Captive Generation Research Articles

Domestication reduces caterpillar response to auditory predator cues.

Domestication can lead to significant changes in the growth and behavior of organisms. While the threat of predation is a strong selective force in the wild, the relaxation or removal of this threat in captive-rearing environments selects for reduced sensitivity to biotic stressors. Previous work has documented such changes in other taxa, but no work has been done on domestication-related losses of predation risk sensitivity in insects. We exposed both wild and domesticated (>50 generations in captivity) Lymantria dispar dispar (Lepidoptera: Erebidae) larvae to recordings of predators (wasp buzzing), nonpredators (mosquito buzzing), or no sound to compare the effects of predation risk on the two stocks. Wasp buzzing, but not mosquito buzzing, decreased survival of wild caterpillars relative to the control; domesticated caterpillars showed no such response. Domesticated L. dispar larvae appear to have reduced sensitivity to predation risk cues, suggesting that captive-reared insects may not always be analogs to their wild counterparts for risk-related behavioral studies.

Effects of generations in captivity and elevated rearing temperature on Ontario hatchery brook trout (Salvelinus fontinalis) fry quality and survival

Effects of generations in captivity and elevated rearing temperature on Ontario hatchery brook trout (Salvelinus fontinalis) fry quality and survival

The fitness consequences of wildlife conservation translocations: a meta-analysis.

Conservation translocation is a common strategy to offset mounting rates of population declines through the transfer of captive- or wild-origin organisms into areas where conspecific populations are imperilled or completely extirpated. Translocations that supplement existing populations are referred to as reinforcements and can be conducted using captive-origin animals [ex situ reinforcement (ESR)] or wild-origin animals without any captive ancestry [in situ reinforcement (ISR)]. These programs have been criticized for low success rates and husbandry practices that produce individuals with genetic and performance deficits, but the post-release performance of captive-origin or wild-origin translocated groups has not been systematically reviewed to quantify success relative to wild-resident control groups. To assess the disparity in post-release performance of translocated organisms relative to wild-resident conspecifics and examine the association of performance disparity with organismal and methodological factors across studies, we conducted a systematic review and meta-analysis of 821 performance comparisons from 171 studies representing nine animal classes (101 species). We found that translocated organisms have 64% decreased odds of out-performing their wild-resident counterparts, supporting claims of systemic issues hampering conservation translocations. To help identify translocation practices that could maximize program success in the future, we further quantified the impact of broad organismal and methodological factors on the disparity between translocated and wild-resident conspecific performance. Pre-release animal enrichment significantly reduced performance disparities, whereas our results suggest no overall effects of taxonomic group, sex, captive generation time, or the type of fitness surrogate measured. This work is the most comprehensive systematic review to date of animal conservation translocations in which wild conspecifics were used as comparators, thereby facilitating an evaluation of the overall impact of this conservation strategy and identifying specific actions to increase success. Our review highlights the need for conservation managers to include both sympatric and allopatric wild-reference groups to ensure the post-release performance of translocated animals can be evaluated. Further, our analyses identify pre-release animal enrichment as a particular strategy for improving the outcomes of animal conservation translocations, and demonstrate how meta-analysis can be used to identify implementation choices that maximize translocated animal contributions to recipient population growth and viability.

Size, fecundity and condition factor changes in endangered delta smelt Hypomesus transpacificus over 10 generations in captivity

AbstractThe once abundant delta smelt Hypomesus transpacificus is now on the verge of extinction. At the UC Davis Fish Conservation and Culture Laboratory, a refuge population has been maintained since 2008 as a safeguard against extinction and to breed and provide fish for research. Due to artificial aquaculture operations, it is assumed that the fish are impacted by life in captivity leading to questions about differences between cultured and captive wild fish. This study looked at the differences in fork length (FL), body weight (BW), fecundity (F) and condition factor (K) of cultured and wild (captive) delta smelt over the last 10 generations (2009–2018) to determine if there were any changes of life‐history traits between the two, which may indicate domestication. Results revealed that the cultured population had significantly higher FL, BW, F and K than the wild population. The correlation tests found significant positive relationships between all measured traits except FL and K of wild fish. Significant changes in the measured traits of the cultured population over time were found, whereas none was observed in most wild fish year‐classes. This study demonstrated changes of life‐history traits in a well‐managed fish population over 10 generations in captivity and provides critical information to the coming supplementation plan for the species.

