CHANGES IN MORPHOLOGY WITH AGE IN MEDITERRANEAN MONK SEALS (MONACHUS MONACHUS)

In order to describe the pelage and external appearance of the Mediterranean monk seal ( Monachus monachus ) and prepare an age-sex classification guide, 120 seals from the Cabo Blanco Peninsula colony in the Western Sahara/Mauritania were periodically photographed between 1993 and 1996. Analysis of the pigmentation pattern, pelage color and pattern of natural markings of each seal established 48 phenetic types, which were, in turn, arranged in five groups (morphological classes) with multivariate cluster analysis (UPGMA). The variables that best define these groups are size and color. The variation related to relative size, sex and age of 26 identified seals monitored over three years showed that: (1) after each molt, external appearance varied considerably only in non-adults, while adult appearance was invariable; (2) marked sexual dimorphism exists in adults' external appearance; and (3) a remarkable similarity of adult and neonate pelage exists. With these results, we propose an age-sex classification guide to facilitate monk seal identification in the field.     

The Mediterranean monk seal Monachus monachus: status,biology, threats,and conservation priorities

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Postrelease movement of rehabilitated harbor seal (Phoca vitulina richardii) pups compared with cohort‐matched wild seal pups

Harbor seal (Phoca vitulina richardii) populations in the inland waters of Washington and British Columbia are at or near carrying capacity. Stranded pups often are collected and admitted to rehabilitation centers, and then released when they reach a weight of 22 kg and meet a variety of preestablished health and release conditions. While rehabilitation is common practice, it is unclear if rehabilitated seal pups behave like wild weaned pups. Using satellite transmitters, we compared movement patterns of 10 rehabilitated pups with 10 wild weaned pups. When released, rehabilitated seals were longer and heavier than wild pups, while wild pups had a larger mean axillary girth. No clinically different blood parameters were detected. On average, rehabilitated harbor seal pups traveled nearly twice as far cumulatively, almost three times as far daily, and dispersed over three times as far from the release site compared to wild weaned seals. Additionally, wild harbor seals transmitted nearly twice as long as did rehabilitated seals. These patterns suggest that learned behavior during the brief 3–4 wk nursing period likely enables wild harbor seal pups to move less daily and remain closer to their weaning site than rehabilitated pups.     

Biogeography and taxonomy of extinct and endangered monk seals illuminated by ancient DNA and skull morphology

Extinctions and declines of large marine vertebrates have major ecological impacts and are of critical concern in marine environments. The Caribbean monk seal, Monachus tropicalis, last definitively reported in 1952, was one of the few marine mammal species to become extinct in historical times. Despite its importance for understanding the evolutionary biogeography of southern phocids, the relationships of M. tropicalis to the two living species of critically endangered monk seals have not been resolved. In this study we present the first molecular data for M. tropicalis, derived from museum skins. Phylogenetic analysis of cytochrome b sequences indicates that M. tropicalis was more closely related to the Hawaiian rather than the Mediterranean monk seal. Divergence time estimation implicates the formation of the Panamanian Isthmus in the speciation of Caribbean and Hawaiian monk seals. Molecular, morphological and temporal divergence between the Mediterranean and “New World monk seals” (Hawaiian and Caribbean) is profound, equivalent to or greater than between sister genera of phocids. As a result, we classify the Caribbean and Hawaiian monk seals together in a newly erected genus, Neomonachus. The two genera of extant monk seals (Monachus and Neomonachus) represent old evolutionary lineages each represented by a single critically endangered species, both warranting continuing and concerted conservation attention and investment if they are to avoid the fate of their Caribbean relative.     

