe social complexity hypothesis (SCH) for communication predicts that species with complex social systems exhibit complex communication systems. Testing the SHC in a broad range of species can contribute to a better understanding of human evolution because a co-evolutionary runaway process between social and vocal complexity may have shaped human language. Here we compare patterns of vocal complexity between the two species of African elephants: the savanna elephant exhibiting a complex social organization and the forest elephant exhibiting a simpler social organization. We review the existing literature and present novel insights into the vocal communication system of the elusive forest elephant, along with a first direct comparison with savanna elephants. Our findings suggest that the African elephants may contradict the SCH, as well as other factors potentially shaping patterns of vocal complexity across species. A better understanding of vocal complexity in the two species of African elephants will depend on continuing advancements in remote data collection technologies to overcome the challenges of observing forest elephants in their dense rainforest habitat, as well as the availability of comparable data quantifying both structural and contextual variability in the vocal production of both species of African elephants.The social complexity hypothesis (SCH) for communication states that the range and frequency of social interactions drive the evolution of complex communication systems. Surprisingly, few studies have empirically tested the SHC for vocal communication systems. Filling this gap is important because a co-evolutionary runaway process between social and vocal complexity may have shaped the most intricate communication system, human language. We here propose the African elephant Loxodonta spec. as an excellent study system to investigate the relationships between social and vocal complexity. We review how the distinct differences in social complexity between the two species of African elephants, the forest elephant L. cyclotis and the savanna elephant L. africana, relate to repertoire size and structure, as well as complex communication skills in the two species, such as call combination or intentional formant modulation including the trunk. Our findings suggest that Loxodonta may contradict the SCH, as well as other factors put forth to explain patterns of vocal complexity across species. We propose that life history traits, a factor that has gained little attention as a driver of vocal complexity, and the extensive parental care associated with a uniquely low and slow reproductive rate, may have led to the emergence of pronounced vocal complexity in the forest elephant despite their less complex social system compared to the savanna elephant. Conclusions must be drawn cautiously, however. A better understanding of vocal complexity in the genus Loxodonta will depend on continuing advancements in remote data collection technologies to overcome the challenges of observing forest elephants in their dense rainforest habitat, as well as the availability of directly comparable data and methods, quantifying both structural and contextual variability in the production of rumbles and other vocalizations in both species of African elephants.

IMMUNO-BIOLOGICAL PROPERTIES OF VAGINAL DISCHARGE IN HEALTHY AND MYCOPLASMOSIS-INFECTED COWS

Genital mycoplasmosis in cows is a disease accompanied by a latent course, which complicates its timely diagnosis and the appointment of adequate therapy. The nonspecific symptomatology of mycoplasmosis, combined with periods of asymptomatic course, leads to the development of functional and morphological changes in the organs of the reproductive system of cows, resulting in infertility. Monitoring studies of livestock farms in the North-West region of the Russian Federation have shown that infection of the genitals of cows with mycoplasmas can be from 20 to 40% of the livestock. Moreover, there is a clear relationship between the high infection rate of the livestock and low reproduction rates. In this regard, livestock enterprises incur significant economic damage. One of the important mechanisms preventing the introduction of various pathogens into the reproductive tract is the resistance of the vaginal mucosa. Among these factors, the most important role is assigned to vaginal autoflora, epithelial desquamation, phagocytosis, acidity of vaginal secretions, the content of immunoglobulins, lysozyme and a number of other nonspecific protective factors in it. We studied the changes in the immuno-biological characteristics of vaginal secretions in the subclinical course of genital mycoplasmosis. Healthy cows with a negative PCR test for Mycoplasma spp. were selected for the study. and infected with Mycoplasma spp., without clinical signs of vaginitis. In both groups of animals, the concentration of hydrogen ions, the activity of lysozyme and immunoglobulins of the classes IgG, IgM, IgA and sIgA were determined in the vaginal secretions. Despite the fact that the persistence of mycoplasmas in the vagina is not accompanied by pronounced clinical signs of vaginitis, but the state of protective factors the mucous membrane undergoes significant changes. The conducted studies made it possible to establish that the long-term presence of mycoplasmas in the vagina of cows is manifested by a significant increase in the concentration of hydrogen ions by 41% and a decrease in the lysozyme activity of vaginal secretions by 2 times, that is, inhibition of the main factors preventing the colonization of mucous pathogenic microflora is observed. In addition, there is a redistribution of classes of immunoglobulins in the vaginal secretion. This is manifested by a significant increase in the content of IgM and sIgA against the background of a tendency towards a decrease in IgA. The noted changes in aggregate create favorable conditions for the introduction of secondary microflora and the development of bacterial-mycoplasma vaginitis, aggravating morpho-functional changes in the reproductive tract and increasing the risk of infertility.