Re-design AC Power Failure Signal to Minimize False Signal of Emergency Shutdown System for Ethylene Plant

Chandra Asri, the largest integrated petrochemical company in Indonesia, requires a reliable electrical system to ensure production. Electrical power was supplied by the grid from PT. PLN through a 150 kV system in parallel with captive generation. The electrical system uses the Emergency Shutdown System (ESD) to protect against various disturbances that can cause equipment damage and work accidents. ESD will only work if things happen according to a logic diagram that has been designed according to the needs. One time, there was a power outage due to the active ESD. This causes huge losses for the company. The results of the investigation showed that there were no disturbances to either the grid or the captive generator. It is suspected that there is a false signal that causes the ESD to activate from the DC charger signal. For this reason, efforts are needed to eliminate the possibility of this nuisance signal occurring in the future by redesigning the logic and signal source of AC power failure by considering the existing secondary selective electrical system. Modification of the ESD system is carried out in 5 stages, namely 1) fault analysis, 2) modification of logic diagram design, 3) system development, 4) testing, and 5) evaluation. The results of the redesign decided that modifications should be made to the ESD system and carried out on the next Turn Around Maintenance schedule because this modification requires an offline electrical system. The analysis and simulation results show that the ESD system is safe against similar disturbances. It is hoped that the redesign and modification of the ESD system can prevent signal interference in the AC Power Failure Signal.

On‐grid solar powered milk processing: Development and cost analysis

This study investigates the development of solar powered milk processor and processing cost analysis of solar processed milk using On-grid solar PV system. A set of 10 series connected On-grid solar panels of 3 kW capacity was mounted on roof top to easily meet the requirement for processing 40 L of milk in batch mode. Commercially available milk boilers of capacity 10 to 40 L are embedded with electrical heater coils of capacity 1 kW to 3 kW. As the proposed work is to design and optimize the solar panel for processing 40 L of milk in batch processor, 10 series connected On-grid solar panels, each of capacity 325 W, were mounted on the roof top with daily power generation capability of 3 kW. The efficiency of roof top mounted On-grid solar panels is 80% which means solar panel rated for 1 kW gives an output of approximately 800 W (0.8 kW). The energy generated in kWH is the product of power (kW) and time (h). The available peak sunshine h (PSH) from 10.00 a.m. to 3.00 p.m. (5 h) was utilized to generate 4 kWh of energy (0.8 kW × 5 h)/day for 1 kW capacity of solar panel. As 10 On-grid solar panels (3 kW) were installed, 12 to 15 kWh of electrical energy was generated per day based on the available peak sunshine hours and was recorded by means of digital energy meter. The milk processing cost analysis were carried out based on the trials conducted on the developed solar powered milk processor at College of Food and Dairy Technology, Koduveli, Chennai. It was found that the total processing cost/L ranged from Rs. 0.6 to 0.35 for various treatments without regenerative action and Rs. 0.58 to 0.16 for various treatments with regenerative action. Novelty impact statement Increased reliability and raw milk processing cost optimization are achieved with Solar solutions. The On-grid inverter provides a baseline electricity demand at village level for dairy farmers for productive/processing purposes. The developed solar powered milk processor ensures captive generation in dairy plants which provides a localized source of power to MSME/Small scale industries, as processing cost is lower.

