Mohammad Nafi Solaiman Al-Sabi, Mariann Chriél, Trine Hammer Jensen, Heidi Larsen Enemark, Endoparasites of the raccoon dog (Nyctereutes procyonoides) and the red fox (Vulpes vulpes) in Denmark 2009–2012 – A comparative study, International Journal for Parasitology: Parasites and Wildlife, Available online 17 April 2013, ISSN 2213-2244, 10.1016/j.ijppaw.2013.04.001.
Invasive species negatively influence the biodiversity of the ecosystems they invade and may introduce pathogens to native species. Raccoon dogs have very successfully invaded Europe, including, recently, Denmark. This study included analyses of gastrointestinal helminths and Trichinella spp. from 99 raccoon dogs and 384 native red foxes collected from October 2009 to March 2012. The sedimentation and counting method used revealed that raccoon dogs and foxes harboured 9 and 13 different helminth species, respectively, of which several known to be zoonotic. Significantly more nematode and cestode species were found in foxes while raccoon dogs had more trematode species. Rodent transmitted parasites were more prevalent in foxes, while amphibian transmitted parasites were more prevalent in raccoon dogs. One fox was infected with Echinococcus multilocularis (0.3%), while no Trichinella spp. were detected in raccoon dogs or foxes. The trematode Brachylaima tokudai was detected for the first time in Denmark in five of 384 foxes (1.3%). Prevalences of Pygidiopsis summa (3.0% and 3.4%) and Cryptocotyle spp. (15.2% and 15.4%) were comparable in raccoon dogs and foxes, respectively. Four helminth species were more prevalent in foxes than in raccoon dogs: Toxocara canis (60.9% and 13.1%); Uncinaria stenocephala (84.1% and 48.5%); Mesocestoides spp. (42.7% and 23.2%); and Taenia spp. (30.7% and 2.0%), respectively. Three helminth species were more prevalent in raccoon dogs than in foxes: Dipylidium caninum (5.1% and 0.3%); Mesorchis denticulatus (38.4% and 4.2%); and Alaria alata (69.7% and 34.4%), respectively. T. canis was more abundant in foxes while A. alata was more abundant in raccoon dogs. The intestinal distribution of a number of helminth species was comparable between hosts, but highly variable between parasite species. Inherent biological factors and host invasion of new areas might have shaped these marked differences in helminth fauna between the invasive raccoon dog and the native red fox.
Demographic influences on cougar residential use and interactions with people in western Washington
Brian N. Kertson, Rocky D. Spencer, and Christian E. Grue
Journal of Mammalogy 2013 94 (2), 269-281
Sound management of large carnivore populations in wildland–urban environments requires accurate information regarding the ecology of these populations and factors contributing to their interactions with people. We quantified cougar (Puma concolor) residential use and interactions with people in western Washington from 2003 to 2008 to characterize the ecology and risks associated with an adaptable large carnivore residing in a wildland–urban environment. We fitted cougars with global positioning system and very-high-frequency radiocollars, quantified residential use, and tested for differences between demographic classes using analysis of variance fixed-effects and multiple-comparison models. We investigated interaction reports to quantify interaction rates and tested for differences among interaction levels for different cougar demographic classes. We captured 32 cougars (16 males and 16 females) and estimated 33 annual utilization distributions (UDs) for 27 individuals. Ninety-three percent of cougars (n = 27; 15 males and 12 females) used residential areas with an average UD overlap of 16.86% (SD = 17.05%, n = 33). There were no differences between male and female (F1,29 = 0.77, P = 0.49) or resident and transient (F1,29 = 0.0003, P = 0.99) use of residential areas, but subadult use was significantly higher than that of adults (F1,29 = 7.20, P = 0.01). Twenty-nine percent of reports were confirmed (n = 73), with livestock depredations accounting for 67% of confirmed reports. The interaction rate for radiocollared cougars was low (1.6 interactions/1,000 radiodays) and all demographic classes were involved in similar numbers of interactions. Use of residential areas in western Washington appears to be a function of the adaptive and mobile nature of the cougar exploiting suitable habitat and resources within the matrix of residential development. Interaction appears to be a function of individual behavior. Management strategies that target problem individuals and maintain older age structures in local populations coupled with proactive landscape planning and public education in residential areas at the wildland–urban interface may provide an effective strategy for decreasing cougar–human interaction.
