Determinants of successful establishment and post‐translocation dispersal of a new population of the critically endangered St. Croix ground lizard (Ameiva polops)

Translocation to areas free of exotic predators, habitat degradation, or disease may be the most viable restoration option for many endangered species. We report on a successful translocation of the critically endangered St. Croix ground lizard, Ameiva polops, extirpated from St. Croix, U.S. Virgin Islands, Caribbean, by predation from introduced mongooses (Herpestes auropunctatus). We translocated 57 adult A. polops from Green Cay to Buck Island in May 2008. We placed 4 females and 3 males each in eight, 100 m², enclosures on Buck Island for 71 days, then the enclosures were opened. During the enclosure period, 20 individuals were identified and 32 others were seen. The average number sighted per survey was only 5.28 (range = 2–10). One hatchling was sighted in an enclosure, indicating a translocated female successfully nested. Body condition of the translocated individuals increased significantly by the end of the enclosure period. Population monitoring surveys at 61 sites across Buck Island showed that 5 years after the initial translocation in June 2013, the new population had grown to an estimated 1,473 individuals and occupied 58.9% of the island. We attribute eradication of mongoose, life history of the species, large propagule size, condition of habitat, soft‐release, use of adults, interagency collaboration, and systematic assessment as primary factors that facilitated this successful translocation. Our findings provide meaningful insights on factors that enhance the potential for successful translocations, and point to new strategies aimed at restoring populations of endangered reptiles in their native ranges.     

Monthly population density and structure patterns of an endangered seahorse Hippocampus capensis: a comparison between natural and artificial habitats

This study investigated aspects of the population ecology of the endangered Knysna seahorse Hippocampus capensis within different habitat types. High densities of H. capensis were found within artificial Reno mattress habitat, within the Knysna Estuary, South Africa. Monthly surveys at three sites were conducted from October 2015 to August 2016 to compare population densities of H. capensis in this artificial habitat with natural eel grass Zostera capensis habitat. Hippocampus capensis densities varied significantly across all sites and highest population densities were consistently observed within the Reno mattress habitat. Hippocampus capensis were also found to be significantly larger within the Reno mattress habitat and pooled data showed that males were significantly larger than females. The overall sex ratio for all three sites was female biased, although this varied across seasons at two sites. The findings suggest that artificial Reno mattresses provide novel habitat for this endangered species and consideration should be given to the usefulness of these structures in future conservation actions.     

Pollination Biology of the Endangered Herbal Medicines <i>Dendrobium chrysotoxum</i> (Orchidaceae)

Pollination biology studies of the endangered herbal medicines Dendrobium chrysotoxum were conducted in natural pollination conditions using flower observation, pollinator observation and artificial pollination experiments. Populations of D. chrysotoxum with fragrance and nectar were pollinated by Ctenoplectra davidi Valhalla (Hymenoptera: Apidae) species. The floral structure of D. chrysotoxum adapted precisely to its pollinators. Flowers had a low capsule setting (0.17%) under natural conditions. However, compared to open pollination, artificial pollination experiments showed a significant increase in capsule setting, and D. chrysotoxum was cross-compatible and self-compatible, but there was pollinator limitation also. This study will provide important information for the preservation of this endangered species.     

Success of Delayed Translocation of Loggerhead Turtle Nests

ABSTRACT Sea turtle embryo mortality in natural nests due to environmental and anthropogenic factors can be very high. To increase hatching success of these endangered species, nest translocation to hatcheries immediately after egg-laying is a common management tool. To test the viability of delayed translocation, we moved 50 loggerhead sea turtle (Caretta caretta) nests to a beach hatchery after various times (0–96 hr) after egg-laying at Boavista Island (Republic of Cabo Verde, western Africa). We transported eggs in a rigid plastic container, being careful to maintain their original vertical orientation. Delayed translocation times of 0 hours, 12 hours, 24 hours, 84 hours, or 96 hours after egg-laying did not have any effect on hatching success, incubation period, or hatchling size and mass. Delayed translocation slightly increased the duration of the translocation process because of extra precautions taken (e.g., maintaining axial orientation, protecting eggs from mechanical shocks). We conclude that delayed nest translocation can be done in a safe and effective way, thereby increasing the efficiency of the whole monitoring program. Finally, delayed translocation, accompanied by an evaluation of fertility, would seem to permit the removal of undeveloped eggs and to facilitate their subsequent exploitation by local communities without affecting turtle nesting success.     

