Endangered Population Research Articles

Common dolphins (Delphinus delphis) in Israel: Unique dynamics of a critically endangered population

The most eastern population of common dolphins (Delphinus delphis) in the Mediterranean Sea inhabits the southern coastal waters of Israel. They are mainly observed in the shallow waters off Ashdod and Ashkelon, between the 15-30 m isobaths, with no reported observations north or west of this area. These dolphins were observed and studied year-round between 2016-2021 using boat-based surveys and photo identification methods. Common dolphins were encountered and photographed 43 times during the study period, resulting in 2,851 identifications of 25 distinctive mature individuals and 12 calves. Most individuals (62%) were sighted over multiple years, with high yearly and monthly sighting rates, indicating long-term site fidelity and residency. Closed population mark-recapture models estimated a total abundance of 25 (95% CI 24 – 37) individuals in 2016 that declined to only 15 (95% CI 15 – 15) individuals in 2021. Social network analysis described these remaining individuals as one closed and well-associated social unit. Survival probabilities for this population appeared lower than those of other delphinid populations. The decrease in their abundance, coupled with their apparent isolation level, qualifies the local population for a re-assessment of their conservation status. This study first describes the Israeli local population of common dolphins, their dynamics and an assessment of their status based on the IUCN Red List framework.

Hair mineral levels as indicator of wildlife demographics?—a pilot study of muskoxen

The tight linkage between mineral status and health and demographics in animals is well documented. Mineral deficiencies have been coupled to population declines in wildlife. Current practices typically rely on liver, kidney and/or serum samples to assess mineral levels. Such destructive sampling strategies are, however, not feasible for remote or endangered populations. Hair may constitute an alternative tissue, sampled through non-invasive means, to investigate mineral levels in wildlife. In the pilot study presented here, we examine whether mineral levels in hair samples from a well-studied muskox (Ovibos moschatus) population in High-Arctic Greenland are associated with a vital rate and may, therefore, serve as indicators of wildlife population demographics. We show that inter-annual variations in levels of three minerals—copper, selenium and molybdenum—are associated with fluctuations in annual calf recruitment, with poor recruitment in years of low mineral levels in hair. Local environmental conditions also varied with calf recruitment but appeared to be less robust predictors of calf recruitment than hair mineral levels. Our results suggest that hair mineral levels may serve as an indicator of vital demographic rates and, ultimately, of wildlife population trends.

The first assessment of the genetic diversity and structure of the endangered West Indian manatee in Cuba.

The coastal waters of Cuba are home to a small, endangered population of West Indian manatee, which would benefit from a comprehensive characterization of the population's genetic variation. We conducted the first genetic assessment of Cuban manatees to determine the extent of the population's genetic structure and characterize the neutral genetic diversity among regions within the archipelago. We genotyped 49 manatees at 18 microsatellite loci, a subset of 27 samples on 1703 single nucleotide polymorphisms (SNPs), and sequenced 59 manatees at the mitochondrial control region. The Cuba manatee population had low nuclear (microsatellites HE = 0.44, and SNP HE = 0.29) and mitochondrial genetic diversity (h = 0.068 and π = 0.00025), and displayed moderate departures from random mating (microsatellite FIS = 0.12, SNP FIS = 0.10). Our results suggest that the western portion of the archipelago undergoes periodic exchange of alleles based on the evidence of shared ancestry and low but significant differentiation. The southeast Guantanamo Bay region and the western portion of the archipelago were more differentiated than southwest and northwest manatees. The genetic distinctiveness observed in the southeast supports its recognition as a demographically independent unit for natural resource management regardless of whether it is due to historical isolation or isolation by distance. Estimates of the regional effective population sizes, with the microsatellite and SNP datasets, were small (all Ne < 60). Subsequent analyses using additional samples could better examine how the observed structure is masking simple isolation by distance patterns or whether ecological or biogeographic forces shape genetic patterns.

Vegetation height and structure drive foraging habitat selection of the lesser kestrel (Falco naumanni) in intensive agricultural landscapes.