CONCENTRATIONS OF ESTRONE SULFATE and PROGESTERONE IN PLASMA and SALIVA, VAGINAL CYTOLOGY, and BIOELECTRIC IMPEDANCE DURING THE ESTROUS CYCLE OF THE HAWAIIAN MONK SEAL (MONACHUS SCHAUNSLAnDI)

Blood and saliva samples, vaginal swabs, and bioelectric impedance measurements were collected 1–3 times per week from a captive adult female Hawaiian monk seal ( Monacbus schauinslandi ) during the spring and summer of 1991. During 1992 saliva only was collected on average 4 times weekly. Concentrations of progesterone and estrone sulfate, and the periodic appearance of cornified epithelial cells from the vagina indicated consecutive estrous cycles ranging 35 ± 3 days in duration. Progesterone concentrations in plasma and saliva had a correlation of 0.868, while estrone sulfate had a correlation of 0.982. Bioimpedance of the whole seal body resulted in a pattern similar to the estrone sulfate concentrations, but shifted forward by 2 d. Bioimpedance of the upper vaginal tissues paralleled the estrone sulfate pattern while the bioimpedance of the lower reproductive tract fluctuated without a distinct pattern. The luteal phase ranged 17–20 d and the follicular phase was 15–18 d in length. These results indicate that: (1) the Hawaiian monk seal, in captivity, is a polyestrous seal, in contrast to other phocid seals that have been studied; (2) salivary concentrations of estrogen and progesterone may provide an accurate, less-invasive method of monitoring reproductive hormones in captive Hawaiian monk seals; and (3) vaginal cytology and bioelectric impedance reflect physiological changes associated with the estrous cycle.     

NEW INFORMATION ON THE NATURAL HISTORY,DISTRIBUTION, AND SKULL SIZE OF THE EXTINCT (?) WEST INDIAN MONK SEAL,MONACHUS TROPICALIS

Our knowledge of the extinct West Indian monk seal, Monachus tropicalis , is scant due to heavy exploitation following European colonization of the New World. We present previously unknown accounts of the species, including unpublished field notes of biologist E. W. Nelson, who observed a small number of wild seals in June of 1900. Records indicate that M. tropicalis may have had a long pupping season, occurred in large groups (up to 100) when abundant, probably ate fish and crustaceans, were preyed upon by sharks, and that young and adult seals may have assorted themselves into different age groups when hauled out. Additional records extend the known range of M. tropicalis to include the north coast of South America as far east as Guyana. We also present previously unavailable measurements from a large series of adult skulls and mandibles ( n = 48). Two cases of histocytosis X, carcinoma, or other disease of the hard palate are documented from among these specimens.     

A Comparative Study of Spider (Araneae) Communities of Rehabilitated Bauxite Mines and Surrounding Forest in the Southwest of Western Australia

A study of spider (Araneae) communities was conducted in rehabilitated bauxite mines at the Jarrahdale mine site of Alcoa of Australia Ltd. and in the nearby native jarrah (Eucalyptus marginata) forest in southwest Western Australia. The study was conducted from March to August 1993 in five rehabilitated sites of different age and method of rehabilitation and in two forest sites. A variety of collection methods was used, including pitfall trapping, litter sampling, sweep netting, tree beating, and visual searching. These methods were the same as those carried out in a previous study of some of these areas in 1983. We collected 151 spider species belonging to 102 genera and 34 families. We examined the relationship between various habitat features, including the age and method of rehabilitation, of the spider communities present. It was found that leaf litter depth and cover and vegetation density had a significant positive influence on recolonization by the various spider guilds. The age and method of rehabilitation were found to influence different vegetational and habitat features; these, in turn, influenced the spider communities. Thus, the older a rehabilitated site the greater the species richness of both plants and spiders. We compared these results with those of the 1983 study to determine the spider succession of the aging rehabilitation. The spider communities and guild composition were found to change as the vegetation matured, from a dominance of pioneer species to a community of species requiring less harsh conditions. By comparison with the pre-1983 rehabilitation, the latest method of rehabilitation increased the rate of recolonization by both plants and spiders.     

