Population Viability Research Articles

Modelling decisions and density dependence in monarch butterflies: A comment on Meehan and Crossley (2023)

Abstract Decisions about which processes to include in a population model can have substantial impact on estimates of population trends and extinction risk. This is particularly important for species of conservation concern, whose conservation status is decided in part on the basis of these models. In their recent paper, Meehan and Crossley (2023) Insect Conservation and Diversity, 16, 566–573 revisit a time series of overwintering monarch butterfly abundances, which previous assessments had characterised as rapidly declining and at risk of extinction. The authors, in contrast, reported no evidence for declines in the past 10 years and characterised extinction risk as low. A primary reason for the difference between these conclusions was that Meehan and Crossley used a more complex model that included a parameter for density dependence. While negative density dependence may play a role in monarch population regulation, there are a variety of unresolved issues with how and if density dependence should be included in models of monarch populations, including widely known issues with separating observation error from density dependence in noisy time series and taxon‐specific issues with fitting models to data surveyed every fourth generation and pooled at continental scales. These issues make the conclusions of Meehan and Crossley about monarch population viability much less robust than implied in their article. They do not provide convincing evidence that density dependence reduces extinction risk in monarch butterflies. Our commentary supports their general conclusion that population viability projections depend on model assumptions, but the ways in which monarch butterfly populations are regulated remains an open question.

Preparation of bi-layer composite films for controlled cefazolin delivery and enhanced antibacterial activity

In the present study, a wide-spectrum antibiotic drug, cefazolin was loaded into novel bi-layer composite films based on chitosan and alginate. The objective was to achieve sustained antibacterial activity at the application site, while enhancing the local efficacy of cefazolin. The physical properties of the composite films were characterized using techniques including FTIR, XRD, and SEM. Additionally, drug content uniformity, contact angle, weight variation, swelling index, drug release profiles, and kinetics were investigated. Antibacterial efficacy of the films was evaluated against Methicillin-resistant Staphylococcus aureus (MRSA), an important drug resistant pathogen. Multiple assays including time-kill, disk diffusion, and microbial penetration assays were employed to comprehensively assess various parameters of antibacterial action. The results demonstrated homogenous drug distribution and minimal weight variation in the films. Well-compatible film formations were shown by the SEM micrographs. Cefazolin release was sustained for 1440 min, and the release kinetics were fitted with the Korsmeyer-Peppas model. The fabricated films exhibited significant and sustained antibacterial activity against MRSA for a duration of 900 minutes, ultimately leading to complete eradication of viable bacterial populations. Taken together, novel films demonstrated good mechanical properties and hold great promise for biomedical applications, offering extended antibiotic release and sustained pathogen eradication.

Ecological dynamics and conservation implications of Indo-Pacific Tarpon (Megalops cyprinoides) in Lake Siombak, North Sumatra, Indonesia

This study presents a comprehensive examination of the Indo-Pacific Tarpon (IPT) population in Lake Siombak, North Sumatra Province, Indonesia. Through a year-long investigation, we analyzed various facets of IPT ecology, encompassing population structure, growth dynamics, reproductive behavior, feeding habits, and mortality parameters. Male dominance in collected specimens, coupled with consistently immature gonads in females, suggests a unique reproductive pattern influenced by the brackish nature of Lake Siombak. Utilizing the von Bertalanffy method, we determined a moderate growth rate in IPT, with a predominance of medium-sized, sexually immature individuals. The dietary analysis revealed an omnivorous nature, with a notable reliance on zooplankton, particularly Cladocera and Copepods. However, the most significant concern arises from the estimation of the exploitation rate (E), surpassing the annual optimum exploitation threshold, indicating a state of overexploitation. This underscores the urgent need for regulatory measures to ensure the sustainability of IPT resources in Lake Siombak. Our findings contribute to a nuanced understanding of IPT ecology in this specific ecosystem, emphasizing the importance of balanced conservation and management practices. The documented reproductive, growth, and feeding patterns provide crucial insights for informing targeted conservation strategies and safeguarding the enduring viability of the IPT population in Lake Siombak. This research serves as a foundational contribution to the broader field of fisheries science, advocating for evidence-based management to preserve the ecological balance of aquatic ecosystems.