THE GENETICS OF ADAPTATION: THE GENETIC BASIS OF RESISTANCE TO WASP PARASITISM IN DROSOPHILA MELANOGASTER

There have been very few genetic analyses of “natural” adaptations, that is, those not involving artificial selection or responses to human disturbance. Here we analyze the genetic basis of geographic variation in Drosophila melanogaster's resistance to parasitism by a wasp, Asobara tabida. Our results suggest that population differences in ability to encapsulate parasitoid eggs have a fairly simple genetic basis: 60% of the D. melanogaster genome plays no role in differences between resistant and susceptible populations. Instead, resistance gene(s) are restricted to chromosome two, and may be further restricted to the centromeric region of this chromosome. This finding suggests that natural adaptations—like many responses to artificial selection and human disturbance—sometimes have a simple genetic basis.     

Population augmentation had no effect on the abundance or body condition of conspecifics and co‐occurring lizard species in a native grassland community

Wildlife translocations have been historically plagued by failure. As more species gain endangered status, we must increase the success rate through use of pre‐emptive empirical, evidence‐based research. The main ecological risk is the potential for the relocated individuals to have competitive advantage at the recipient site, acting invasively and, potentially, outcompeting the native fauna for food, shelter or other resources. Here we investigated the ecological risk of increased population density, following a population augmentation of the pygmy bluetongue lizard (Tiliqua adelaidensis) an endangered lizard, endemic to South Australia. We experimentally increased T. adelaidensis density to ascertain if a sudden increase in T. adelaidensis density would negatively affect the abundance or body condition of the resident conspecifics and co‐existing lizard species found at the recipient site. Twenty‐four individuals, from two populations, were relocated into previously built enclosures at a recipient site in grassland habitat, north of Adelaide, South Australia. For one activity‐season pre and post the augmentation, co‐existing lizard species were sampled in an effort to detect any changes inabundance or body condition. Comparisons were also made between experimental enclosures, containing residents and translocated individuals and control enclosures, containing only residents. Using Menetia greyii as a proxy for all of the competing species, our results show there was no reduction in abundance or body condition post augmentation. Our lack of evidence indicating a negative impact of the T. adelaidensis translocation on the body condition and abundance of the resident lizard species is a positive outcome for future conservation of this species. This study provides a new way of approaching wildlife movements, through identification of potential risks using small‐scale translocations in an enclosed area before conducting large‐scale releases into unfenced areas; the results are intended to facilitate higher translocation success rates and limit the negative effects upon the wider ecological community at recipient sites.     

Evaluation of Factors Restricting Distribution of the Endangered Key Largo Woodrat

ABSTRACT We examined a suite of models in an information theoretic framework to identify factors restricting presence of the endangered Key Largo woodrat (Neotoma floridana smalli) throughout its remaining habitat. Models containing variables related to availability of nest sites and mammalian predator abundances were supported by our data. Abundance of natural (large overstory trees) and artificial (rock and debris piles) nest substrate were the most important predictor variables, followed by indices of feral cat and raccoon (Procyon lotor) abundance. We recommend increasing abundance of nest substrate in the short term through addition of artificial nest substrate and in the long term through continued protection of remaining forest habitat.     