Ant Community Development on Rehabilitated Ash Dams in the South African Highveld

Ant communities have been widely used as indicators of minesite rehabilitation in Australia and are beginning to play a similar role in other parts of the world. Here we examine ant communities on rehabilitated ash dams associated with a coal‐fired power station on the highveld of South Africa, to improve our understanding of ecosystem development on these substrates. Ants were sampled using pitfall traps at 11 ash‐dam sites, ranging from unrehabilitated to 9‐year‐old rehabilitated sites, as well as two adjacent natural grassland sites. Sampling was conducted on 12 occasions from March 1997 to January 1999. Forty‐nine ant species from 19 genera were recorded during the study. Site species richness was positively correlated with rehabilitation age, ranging from 10 to 25 at ash‐dam sites, compared with 28 and 34 at the two natural grassland sites. There was a humped relationship between total ant abundance and rehabilitation age, with abundance peaking after 5–7 years at levels far higher than those at natural sites. Ordination analysis showed clear separation between ash‐dam and natural sites along the first axis. The unrehabilitated ash‐dam site was also separated from rehabilitated sites along the first axis. Sites of different rehabilitation age were separated along the second axis. Individual ant species showed clear successional patterns across the rehabilitation gradient. Although there was a clear successional trend for the development of ant communities on rehabilitated ash dams, this trend was not toward natural grassland. The lack of convergence toward ant communities of natural grasslands reflects the markedly different substrate and plant composition on ash dams and supports the widely held view that restoration of natural grassland communities is not a realistic goal of ash‐dam rehabilitation. However, the development of species‐rich ant communities, containing at least some late‐successional species, indicates the potential for rehabilitated ash dams to support diverse and complex ecosystems.     

Effects of ecological restoration on beetle assemblages: results from a large-scale experiment in a Mediterranean steppe rangeland

Given that biological conservation cannot prevent the full range of negative impacts on biodiversity, ecological restoration is nowadays commonly acknowledged as a necessary tool for conservation purposes. Here, we report on an ecological rehabilitation project in the La Crau area (south-eastern France), beginning in 2009 when a former industrial orchard (357 ha) was rehabilitated into a Mediterranean rangeland. We assessed the effect of ecological rehabilitation and different additional restoration treatments on beetle assemblages. Seven treatments were considered: the reference steppe, the rehabilitated treatment alone, three additional experimental restoration treatments (soil transfer; nurse species seeding and hay transfer), the control and the edge between the steppe and the former industrial orchard area. All beetle families were considered. Beetles were sampled with pitfall traps for 3 years (2011–2013). Our major finding was a positive effect of soil transfer and nurse species seeding treatments, which promote the characteristic beetle composition of the reference steppe. Nevertheless, strong differences remain between the steppe and the various assessed treatments in terms of composition. Long-term monitoring should therefore now focus on particular beetle indicator species that could reflect the response of the overall characteristic beetle assemblage of the reference steppe.     

SURVIVAL RATES FOR THE HAWAIIAN MONK SEAL (MONACHUS SCHAUINSLANDI)

Abstract: Endangered Hawaiian monk seal ( Monachs schauinslandi ) pups at all the major breeding islands in the Northwestern Hawaiian Islands have been tagged since the early 1980s. Pups were double flipper tagged as soon as possible post-weaning. With few exceptions, an extensive tag resighting effort was conducted annually at the same islands. These resighting data were used to estimate seal survival rates from the time of tagging to age one at all locations using the ratio of seals alive in the second year to number of pups tagged. These survival rates among the islands, from weaning to age one, averaged over the years of the study, ranged from 0.80 to 0.90. For young seals over age one, capture-recapture methods were used to calculate survival pooled through several years, and these rates ranged from 0.85 to 0.98. At French Frigate Shoals and Laysan Island, the higher numbers of tagged pups allowed separate estimates of male and female survival to be calculated. These rates suggested that survival of immature females was better than males. Beginning in 1989, survival of immature seals at French Frigate Shoals declined sharply.     

Postrelease dive ability in rehabilitated harbor seals

The efficacy of seal rehabilitation is examined in a postrelease study of dive ability in harbor seal pups (Phoca vitulina) in the Wash, United Kingdom. Six rehabilitated seals were fitted with Sea Mammal Research Unit (SMRU) Argos Satellite Relay Data Logger tags and their individual dive behavior was monitored for an average of 122 d. The upper 90 percentile edge of dive behavior (dive duration [DD₉₀] and percentage of time at‐sea spent in a dive [PD₉₀]), in 7 d bins, was used as a proxy for physiological dive ability. The results are compared with data from five wild adult harbor seals. There was no statistically significant difference between (1) the mean track duration of rehabilitated seals (126.20 ± 27.48 [SD] d) and adult seals (150.2 ± 24.62 d) (P= 0.108), indicating no evidence that short‐term survival was less in the rehabilitated group; (2) the mean mass‐scaled DD₉₀ of rehabilitated seals (3.95 ± 0.37 min) and adult seals (4.09 ± 0.55 min) (P= 0.632); and (3) the mean PD₉₀ of rehabilitated seals (81.62 ± 1.21%) and adult seals (81.48 ± 3.93%) (P= 0.943). These three results all suggest the success of the rehabilitation program in terms of short‐term survival and dive ability.     