Small translocations of endangered Gallinula galeata sandvicensis (Hawaiian Common Gallinule) may be sufficient to generate a viable reintroduced population

Abstract Where stable source populations of at-risk species exist, translocation may be a reasonable strategy for re-establishing extirpated populations. However, the success rates of such efforts are mixed, necessitating thorough preliminary investigation. Stochastic population modeling can be a useful method of assessing the potential success of translocations. Here, we report on the results of modeling translocation success for the Gallinula galeata sandvicensis or ‘alae ‘ula (Hawaiian Common Gallinule), an endangered waterbird endemic to the Hawaiian Islands. Using updated vital rates, we constructed a model simulating 3 existing extant (wild) source populations and a hypothetical recipient site on another island. We then projected the effects of 6 different translocation scenarios and sensitivity of the results to variation of three important demographic parameters on the probability of extinction (PE) of the reintroduced and donor populations. Larger translocations, of at least 30 birds, had low probability of extinction in the reintroduced population, but raised extinction risk of the smallest source population. Spacing out translocations in time (e.g., 10 birds translocated in total in 3 installments over 9 years), led to lower PE than translocating all individuals at once (i.e., bulk translocations) for both the source and reintroduced populations. Brood size and hatch-year juvenile survival had a disproportionate impact on reintroduced population viability. Importantly, the reported juvenile survival rate is very near the threshold for population failure. This suggests that post-introduction and subsequent management of wetlands, particularly predator control, could be critical to reintroduction success. We recommend that individuals should be translocated from multiple, genetically distinct subpopulations to reduce the possibility of inbreeding depression. Based on this analysis, the recipient wetland should be sufficiently large that it can support at least 25 pairs of gallinules. Based on recent estimates of population densities on O‘ahu, such a wetland would need to be between 3.75 and 74.6 ha.

Evaluation of extinction risk for stream fishes within an urban riverscape using population viability analysis

Abstract1. The Santa Ana River in the Los Angeles region of California demonstrates common habitat degradation symptoms that are characteristic of the urban stream syndrome. These impacts have altered the Santa Ana River community structure, with few species as impacted as the native Santa Ana sucker (sucker; Pantosteus santaanae). 2. Consequently, a recovery plan developed for sucker identified the need for a population viability analysis (PVA) to assess sucker extirpation risk. However, PVAs can be data‐intensive and are subject to several sources of bias when standardized protocols are absent. 3. More than 20 years of sucker and arroyo chub (chub; Gila orcuttii) surveys using different methods were compiled to build an integrated hierarchical multi‐population PVA to estimate trends in abundance and extirpation probability of these native fishes from the Santa Ana River. 4. PVA modelling indicated similar patterns in sucker and chub abundance along the Santa Ana River, with the highest abundance of both species in the upper regions of the river during the early 2000s and downstream in recent years (2018–2022). Extirpation risk was estimated to be greatest near wastewater treatment facilities, where native fish abundance estimates have been zero since 2018. Extirpation risk was lower downstream of the wastewater treatment facilities for both species, although extinction risk was higher for sucker than chub throughout the river. 5. As the model evolves and more data are collected, the PVA could be used to assess the effects of various management actions, such as non‐native predator removals and native fish re‐introductions, on sucker and chub persistence.

Little evidence of inbreeding depression for birth mass, survival and growth in Antarctic fur seal pups

Inbreeding depression, the loss of offspring fitness due to consanguineous mating, is generally detrimental for individual performance and population viability. We investigated inbreeding effects in a declining population of Antarctic fur seals (Arctocephalus gazella) at Bird Island, South Georgia. Here, localised warming has reduced the availability of the seal’s staple diet, Antarctic krill, leading to a temporal increase in the strength of selection against inbred offspring, which are increasingly failing to recruit into the adult breeding population. However, it remains unclear whether selection operates before or after nutritional independence at weaning. We therefore used microsatellite data from 885 pups and their mothers, and SNP array data from 98 mother–offspring pairs, to quantify the effects of individual and maternal inbreeding on three important neonatal fitness traits: birth mass, survival and growth. We did not find any clear or consistent effects of offspring or maternal inbreeding on any of these traits. This suggests that selection filters inbred individuals out of the population as juveniles during the time window between weaning and recruitment. Our study brings into focus a poorly understood life-history stage and emphasises the importance of understanding the ecology and threats facing juvenile pinnipeds.