Habitat selection in animals is a fundamental ecological process with key conservation implications. Assessing habitat selection in endangered species and populations occupying the extreme edges of their distribution range, or living in highly anthropized landscapes, may be of particular interest as it may provide hints to mechanisms promoting potential range expansions. We assessed second- and third-order foraging habitat selection in the northernmost European breeding population of the lesser kestrel (Falco naumanni), a migratory falcon of European conservation interest, by integrating results obtained from 411 direct observations with those gathered from nine GPS-tracked individuals. The study population breeds in the intensively cultivated Po Plain (northern Italy). Direct observations and GPS data coincide in showing that foraging lesser kestrels shifted their habitat preferences through the breeding cycle. They positively selected alfalfa and other non-irrigated crops during the early breeding season, while winter cereals were selected during the nestling-rearing phase. Maize was selected during the early breeding season, after sowing, but significantly avoided later. Overall, vegetation height emerged as the main predictor of foraging habitat selection, with birds preferring short vegetation, which is likely to maximise prey accessibility. Such a flexibility in foraging habitat selection according to spatio-temporal variation in the agricultural landscape determined by local crop management practices may have allowed the species to successfully thrive in one of the most intensively cultivated areas of Europe. In the southeastern Po Plain, the broad extent of hay and non-irrigated crops is possibly functioning as a surrogate habitat for the pseudo-steppe environment where most of the European breeding population is settled, fostering the northward expansion of the species in Europe. In intensive agricultural landscapes, the maintenance of alfalfa and winter cereals crops and an overall high crop heterogeneity (deriving from crop rotation) is fundamental to accommodate the ecological requirements of the species in different phases of its breeding cycle.

Links between individual performance, trace elements and stable isotopes in an endangered caribou population

Foraging is a key behaviour, and several aspects of foraging remain to be investigated in many wild species. Low energy gain or reduced protein, nutrient, and mineral intake may explain poor individual condition, low reproductive output, high mortality, and, in extreme cases, population declines. Our study explores how foraging ecology, diet composition, and nutritional status could influence individual performance in an endangered population of caribou (Rangifer tarandus caribou). We measured stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) as well as the concentration of 21 trace elements in hairs of 44 caribou (~ 50% of the population). Our results showed that the Atlantic-Gaspésie caribou population consumed mainly lichens, horsetails, deciduous shrubs, and deciduous trees. We found a correlation between diet (described using stable isotope ratios) and accumulation of trace elements in hair using a redundancy analysis, and we detected relationships between diet, trace elements and vital rates using logistic and Cox models. Pregnancy and calf survival probabilities were higher when the δ13C signature of female caribou was higher, and the adult survival probability was higher in caribou that had higher concentrations of zinc and sodium, and lower concentrations of cesium and manganese in their hair. Based on the correlation we found between nutrition and individual performance, our study suggests that nutrition may be an important factor to consider in the recovery of this endangered caribou population.

Demographic study of a peripheral population of the rare amphicarpic species Scrophularia arguta

Scrophularia arguta (Scrophulariaceae) is a rare amphicarpic annual species with a fragmented distribution in North Africa, part of the Arabian Peninsula, and Macaronesia, with several peripheral populations on the Iberian Peninsula (south-western Europe) as well. The Iberian populations have a disjunct distribution: several endangered or critically endangered populations are present in the southeast versus a few non-listed ones representing a relict lineage with a unique plastid haplotype inhabiting the west-central region (Extremadura). In this study, we examined the largest and most important population of this relict lineage to assess potential threats to its survival. We evaluated pollination and reproductive systems, floral rewards, fruit and seed set from chasmogamous and cleistogamous flowers, and population dynamics (i.e., phenology, survival, reproductive success, and predation level). We found that the main threats to the population are predation by wild herbivores, such as red deer and, to a lesser extent, Cucullia scrophulariae caterpillars. These threats decrease reproductive success to such an extent that population survival may be in jeopardy if no action is taken to reduce the effects of herbivores. In addition, the existence of nearby beehives alters the presence and density of wild pollinators that contribute to gene flow via pollen transfer and increase genetic variability. Cleistogamous seeds may help maintain the population in specific microhabitats (mainly quartzite rock cracks), although at the cost of reducing genetic variability. Finally, we recommend that regional/national administrations responsible for biodiversity matters adopt measures to ensure the conservation and survival of west-central populations. Scrophularia arguta predation by vertebrates. Left, group of several individuals before and after vertebrate predation. Right, vertebrate predation level. • Wild vertebrates and caterpillars threaten a relict Scrophularia arguta population. • Managed honeybees displace natural pollinators. • The conflict between plant and animal conservation requires monitoring. • The action of regional/national administrations is needed to conserve this species.