Forces shaping major histocompatibility complex evolution in two hyena species
Katy J. Califf, Elizabeth K. Ratzloff, Aaron P. Wagner, Kay E. Holekamp, and Barry L. Williams
Journal of Mammalogy 2013 94 (2), 282-294
Genes of the mammalian major histocompatibility complex (MHC) are central to adaptive immunity. High levels of observed polymorphism at MHC loci have been hypothesized to be maintained by natural selection acting to preserve alleles for pathogen resistance. Here we examined patterns of multilocus MHC diversity in natural populations of 2 closely related carnivore species: spotted hyenas (Crocuta crocuta) and striped hyenas (Hyaena hyaena). We also tested hypotheses suggesting specific selection pressures favoring MHC diversity in these hyena species. We found several lines of evidence consistent with positive selection acting at multiple MHC loci in both species. These included high allelic variation, pervasive gene duplication, transspecies segregation of alleles, and codons evolving under positive selection that disproportionately map to known antigen-binding regions. Despite striking behavioral differences between these 2 hyaenids with respect to their mating systems and social behavior, we found no qualitative species differences in MHC loci, nor did we detect differences in the strength of natural selection. Our findings suggest that ancient shared selection pressures, including a common ancestral pattern of carrion feeding, has influenced MHC diversity more strongly in these hyena species than have selection pressures imposed relatively recently by sociality or sexual selection.
Lethal and sublethal effects of black-backed jackals on cape foxes and bat-eared foxes
Jan F. Kamler, Ute Stenkewitz, and David W. Macdonald
Journal of Mammalogy 2013 94 (2), 295-306
Little is known about the sublethal effects of mesocarnivores on small carnivores, which can have important implications regarding the ecology and behavior of the latter. We investigated the ecology of cape foxes (Vulpes chama) and bat-eared foxes (Otocyon megalotis) in the absence of black-backed jackals (Canis mesomelas), a dominant mesocarnivore and predator of both fox species. were compared with a concurrent study that investigated the ecology of both fox species in the presence of jackals, at a site
Roost selection in suburban bushland by the urban sensitive bat Nyctophilus gouldi
Caragh G. Threlfall, Bradley Law, and Peter B. Banks
Journal of Mammalogy 2013 94 (2), 307-319
The persistence of wildlife in fragmented landscapes is predicted to rely on the presence of critical habitat elements. In urban landscapes, the persistence of hollow-dependent bats arguably depends upon the protection of roosting habitat, yet knowledge of bat roosting requirements within these landscapes is limited. We used radiotelemetry to locate day roosts of a species considered sensitive to urbanization, Gould’s long-eared bat (Nyctophilus gouldi), in suburban bushland in Sydney, New South Wales, Australia. We compared roost selection data collected for 9 individuals during the mating season (March–April 2009) and 10 individuals during the maternity season (November–December 2009). We found 41 roosts of N. gouldi under decorticating bark and in tree hollows, which were all located in 1 suburban bushland reserve (40 ha), with roosts rarely located elsewhere, despite the abundance of available trees in smaller patches outside of the reserve. N. gouldi displayed a clear preference for trees with a greater amount of understory and canopy cover, and only roosted where the extent of forest cover in the local landscape was greatest. Maternity roosts also were predominately located in gullies, and closer to creek lines than expected. Roost switching differed significantly between seasons, with lactating females switching roosts significantly more often than nonlactating females, where roost switching occurred after 1 day on 71% of occasions. Because competition with other fauna for hollows has been suggested as a potential threat, systematic observations of hollow-using bird species, including rainbow lorikeets (Trichoglossus haematodus), were conducted. We observed birds occupying bat roosts on days following bat occupancy, and bats roosted in trees where there were fewer hollow-using birds than randomly available trees. We recommend that further examination of hollow competition be undertaken because abundant, urban-adapted, hollow-nesting birds may render hollows a limiting resource to hollow-users such as bats in urban landscapes. Protection of a network of potential roost trees in suburban bushland remnants, particularly along creek lines, will assist in maintaining this critical resource for bats.