The relative importance of precipitation change and temperature sensitivity in determining the population viability of a threatened sub‐tropical rainforest endemic plant Triunia robusta (Proteaceae)

AbstractThreatened species in rainforests may be vulnerable to climate change, because of their potentially narrow thermal tolerances, small population sizes, restricted distributions and limited dispersal. We investigated the relative influence of potential climate change on the population viability of Triunia robusta (Proteaceae), an endangered rainforest shrub endemic to southeast Queensland, Australia. A spatially explicit, stochastic population model with seven stage classes was developed and linked with the species distribution model (SDM) to explore a variety of hypothetical climate change simulations over a 90‐year period from 2010 to 2100: (1) constant population dynamics, (2) changes in habitat distributions as trend in carrying capacity and (3) changes in habitat distributions, precipitation and temperature regime as relative change in seedling survival and fecundity. The results revealed high vulnerability of small populations to local extinction regardless of geographical location or climatic stressors, while some larger populations located in the southern end of the species distribution range showed persistence in‐situ. Triunia robusta was found to be sensitive to reduced precipitation and increased temperature, limiting the species reproductive activities and seedling establishment and reducing the overall abundance consequently. Integration of population models and SDM allowed for the evaluation of multiple climatic stressors that may affect habitat distributions and population dynamics of T. robusta and ultimately suggest potential implications for future conservation and management planning with respect to climate change.

How do Management Goals for Wild Chinook Salmon Align with Feasibility?

Evaluation of goals is crucial for effective management to conserve viable and diverse fish populations and to support harvest. Management of wild Chinook Salmon Oncorhynchus tshawytscha in the Snake River basin exemplifies the struggle to meet fisheries goals. Considering contemporary production of juvenile emigrants, it is imperative to determine the survival from emigration to adult (Se‐a) required to meet abundance goals. Increased anthropogenic impact on spawning and rearing habitats leads to higher Se‐a required to attain goals. Wilderness populations exhibit viability and could sustain fisheries with Se‐a lower than required elsewhere. Conversely, populations targeted for habitat restoration demand higher Se‐a to fulfill goals, indicating a need to enhance egg‐to‐smolt survival. However, Se‐a has fallen below the threshold needed for replacement in all populations, even at current low abundances. Despite these challenges, most populations still possess the potential to achieve abundance goals, emphasizing the importance of strategic interventions to bolster their resilience.

Capture of a new-born shortfin mako shark Isurus oxyrinchus (Lamniformes: Lamnidae), with updated records from the Turkish marine waters

The study reports on the capture of a new-born specimen of shortfin mako shark Isurus oxyrinchus Rafinesque, 1810 off Karantina islet coast, Urla, Izmir (north Aegean Sea). This specimen measured 761 mm in total length and weighed 2900 g. The historical and recent captures of the species in the area shows the presence of new-born, juvenile and adult males and females. The distribution of these specimens suggests the potential occurrence of a nursery ground in the same area. To preserve the extirpation of the species throughout the area where it finds favourable environmental parameters to live, a management plan should be conducted to ensure the establishment of a viable population in the Turkish marine waters

Population connectivity of small yellow croaker (Larmichthys polyactis) in the southern Yellow Sea: Implications from multiple otolith-based approaches