Importance of species traits on individual-based seed dispersal networks and dispersal distance for endangered trees in a fragmented forest.

Although mutualistic network analyses have sparked a renewed interest in the patterns and drivers of network structures within communities, few studies have explored structural patterns within populations. In an endangered tree species population, plant individuals share their bird seed dispersers; however, the factors affecting individual interaction patterns are poorly understood. In this study, four individual-based networks were built for the endangered Chinese yew, Taxus chinensis, in a fragmented forest based on bird foraging type (swallowing and pecking networks) and habitat type (networks in a bamboo patch and an evergreen broad-leaved forest patch). Species-level network metrics (species degree and specialization, d’) were used to evaluate the effects of species traits (bird and plant traits) on species-level networks and dispersal distance for T. chinensis. It was revealed that the interaction networks between T. chinensis individuals and their bird partners were influenced by foraging type and the habitat of plant distribution. Compared to the other two networks, bird swallowing and bird–fruit networks in the evergreen broad-leaved patch habitat had higher nestedness and connectance but lower modules and specialization. Bird (body weight and wing and bill lengths) and plant traits (height, crop size, and cover) significantly affected species-level network metrics such as degree and specialization. Furthermore, seed dispersal distance was influenced by species traits and the species-level metrics of fruit–bird interaction networks. These results provide new insights into individual-based seed dispersal mutualistic networks of endangered plant species under habitat fragmentation. Moreover, these findings have relevant implications for conserving and managing individual endangered trees in increasingly disturbed ecosystems.

Interpopulation variation in thermal physiology among seasonal runs of Chinook salmon

Conservation of species facing environmental change requires an understanding of interpopulation physiological variation. However, physiological data are often scarce and therefore pooled across populations and species, erasing potentially important variability between populations. Interpopulation variation in thermal physiology has been observed within the Salmonidae family, although it has not been associated with seasonally distinct migratory phenotypes (i.e., seasonal runs). To resolve whether thermal physiology is associated with life-history strategy, we acclimated four Sacramento River juvenile Chinook salmon ( Oncorhynchus tshawytscha) populations (Coleman fall-run, Feather River fall-run, Feather River spring-run, and Sacramento River winter-run) exhibiting different seasonal migratory phenotypes (fall-, spring-, and winter-run), at 11, 16, and 20 °C and assessed variation in growth rate, critical thermal maxima, and temperature-dependent metabolic traits. We identified population differences in the physiological parameters measured and found compelling evidence that the critically endangered and endemic Sacramento River winter-run Chinook population exhibits thermal physiology associated with its early-migration life-history strategy. Acclimation to warm temperatures limited the growth and metabolic capacity of winter-run Chinook salmon, highlighting the risk of future environmental warming to this endemic population.

Evaluating the suitability of close-kin mark-recapture as a demographic modelling tool for a critically endangered elasmobranch population.

Estimating the demographic parameters of contemporary populations is essential to the success of elasmobranch conservation programmes, and to understanding their recent evolutionary history. For benthic elasmobranchs such as skates, traditional fisheries-independent approaches are often unsuitable as the data may be subject to various sources of bias, whilst low recapture rates can render mark-recapture programmes ineffectual. Close-kin mark-recapture (CKMR), a novel demographic modelling approach based on the genetic identification of close relatives within a sample, represents a promising alternative approach as it does not require physical recaptures. We evaluated the suitability of CKMR as a demographic modelling tool for the critically endangered blue skate (Dipturus batis) in the Celtic Sea using samples collected during fisheries-dependent trammel-net surveys that ran from 2011 to 2017. We identified three full-sibling and 16 half-sibling pairs among 662 skates, which were genotyped across 6291 genome-wide single nucleotide polymorphisms, 15 of which were cross-cohort half-sibling pairs that were included in a CKMR model. Despite limitations owing to a lack of validated life-history trait parameters for the species, we produced the first estimates of adult breeding abundance, population growth rate, and annual adult survival rate for D.batis in the Celtic Sea. The results were compared to estimates of genetic diversity, effective population size (N e ), and to catch per unit effort estimates from the trammel-net survey. Although each method was characterized by wide uncertainty bounds, together they suggested a stable population size across the time-series. Recommendations for the implementation of CKMR as a conservation tool for data-limited elasmobranchs are discussed. In addition, the spatio-temporal distribution of the 19 sibling pairs revealed a pattern of site fidelity in D.batis, and supported field observations suggesting an area of critical habitat that could qualify for protection might occur near the Isles of Scilly.