The necessity of considering founder kinships in conservation breeding programs

AbstractConservation breeding programs pursue the double objective of preserving genetic diversity and producing individuals to support in situ conservation measures. Genetic management and monitoring are commonly based on pedigree analyses and are therefore dependent on the pedigree quality and the underlying assumption that founders of the captive population are neither inbred nor related to each other or to the captive population. Should founders be related, this assumption may lead to an overestimation of genetic diversity and an underestimation of inbreeding in captivity. In this study, we examined the effects of the founder assumption on estimates of genetic diversity by combining three approaches: (1) computer simulations of pedigrees of theoretical captive populations and their associated in situ source populations, (2) analysis of pedigrees of real conservation breeding programs and (3) microsatellite‐based computation of kinship among founders from a captive population of houbara bustard. The theoretical approach revealed that the captive population's average mean kinship Mk increases linearly with founder average Mk. The bias in Mk due to the founder assumption was strongly related to the effective size of the source population and to pedigree quality while remaining critical after 25 generations of captivity. Results based on real populations were consistent with theoretical ones and confirmed the overestimation of genetic diversity in captive populations. Overall, our results indicate that under situations classically encountered in conservation breeding programs (e.g. small and isolated source population, incomplete pedigrees), estimates of genetic diversity are potentially highly overestimated, challenging the genetic management of captive populations of species of conservation concern.

Early fish domestication affects methylation of key genes involved in the rapid onset of the farmed phenotype

ABSTRACT Animal domestication is a process of environmental modulation and artificial selection leading to permanent phenotypic modifications. Recent studies showed that phenotypic changes occur very early in domestication, i.e., within the first generation in captivity, which raises the hypothesis that epigenetic mechanisms may play a critical role on the early onset of the domestic phenotype. In this context, we applied reduced representation bisulphite sequencing to compare methylation profiles between wild Nile tilapia females and their offspring reared under farmed conditions. Approximately 700 differentially methylated CpG sites were found, many of them associated not only with genes involved in muscle growth, immunity, autophagy and diet response but also related to epigenetic mechanisms, such as RNA methylation and histone modifications. This bottom-up approach showed that the phenotypic traits often related to domestic animals (e.g., higher growth rate and different immune status) may be regulated epigenetically and prior to artificial selection on gene sequences. Moreover, it revealed the importance of diet in this process, as reflected by differential methylation patterns in genes critical to fat metabolism. Finally, our study highlighted that the TGF-β1 signalling pathway may regulate and be regulated by several differentially methylated CpG-associated genes. This could be an important and multifunctional component in promoting adaptation of fish to a domestic environment while modulating growth and immunity-related traits.

Pattern and pace of morphological change due to variable human impact: the case of Japanese macaques

Human impact influences morphological variation in animals, as documented in many captive and domestic animal populations. However, there are different levels of human impact, and their influence on the pattern and rate of morphological variation remains unclear. This study contributes to the ongoing debate via the examination of cranial and mandibular shape and size variation and pace of change in Japanese macaques (Macaca fuscata). This species is ideal for tackling such questions because different wild, wild-provisioned, and captive populations have been monitored and collected over seven decades. Linear measurements were taken on 70 skulls from five populations, grouped into three ‘human impact groups’ (wild, wild-provisioned, and captive). This made it possible to investigate the pattern and pace of skull form changes among the human impact groups as well as over time within the populations. It was found that the overall skull shape tends to differ among the human impact groups, with captive macaques having relatively longer rostra than wild ones. Whether these differences are a result of geographic variation or variable human impact, related to nutritional supply and mechanical properties of the diet, is unclear. However, this pattern of directed changes did not seem to hold when the single captive populations were examined in detail. Although environmental conditions have probably been similar for the two examined captive populations (same captive locality), skull shape changes over the first generations in captivity were mostly different. This varying pattern, together with a consistent decrease in body size in the captive populations over generations, points to genetic drift playing a role in shaping skull shape and body size in captivity. In the captive groups investigated here, the rates of change were found to be high compared to literature records from settings featuring different degrees of human impact in different species, although they still lie in the range of field studies in a natural context. This adds to the view that human impact might not necessarily lead to particularly fast rates of change.

Polar bear-adapted Ursidibacter maritimus are remarkably conserved after generations in captivity.