Connectivity is a fundamental aspect governing the viability of marine species populations, particularly during their early life stage. However, a dearth of comprehensive studies exists regarding connectivity patterns in Larmichthys polyactis within the southern Yellow Sea region. To address this gap, we conducted a thorough investigation into the population connectivity of L. polyactis collected from Haizhou Bay (HZB) and Lvsi (LS) fishing grounds, employing a suite of otolith-based methodologies. Initially, our analysis of otolith microstructure revealed a notable incubation peak occurring between early and mid-April for juvenile L. polyactis sampled in HZB, despite the sea surface temperature (SST) during that period not aligning with the known spawning requirements of L. polyactis. By juxtaposing the spawning period and associated SST conditions of L. polyactis across different fishing grounds, we deduced a high likelihood that the HZB samples originated from the LS. Subsequently, we investigated the stable isotope ratios (δ13C and δ18O) of L. polyactis collected in HZB, LS, and offshore locations, focusing on the core zone indicative of the early life stage. Statistical analysis using Dunn’s multiple comparison test revealed that no significant disparity in otolith δ13C and δ18O values between HZB and LS samples (P > 0.01). However, these values were notably lower than those observed I n offshore samples (P < 0.01). Furthermore, through otolith morphological analysis, we identified two distinct aggregations within the HZB samples, one aligning with the entirety of the LS samples and another representing the remaining HZB sample subset. This finding provides additional support for the population connectivity between HZB and LS stocks. Drawing upon these findings, we posit the existence of a a mixed population of L. polyactis within HZB, likely resulting from the transportation of eggs or larvae originating from LS to HZB via prevailing northward currents. An enhanced understanding of connectivity dynamics among L. polyactis holds significant implications for the formulation of effective management strategies aimed at bolstering stock recovery efforts.

Capacity for recovery in Bornean orangutan populations when limiting offtake and retaining forest

AbstractAimWe assess the potential long‐term viability of orangutan populations across Borneo, considering the effects of habitat loss, and various forms of population reduction, including hunting, retaliatory killings and capture and translocation.LocationThe study focused on the island of Borneo, a region that has experienced substantial deforestation over the past four decades, resulting in the degradation and fragmentation of its lowland forests, thereby threatening the island's unique biodiversity, including orangutan populations.MethodsTo evaluate the long‐term viability of orangutan populations, we employed a spatially explicit individual‐based model. This model allowed us to simulate various scenarios, including the impact of removing habitat fragments or individuals from the population.ResultsOur findings revealed that small forest fragments facilitate orangutan movement, thereby increasing the number of individuals settling in non‐natal patches. Crucially, orangutan populations proved highly vulnerable to even small levels of offtake. Annual removal rates exceeding 2% diminished the positive role of small forest patches in sustaining population connectivity, the long‐term viability of populations and prospects for recovery.Main ConclusionsOur results suggest that orangutan populations in Borneo could potentially recover from recent declines if removal of orangutans by hunting, retaliatory killings, capture and translocation is reduced, and habitat connectivity is maintained within human‐modified landscapes. These findings emphasize the urgent need for conservation strategies that mitigate negative human–wildlife interactions, and/or help preserve habitat and fragments as stepping stones. Measures could include promoting coexistence with local communities and translocating orangutans only in rare cases where no suitable alternative exists, to ensure the long‐term survival of orangutan populations in Borneo.

Gradient boosted regression as a tool to reveal key drivers of temporal dynamics in a synthetic yeast community.

Microbial communities are vital to our lives, yet their ecological functioning and dynamics remain poorly understood. This understanding is crucial for assessing threats to these systems and leveraging their biotechnological applications. Given that temporal dynamics are linked to community functioning, this study investigated the drivers of community succession in the wine yeast community. We experimentally generated population dynamics data and used it to create an interpretable model with a gradient-boosted regression tree approach. The model was trained on temporal data of viable species populations in various combinations, including pairs, triplets, and quadruplets, and was evaluated for predictive accuracy and input feature importance. Key findings revealed that the inoculation dosage of non-Saccharomyces species significantly influences their performance in mixed cultures, while Saccharomyces cerevisiae consistently dominates regardless of initial abundance. Additionally, we observed multispecies interactions where the dynamics of Wickerhamomyces anomalus were influenced by Torulaspora delbrueckii in pairwise cultures, but this interaction was altered by the inclusion of S. cerevisiae. This study provides insights into yeast community succession and offers valuable machine learning-based analysis techniques applicable to other microbial communities, opening new avenues for harnessing microbial communities.

