Arthur D. Middleton, Thomas A. Morrison, Jennifer K. Fortin, Charles T. Robbins, Kelly M. Proffitt, P. J. White, Douglas E. McWhirter, Todd M. Koel, Douglas G. Brimeyer, W. Sue Fairbanks, and Matthew J. Kauffman
Grizzly bear predation links the loss of native trout to the demography of migratory elk in Yellowstone
Proc. R. Soc. B July 7, 2013 280 1762 20130870; doi:10.1098/rspb.2013.0870 1471-2954
The loss of aquatic subsidies such as spawning salmonids is known to threaten a number of terrestrial predators, but the effects on alternative prey species are poorly understood. At the heart of the Greater Yellowstone ecosystem, an invasion of lake trout has driven a dramatic decline of native cutthroat trout that migrate up the shallow tributaries of Yellowstone Lake to spawn each spring. We explore whether this decline has amplified the effect of a generalist consumer, the grizzly bear, on populations of migratory elk that summer inside Yellowstone National Park (YNP). Recent studies of bear diets and elk populations indicate that the decline in cutthroat trout has contributed to increased predation by grizzly bears on the calves of migratory elk. Additionally, a demographic model that incorporates the increase in predation suggests that the magnitude of this diet shift has been sufficient to reduce elk calf recruitment (4–16%) and population growth (2–11%). The disruption of this aquatic–terrestrial linkage could permanently alter native species interactions in YNP. Although many recent ecological changes in YNP have been attributed to the recovery of large carnivores—particularly wolves—our work highlights a growing role of human impacts on the foraging behaviour of grizzly bears.
Kristina M. Ramstad, Rogan M. Colbourne, Hugh A. Robertson, Fred W. Allendorf, and Charles H. Daugherty
Genetic consequences of a century of protection: serial founder events and survival of the little spotted kiwi (Apteryx owenii)
Proc. R. Soc. B July 7, 2013 280 1762 20130576; doi:10.1098/rspb.2013.0576 1471-2954
We present the outcome of a century of post-bottleneck isolation of a long-lived species, the little spotted kiwi (Apteryx owenii, LSK) and demonstrate that profound genetic consequences can result from protecting few individuals in isolation. LSK were saved from extinction by translocation of five birds from South Island, New Zealand to Kapiti Island 100 years ago. The Kapiti population now numbers some 1200 birds and provides founders for new populations. We used 15 microsatellite loci to compare genetic variation among Kapiti LSK and the populations of Red Mercury, Tiritiri Matangi and Long Islands that were founded with birds from Kapiti. Two LSK native to D’Urville Island were also placed on Long Island. We found extremely low genetic variation and signatures of acute and recent genetic bottleneck effects in all four populations, indicating that LSK have survived multiple genetic bottlenecks. The Long Island population appears to have arisen from a single mating pair from Kapiti, suggesting there is no genetic contribution from D’Urville birds among extant LSK. The Ne/NC ratio of Kapiti Island LSK (0.03) is exceptionally low for terrestrial vertebrates and suggests that genetic diversity might still be eroding in this population, despite its large census size.
Samrat Mondol, Michael W. Bruford, and Uma Ramakrishnan
Demographic loss, genetic structure and the conservation implications for Indian tigers
Proc. R. Soc. B July 7, 2013 280 1762 20130496; doi:10.1098/rspb.2013.0496 1471-2954
India is home to approximately 60 per cent of the world’s remaining wild tigers, a species that has declined in the last few centuries to occupy less than 7 per cent of its former geographical range. While Indian tiger numbers have somewhat stabilized in recent years, they remain low and populations are highly fragmented. Therefore, the application of evidence-based demographic and genetic management to enhance the remaining populations is a priority. In this context, and using genetic data from historical and modern tigers, we investigated anthropogenic impacts on genetic variation in Indian tigers using mitochondrial and nuclear genetic markers. We found a very high number of historical mitochondrial DNA variants, 93 per cent of which are not detected in modern populations. Population differentiation was higher in modern tigers. Simulations incorporating historical data support population decline, and suggest high population structure in extant populations. Decreased connectivity and habitat loss as a result of ongoing fragmentation in the Indian subcontinent has therefore resulted in a loss of genetic variants and increased genetic differentiation among tiger populations. These results highlight that anthropogenic fragmentation and species-specific demographic processes can interact to alter the partitioning of genetic variation over very short time scales. We conclude that ongoing strategies to maximize the size of some tiger populations, at the expense of losing others, is an inadequate conservation strategy, as it could result in a loss of genetic diversity that may be of adaptive significance for this emblematic species.