Space use by giant otter groups in the Brazilian Pantanal
Caroline Leuchtenberger, Luiz Gustavo Rodrigues Oliveira-Santos, William Magnusson, and Guilherme Mourão
Journal of Mammalogy 2013 94 (2), 320-330
Giant otters (Pteronura brasiliensis) live in groups that seem to abandon their territories during the flooding season. We studied the spatial ecology of giant otter groups during dry and wet seasons in the Vermelho and Miranda rivers in the Brazilian Pantanal. We monitored visually or by radiotelemetry 10 giant otter groups monthly from June 2009 to June 2011.We estimated home-range size for all groups with the following methods: linear river length, considering the extreme locations of each group, and fixed kernel. For the radiotracked groups, we also used the k-LoCoh method. Spatial fidelity and habitat selection of giant otter groups were analyzed seasonally. On the basis of k-LoCoh (98%) method, home-range sizes during the wet season (3.6–7.9 km2) were 4 to 59 times larger than during the dry season (0.1–2.3 km2). Home-range fidelity between seasons varied among giant otter groups from 0% to 87%, and 2 radiotagged groups shifted to flooded areas during the wet seasons. Giant otter groups were selective in relation to the composition of the landscape available during the dry seasons, when the river was used more intensively than other landscape features. However, they seemed to be less selective in positioning activity ranges during the wet season. During this season, giant otters were frequently observed fishing in the areas adjacent to the river, such as flooded forest, grassland, and swamps.
Vibrissae growth rates and trophic discrimination factors in captive southern sea otters (Enhydra lutris nereis)
Luke P. Tyrrell, Seth D. Newsome, Marilyn L. Fogel, Marissa Viens, Roxane Bowden, and Michael J. Murray
Journal of Mammalogy 2013 94 (2), 331-338
Isotopic analysis of serially sampled vibrissae (whiskers) is a powerful method to investigate changes in an individual’s resource and habitat use over time, which is difficult or impossible to accomplish using traditional dietary proxies such as observation or scat analysis. A vibrissae-based isotopic approach is limited by knowledge of vibrissae growth rates, which are required to determine the time period represented by each subsampled segment. Likewise, determining the magnitude of, and variation in, isotopic differences between a consumer and its diet, commonly referred to as trophic discrimination factors (TDFs), is a crucial step in quantifying diet composition using stable isotopes. TDF estimates are available only for a few mammalian taxa. We measured vibrissae growth rates and δ13C and δ15N TDFs in captive southern sea otters (Enhydra lutris nereis). Sea otters were administered 15N-enriched glycine intravenously and vibrissae were collected periodically and serially sampled for carbon (δ13C) and nitrogen (δ15N) isotope analysis. Growth of adult sea otter vibrissae was linear with a mean (±SD) rate of 7.7 (± 1.2) cm/year. Mean (±SD) whole diet–vibrissae TDFs were 2.8‰ (±0.2‰) for δ13C and 5.5‰ (±0.2‰) for δ15N. Mean (±SD) lipid-extracted diet–vibrissae TDFs were 2.4‰ (±0.2‰) for δ13C and 4.9‰ (±0.3‰) for δ15N. δ13C TDFs were similar to previously reported values for mammalian carnivores, but δ15N TDFs were higher than expected. These results will increase the accuracy of isotopic diet analyses of mustelids and other carnivores for which there are few estimates of TDFs and no estimates of vibrissae growth rates.