Small but connected islands can maintain populations and genetic diversity under climate change

In response to the striking effects of environmental change, conservation strategies often include the identification of conservation areas that can effectively maintain vulnerable species. Consequently, identifying system‐specific conditions that maintain the demographic and genetic viability of species of conservation concern is essential. Connectivity plays a critical role in the persistence of populations. Islands have been model systems to understand connectivity and metapopulation processes and have emerged as particularly favorable targets for conservation. While islands can be isolated from mainland disturbances, it is unknown what degree of isolation is necessary to avoid unfavorable changes but remain sufficiently connected to maintain population viability. To test this question, we explored connectivity within the Apostle Islands, an archipelago of 22 islands within Lake Superior, by comparing historical and contemporary trends in ice bridge connectivity and by simulating the effect of reduced connectivity within this system. We developed a demographically informed individual‐based model to explicitly test the role of connectivity to influence the persistence and genetic diversity of American marten Martes americana, a forest carnivore at risk across its southern range boundary. We found that genetic diversity was resilient to moderate changes in ice cover, but a complete loss of connectivity resulted in rapid genetic erosion. Despite genetic erosion, populations persisted as long as nominal connectivity occurred between islands. Our work suggests that connectivity will decline, but martens would be resilient to moderate changes and, in the short term, the Apostle Islands can act as a refuge along this species' southern range boundary. Identifying thresholds in connectivity that maintain populations but allow for isolation from disturbance will be necessary to identify suitable areas for species conservation across space and time.

Effectiveness of the trap-neuter-return method for free-roaming dog management in an urban protected area: Wildlife cannot wait

Free-roaming dogs (Canis familiaris) are invasive species that pose serious threats to wildlife, and this necessitates active management. In Taiwan, resistance to euthanizing shelter dogs has led to overcrowded shelters, which prompted a shift to trap-neuter-return (TNR) as the primary method for managing free-roaming dogs. Shoushan National Nature Park in Kaohsiung, Taiwan has experienced this problem and, therefore, implemented a high-intensity TNR program in 2018–2020. We evaluated effectiveness of TNR in dog population management and its applicability to wildlife conservation in this urban protected area. We conducted camera trapping surveys during 2014–2022 to estimate the population dynamics of dogs and wildlife. The camera traps collected 21,884 trap nights of data and 30,396 trap events of invasive and native mammals. The dog population increased significantly from 2014 to 2017 (relative abundance index (RAI): +318%; occupancy: +17%), which was probably attributed to the implementation of a no-kill policy. Afterwards, the population declined marginally from 2018 to 2021 following the TNR that was conducted (RAI: −29%; occupancy: −9%). In contrast, Reeves' muntjacs (Muntiacus reevesi) decreased significantly from its peak in 2014 to a low in 2022 (RAI: −96%; occupancy: −41%). Similarly, masked palm civets (Paguma larvata) also experienced a decline (RAI: −60%; occupancy: −25%). Population viability analysis predicted that maintaining a sterilization rate of > 75% for female dogs could theoretically control the dog population, but the 50–100 immigrants that entered the population each year would disrupt the effectiveness of the TNR treatment severely. We concluded that TNR was not sufficient in areas with conservation concerns. In addition to neutering, strategies to reduce immigration and to increase the number of dogs removed were crucial for effective management.

Population viability analysis on the Iranian endangered goat breeds

Iranian goat breeds, including Markhoz, Adani, and Najdi, are considered as endangered populations because of the downward trend of breeding goats and flocks, habitat loss, using other breeds in reproduction, and the presence of survival-threatening factors. This research aims to investigate the current status and provide the necessary information to conserve these three endangered populations. For this purpose, the census data and the required parameters were collected from the available resources and flocks during the years of the project implementation. Then, two scenarios, the past and future dynamics of the population assuming continuing existing conditions, were simulated using the population viability analysis (PVA) method. Finally, the sensitivity analyses of parameters affecting the viability criteria were done. PVA was conducted using the Vortex simulation program version 10.5.6. The past dynamics simulation of the population showed that the biological parameters and assumptions used in the model have valid and reliable values and frequencies, and they can be used in the simulation of different management scenarios. Based on this scenario, the inbreeding rates (∆F) for the Markhoz and Adani populations have reached above the critical level of 0.5%. The future dynamics simulation of the population showed that the process of increasing inbreeding and decreasing genetic diversity would accelerate, and the breeds' extinction probability would start in 2026, 2033, and 2031 for Markhoz, Adani, and Najdi, respectively. The mean time to the first extinction was also 15.4 ± 2.53, 26.68 ± 3.75, and 13.96 ±1.78 years, respectively. The sensitivity analyses indicated that adult does overharvest, the frequency of feed limitation, and competition with other breeds had the highest effect on the population viability criteria of the investigated breeds. Markhoz, Najdi, and Adani goats need urgent conservation measures. The results obtained in this research may prepare a suitable framework for providing conservation programs.