Trapping mortality accelerates the decline of the fisher, an endangered mesocarnivore, in British Columbia, Canada

Understanding the environmental, demographic, and anthropogenic factors driving the population dynamics of endangered species is critical to effective conservation. Habitat loss, fragmentation, and trapping all have been linked to declines in the endangered population of fishersPekania pennantiin central British Columbia (BC), Canada, hereafter referred to as the Columbian population. Although the commercial trapping season for fishers has recently been closed in central BC, the animals are still taken in traps legally set for other furbearer species, and with this continuing source of mortality, the sustainability of this vulnerable population remains unclear. We constructed population viability models in the program Vortex to evaluate the specific impacts that trapping mortality would have on Columbian fisher population persistence under different trapping scenarios. Our modeling predicted that current mortality sources, including deaths in traps set for other species, will cause the population to disappear within 11 yr. When fur harvest mortality was removed from our modeling, the Columbian population appeared unlikely to persist beyond 37 yr. Our analysis provides evidence that along with the continued trapping closure for fishers in central BC, it is likely necessary to modify trapping regulations and methods (including restricting the use of kill traps) for other furbearers within Columbian fisher range to sufficiently reduce mortality from bycatch and help to avoid extirpation of the population in the near future. Additionally, identifying areas where fishers are actively breeding and protecting these habitats from further disturbances will be needed to increase survival and reproductive rates to levels high enough to reverse population declines over the longer term.

Long-term monitoring of an endangered population of Yellow-bellied Glider Petaurus australis on the Bago Plateau, New South Wales, and its response to wildfires and timber harvesting in a changing climate

ABSTRACT A population of Yellow-bellied Glider Petaurus australis on the Bago Plateau, on the NSW south-western slopes, was first surveyed across 126 sites in 1995 and this subsequently became the baseline for further population monitoring. A subset of 48 sites was resurveyed in 2010, and about one third of the sites (~40) were surveyed annually on a rotating panel between 2013–2019. Wildfire significantly impacted the Bago Plateau during 2020 and 51 sites were resurveyed post-fire in 2020/21. An occupancy modelling approach was used to estimate trends in occupancy between 1995 and 2020/21, including the influence of various covariates. Initial occupancy was positively associated with the extent of Montane Gums and mixed Wet Peppermint/Montane Gum forest types within a 450 m radius of the survey site. Supported models revealed that colonisation over time was positively associated with the density of hollow-bearing trees at a site, while extinction was positively associated with the extent of high severity wildfire at a site. Despite wide confidence intervals, the long-term occupancy trend showed a stable to slight increase between 1995 and 2019, but a ~26% reduction following wildfire. The increasing trend occurred despite a long-term rainfall deficit that was punctuated by occasional above average years during the survey period. There was no evidence that timber harvesting influenced occupancy by the gliders, although harvesting is predominantly focused within stands containing Alpine Ash Eucalyptus delegatensis, with monospecific stands generally avoided by the glider.