Distribution of Lyncodon patagonicus (Carnivora, Mustelidae): changes from the Last Glacial Maximum to the present
Mauro I. Schiaffini, Gabriel M. Martin, Analía L. Giménez, and Francisco J. Prevosti
Journal of Mammalogy 2013 94 (2), 339-350
The Patagonian weasel (Lyncodon patagonicus) is one of the least known carnivores from South America, and excluding some contributions, knowledge of it seems anecdotal. It is supposed to inhabit herbaceous and arid environments of Argentina and Chile. Here we assess the potential distribution of the Patagonian weasel both during the present and the Last Glacial Maximum (LGM). We also integrate some of this information, providing a historical and geographic analysis (both through ecological niche modeling and biogeographic schemes) of the distribution of L. patagonicus. We found 2 major core areas of distribution, 1 in northwestern Argentina and another in southern Argentina (i.e., Patagonia). Patagonian weasel distribution seems to be primarily related to cold areas with marked temperature seasonality and elevations below 2,000 m above sea level. From LGM to the present, we observed a major retraction in potential distribution areas that might indicate the existence of a vicariance process affecting Patagonian weasel distribution.
Rick Bruintjes, Andrew N. Radford, Context-dependent impacts of anthropogenic noise on individual and social behaviour in a cooperatively breeding fish, Animal Behaviour, Available online 17 April 2013, ISSN 0003-3472, 10.1016/j.anbehav.2013.03.025.
Anthropogenic (man-made) noise is a global problem and present in virtually all terrestrial and aquatic environments. To date, most studies investigating the potential impact of this pollutant have focused on individual behavioural responses and simply considered whether noise has an effect. However, most animals engage in social interactions, which may be vulnerable to the adverse effects of noise, and work in other fields suggests that individuals might react differentially to comparable noise stimuli depending on their own characteristics and the current situation. We used controlled experiments and standardized tests to investigate the impacts of playback of the noise of a passing boat, a dominant acoustic stressor in the aquatic environment, on nest-digging behaviour, antipredator defence and social interactions in small groups of Neolamprologus pulcher, a territorial and cooperatively breeding cichlid fish. Our results show that, in comparison to ambient noise, playback of boat noise: (1) reduced digging behaviour, which is vital to maintain hiding and breeding shelters; (2) decreased defence against predators of eggs and fry, with direct consequences for fitness; and (3) increased the amount of aggression received and submission shown by subordinates. Moreover, the context (presence or absence of eggs) affected individual and social behaviours in response to the same noise source. Our results demonstrate the need to consider whole behavioural repertoires for a full understanding of the impact of anthropogenic noise, and indicate that the effects of this global pollutant are likely to be context dependent.
Lucy M. Aplin, Ben C. Sheldon, Julie Morand-Ferron, Milk bottles revisited: social learning and individual variation in the blue tit, Cyanistes caeruleus, Animal Behaviour, Available online 17 April 2013, ISSN 0003-3472, 10.1016/j.anbehav.2013.03.009.
Blue tits are famous for the ‘milk bottle’ innovation, which emerged at numerous sites across Britain in the early 20th century. However, overall we still know little about the factors that foster or hinder the spread of innovations, or of the impact of individual differences in behaviour on social transmission. We used a two-action and control experimental design to study the diffusion of innovation in groups of wild-caught blue tits, and found strong evidence that individuals can use social learning to acquire novel foraging skills. We then measured six individual characteristics, including innovative problem solving, to investigate potential correlates of individual social-learning tendency. Consistent with a hypothesis of common mechanisms underlying both processes, we found evidence for a relationship between social learning and innovativeness. In addition, we observed significant age- and sex-biased social learning, with juvenile females twice as likely to acquire the novel skill as other birds. Social learning was also more likely in subordinate males than dominant males. Our results identify individual variation and transmission biases that have potential implications for the diffusion of innovations in natural populations.
Maria José Hurtado, Renée Fénéron, Patrick Gouat, Specialization in building tasks in the mound-building mouse, Mus spicilegus, Animal Behaviour, Available online 17 April 2013, ISSN 0003-3472, 10.1016/j.anbehav.2013.03.020.