Endocrine-Disrupting Chemical Exposure Induces Adverse Effects on the Population Dynamics of the Indo-Pacific Humpback Dolphin.

Cetaceans play a pivotal role in maintaining the ecological equilibrium of ocean ecosystems. However, their populations are under global threat from environmental contaminants. Various high levels of endocrine-disrupting chemicals (EDCs) have been detected in cetaceans from the South China Sea, such as the Indo-Pacific humpback dolphins in the Pearl River Estuary (PRE), suggesting potential health risks, while the impacts of endocrine disruptors on the dolphin population remain unclear. This study aims to synthesize the population dynamics of the humpback dolphins in the PRE and their profiles of EDC contaminants from 2005 to 2019, investigating the potential role of EDCs in the population dynamics of humpback dolphins. Our comprehensive analysis indicates a sustained decline in the PRE humpback dolphin population, posing a significant risk of extinction. Variations in sex hormones induced by EDC exposure could potentially impact birth rates, further contributing to the population decline. Anthropogenic activities consistently emerge as the most significant stressor, ranking highest in importance. Conventional EDCs demonstrate more pronounced impacts on the population compared to emerging compounds. Among the conventional pollutants, DDTs take precedence, followed by zinc and chromium. The most impactful emerging EDCs are identified as alkylphenols. Notably, as the profile of EDCs changes, the significance of conventional pollutants may give way to emerging EDCs, presenting a continued challenge to the viability of the humpback dolphin population.

Novel cereal bran based low-cost liquid medium for enhanced growth, multifunctional traits and shelf life of consortium biofertilizer containing Azotobacter chroococcum, Bacillus subtilis and Pseudomonas sp.

The present study was carried out to valorise cereal (rice and wheat) bran for the development of low-cost liquid consortium bioformulation. Different concentrations of bran-based liquid media formulations were evaluated for the growth of consortium biofertilizer cultures (Azotobacter chroococcum, Bacillus subtilis and Pseudomonas sp.). Among the bran-based formulations, wheat bran-based formulation WB5, exhibited the highest viable cell of 10.68 ± 0.09 Log10 CFU/ml and 12.63 ± 0.04 Log10 CFU/ml for Azotobacter chroococcum and Bacillus subtilis whereas for Pseudomonas sp., rice bran based bioformulation RB5 recorded maximum viability (12.71 ± 0.05 Log10 CFU/ml) after 72 h of incubation. RB51RB1: 1:10 (Rice bran: distilled water)RB2: 1:10 (Rice bran: distilled water)RB3: 1:10 (Rice bran: distilled water)RB4: 1:10 (Rice bran: distilled water)RB5: 5:10 (Rice bran: distilled water)1 and WB52WB1: 1:10 (wheat bran: distilled water)WB2: 2:10 (wheat bran: distilled water)WB3: 3:10 (wheat bran: distilled water)WB4: 4:10 (wheat bran: distilled water)WB5: 5:10 (wheat bran: distilled water)2liquid formulations were further optimized for enhanced shelf life using 5, 10 and 15 mM of trehalose, 0.05 and 0.1% carboxymethyl cellulose, and 0.5 and 1.0% glycerol. Following the peak growth at 72 h of incubation, a gradual decrease in the viable population of consortium biofertilizer cultures was observed in all the liquid formulations. The WB5 and RB5 formulations with 15 mM trehalose and 0.1% CMC, not only recorded significantly highest cell count of consortium biofertilizer cultures, but also maximally supported multi-functional traits i.e., phosphate and zinc solubilization, ammonia and IAA production up to 150 days. Further evaluation of seedling emergence and growth of wheat (PBW 826) under axenic conditions recorded WB5 amended with 15 mM trehalose-based consortium bioformulation to exhibit maximum emergence and growth of wheat seedlings. This low-cost liquid formulation can be used for large-scale biofertilizer production as a cost-effective liquid biofertilizer production technology.