Most species in the bacterial family of Pasteurellaceae colonize one specific host species. Vertebrates of very different evolutionary descent including fish, turtles, marsupials, eutherians and birds are colonized by different members of Pasteurellaceae. This one-to-one microbial-host species partnership makes Pasteurellaceae species valuable candidates to study biodiversity, bacterial-host co-evolution and host adaptation, and their widespread distribution across vertebrates provide the possibility to collect a wide array of data, where wildlife species are essential. However, obtaining samples from wild animals comes with logistic, technical and ethical challenges, and previous microbiota studies have led to the presumption that captive animals are poor models for microbial studies in wildlife. Here, we show that colonization of polar bears by Ursidibacter maritimus is unaffected by factors related to captivity, reflecting a deep symbiotic bond to the host. We argue that the study of ecological and evolutionary principles in captive wildlife is possible for host-adapted taxa such as those in the Pasteurellaceae family. Moreover, studying captive, often trained animals protects wild populations from the stress associated with obtaining samples.

Offspring survival changes over generations of captive breeding

Conservation breeding programs such as zoos play a major role in preventing extinction, but their sustainability may be impeded by neutral and adaptive population genetic change. These changes are difficult to detect for a single species or context, and impact global conservation efforts. We analyse pedigree data from 15 vertebrate species – over 30,000 individuals – to examine offspring survival over generations of captive breeding. Even accounting for inbreeding, we find that the impacts of increasing generations in captivity are highly variable across species, with some showing substantial increases or decreases in offspring survival over generations. We find further differences between dam and sire effects in first- versus multi-generational analysis. Crucially, our multispecies analysis reveals that responses to captivity could not be predicted from species’ evolutionary (phylogenetic) relationships. Even under best-practice captive management, generational fitness changes that cannot be explained by known processes (such as inbreeding depression), are occurring.

Reproductive performance in houbara bustard is affected by the combined effects of age, inbreeding and number of generations in captivity

Although captive breeding programs are valuable for conservation, they have been shown to be associated with genetic changes, such as adaptation to captivity or inbreeding. In addition, reproductive performance is strongly age-dependent in most animal species. These mechanisms that potentially impact reproduction have often been studied separately, while their interactions have rarely been addressed. In this study, using a large dataset of nine male and female reproductive parameters measured for 12,295 captive houbara bustards (Chlamydotis undulata undulata) over 24 years, we investigated the relative and interactive effects of age, inbreeding and number of generations in captivity on reproduction. We clearly identified (1) senescence patterns in all parameters studied; (2) negative effects of inbreeding on sperm characteristics, display behavior, egg weight, egg volume and hatching probability; and (3) changes in phenotypic values for seven parameters according to number of generations in captivity. However, the effect sizes associated with age were substantially greater than those associated with inbreeding and number of generations in captivity. Beyond the independent effects of these three factors on reproductive parameters, the results highlighted their interactive effects and thus the importance of integrating them in the design of genetic management plans for conservation breeding programs.

Genomics for conservation: a case study of behavioral genes in the Tasmanian devil

The increased availability of genomic resources for many species has expanded perspectives on problems in conservation by helping to design management strategies for threatened species. Tasmanian devils (Sarcophilus harrisii) are an iconic and endangered marsupial with an intensively managed breeding program aimed at preventing extinction in the wild caused by devil facial tumour disease. Between 2015 and 2017, 85 devils from this program were released to three sites in Tasmania to support wild populations. Of these, 26 were known to have been killed by vehicles shortly after release. A previous analysis indicated that increased generations in captivity was a positive predictor of vehicle strike, with possible behavioural change hypothesised. Here we use 39 resequenced devil genomes to characterise diversity at 35 behaviour-associated genes, which contained 826 single nucleotide polymorphisms (24 were non-synonymous). We tested for a predictor of survival by examining three genes (AVPR1B, OXT and SLC6A4) in 62 released devils with known fates (survived, N = 39; died, N = 23), and genome-wide associations via reduced-representation sequencing (1727 single nucleotide polymorphisms [SNPs]), in 55 devils with known fates (survived, N = 38; died, N = 17). Overall, there was little evidence of an association between genetic profile and probability of being struck by a vehicle. Despite previous evidence of low genetic diversity in devils, the 35 behaviour-associated genes contained variation that may influence their functions. Our dataset can be used for future research into devil behavioural ecology, and adds to the increasing body of research applying genomics to conservation problems.