Temporal Trends and Effects of Noise on Upsweep Calls of Eastern South Pacific Southern Right Whales

Eastern South Pacific southern right whales (ESPSRW) are a subpopulation of southern right whales (Eubalaena australis) off the coasts of Peru and Chile recognized by the International Union for the Conservation of Nature (IUCN) as critically endangered as a result of heavy whaling efforts in the late 18th to 20th centuries. Most recent population estimates put their numbers around 50 individuals. To test for the efficacy of passive acoustic monitoring of this population, we recorded 5 months of continuous acoustic data (January 2012-June 2012) off the southwestern tip of Isla de Chiloé. To test for trends in occurrence, we identified 11,313 individual ESPSRW upsweep calls, which have been associated with maintaining contact with conspecifics. Call occurrence increased over the course of the deployment and peaked between April and June, indicating an increase in use of this area. A clear diel pattern in which upsweep calls were predominately detected during dusk and night hours was identified, indicating ESPSRW are likely foraging during daylight hours, as upsweep calls are inversely related to foraging behavior. We quantified noise levels in the frequency range of their communication (100 Hz third octave) to understand the change in active space whales may be experiencing. We measured noise levels from 90 dB re 1 μPa to 111 dB re 1 µPa (5th and 95th percentile), a 21 dB fluctuation that results in an order-of-magnitude decrease in active space area. We identified sources of high noise at or above the 75th percentile as predominately blue whale calls (occurring in 71.6% of total sampled minutes) and ship noise (occurring in 69.4% of total sampled minutes). Ship noise was responsible for outliers in excess of 140 dB re 1 µPa. In a population as diminished as ESPSRW, such disruptions of their communication range could result in significant barriers to maintaining contact with conspecifics. Passive acoustic monitoring is a powerful tool for monitoring populations as rarely sighted as ESPSRW. Understanding trends in presence and behavior as well as potential sources of disruption to their calling behavior is vital to determining conservation measures that will be most effective toward helping this critically endangered population.

Evaluation of the “Bottleneck” Effect in an Isolated Population of Microtus hartingi (Rodentia, Arvicolinae) from the Eastern Rhodopes (Bulgaria) by Methods of Integrative Analysis

An integrative analysis of an isolated population of Harting’s vole (Microtus hartingi) from the Eastern Rhodope Mountains (Bulgaria) was carried out by morphological and morphometric methods, computed tomography, Cytb variation data, and experimental hybridization. Substantial changes in the development of the skull and teeth were found. Nevertheless, those voles can live to the senex stage. A phylogenetic reconstruction based on Cytb sequences showed that M. hartingi from the Eastern Rhodopes forms a separate clade, which is a sister clade to the voles from Northeastern Greece (also from the foothills of the Rhodopes). M. hartingi from the Rhodopes is mostly isolated reproductively from M. h. ankaraensis from Anatolia (Turkey), as evidenced by a decrease in the proportion of pairs that started breeding, relatively high mortality of pups, and increased sterility of hybrid males. Possible time of isolation of the Rhodopean population and consequences of the “bottleneck” effect on its current state are discussed. At the same time, we believe that, at present, it is impossible to determine its taxonomic status. It is necessary to recognize M. hartingi from the Bulgarian Rhodopes as an endangered population and to include it in regional Red Lists of Bulgaria.

Morphometrics of mammal‐eating killer whales from drone photogrammetry, with comparison to sympatric fish‐eating killer whales in the eastern North Pacific

AbstractAerial photogrammetry has provided increased power for monitoring the health of individuals in the endangered population of Southern Resident killer whales (SRKW,Orcinus orca) in the eastern North Pacific. These data have shown evidence of nutritional stress, with individual growth and body condition correlating with the availability of their primary prey, Chinook salmon (Oncorhynchus tshawytscha). We used drones to derive similar but novel photogrammetry measurements from a sympatric population of mammal‐eating Bigg's killer whales (BKWs) that has been increasing in abundance in recent decades. From 2014 to 2019 we photographed 95 individual BKWs in Canadian waters off Vancouver Island and US waters in the Salish Sea; we estimated asymptotic lengths of 6.4 m for adult females and 7.3 m for adult males, both longer than corresponding length estimates for SRKWs. As a proxy for body condition, we measured head width at a standardized distance behind the blowhole, expressed as proportion of the length between the blowhole and dorsal fin, and estimated that on average, all age/sex classes of BKWs were more robust than corresponding classes of SRKWs. These differences likely reflect divergent adaptive selection in these prey‐specialist ecotypes, but may also partially indicate recent impacts of differential prey availability.