Understanding morphological variation in the extant koala as a framework for identification of species boundaries in extinct koalas (Phascolarctidae; Marsupialia)
Karen H. Black, Julien Louys, Gilbert J. Price
Journal of Systematic Palaeontology
We document morphological variation (both geographical and sexual) in the dentition of the extant koala, Phascolarctos cinereus, in order to facilitate discrimination of species boundaries in extinct phascolarctids. Considerable variation is evident in dental structures previously used to diagnose several phascolarctid fossil species. Consistent patterns of morphological variation are not evident between sexes or geographic regions, with variation as great between samples as within them. Metric variation is evident between the sexes in upper molar dimensions with Victorian (southern) males significantly larger than Victorian females, although this is not reflected in lower molar dimensions or in the Queensland (northern) sample. Male koalas from southern populations generally display significantly larger molars than their northern counterparts; however this trend is not evident in female upper molar dimensions. In both males and females, some, but not all, lower molar dimensions are larger in southern populations than northern. In light of these results, a systematic revision of species of Litokoala suggests L. ‘dicktedfordi’ is a junior synonym of L. kutjamarpensis, and the poorly known L. thurmerae is regarded to be a nomen dubium. Further, we describe a partial cranium of a new species of koala from Early Miocene sediments in the Riversleigh World Heritage Area, northern Australia. Litokoala dicksmithi sp. nov. is the fifth koala species recorded from the diverse rainforest assemblages of Riversleigh and the third species referred to the Oligo-Miocene genus Litokoala. Aspects of cranial morphology, including a shortened robust rostrum and broad, irregular nasal aperture, confirm placement of Litokoala as sister taxon to the modern genus Phascolarctos. Relatively large orbits and small body size suggest the possibility that L. dicksmithi was nocturnal, had enhanced visual acuity, and was a more agile arboreal species than the relatively sedentary extant koala.
Peng Ding, Ming Ma, Kedeerhan Bayaheng, Rui Xing, Tong Zhang, Xu-mao Zhao, Ya-hui Huang, Golden eagle Aquila chrysaetos in Xinjiang: Nest-site selection in different reproductive areas, Acta Ecologica Sinica, Volume 33, Issue 3, June 2013, Pages 139-144, ISSN 1872-2032, 10.1016/j.chnaes.2013.03.003.
The reports about the geographical distribution, reproductive ecology and population dynamics of the golden eagle Aquila chrysaetos were mostly descriptive in China, and lack quantified studies for the nest-site selection of this species. We carried out our investigations by direct observations in the northern Xinjiang during 2004–2011, attempting to reveal the main factors that affected on the nest-site selection and the differences of ecological variables of reproductive areas in the species (Mts. Tian Shan spurs and Mt. Kalamaili). We measured 38 nests totally belonging to the 16 home ranges. The average number of nests in each home range was 2.38±0.41, and with no significant difference between different reproductive areas. In all cases golden eagles nested on cliffs (n =38) in our study area. The average external diameter of nests was (198.4±8.2) cm × (159.3±14.2) cm (Mean±SE, n =9), and inner diameter was (91.1±4.4) cm. The nest-site selection was extremely significant difference for the different reproductive areas, i.e. elevation, hill height, nest-site