Specialization can be defined as when specific individuals perform a specific task for a relatively long period of time. The mound-building mouse is a suitable species to study specialization during a collective construction task, as juveniles build imposing mounds in which to overwinter. The process includes several successive phases involving the transport and piling up of different kinds of materials along with covering up the mound with dirt and digging galleries. Laboratory studies revealed that within a group of six individuals, two individuals transported most of the material provided for building. We tested whether this behavioural differentiation corresponded to a real specialization. Mice were given two different transport tasks corresponding to different phases of the building process. Experimental groups received two different building materials in two consecutive periods while control groups received the same building material for both periods. As predicted, in experimental groups, carriers of one material were not the same individuals as the carriers of the second material. This shift in the identity of the carrier according to the material we provided indicates a specialization for a different transport task. By contrast, in control groups, mice tended to keep their carrier status during the two periods. We concluded that, at least under controlled laboratory conditions, a task-related specialization occurred during the collective construction of the mound. This specialization could be explained as part of a division of labour in the mound-building mouse.
Jin-Quan Yang, Wen-Qiao Tang, Yang Sun, Kun-Chan Tsai, Zhuo-Cheng Zhou, Zhi-Zhi Liu, Dong Liu, Hung-Du Lin, Microsatellite diversity and population genetic structure of Squalidus argentatus (Cyprinidae) on the Island of Hainan and mainland China, Biochemical Systematics and Ecology, Volume 50, October 2013, Pages 7-15, ISSN 0305-1978, 10.1016/j.bse.2013.03.023.
Squalidus argentatus is a small-sized cyprinid fish and widely distributed in mainland China. A total of nine polymorphic microsatellite markers were employed to study 216 individuals collected from nine populations. The average number of alleles among nine populations was 8.0 with a range from 6.5 to 9.7. The mean observed (HO) and expected (HE) heterozygosity ranged from 0.56 to 0.68 and from 0.74 to 0.86, respectively. The analysis of molecular variance (AMOVA) showed that most genetic variation was maintained within individual component, rather than shaped according to geographical regions. Small but highly significant values of pairwise FST values were detected among nine populations. The genetic homoplasy and overfishing are supposed to be major factors responsible for the current genetic structure. This study can be not only helpful for sustainable management of genetic resources, but also valuable to demonstrate genetically how freshwater species is vulnerable to human activity.
Chris T. Amemiya, Jessica Alföldi, Alison P. Lee, Shaohua Fan et al.
The African coelacanth genome provides insights into tetrapod evolution
Nature Volume: 496, Pages: 311–316, (18 April 2013), doi:10.1038/nature12027
The discovery of a living coelacanth specimen in 1938 was remarkable, as this lineage of lobe-finned fish was thought to have become extinct 70 million years ago. The modern coelacanth looks remarkably similar to many of its ancient relatives, and its evolutionary proximity to our own fish ancestors provides a glimpse of the fish that first walked on land. Here we report the genome sequence of the African coelacanth, Latimeria chalumnae. Through a phylogenomic analysis, we conclude that the lungfish, and not the coelacanth, is the closest living relative of tetrapods. Coelacanth protein-coding genes are significantly more slowly evolving than those of tetrapods, unlike other genomic features. Analyses of changes in genes and regulatory elements during the vertebrate adaptation to land highlight genes involved in immunity, nitrogen excretion and the development of fins, tail, ear, eye, brain and olfaction. Functional assays of enhancers involved in the fin-to-limb transition and in the emergence of extra-embryonic tissues show the importance of the coelacanth genome as a blueprint for understanding tetrapod evolution.