Assessing evolutionary processes over time in a conservation breeding program: a combined approach using molecular data, simulations and pedigree analysis

Captive breeding for conservation is widely used to prevent extinction, however these programs face many challenges due to small population size, founder effects, lack of migration and potential adaptation to captivity. Together these influence how selection, genetic drift and gene flow shape the genetic makeup of small populations, so examining these in a captive setting is valuable for appropriate biodiversity management. We have quantified the effects of selection, drift and gene flow in 503 individuals across five generations from the Tasmanian devil insurance population. To determine whether different processes were acting in different settings, we separately analysed animals housed under individual-based management, versus those that were released to an island site. We found that a greater proportion of alleles were lost over time in the smaller island population than in captivity and propose that genetic drift is the most likely process influencing this result. We found that the captive population became more heterozygous over time, while the island population stayed constant. Our molecular measure of inbreeding found a decrease over generations in captivity that is not captured by pedigree-based analysis. As management of breeding interactions only takes place in the captive population, our results are consistent with gene flow through managed breeding in captivity minimising inbreeding over time. Gene flow was also evident through changes to population structure in the captive population. Our findings serve as an example of how conservation managers can assess the impact of evolutionary processes on managed populations and adapt management practices if required.

Do captive golden mantella frogs recognise wild conspecifics calls? Responses to the playback of captive and wild calls

With so many species being threatened with extinction, captive breeding programmes are becoming an important aspect of ex-situ conservation. Captive populations are important for species conservation and for reintroduction back into the wild. Some of the most important wild behaviours to maintain in captive animals are those associated with sexual reproduction, such as courtship and mating. Amphibian reproductive behaviour is associated with call patterns, with studies demonstrating that male advertisement calls elicit positive behavioural responses from females. This study evaluated the response of captive golden mantella frogs Mantella aurantiaca to playback calls from different wild and captive populations (one generation in captivity and more than five generations in captivity). During the experiment, three different calls were used as treatments: one from wild populations, and two from captive populations. Generalised linear mixed models were used to evaluate the effects of the playback treatments on the behaviour of captive frogs: replicates and enclosures were used as random factors. The model showed that vocalisations from wild individuals led to an increase in movement and social behaviours while calls from captive frogs did not. This was especially true of frogs bred for more than five generations in captivity. This could have negative consequences on the reproduction of captive frogs if released to the wild.

Differences in wing shape of captive, critically endangered, migratory Orange-bellied Parrot Neophema chrysogaster relative to wild conspecifics

ABSTRACT Living in a captive environment may compromise phenotypic traits critical to survival in the wild. Captive animals that differ from the ideal wild phenotype may have impaired fitness after release, especially if there is extreme phenotypic selection during some life history stages. Wing shape of migratory birds is crucial to migration efficiency, and changes to wing shape in captivity may severely affect survival after release. We investigate wing shape of migratory Orange-bellied Parrots Neophema chrysogaster in captivity and the wild. The first two flight feathers were shorter in captive birds, and the fifth and sixth feathers were longer than wild conspecifics. These differences altered wing shape, producing a more proximal tip and a more convex trailing edge than the wild phenotype, which likely alters flight performance. This wing shape contravenes expectations from general patterns of wing shape in migratory birds. Wing shape in the captive birds sampled was independent of inbreeding, generations in captivity and ancestry. Captive environments may affect feather development or impose some selective pressure on wing shape. Alternatively, release from intense phenotypic selection during migration may allow parrots with wing shapes poorly adapted to migration to survive and breed in captivity. Altered wing shape may contribute to low observed survival of parrots released to the wild.