Presence of Southeast Pacific blue whales (Balaenoptera musculus) off South Georgia in the South Atlantic Ocean

AbstractThe Southeast Pacific (SEP) or Chilean blue whale population is largely distributed between Northern Chilean Patagonia and the Eastern Tropical Pacific. Off South Georgia (SG), the majority of blue whales caught were Antarctic blue whales, but recent genetic and acoustic records indicate the possible presence of SEP individuals. To assess the presence of SEP blue whales off SG, we carried out new analyses of acoustic data previously reported as containing pygmy blue whale song and analyzed the length frequencies from 20th century catch data. The month of acoustic data reported to contain the presumed pygmy blue whale song was examined (August 2006), and 13 days were found to have songs which visually and quantitatively matched SEP2 songs from Northern Chilean Patagonia. The fundamental frequency of SEP2 song off SG, however, was not in line with the predicted frequency shift trend of the SEP2 songs in the SEP. A mixture analysis of lengths in historic whaling catches indicated that 3.3% of the catches from SG could be SEP blue whales, although this declined to 0.6%, 95% CI [0.0, 2.6] when fit to nonrounded lengths. Our results suggest that any SEP blue whales off SG are likely rare vagrants, at the edge of an endangered population.

Assessment of endangered freshwater pearl mussel populations in the Northern Iberian Plateau in relation to non–native species: xenodiversity as a threat

In the last two decades, small populations of freshwater pearl mussels, Margaritifera margaritifera, have been recorded in Mediterranean rivers of the Iberian Northern Plateau. A survey was carried out in Castilla and León in 2018 to assess the development of populations of this species in all the rivers of known distribution and to update the threat classification. Thirty sections in the rivers Negro, Tera, Alberche and Águeda were positive for its presence, and another 50 stretches of seven rivers were negative. The species is currently distributed over about 22.5 km. Águeda and Tera populations have decreased dramatically in the last 14 years and are on the threshold of extinction. The Negro river supports the largest population, although the species has now disappeared in at least 61 % of the stretches that were inhabited in 2004. All populations showed very low densities and an ageing population structure, with no recruitment for decades. The presence of non-native invasive alien species (NIS) was higher than in a previous regional survey, with the signal crayfish representing the greatest threat. We observed changes in benthic microhabitats and direct predation of adults and glochidia conglutinates. In the Alberche River, in strict syntopy with M. margaritifera and two other mussel species, 10 NIS were detected. The current hydrological and ecological conditions in the Duero watershed support the settlement of exotic species to the disadvantage of native mollusks, which are more demanding in terms of microhabitats.

Genetic differentiation of a critically endangered population of the limpet Patella candei candei d’Orbigny, 1840, in the Canary Islands

The adoption of measures to protect the viability of threatened populations should be supported by empirical data identifying appropriate conservation units and management strategies. The global population of the majorera limpet, P. candei candei d’Orbigny, 1840, is restricted to the Macaronesian islands in the NE Atlantic, including near-to-extinct and healthy populations in Fuerteventura and Selvagens, respectively. The taxonomic position, genetic diversity and intra- and interspecific relationships of these populations are unclear, which is hindering the implementation of a recovery plan for the overexploited majorera limpet on Fuerteventura. In this study, ddRAD-based genome scanning was used to overcome the limitations of mitochondrial DNA-based analysis. As a result, P. candei candei was genetically differentiated from the closely related P. candei crenata for the first time. Moreover, genetic differentiation was detected between P. candei candei samples from Selvagens and Fuerteventura, indicating that translocations from the healthy Selvagens source population are inadvisable. In conclusion, the majorera limpet requires population-specific management focused on the preservation of exceptional genetic diversity with which to face future environmental challenges.