Interannual dynamics of size, age composition and parameters of growth for japanese sardine <i>Sardinops melanostictus</i> in periods of its high abundance in the North-West Pacific

Interannual dynamics of size composition, age structure, and growth parameters are considered for japanese sardine Sardinops melanostictus in context of its recent and previous blooms and mass migrations to the Pacific waters at Kuril Islands and to the northern Japan Sea. Before the post-bloom catastrophic decline in the 1990s, in conditions of the highest density of the sardine population, small-sized fish with relatively slow growth rate became dominant, distinguished by lowered reproductive potential because of low population fecundity and reproduction rate. In the new, modern bloom of sardine population, two modal groups are observed in the year-classes size composition, in particular in the Japan Sea, with different exterior and biological parameters. There is assumed that they correspond with two morphological types, which alter each other at different stages of the demographic cycle, that determines total abundance of sardine population in the North-West Pacific and its long-term dynamics.

Reproductive one health in primates.

One Health is a collaborative trans-disciplinary approach to health; integrating human, animal, and environmental health. The focus is often on infection disease transmission and disease risk mitigation. However, One Health also includes the multidisciplinary and comparative approach to disease investigation and health of humans, animals, and the environment. One key aspect of environmental/ecosystem health is conservation, the maintenance of healthy, actively reproducing wildlife populations. Reproduction and reproductive health are an integral part of the One Health approach: the comparative aspects of reproduction can inform conservation policies or breeding strategies (in situ and ex situ) in addition to physiology and disease. Differences in reproductive strategies affect the impact poaching and habitat disruption might have on a given population, as well as ex situ breeding programs and the management of zoo and sanctuary populations. Much is known about chimpanzees, macaques, and marmosets as these are common animal models, but there is much that remains unknown regarding reproduction in many other primates. Examining the similarities and differences between and within taxonomic groups allows reasonable extrapolation for decision-making when there are knowledge gaps. For example: (1) knowing that a species has very low reproductive rates adds urgency to conservation policy for that region or species; (2) identifying species with short or absent lactation anestrus allows ex situ institutions to better plan contraception options for specific individuals or prepare for the immediate next pregnancy; (3) recognizing that progestin contraceptives are effective contraceptives, but may be associated with endometrial hyperplasia in some species (in Lemuridae but not great apes) better guides empirical contraceptive choice; (4) recognizing the variable endometriosis prevalence across taxa improves preventive medicine programs. A summary of anatomical variation, endocrinology, contraception, pathology, and diagnostics is provided to illustrate these features and aid in routine physical and postmortem examinations as well as primate management.

Phenotypic integration approaches predict a decrease of reproduction rates of Caribbean pine populations in dry tropical areas

• Key message The combination of structural equation modelling and linear mixed-effects models opens a new perspective to investigate trait adaptation syndromes through phenotypic integration prediction at large geographical scales, a necessary step to understand the future of organisms under climate change. In the case of Pinus caribaea Morelet, reproduction limits the species suitability, decreasing towards southernmost latitudes where dry conditions increase.ContextCaribbean pine is an ecologically and economically important species planted in all the tropical regions of the world, where it shows optimal growth and survival but low reproduction rates.AimsThis study investigates Caribbean pine fitness-related traits, accounting for phenotypic plasticity and local adaptation, to detect co-variation among traits and predict their relationship across the tropics.MethodsI re-analysed earlier data of survival, growth, reproduction, stem quality and development stage from 25 provenances of Caribbean pine planted in 16 trials in the tropical regions in a two-step modelling approach including (i) structural equation modelling (SEM) based on the current knowledge of the species and theoretical expectations coming from other species; (ii) mixed-effects model accounting for trait-relationships as defined by SEM and allowing for trait prediction.ResultsGrowth, survival and reproduction showed a slight but significant provenance effect indicating population differentiation and a positive co-variation between growth and reproduction, suggesting that trees reached optimal growth before they reproduced. Models predicted low reproduction rates of Caribbean pine across the tropics, decreasing towards southern latitudes where dry conditions increased.ConclusionThis study opens new perspectives to investigate trait adaptation syndromes through phenotypic integration prediction at large geographical scales.