Long-term genetic monitoring of a translocated population of collared brown lemurs

Post-release monitoring is important to improve translocation success because it provides an opportunity to identify factors relevant to the survival of local populations. We studied a population of the endangered collared brown lemur (Eulemur collaris) translocated from a degraded forest fragment to a nearby littoral forest within the Mandena Conservation Area in southeast Madagascar from 2000–2011. We compared genetic surveys of mitochondrial and nuclear markers with the genetic profile of nearby populations to examine the dispersal capacity of the collared brown lemur. We also performed a landscape analysis to assess changes in connectivity between forest fragments. There was a fluctuating trend characterized by a phase of demographic and genetic stability shortly after translocation, followed by an increase in genetic diversity coinciding with a population decrease and a gradual recovery of initial conditions. These results demonstrated the ability of the collared brown lemur to disperse through unfavorable landscapes and to recover after translocation. Our study revealed the importance of monitoring translocated populations over time using a multidisciplinary approach.     

Potential Risk of Hybridization in Ex Situ Collections of Two Endangered Species of Sinojackia Hu （Styracaceae）

Spontaneous hybridization in ex situ facilities can undermine the genetic integrity of ex situ collections and potentially contaminate open-pollinated seeds or seedlings destined for the reintroduction of endangered plant species into the wild. In the present study, the potential risk of hybridization between two endangered Chinese endemic species, namely Sinojackia xylocarpa Hu and S. rehderiana Hu, which are naturally allopatric species but were conserved ex situ in Wuhan Botanical Garden （WBG）, Wuhan, China, were investigated over three consecutive years from 2003 to 2005. The entire overlapping flowering period of the two species was 14-20 d and the two species shared the same pollinator insects during the entire flowering season in WBG. The floral isolation between the two species was not an issue in the ex sltu collection at WBG. The results suggest an opportunity for pollen transfer between species and a potential risk of genetic Introgression and loss of genetic identity of open-pollinated seeds produced in the ex sltu Collection of these two endangered species. An artificial reciprocal cross between S xylocarpa and S. rehderlana confirmed that the two congener species could readily set seeds, indicating no post-pollination barriers to hybridization and the importance of spatial isolation as a barrier to inter-specific crossing. Therefore, to manage these crossable species with overlapping flowering times and shared pollination vectors in ex situ facilities, spatial isolation should be carefully considered to minimize the possibility of spontaneous hybridization.     

Short-Term Dispersal Response of an Endangered Australian Lizard Varies with Time of Year

Dispersal is an important component in the demography of animal populations. Many animals show seasonal changes in their tendency to disperse, reflecting changes in resource availability, mating opportunities, or in population age structure at the time when new offspring enter the population. Understanding when and why dispersal occurs can be important for the management of endangered species. The pygmy bluetongue lizard is an endangered Australian species that occupies and defends single burrow refuges for extended periods of time, rarely moving far from the burrow entrance. However, previous pitfall trapping data have suggested movement of adult males in spring and of juveniles in autumn of each year. In the current study we compared behaviours of adult lizards each month, over the spring-summer activity period over two consecutive field seasons, to provide deeper understanding of the seasonal dispersal pattern. We released adult pygmy bluetongue lizards into a central area, provided with artificial burrows, within large enclosures, and monitored the behaviour and movements of the released lizards over a four day period. There was a consistent decline in time spent basking, amount of movement around burrow entrances, and rates of dispersal from the central release area from early spring to late summer. Results could be relevant to understanding and managing natural populations and for any translocation attempts of this endangered lizard species.     

Optimizing the genetic composition of a translocation population: Incorporating constraints and conflicting objectives