Maternal Lineage and Habitat Use Patterns Explain Variation in the Fecundity of a Critically Endangered Baleen Whale

The critically endangered North Atlantic right whale population (Eubalaena glacialis) has experienced multiple periods of decreased reproduction within its observable history, which have played a role in the overall decline of the species. In addition to this synchronized variation in reproduction across the population, there exists considerable individual variation in fecundity. To determine the impacts of family history and habitat use behavior on these individual variations in fecundity, photo identification data collected during four decades of visual monitoring were used to create a calving index for sexually mature females that could be used to evaluate matrilineal influence on fecundity. Reproductive life histories were analyzed to assess fecundity variation within matrilines over time. Individual variations in fecundity were also assessed with respect to a recent climate-driven habitat distribution shift by a loyal cohort of right whales that use the Gulf of St. Lawrence during the summer and autumn seasons. Lifetime fecundity in the oldest known living reproductive female, or matriarch, in a matriline was positively associated with the fecundity of her female progeny. Sexually mature females that have used the Gulf of St. Lawrence since 2015 were significantly more likely to give birth over this time period compared to individuals who did not use that habitat. Individuals of both sexes were significantly more likely to use the Gulf of St. Lawrence if their mothers did as well; however, this association declined as offspring aged. These results provide insight on the environmental, behavioral, and genetic factors that contribute to individual variation in fecundity. Low calving rates and increased dangers posed by habitat use shifts in the past decade have played a major role in the species’ decline, and these new insights into the mechanistic drivers of right whale reproduction and habitat use show that lineage guides progeny behavior and reproductive success. As anthropogenic climate change continues to disrupt right whale seasonal distributions through changing ocean circulation patterns, understanding the demographic consequences of novel habitat use patterns will be essential to updating protective policies.

Impacts of the Gospers Mountain Wildfire on the flora and fauna of mining-impacted Newnes Plateau Shrub Swamps in Australia’s Eastern Highlands

ABSTRACT The Gospers Mountain Fire was the largest wildfire on record in New South Wales. All of the swamps on the Newnes Plateau were burnt, with some areas experiencing fire of very high severity. Despite this severity, the vegetation in all unmined reference swamps recovered relatively quickly, with substantial vegetation cover and biomass returning within 10 weeks. These swamps retained most of their peat and plant species, and both their surveyed endangered fauna species (Blue Mountains Water Skink Eulamprus leuraensis; Giant Dragonfly Petalura gigantea). This demonstrated the resilience of reference Newnes Plateau Shrub Swamps and their endangered species populations to significant bushfire events. In stark contrast, after the wildfire there was evidence of extensive combustion and oxidization of peat soils in swamps located above the footprint of prior longwall coal mining operations. Populations of endangered species, which were already in significant decline (due to longwall mining impacts on swamp hydrology), are now vulnerable to localised extinctions in these undermined swamps. Mining is ongoing in these areas and failure to protect the remaining Newnes Plateau Shrub Swamps from the hydrological impacts of longwall mining will likely lead to further ecosystem collapse in undermined swamps, and further localised extinctions of endangered species populations in these swamps.

Franciscana dolphins, Pontoporia blainvillei, as environmental sentinels of the world's largest mining disaster: Temporal trends for organohalogen compounds and their consequences for an endangered population

On November 5th, 2015, the Fundão dam collapsed in Minas Gerais, southeastern Brazil, releasing millions of cubic meters of mud containing mining residue into the Doce River. Two weeks later, the mud arrived to the marine environment, triggering changes in franciscana dolphin habitat, Pontoporia blainvillei, from Franciscana Management Area Ia. This is an isolated population of the most endangered cetacean species in the South Atlantic Ocean. Organohalogen compounds (OHCs) may pose a threat to this endangered population because of their endocrine disrupting properties. Hence, this study sought to determine if there were differences in the bioaccumulation profile of OHC (PCBs, DDTs, Mirex, HCB, HCHs, PBDEs, PBEB, HBBZ and MeO-BDEs) in franciscana dolphins before and after dam collapse and to build a temporal trend. Blubber of 33 stranded individuals was collected in Espírito Santo state for organohalogen assessment between 2003 and 2019. Differences were found between franciscana dolphins collected prior to and after the disaster. Additionally, significant temporal trends for organochlorine pesticides and natural and anthropogenic organobromine were detected. The increase in pesticide concentrations after 2015 is suggestive of their reavailability in the environment. The decline in organobromine over time could be due to their debromination in the marine environment and alterations in the composition of their natural producers. PCBs remained stable during the period of the study. Our findings show an increase in endocrine disruptor concentrations, which is of great concern for this endangered population.