height, cliff height, gradient, the distance to water resource, and the distance to residential area. The distance from the cliff bottom and from the cliff top were significant difference. However, the slope position, nest position, distance to unpaved and paved road were not significant difference. In Mts. Tian Shan spurs, the elevation was obviously selective (χ2 =13.99, df =4, P <0.01), and mainly nested in altitude of 1 932–2 197m, where the main aspects were SW (36.4%, n =22) or SE (31.8%), and the slope gradient was above 85°. In Mt. Kalamaili, also it was found the significant differences for elevations (χ2 =11.44, df =3, P <0.01), the eagle mainly nested in altitude of 1 112–1 423m, with aspects of NW (68.8%, n =16), and the gradient was relatively flat. In reproductive areas, eagles nested in the mid-slope parts and higher slope position (92.1%, n =38). Eagles nested far from the seriously disturbed places by human, especially roads, residential area, mineral mines, etc. The principal component method of the factor analysis indicated that there were four main factors affecting on the nest-site selection by golden eagle in Mts. Tian Shan spurs: human disturbance factor (eigenvalue is 4.800, Ratio of contribution is 34.28%), nest position factor (3.002%, 21.44%), prey factor (2.601%, 18.58%), and terrain factor (1.305%, 9.32%). In Mt. Kalamaili, there are five main factors as following: terrain factor (eigenvalue is 5.110, Ratio of contribution is 34.07%), nest position factor (3.747%, 24.98%), human disturbance factor (2.123%, 14.16%), prey factor (1.584%, 10.56%), and gradient factor (1.111%, 7.41%). To conclude, human disturbance and landscape are the two main factors affecting on the nest-site selection of the eagle. The nest-site selection is a result of trade-off among the human disturbance, landscape and prey amount. Eagles take corresponding strategy of nest-site selection for adaptation to the various environments, having different conditions for the eagle reproductive. So, we recommended the improvement of the habitat fitness for the increasing of the reproductive success of the golden eagle.
Liang Cao, Xu-Fang Liang, Wenqiao Tang, Jun Zhao, Phylogeography of Coreoperca whiteheadi (Perciformes: Coreoperca) in China based on mitochondrial and nuclear gene sequences, Biochemical Systematics and Ecology, Volume 50, October 2013, Pages 223-231, ISSN 0305-1978, 10.1016/j.bse.2013.04.007.
The phylogeography of Coreoperca whiteheadi was studied using sequences from the mitochondrial cytochrome b (cytb) gene and first intron of the S7 ribosomal protein gene. The reciprocal monophyly mitochondrial cytb and nuclear sequences strongly suggest that C. whiteheadi has significantly reduced gene flow between populations and may be in the process of speciation. Phylogenetic analysis revealed phylogeographical structuring into two major clades (highly supported by bootstrap analysis) corresponding to the two regions divided by Nanling-Wuyi Mountain Range. Subsequent nested clade analysis confirmed this structure. The results suggest that Nanling-Wuyi Mountain Range represents a major phylogeographic barrier for C. whiteheadi. Six evolutionarily significant units of C. whiteheadi were designated from the genetic analysis for conservation and management.
Hanwei Zhang, Guoping Yu, Qian Chen, Zheng Wang, Longhui Lin, The effects of ambient temperature and thermoregulation on locomotor performance of newborn Guide toad-headed lizards (Phrynocephalus putjatia), Acta Ecologica Sinica, Volume 33, Issue 3, June 2013, Pages 127-131, ISSN 1872-2032, 10.1016/j.chnaes.2013.03.001.