PUP SURVIVAL IN THE MEDITERRANEAN MONK SEAL (MONACHUS MONACHUS) COLONY AT CABO BLANCO PENINSULA (WESTERN SAHARA-MAURITANIA)

We surveyed pup survival in Mediterranean monk seals ( Monachus monachus ), at Cabo Blanco Peninsula (Western Sahara-Mauritania) colony from May 1993 to December 1997. This species breeds and hauls out on beaches inside two main caves. During the study period we detected a total of 93 pups that died or disappeared. The survival rate of 84 pups through the age of first moult (approximately two months) was 0.47. This value is similar to those reported for other pinnipeds breeding in caves but lower than for those breeding on open beaches. Mortality varied seasonally and appeared to increase as a result of storms, large ocean swells, and high tides. Mother-pup pair separation (and resulting pup starvation) and physical injury caused by impact against the rock walls of the cave and cliffs were established as the causes of most deaths. Beach surface area inside the caves also appeared to be a mediating factor in the effects of sea conditions. High pup mortality may be a limiting growth factor in this population, although cave dwelling protects the population from predators and human disturbance.     

Assessing the genetic effects of rehabilitating harbor seals (<Emphasis Type="Italic">Phoca vitulina</Emphasis>) in the Wadden Sea using stochastic simulations

Rehabilitation of marine mammals with the intent of releasing them back into nature is carried out for several species. Rehabilitation can help supporting critically endangered species, increase public awareness, and serve scientific purposes, but rehabilitation also causes concern due to risk of introducing diseases into the wild populations and genetic changes from disruption of natural selection and host-pathogen co-evolution. In this study, we investigate another potential risk from rehabilitation that has not previously been considered, i.e., anthropogenic increase in population inbreeding level. For this purpose, we performed stochastic population viability analyses of the Wadden Sea harbor seal population using VORTEX. In the Wadden Sea, rehabilitation takes place in several rehabilitation centers, and many of the seals suffer from parasitic bronchopneumonia or are orphaned. Several studies have found a correlation between helminth infection and inbreeding level. Moreover, a relation between fitness traits such as pup survival and inbreeding has been demonstrated. On this basis, we assess the effects from rehabilitating relatively inbred seals on population size and genetic diversity. We find that releasing seals significantly affect population inbreeding level and to a lesser extent population size. The effect depends on the level of inbreeding in rehabilitated seals as well as the actual number of inbred seals released.     

HAWAIIAN MONK SEALS (MONACHUS SCHAUINSLANDI) FORAGING IN DEEP-WATER CORAL BEDS

Plans to harvest deep-water corals in the remote Northwestern Hawaiian Islands, close to populations of endangered Hawaiian monk seals ( Monachus schauinslandi ), have raised concerns about the seals' use of deep-water habitats. Movements and diving patterns of seals studied at French Frigate Shoals (FFS) Atoll indicated two areas where five males out of 33 instrumented seals dove deep enough (300–500 m) to encounter commercially sought deep-water corals. Submarine surveys conducted at each location found beds of gold ( Gerurdia sp.) and pink ( Corallium sp.) precious coral suggesting an overlap between the foraging habitat of some seals and the target of the coral fishery. Areas adjacent to the coral beds that were visually censused using submersibles showed significantly fewer precious corals. Precious coral beds were not found on previous submarine surveys at other regions around FFS, supporting the notion that seals were selecting the areas with corals as forage habitat. Five male seals were fitted with back-mounted video cameras to document feeding among precious corals. None of the five seals dove deep enough to encounter precious corals (>300 m). However, three of the seals visited beds of black coral ( Cirrhipdhes sp.) at shallower depths (∼ 80 m). One seal was observed revisiting the black coral beds on three successive nights to feed on fish hiding among the coral stems.     