Adults Born Preterm–Long-Term Health Risks of Former Very Low Birth Weight Infants.

Advances in neonatology now enable increasing numbers of very low birth weight neonates (<1500 g) to survive into early adulthood and beyond. What are the implications for their long-term care? Selective literature search on the outcome of very low birth weight neo - nates in adulthood ("adults born preterm"). Robust data are available on the pulmonary, metabolic, cardiovascular, renal, neurocognitive, sensory-visual, social-emotional, mental, reproductive, and musculoskeletal long-term risks. On the somatic level, elevated rates have been documented for asthma (odds Ratio [OR] 2.37), diabetes mellitus (OR 1.54), and chronic renal disease (hazard ratio [HR] 3.01), along with the cardiovascular and cerebrovascular sequelae of a tendency toward arterial hypertension. On the psychosocial level, the main findings are deficits in romantic partnerships (OR 0.72) and a lower reproduction rate (relative risk [RR] male/female 0.24/0.33). The affected women also have an elevated risk of preterm delivery. A risk profile with both somatic and psychosocial aspects can be discerned for adults who were born prematurely, even if some of these risks are present in low absolute numbers. As the ability to compensate for latent deficits declines with age, such adults may suffer from "premature aging as the late price of premature birth." A holistic approach to care with personalized prevention strategies- which for most of them was discontinued at discharge from pediatric followup- therefore seems appropriate in adulthood as well.

Characterization of resistance to rice leaf folder,Cnaphalocrocis medinalis,in mutant Samba Mahsuri rice lines

AbstractThe rice leaf folder,Cnaphalocrocis medinalisGuenée (Lepidoptera: Crambidae), an important foliage feeding insect in rice,Oryza sativaL. (Poaceae), is widely distributed throughout Asia, causing frequent outbreaks and considerable yield losses. Mutants of the rice strain Samba Mahsuri (MSM) represent unique plant material and are explored here for the first time for resistance to the rice leaf folder. Stringent rapid field screening for two consecutive seasons led to the identification of 10 lines as moderately resistant, with low damage area as well as low damage score. Upon assessment of various morphological traits potentially contributing to the resistance, damage area was negatively correlated with leaf length and positively with leaf width. Among the biochemical traits, leaf nitrogen content was positively correlated with leaf folder damage whereas silica was negatively correlated. Oviposition preference by leaf folder adult moths and larval settling preference were low on MSM 139 and MSM 127. We also observed that leaf folder larvae took more time for leaf selection (3.1 min) and making a primary fold (41.5 min), with more head swings (846) in moderately resistant MSM lines. Similarly, in these lines, leaf folders showed a low intrinsic rate of increase (rm = 0.15 females per female per day), low weekly multiplication rate (2.85), and low net reproductive rate (R0 = 137.5 females per female per generation) with increased generation time (T = 32.8 days) and doubling time (4.5 days), indicating their relatively poor population growth potential. Overall, the moderately resistant mutant lines we identified showed reduced ovipositional preference and larval settling preference, extended larval developmental period with low survival, reduced primary fold length, and an increased number of binds and head swings with a low intrinsic rate of increase resulting in reduced population build‐up. These lines possessing a good genetic makeup have a great potential to be used in breeding programs for the development of leaf folder resistant varieties.

All we know about the crocodile shark (Pseudocarcharias kamoharai): Providing information to improve knowledge of this species

Despite their global distribution across major oceans, biological and fisheries information related to the crocodile shark (Pseudocarcharias kamoharai) is still scarce. The crocodile shark has become a frequently observed bycatch shark in many commercial fisheries. Their catch rates might be underreported by commercial fisheries, maybe because of the species’ small size and low commercial value. Moreover, stock assessment of crocodile shark has not yet been conducted, greatly due to lack of data, and their stock status, movement and genetic connectivity are still poorly known. Previous works have shown that crocodile shark has a low reproductive rate (often 4 pups reported), therefore, fishing mortality caused by fisheries targeting economic important species such as tuna, may cause their population to greatly decline. Major tuna Regional Fishery Management Organization (RFMO), have implemented non-retention of shark species. However, specific measures related to crocodile shark is lacking. Even though it is listed as Least Concern by the International Union for the Conservation of Nature (IUCN) Red List, effort must be directed towards the conservation and management of its population in their range of habitat. In other to avoid a stock collapse for this species in the future, this work summarized existing information on the state of the fishery and biology information for this species and have proposed future research directions to fill in missing information gaps to conserve this crocodile shark’s population from declining as has been the case with many other shark species.