Exotic animal cafes are increasingly home to threatened biodiversity

AbstractExploitation of species for wildlife trade, including the demand for exotic pets (likely sourced from the wild or recent generations of captivity) is a major threat to biodiversity. Although not traditionally considered “pet keeping” countries, pet ownership is growing in Asia. Exotic animals are also appearing in cafes, which are growing in popularity and have the potential to impact wild populations by stimulating exotic pet trade. We identified 406 animal cafes across Asia, of which 27% housed exotic species, including mammals (e.g., otter, slow loris, meerkat), birds (e.g., owls, hawks, parrots), and reptiles (e.g., geckos, pythons, turtles). Of the 252 exotic species recorded, 46% were threatened either as classified by the IUCN Red List, having a decreasing population trend, and/or threatened by the pet trade. These results, alongside the alignment of cafe traits with recognized factors influencing exotic pet trade, demonstrate as yet unclear (but potentially dramatic) implications for conservation.

Relation between electricity consumption and economic growth in Karnataka, India: An aggregate and sector-wise analysis

Karnataka is a highly progressive and rapidly growing state in India, with huge potential for industrial growth, however, it grapples with power deficits and other problems in electricity sector, which make it a good case study for Indian electricity sector. Given the importance of electricity in the urbanisation and growth process, the paper analyses the electricity consumption trend in Karnataka, examine its causality with economic growth at aggregate and sectoral levels using Granger causality test, and forecast the future electricity consumption applying Holt-Winters smoothening (no seasonality) technique. The general trend reflects higher consumption by the agricultural consumers, compared to the revenue-generating 'Industries' and 'Commercial' categories, mainly due to the policy of de-metering and providing 'free' power to agricultural consumers since late 1980s. The Granger causality tests reveal that there is no causality relation (neutrality hypothesis) between electricity consumption and economic growth in Karnataka, for total, agricultural and industrial consumption. This basically stems from the inaccurate measurements of agricultural consumption, higher dependence on captive generation, and poor quality grid supply. Finally, electricity consumption is predicted to be around 69,347 GW h by 2019−20. Future policies should focus on universal metering, reducing cross-subsidization, supplying good quality and reliable power to all sectors, and economical planning of resource-mix to achieve adequate, productive and efficient electricity consumption.

Effect of Penetration of Wind DGs on Transient Stability of Captive Power Generation Units

This paper presents the analysis of transient stability for industrial generators and the effect of distributed generator units on transient stability has been studied. Here we considered IEEE 39 busses system having one utility bus and 9 captive generation units. It is observed that the voltages at all the buses, decreased when Wind Power DGs are connected. Voltages at all the buses in the system are reduced because of reactive power demand by Induction Generators. The total load of the system is 121.57 MW + j 56.6 MVAr. Critical Clearing Times (CCTs) are obtained without introducing any DG and later, CCTs are obtained with four Wind Power DGs. Their capacities are 7.0 MW, 8.0 MW, 9.0 MW and 5.0 MW with 0.8, 0.85, 0.9 and 0.95 power factors respectively. The Induction Generators used in Wind DGs inject active power and consume reactive power. It is observed that the voltages at all the buses, decreased when Wind Power DGs are connected. Voltages at all the buses in the system are reduced because of reactive power demand by Induction Generators. LLLG faults at seven load buses and nine Generator buses and are considered for obtaining Critical Clearing Times (CCT). It is observed that transient stability of system is improved by placing DGs. DGs used in this system improves the critical clearing time (CCT) for faults at load buses by 30% and faults at generator buses by 15.5%. The detailed results are tabulated in this paper.

Effect of Penetration of Solar DGs on Transient Stability of Captive Power Generation Units

In this work, transient stability analysis of industrial generator units is carried out using rigorous simulation study. The effect of Solar Distributed Generator Units on transient stability of captive power units is studied in this work. Industrial system with 39 Buses is considered with one utility bus, and nine captive generation units. The total active power load of the system is 121.57 MW and reactive power demand is 56.6 MVAr. The work is carried out in two stages. In the first stage, Critical Clearing Times (CCTs) are obtained without introducing any DG. In the second stage, CCTs are obtained with four Solar Power DGs at four different load buses. Triple line to ground faults at 9 Generator buses and 7 load buses are considered for obtaining Critical Clearing Times (CCT). It is observed that transient stability of system is improved by placing DGs. For the faults on Generator buses, CCTs are improved by 14.6% with DGs on average. For the faults on load buses, CCTs are improved by 27% with DGs on average. The detailed results are tabulated in this paper.