Rehabilitation of Logged Rain Forests: Avifaunal Composition,Habitat Structure,and Implications for Biodiversity‐Friendly REDD+

The inclusion of carbon stock enhancements under the Reducing Emissions from Deforestation and Forest Degradation (REDD+) framework will likely drive a rapid increase in biosequestration projects that remove carbon from the atmosphere through rehabilitation of degraded primary rain forests. Such projects could also present an important opportunity to reverse losses of biodiversity from degraded rain forests, but concern has recently been expressed that management interventions to increase carbon stocks may conflict with biodiversity conservation. Focusing on a large‐scale rain forest rehabilitation project in northern Borneo, we examine: (i) how intensive rehabilitation of selectively logged forests affected patterns of bird community composition and (ii) whether changes in vegetation structure explain observed shifts in avian guild structure and species composition. Bird composition differed between unlogged, naturally regenerating logged, and rehabilitated logged habitats, with the avifauna of rehabilitated forest more similar to that of naturally regenerating forest. Crucially, rehabilitation did not adversely affect either those species that declined after logging or those species that are IUCN Red Listed. Rehabilitation reduced the prevalence of vines and shrubs within regenerating forest, and across all habitats, the abundance and species richness of all birds and of obligate frugivores were positively related to vine prevalence. In contrast, the abundance and richness of frugivore–insectivore generalists and of salliers were negatively related to vines, suggesting that avifaunal responses to forest rehabilitation were attributable to liberation cutting of vines. Management intervention to increase carbon stocks had little adverse effect on avian biodiversity and we therefore argue that rain forest rehabilitation should play a strong role in future REDD+ agreements.     

Do monk seals exert top‐down pressure in subphotic ecosystems?

Patterns of subphotic fish assemblages on seamounts in the Northwestern Hawaiian Islands were identified and compared for potential structuring influences, including the bottom-up effects of regional oceanic productivity and top-down predation pressure exerted by visiting monk seals ( Monachus schauinslandi ). Patterns in fish size, density, and biomass were evaluated at the deep extreme (350–500 m) of the seals feeding range to avoid confounding effects of diverse shallow habitats ( e.g. , coral reefs). Fish number and size were used to calculate biomass density of the seamount fish assemblages that were then compared to the independent variables of summit depth, substrate type, relief, oceanic productivity, distance to seal colonies, and seal colony population. Only the variables of distance to seal colony and seal colony population were retained in a multiple regression model that explained 31% of the variance. Despite the presence of obvious regional differences in oceanic productivity, the overall patterns in the subphotic fish assemblages are better explained by the top-down hypothesis of predation pressure from monk seals.     

Rookery through rehabilitation: Microbial community assembly in newborn harbour seals after maternal separation

Microbial community assembly remains largely unexplored in marine mammals, despite its potential importance for conservation and management. Here, neonatal microbiota assembly was studied in harbour seals (Phoca vitulina richardii) at a rehabilitation facility soon after maternal separation, through weaning, to the time of release back to their native environment. We found that the gingival and rectal communities of rehabilitated harbour seals were distinct from the microbiotas of formula and pool water, and became increasingly diverse and dissimilar over time, ultimately resembling the gingival and rectal communities of local wild harbour seals. Harbour seal microbiota assembly was compared to that of human infants, revealing the rapid emergence of host specificity and evidence of phylosymbiosis even though these harbour seals had been raised by humans. Early life prophylactic antibiotics were associated with changes in the composition of the harbour seal gingival and rectal communities and surprisingly, with transient increases in alpha diversity, perhaps because of microbiota sharing during close cohabitation with other harbour seals. Antibiotic-associated effects dissipated over time. These results suggest that while early life maternal contact may provide seeding for microbial assembly, co-housing of conspecifics during rehabilitation may help neonatal mammals achieve a healthy host-specific microbiota with features of resilience.     