Bat Overpasses Help Bats to Cross Roads Safely by Increasing Their Flight Height

Roads have a multitude of negative effects on wildlife, including bat casualties. Most bat species rely on life history traits characterised by high adult survival (associated with greater longevity) and low reproduction rates (hence slow population growth rates). Therefore, road kills are expected to negatively affect local abundance and bat population dynamics. Bat overpasses are among the proposed improvements intended to increase bat flight height to reduce collisions, but their effectiveness has rarely been tested. In this study, we performed a before-after analysis to assess the effectiveness of one bat overpass on bat flight height. We used a novel approach, the bat tracking toolbox (BTT), to reconstruct bat flight paths from thermal videos. We obtained 268 bat flight paths and our results showed that the flight height of bats increased significantly after the installation of the bat overpass. Considering that bat overpasses can help in some situations to increase habitat connectivity and reduce the collision risk, this mitigation measure needs to be further investigated in different contexts of road construction and/or road requalification.

Research progress on culture technologies,chemical components,and pharmacological activities of Saussurea involucrata cells

Saussurea involucrata,a traditional Chinese medicinal material,is effective in the treatment of rheumatoid arthritis with cold-dampness blockage syndrome,cold pain in lower abdomen,and menstrual irregularities. However,due to the specific habitat,low natural reproduction rate,slow growth,and overexploitation,it is at the high risk of extinction. S. involucrata cells can be obtained through callus culture,suspension culture,and hairy root culture. This study highlighted the influences of reactor type,culture system,precursor,elicitor type, and light wavelength on the suspension culture of S. involucrate cells. The chemical components of S. involucrata cells mainly include phenylpropanoids,flavonoids,lignans,and steroids,among which phenylpropanoids are the most abundant. S. involucrata cells have multiple pharmacological activities of anti-inflammation,analgesia,activating blood and resolving stasis,immunoregulation,increasing bone density,lowering blood lipids,anti-hypoxia,anti-exercise fatigue,anti-radiation,anti-obesity,and anti-oxidation. Moreover,it has the potential of treating aplastic anemia. This study reviews the cell culture technologies,chemical components,and pharmacological activities of S. involucrata cells,laying a basis for the further research,development,and utilization.

Causes of Abortions in South American Camelids in Switzerland-Cases and Questionnaire.

Simple SummarySouth American camelids (SAC) are increasingly popular in Switzerland for keeping as pets. For many farmers, SACs are a supporting leg when offered for trekking. Products made from alpaca fibers are in demand, and even the market for meat is increasing as they are extensively hold. Low reproductive rates and abortions/stillbirths are one of the main complaints among alpaca and llama breeders. The purpose of this study was to investigate the reasons for pregnancy loss and perinatal death in SAC herds in Switzerland. Aborted and stillborn fetuses were collected, necropsied and analyzed for infectious causes. This was complemented with a nationwide survey among breeders. During a 1.5-year period, eight cases of aborted or stillborn alpaca and llama have been analyzed. For the first time, the bacterium Coxiella burnetii, a known cause of abortions and stillbirths in small ruminants and cattle, could be detected in aborted alpacas and llamas. As this pathogen has the possibility to infect humans (=zoonotic potential), it is important to gain more knowledge about its significance among SAC. This study has set the ground stone for further investigations about abortifacients in Swiss SAC herds.Over the last decade, South American camelids (SAC) have gained increasing popularity in Switzerland. They are used for several purposes such as fiber and meat production, as companion or guard animals and for trekking activities. The purpose of this study was to investigate the frequency and reasons for pregnancy loss and perinatal death in SAC herds. Within the scope of this study, early embryonic losses could not be identified, as pregnancy examinations by ultrasonography are not performed routinely. Aborted and stillborn fetuses were collected, necropsied and analyzed for infectious abortifacients. A nationwide survey among breeders was carried out. During a 1.5-year period, only eight cases of aborted or stillborn alpaca and llama (out of a population of 6550 animals) were reported by the breeders, and their causes were subsequently analyzed. In half of the cases, Coxiella burnetii was identified in the fetoplacental material. Abortions and stillbirths were reported to be rare in Swiss herds. As a conclusion, recording of embryonic losses through ultrasound training of veterinarians should be impaired and breeders motivated to have abortions and perinatal mortality examined. Special focus should be laid on C. burnetii due to its zoonotic risk.