Genomics-informed captive breeding can reduce inbreeding depression and the genetic load in zoo populations.

Zoo populations of threatened species are a valuable resource for the restoration of wild populations. However, their small effective population size poses a risk to long-term viability, especially in species with high genetic load. Recent bioinformatic developments can identify harmful genetic variants in genome data. Here, we advance this approach, analysing the genetic load in the threatened pink pigeon (Nesoenas mayeri). We lifted the mutation-impact scores that had been calculated for the chicken (Gallus gallus) to estimate the genetic load in six pink pigeons. Additionally, we perform in silico crossings to predict the genetic load and realized load of potential offspring. We thus identify the optimal mate pairs that are theoretically expected to produce offspring with the least inbreeding depression. We use computer simulations to show how genomics-informed conservation can reduce the genetic load whilst reducing the loss of genome-wide diversity. Genomics-informed management is likely to become instrumental in maintaining the long-term viability of zoo populations.

Demographic modeling of the endangered subtropical rainforest shrub Graptophyllum reticulatum

AbstractThe subtropical rainforest shrub Graptophyllum reticulatum (Acanthaceae) occurs in only a few populations within a 20‐kilometer range in the Sunshine Coast, south‐east Queensland, Australia. This endangered plant has been subject to habitat degradation and loss, mostly due to land clearing and urbanization. In the past decades, conservation measures such as land protection and translocation have been put in place to protect the species' wild populations. The aim of the study was to analyze the viability of the species' populations in the long term while assessing the effectiveness of land protection and translocation. Demographic data was collected every decade since 2000; for this study, we resurveyed all known populations including a translocated population and two recently discovered populations. We found that the average number of plants per population has doubled since 2000, except in one population that underwent land clearing. However, after being reduced by 70%, plant abundance in this population has been increasing, giving evidence of natural post‐clearing recovery. We developed population growth models for population viability analysis in best, average, and worst‐case scenarios to predict the species' viability over the next 100 years. All populations are expected to grow in the next 100 years, except in the worst‐case scenario in which removing land protection from the model led to an 80% decline in the total number of plants within 100 years, highlighting the importance of land protection for species' conservation. Overall, if current conservation efforts are maintained, this endangered species is likely to persist for the next 100 years.

Anthropogenic land-use change decreases pollination and male and female fitness in terrestrial flowering plants

Abstract Background and Aims The majority of the earth's land area is currently occupied by humans. Measuring how terrestrial plants reproduce in these pervasive environments is essential for understanding their long-term viability and their ability to adapt to changing environments. Methods We conducted hierarchical and phylogenetically-independent meta-analyses to assess the overall effects of anthropogenic land-use changes on pollination, and male and female fitness in terrestrial plants. Key Results We found negative global effects of land use change (i.e., mainly habitat loss and fragmentation) on pollination and on female and male fitness of terrestrial flowering plants. Negative effects were stronger in plants with self-incompatibility (SI) systems and pollinated by invertebrates, regardless of life form and sexual expression. Pollination and female fitness of pollination generalist and specialist plants were similarly negatively affected by land-use change, whereas male fitness of specialist plants showed no effects. Conclusions Our findings indicate that angiosperm populations remaining in fragmented habitats negatively affect pollination, and female and male fitness, which will likely decrease the recruitment, survival, and long-term viability of plant populations remaining in fragmented landscapes. We underline the main current gaps of knowledge for future research agendas and call out not only for a decrease in the current rates of land-use changes across the world but also to embark on active restoration efforts to increase the area and connectivity of remaining natural habitats.