Zootaxa 3640 (4): 501–520 (19 Apr. 2013)
Amietia angolensis and A. fuscigula (Anura: Pyxicephalidae) in southern Africa: A cold case reheated
ALAN CHANNING & NINDA BAPTISTA
A study combining DNA sequences of the mitochondrial 16S rRNA gene, advertisement calls and morphology of some southern African river frogs confirms Amietia vandijki (Visser & Channing, 1997) as a good species. The form presently referred to as Amietia angolensis in southern Africa is shown to comprise two species: Amietia angolensis
(Bocage, 1866) known from Angola, and Amietia quecketti (Boulenger, 1895) known from South Africa, Zimbabwe and Lesotho. Junior synonyms of A. quecketti include Rana theileri Mocquard, 1906 and Afrana dracomontana Channing, 1978. The form presently known as Amietia fuscigula is shown to consist of two distantly related taxa:
Amietia fuscigula (Duméril & Bibron, 1841) from the south-western Cape and an undescribed species that we here name Amietia poyntoni sp. nov. Channing & Baptista, known from the rest of South Africa and Namibia. These five species have large differences in 16S sequences, as well as differences in morphology and advertisement call. Call and molecular data are both diagnostic, while morphology shows some overlap between taxa. An extended study of the genus across Africa is in preparation.
Zootaxa 3640 (4): 521–549 (19 Apr. 2013)
Revision of the genus Leopoldamys (Rodentia, Muridae) as inferred from morphological and molecular data, with a special emphasis on the species composition in continental Indochina
A.E. BALAKIREV, A.V. ABRAMOV & V.V. ROZHNOV
A revision of the genus Leopoldamys is presented, and both the species composition and distribution in Indochina and Sundaic regions is reinvestigated. The phylogeny of the genus is recovered based on Cyt b, COI, and IRBP gene analyses. Five basal and 16 secondary monophyletic phylogenetic lineages were identified. A taxonomic reassessment of the continental and Sundaic populations is performed based on morphological verification of the genetically defined clades. Six clades were recovered in the phylogenetic analyses and correspond to morphologically defined species: L. revertens (distributed in lowlands of eastern and central Indochina), L. herberti (western and central Indochina, northward to northern Vietnam), L. edwardsi (China and northern Vietnam, northward of 21°N), L. milleti (endemic of Dalat Plateau, southern
Vietnam), L. sabanus (Borneo), and L. vociferans (lowlands of the Malacca Peninsula, northward to southwestern Thailand). The absence of proper L. sabanus in continental Indochina is revealed. The substitute name for the species known from the majority of Indochina under the name of L. sabanus should be L. revertens. The name L. neilli, which has been ascribed to populations from Thailand and Vietnam, is a junior synonym of L. herberti. Two related but rather divergent clades are found in Sumatra and the Malacca Peninsula. Based on their considerable genetic distances, these forms should be regarded as separate species from the L. sabanus type-bearing populations of Borneo, or as the members of L. sabanus polytypic superspecies. The substitute name for the lineage-bearing taxon from Malacca should be L. vociferans. The continental
populations of Leopoldamys can be distinguished from each other by external and cranial characters and may be subdivided into four species. Two of these species (L. revertens and L. milleti) are well distinguished by external and cranial morphology, whereas the other two species (L. herberti and L. edwardsi) may be treated as sibling species that are difficult to distinguish based on morphological characters.
Zootaxa 3640 (4): 557–571 (19 Apr. 2013)
Description of Loraxichthys lexa, new genus and species (Siluriformes: Loricariidae) from the Río Huallaga Basin, central Peru, with notes on the morphology of the enigmatic Lipopterichthys carrioni Norman, 1935
NORMA J. SALCEDO
A new genus and species of armored catfish, Loraxichthys lexa, collected in 1955 by the Catherwood Foundation Peruvian-Amazon Expedition from the vicinity of Tingo María, Huánuco, is described herein. Loraxichthys is diagnosed by two uniquely derived characters: two to four robust evertible posterior cheek odontodes with hooked tips, longer than odontodes anterior to them but no more than twice their length; and skin folds on dorsal border along first pelvic-fin ray crenulated in mature males. Loraxichthys lexa, new species, is only known from clear water tributaries of the Río Huallaga in the vicinity of Tingo María. Additionally, notes on the morphology of the enigmatic species Lipopterichthys carrioni are
included, and an artificial key for the genera Chaetostoma, Cordylancistrus, Dolichancistrus, Leptoancistrus, Lipopterichthys,
and Loraxichthys is provided.