Translocations of threatened species can reduce the risk of extinction from a catastrophic event. For plants, translocation consists of moving individuals, seeds, or cuttings from a native (source) population to a new site. Ideally a translocation population would be genetically diverse and consist of fit founding individuals. In practice, there are challenges to designing such a population, including constraints on the availability of material, and tradeoffs between different goals. Here, we present an approach for designing a translocation population that identifies sets of founders that are optimized according to multiple criteria (e.g., genetic diversity), while also conforming to constraints on the representation of different founders (e.g., propagation success). It uses flexible inputs, including SNP genotypes, matrices of similarity between individuals, and vectors of phenotype data. We apply the approach to a critically endangered plant, Hibbertia puberula subsp. glabrescens (Dilleniaceae), which was genotyped at thousands of SNP loci. The goals of minimizing genetic similarity among the founding individuals and maximizing genetic diversity were largely complementary: populations optimized for one of these criteria were near‐optimal for the other. We also performed analyses in which we minimized genetic similarity among founding individuals while imposing selection (against hypothetical deleterious alleles, and against undesirable phenotypes, respectively), and here characterized sharp tradeoffs. This was useful in allowing the benefits of selection to be weighed against costs in terms of genetic similarity. In summary, we present an approach for designing a translocation population that allows flexible inputs, the imposition of realistic constraints, and examination of conflicting goals.     

Occupancy of spoil dumps by the Mountain Pygmy‐possum Burramys parvus in Kosciuszko National Park

Summary The Mountain Pygmy‐possum Burramys parvus has been listed as an endangered species across its range in the alpine and subalpine areas of New South Wales and Victoria. This study reports on the occurrence of the species in an artificial habitat, spoil dumps that were created in the 1950s as a result of the construction of underground tunnels associated with the Snowy Hydro‐electric Scheme. Thirty‐four B. parvus were captured in 1065 trapnights on spoil dumps in Happy Jacks Creek valley, in northern Kosciuszko National Park in October and November 2011. In January 2012, 22 individuals were captured in 360 trapnights on a spoil dump at Guthega Adit Camp in southern Kosciuszko National Park. Seven radio‐collared individuals tracked in Happy Jacks Creek valley resulted in the location of 5 day shelters in spoil dump habitat, including individuals that were originally trapped in nearby natural habitat. This study indicates that there may be opportunity to create further artificial habitat on sites not currently used by this highly restricted species.     

Restoration genetics of the vernal pool endemic Lasthenia conjugens (Asteraceae)

Restoration of habitat for endangered species often involves translocation of seeds or individuals from source populations to an area targeted for revegetation. Long-term persistence of a species is dependent on the maintenance of sufficient genetic variation within and among populations. Thus, knowledge and maintenance of genetic variability within rare or endangered species is essential for developing effective conservation and restoration strategies. Genetic monitoring of both natural and restored populations can provide an assessment of restoration protocol success in establishing populations that maintain levels of genetic diversity similar to those in natural populations. California’s vernal pools are home to many endangered plants, thus conservation and restoration are large components of their management. Lasthenia conjugens (Asteraceae) is a federally endangered self-incompatible vernal pool annual with gravity- dispersed seeds. Using the molecular technique of intersimple sequence repeats (ISSRs), this study assessed levels and patterns of genetic variability present within natural and restored populations of L. conjugens. At Travis Air Force Base near Fairfield, California, a vernal pool restoration project is underway. Genetic success of the ecologically based seeding protocol was examined through genetic monitoring of natural and restored populations over a three-year period. Genetic diversity remained constant across the three sampled generations. Diversity was also widely distributed across all populations. We conclude that the protocol used to establish restored populations was successful in capturing similar levels and patterns of genetic diversity to those seen within natural pools. This study also demonstrates how genetic markers can be used to inform conservation and restoration decisions.     

St Lucia Whiptail Lizard Cnemidophorus vanzoi (Sauria: Teiidae) microsatellite primers

Eight polymorphic microsatellite loci have been characterized for the endangered St Lucia Whiptail Lizard Cnemidophorus vanzoi. Endemic to two small islets, Maria Major and Maria Minor, off the coast of St Lucia, Lesser Antilles, the world population is estimated at < 1000 individuals. However, representatives of the systematically complex genus Cnemidophorus, containing sexual species and parthenogenetic allopolyploids, are distributed widely in North, Central and South America, and on several islands in the Caribbean Sea. These microsatellite markers are being used to monitor the genetic structure of a population of St Lucia Whiptails, recently founded through translocation, on the nearby Praslin Island.     