Characterization of Molecular Markers of Testicular Cells in Red Pandas (Ailurus fulgens styani)

Self-sustained populations of captive red panda were challenged by low reproductive success rate. Defining the different types of testicular cell and increasing the knowledge of male fertility was critical for the improvement of reproductive efficiency in red panda captive populations. Here, we firstly report the histological structure in red panda testes at various ages. Besides, our data also showed that markers for red panda testicular cells including ITGA6, PLZF, THY1, VASA, DAZL, GATA4, VASA, and αSMA were expressed in adult testis tissue. To further examine the localizations of ITGA6, VASA, VIM, and αSMA, the immunohistochemical analysis was performed and the result showed the typical staining patterns of undifferentiated spermatogonia, multiple types of germ cells, Sertoli cells, and peritubular myoid cells (PMCs), respectively. For the testicular tissue digestion, two-step enzyme digestion was used to obtain the cell suspension. The red panda Sertoli cells, expressing Sertoli cell marker VIM, were cultured and conserved in this study, which can be used for red panda Sertoli cell establishment and as the feeder cells for red panda spermatogonial stem cells (SSCs) growing.

Habitat fragmentation effect on the characteristics of orangutan nest tree selection

Orangutans are an endemic to Indonesia and Malaysia with an almost extinct with critically endangered status and only found on the islands of Sumatra and Kalimantan/Borneo. Orangutan extinction is mainly threat by habitat loss and fragmentation as well as low reproduction rates. Habitat fragmentation, along with habitat loss, should be clearly considered when assessing implications of landscape change for population extinctions. Environmental changes force species to immediately adapt both behaviourally and physiologically. Forest structure affects the adaptability and nesting behaviour of orangutans. One of the steps to prevent orangutan extinction is by increasing habitat connectivity through corridors and reducing fragmentation of landscapes as well as stopping habitat lost.

The effect of group size on reproduction in cooperatively breeding gray wolves depends on density

AbstractIn cooperatively breeding species, large group size is often positively related to reproductive success and group persistence. We have a poor understanding, however, of how group sizes within a population affect reproduction particularly as density varies. We hypothesized that at low densities, wolves in both small and large groups would have similar reproductive rates. At high densities, however, wolves in small groups would have lower reproductive rates compared to those in large groups. Using empirical data from radio‐collared wolves in Idaho and Yellowstone National Park, WY, USA (1996–2012), we compared reproductive rates (i.e. proportion reproducing, litter size, pup survival) among small and large groups of wolves as density fluctuated within the populations. Reproductive rates were generally lower for individuals in small groups compared to those in large groups, particularly as density increased. Pup survival, however, was slightly higher for wolves in small groups compared to large groups except at very high densities. Polygamy increased with density regardless of group size, suggesting a polygamy threshold for wolves. Large group size resulted in less parturition failure, more breeding females per group, larger litter sizes, and ultimately more pups recruited per group. Large group size appears advantageous for several, but not all, aspects of reproduction particularly when population density is high.

Parthenogenesis in UK field populations of the tomato leaf miner, Tuta absoluta, exposed to the mating disruptor Isonet T.