Effectiveness of the Natura 2000 network to cover threatened species
Audrey Trochet, Dirk S. Schmeller
Nature Conservation 4 (2013): 35-53
Date published: 18.04.2013
The world‘s biodiversity is currently in rapid decline – Europe being no exception – with as principal cause a human-mediated global change. The Natura 2000 network is an important conservation tool for European biodiversity; it is a network of natural and semi-natural sites within Europe with high heritage values due to the exceptional flora and fauna they contain. Here, we evaluated the coverage of 300 threatened species by the Natura 2000 network, and determined potential factors influencing the designation of sites and the structure of the network within a country (social, ecological and demographic national factors). Our analysis was based on a coverage ratio between the Natura 2000 sites and distribution maps of threatened European species. We showed that the distributions of a large proportion of threatened species of mammals, birds and reptiles considered in our study were highly covered (above 90%) by the current Natura 2000 network, demonstrating that the Natura 2000 network also covers species not listed in the annexes of the Nature Directives. However, our results confirm that a large proportion of threatened species (some of them listed on the European annexes), especially fishes, are currently poorly covered by the Natura 2000 network. The coverage of species likely seemed to be highly related to national demographic factors, i.e. the proportion of the national urban population. Our analysis also suggested that the designation of sites depends too strongly on governmental politics, economic and cultural criteria, and interactions between society and the environment. A more effective process might be necessary to ensure the Natura 2000 network reaches its potential as the most important and comprehensive network of protected areas intended to halt the loss of biodiversity in Europe in the near future.
Kelley, M.C.; Garstang, M. On the Possible Detection of Lightning Storms by Elephants. Animals 2013, 3, 349-355.
Theoretical calculations suggest that sounds produced by thunderstorms and detected by a system similar to the International Monitoring System (IMS) for the detection of nuclear explosions at distances ≥100 km, are at sound pressure levels equal to or greater than 6 × 10−3 Pa. Such sound pressure levels are well within the range of elephant hearing. Frequencies carrying these sounds might allow for interaural time delays such that adult elephants could not only hear but could also locate the source of these sounds. Determining whether it is possible for elephants to hear and locate thunderstorms contributes to the question of whether elephant movements are triggered or influenced by these abiotic sounds.
Estimating the rate of increase for the finless porpoise with special attention to predictions for the Inland Sea population in Japan
Midori Hashimoto, Kunio Shirakihara, Miki Shirakihara, Kazuhiko Hiramatsu
Population Ecology, April 2013
The finless porpoise Neophocaena asiaeorientalis inhabits coastal waters and rivers in East Asia and is exposed to various human activities. This species is listed on the IUCN Red List of Threatened Species due to a reduction in abundance. Although human-induced mortality can be a threat to porpoise populations, future anthropogenic impacts have not been quantitatively evaluated due to lack of demographic information. Adequate future population projections are needed to form the basis for conservation measures before the population declines to critical levels. We conducted a population viability analysis for the population of finless porpoise in the Inland Sea, Japan using a Leslie matrix model composed of age-specific survival and fertility rates. We described the uncertainty in the annual rate of increase (λ) for the finless porpoise using randomly sampled estimates of survival rate for other cetaceans with similar life histories. Plausible median estimates of λ ranged from 1.041 (age at first reproduction [AFR] = 7) to 1.056 (AFR = 5). Future population changes and extinction probabilities were predicted after combining these estimates with a predicted human-induced mortality rate (M) and available abundance estimates. The extinction probability after 100 years was 0 %. However, the probability of the quasi-extinction (<100 individuals) was as high as 79.0 % after 100 years. The results also suggest that the persistence of the finless porpoise population could be achieved with a small effort to reduce anthropogenic mortality.