In situ and in vitro colonization of Cathaya argyrophylla (Pinaceae) by ectomycorrhizal fungi

Cathaya argyrophylla, a critically endangered conifer, is found to grow at four isolated areas located in subtropical mountains of China. To examine the involvement and usefulness of mycorrhizas for sustaining the population of this tree, we compared the root system, morphology, and structure of mycorrhizal roots of C. argyrophylla, which were collected from a natural stand and an artificial stand, each grown at a different location. More mycorrhizal roots were found for trees from an artificial stand. The presence of extramatrical mycelium, mantle, and Hartig net revealed that C. argyrophylla formed an ectomycorrhizal association in both sampling sites. Starch granules were found in mycorrhizal roots collected only from a natural stand. The aseptic synthesis of C. argyrophylla and Cenococcum geophilum was established for the first time in vitro. Typical ectomycorrhizas formed on seedlings on RM medium containing 0.1 g/l glucose, 5 weeks after inoculation. By light microscopy, the synthesized mycorrhizas showed a thin mantle from which emanated extramatrical hyphae and highly branched Hartig net. A simple, rapid, and convenient mycorrhiza synthesis system was developed, which facilitates further studies on ectomycorrhizal development of C. argyrophylla.     

Larval rearing of chub, Leuciscus cephalus (L.), using decapsulated Artemia as direct food

Little is known about the larviculture of the chub, Leuciscus cephalus (L.), an endangered cyprinid species endemic to European flowing waters. The use of decapsulated Artemia cysts as food for chub larviculture was investigated. After 3‐day feeding with the rotifer Brachionus calyciflorus, the larvae were fed on different diets: (i) dried decapsulated Artemia cysts, (ii) Artemia nauplii, (iii) rotifers for seven more days and then Daphnia collected from a pond, and (iv) an artificial diet. After a 24‐day rearing period, the highest survival rate was obtained with the larvae receiving decapsulated Artemia cysts. Feeding of the larvae with an artificial diet resulted in a significantly lower survival rate compared with the other groups. At the end of the experiment, the larvae fed on Artemia nauplii yielded a significantly higher mean length compared with the other groups. Feeding an artificial diet resulted in a significantly lower average weight and mean length gain compared with the other groups.     

Assisted Colonization of Foundation Species: Lack of Consideration of the Extended Phenotype Concept—Response to Kreyling et al. (2011)

Assisted colonization (AC), or the intentional translocation of populations to compensate for risks related to climate change, is receiving increasing attention. It has been recently suggested by Kreyling et al. (2011) that rather than relocating endangered species, a focus should be placed on local adaptations of foundation or keystone species, and that these local ecotypes should be moved within their own range. Hence, this type of relocation could be applied with minimal risk in many restoration efforts. We think that caution is needed when considering the translocation of these foundation species, even within their range. Many recent studies have shown that foundation species can influence community structure and ecosystem processes through heritable traits, which suggests a genetic basis for ecosystem services. Thus, the translocation of different genotypes of foundation species might lead to unexpected results of colonization and might not be as “predictable” as Kreyling et al. have argued. Here, in our response, we stress how AC of foundation species can have important evolutionary consequences that might be impossible to reverse. We propose, whenever possible, (1) to favor population mixes of the foundation species to minimize the potential negative effects of specific genotypes; and (2) to collect from adjacent populations along ecological clines of the foundation species to mimic natural processes of migration under climate change.     

Collection of semen by manual stimulation and ejaculate characteristics of the black flying‐fox (Pteropus alecto)

Semen collection and preservation is the first step toward the development of an artificial insemination program in endangered Pteropus spp. Semen was collected by manual stimulation from a single “human‐habituated” P. alecto. Manual stimulation resulted in the successful collection of motile spermatozoa on 17 of 34 attempts. The semen had a pH of 8.2 (n=2). With the exception of volume, seminal characteristics (concentration, motility, acrosome and plasma membrane status) were similar to those collected previously by electro‐ejaculation. Zoo Biol 27:159–164, 2008. © 2008 Wiley‐Liss, Inc.