The tomato leafminer, Tuta absoluta is a damaging pest of tomato crops worldwide. In the UK T. absoluta is controlled using an integrated pest management (IPM) strategy that includes pheromone-based mating disruption. However, some growers have reported a loss of efficacy of this technology, and there are concerns that T. absoluta may evolve resistance via changes in its capacity to reproduce asexually. In this study we investigated the reproductive capacity of virgin populations of T. absoluta collected from a UK glasshouse before (EVH2016) and after (EVH2019) the introduction of the mating disrupter Isonet T. In line with earlier reports, we demonstrate that UK populations of T. absoluta can reproduce parthenogenetically, and observed a small but significant increase in the rate of parthenogenesis associated with the use of Isonet T. Marked differences in several other life history traits associated with reproduction were also observed between the two virgin populations, with the EVH2019 strain producing fewer eggs, a delayed onset of egg laying and increased lifespan. The low rate of parthenogenetic reproduction seen in this study is unlikely to result in loss of efficacy of mating disruption. However, the observed changes in longevity and egg laying may allow T. absoluta to persist for longer within the crop, and, together with the increased rate of parthenogenesis, may reflect selection from the use of Isonet T. Thus, regular monitoring of the reproductive capacity of UK populations should be conducted, and mating disruption used only as part of IPM to avoid the emergence of resistance. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Development of activity collecting system for grazing cattle in vast land

AbstractDairy farming in Japan has low milk supply and reproductive rate per cattle, which is considered to be due to lack of proper breeding management. In order to solve this problem, there is a demand for a breeding management system that does not require human intervention, utilizing the ICT and robot technology. Studies on cow health and breeding management using various sensors have been reported; in this paper, we develop the system to collect the amount of activity and position of the grazing cattle in vast land. The developed system is (i) the “cattle sensor” composed of a GPS module and an acceleration sensor and (ii) the data transfer system composed of a wireless module and solar cells. The cow sensor can be used continuously for 2 months without battery replacement and is a system that can be used in vast land and mountain areas. And the data obtained from the sensor suggest the possibility of estrus detection.

Assessing the prevalence of protected species consumption by rural communities in Makira Natural Park, Madagascar, through the unmatched count technique

AbstractIn tropical Africa, wild meat consumption by rural communities who live in or near protected areas can be a major challenge in the conservation of threatened species. Lemurs and the fossa are among the species consumed in Makira Natural Park, Madagascar. Because of their low reproductive rates and the high human population density, these species are known to be hunted unsustainably. We estimated the prevalence of lemur and fossa meat consumption in villages within and around Makira Natural Park using an indirect questioning method, the unmatched count technique (UCT), and compared it with results from direct questioning. The UCT revealed that 53.0% of households had eaten lemur meat over the previous year (95% confidence interval [CI]: 42.0–64.1%) and 24.2% had eaten fossa meat (95% CI: 14.2–34.2%). The percentage of households that ate lemur meat estimated through the UCT was more than 3.3 times higher than that obtained from direct questioning, and 12 times higher for fossa. Our estimates will be used to define the scale needed for a behavior change campaign to be conducted in the study area and will serve as a baseline to assess the impact of conservation activities aimed at reducing the consumption of lemurs and fossas.

Conservation of Amazonian aquatic mammals

Abstract Aquatic mammals worldwide are highly threatened in freshwater ecosystems where they are affected by direct human activities (e.g. hunting) as well as indirect human alteration of freshwater ecosystems (e.g. dams, mining activity). Although aquatic mammals of the Amazon Basin are experiencing many growing threats, little is known about the escalating impacts on them, current limitations in protection mechanisms, and possible strategies to ensure their conservation. This study synthesizes the available information on Amazonian aquatic mammals, including the ecological characteristics of these species, key threats, population status and conservation prospects. Amazonian aquatic mammals comprise seven species – Inia geoffrensis, Inia boliviensis, Inia araguaiaensis, Sotalia fluviatilis, Trichechus inunguis, Pteronura brasiliensis and Lontra longicaudis – which are characterized by low reproductive rates and keystone ecosystem roles. These species are endangered mainly by biological resource use, natural ecosystem modifications, energy production and mining, and climate change. Although information is sparse, there is evidence that these threats are inducing population declines of Inia spp., and hindering the recovery of populations of P. brasiliensis. Protection mechanisms for these species mostly include national and international laws and agreements, legislation governing environmental licensing and protected areas. Each of these protection mechanisms, however, has limited capacity to protect Amazonian aquatic mammals, largely because they are poorly enforced, lack transnational coordination or require population trend data that do not exist. Reversing the current state of affairs for Amazonian aquatic mammals requires an integrated research and policy approach that, at a minimum, substantially increases the present capacity to monitor their population responses to human impacts, establishes effective enforcement of existing legislation and prevents further impacts from hydropower development. To implement such an approach, information on the ecology of these species is necessary to create public and scientific awareness.