Comparative Study of Ant Communities of Rehabilitated Mineral Sand Mines and Heathland, Western Australia

We conducted a survey of ants in April 1997 in seven rehabilitated (2- to 20-year-old) and three native heathland reference sites of the Renison Goldfields Corporation (RGC) Mineral Sands operations at Eneabba, Western Australia. We employed a variety of collecting methods, including pitfall trapping, litter and soil sampling, sweeping and beating of vegetation, and collecting by hand in the day and after dark, replicating those used by previous researchers in a similar study conducted in the same area in 1980. We found a total of 96 ant species representing 30 genera in 1997, compared with 46 species from 18 genera in 1980. Ant species richness increased with age of rehabilitation and exceeded that of heath controls by the time it reached 11 years. Ant species richness related to rehabilitation age was represented by a logarithmic curve, and the slope for current rehabilitation was steeper than that for the earlier rehabilitation studied in 1980. This probably reflects improved rehabilitation practices. Ordination of the sites in terms of ant species composition indicated differences between ant species in the rehabilitated sites studied in 1980 and 1997, and also between all rehabilitated sites and heath controls. Classification of the sites in terms of the distribution of ants across functional groups also indicated differences between rehabilitation and heath control sites. According to species composition and functional group profiles from rehabilitated and control sites, we concluded that although the current rehabilitation allows for a rapid return of ant species, even after 20 years the fauna still had not attained the composition of the original heath fauna.     

运用植物区系质量指数快速评估湿地植被恢复成效

目前通常采用的评估湿地保护和恢复成效的指标体系较为复杂, 常涉及生物学、环境科学和社会学等多个学科, 导致监测评估成本高, 并难以实现综合的定量评估, 因此有必要提出能够在较大程度上表达生态环境状况的综合生态指标。植物区系质量指数(Floristic Quality Assessment Index, FQAI)反映了植物区系中物种的生态保守性程度, 作者将其作为主要生态指标, 来验证该指标用于湿地植被恢复成效定量评估的有效性。作者以四川盆地丘陵和平原地区湿地植物为对象, 构建了区域库塘及河滩湿地植物区系质量指数计算方法与赋值表, 以成都市重要水源地——云桥湿地的3年生态恢复成效为案例进行了检验。结果表明, 在云桥湿地3年恢复期间, 植物物种组成及其比例在恢复年限间无显著差异, Shannon-Wiener指数、Pielou指数和Simpson指数在3年中也并未发生显著变化, 但生态保守性系数平均值(CC_mean)和植物区系质量指数(FQAI)均随恢复年限显著上升, 表明FQAI可以快速、有效地实现生态系统水平湿地植被恢复成效的比较和定量评估。     

BODY SIZE,SURVIVAL, AND DECLINE OF JUVENILE HAWAIIAN MONK SEALS,MONACHUS SCHAUINSLANDI

In the mid 1980s half of the entire Hawaiian monk seal species was located at French Frigate Shoals, and this colony may have reached environmental carrying capacity. Since 1989 this colony has declined by 55%, primarily from poor juvenile survival. Only 8%–25% of weaned pups have survived to age 2 during this period, compared to at least 80% between 1984 and 1987. We characterize (1) this drop in survival, (2) a strong, but variable, correlation between survival and size at weaning, (3) interisland differences in size from weaning to age 2 in 1991 through 1993, and (4) decadal-scale changes in mean measures of size at weaning. We compare observations at French Frigate Shoals with the colony at Laysan Island where abundance is well below historical levels and was therefore expected to be below carrying capacity. At Laysan Island juvenile survival has also been poor (30%-70%), and the size of weaned pups has decreased during the past decade. Our hypothesis is that poor survival may be due to reduced prey availability at both sites, but particularly at French Frigate Shoals. Evidence to support this hypothesis includes a large increase in total abundance at French Frigate Shoals; reduced size of weaned pups; decreased survival, emaciation, and slower growth rates of juvenile seals; and declining primary productivity. Regardless of cause, the immediate consequences at French Frigate Shoals and Laysan Island, and for the species overall, will likely be poor recruitment and productivity. Because the decline is still in progress, the ultimate consequences for the species' viability are of great concern in light of its already low abundance.