The effect of thermal environments during embryonic development as a proximate source of variation in the fitness of offspring has been examined in a wide variety of taxa, and reptiles have been proved to be excellent mode systems for research in this field. Here, we describe a study revealing the effects of ambient temperature and thermoregulation on locomotor performance of newborn ovoviviparous lizards. A 2 (background temperatures set at 18°C or 22°C)×2 (allowing thermoregulation for 14h or 10h daily) factorial design experiment was carried out to examine the effects of ambient temperature and thermoregulation on the locomotor performance of newborn Guide toad-headed lizards (Phrynocephalus putjatia; Agamidae). Gravid females were collected in May 2010 from a population in Guide, Qinghai, northwestern China, and were transported to our laboratory in Hangzhou. Ten to fifteen females were housed together in 1200mm×600mm×700mm (length×width×height) communal cages, which were placed in AAPS (artificial atmospheric phenomena simulator) rooms, and contained a substrate of sand (∼400mm depth), with rocks and pieces of clay tiles provided as shelter and basking sites. One light bulb (200W) was suspended above one end of the cage to create a thermal gradient ranging from room temperature to 60°C for 14h or 10h daily, and overnight temperatures followed AAPS temperatures (18°C or 22°C). Food (mealworms and house crickets) dusted with multivitamins and minerals and water were provided daily. Cages were checked twice daily for neonates after the first female gave birth, and neonates were immediately collected and weighed after birth. Twenty neonates from single litters of each testament were measured at birth for locomotor performance. All running trials were conducted at a body temperature of 30°C, which was achieved by placing the newborns in an incubator at 30°C for 30min prior to testing. Locomotor performance was assessed by chasing the neonates along a 2-m-long racetrack, which was placed in a room at constant 30°C, with one side of the racetrack transparent, allowing videoing with a Panasonic NV-DS77 digital video camera. The tapes were later examined with a computer using MGI VideoWave III software for PC (MGI Software Co., Toronto, Canada) for sprint speed in the fastest 250-mm interval and the maximal length. Each individual was measured five times after birth, at 15-day intervals, until 60days. We found that locomotor performance of neonates was affected by thermoregulating opportunity, but not by background temperature. Neonates produced by females thermoregulated for 14h daily performed better (both sprint speed and the maximal length) in the racetrack than those produced by females thermoregulated for 10h daily. However, the interaction between background temperature and thermoregulatingopportunity was not a significant source of variation in locomotor performance. Moreover, sprint speed was positively correlated to the maximal length in newborn P. putjatia. In summary, locomotor performance is a highly fitness-related trait, and this study implies that viviparity allows female P. putjatia to provide optimal temperatures for embryo development through thermoregulation, thereby producing well-performed offspring.
Ramūnas Žydelis, Cleo Small, Gemma French, The incidental catch of seabirds in gillnet fisheries: A global review, Biological Conservation, Volume 162, June 2013, Pages 76-88, ISSN 0006-3207, 10.1016/j.biocon.2013.04.002.
Based on bird feeding ecology we identified 148 seabird species as susceptible to bycatch in gillnets, of which 81 have been recorded caught. The highest densities of susceptible species occur in temperate and sub-polar regions of both hemispheres, with lower densities in tropical regions. Gillnet fisheries are widespread and particularly prevalent in coastal areas. A review of reported bycatch estimates suggests that at least 400,000 birds die in gillnets each year. The highest bycatch has been reported in the Northwest Pacific, Iceland and the Baltic Sea. Species suffering potentially significant impacts of gillnet mortality include common guillemot (Uria aalge), thick-billed guillemot (Uria lomvia), red-throated loon (Gavia stellata), Humboldt penguin (Spheniscus humboldti), Magellanic penguin (Spheniscus magellanicus), yellow-eyed penguin (Megadyptes antipodes), little penguin (Eudyptula minor), greater scaup (Aythya marila) and long-tailed duck (Clangula hyemalis). Although reports of seabird bycatch in gillnets are relatively numerous, the magnitude of this phenomenon is poorly known for all regions. Further, population modelling to assess effects of gillnet bycatch mortality on seabird populations has rarely been feasible and there is a need for further data to advance development of bycatch mitigation measures.
Matthew Linkie, Gurutzeta Guillera-Arroita, Joseph Smith, Anton Ario, Gregoire Bertagnolio, Francis Cheong, Gopalasamy Reuben Clements, Yoan Dinata, Somphot Duangchantrasiri, Gabriella Fredriksson, Melvin T. Gumal, Liang Song Horng, Kae Kawanishi, Faesal Rakhman Khakim, Margaret F. Kinnaird, Dedy Kiswayadi, Abu H. Lubis, Antony J. Lynam, Maryati, Myint Maung, Dusit Ngoprasert, Wilson Novarino, Timothy G. O’Brien, Karmila Parakkasi, Helga Peters, Dolly Priatna, D.Mark Rayan, Naret Seuaturien, Nay Myo Shwe, Robert Steinmetz, Arif M. Sugesti, Sunarto, Melvin E. Sunquist, Mayuree Umponjan, Hariyo T. Wibisono, Christopher C.T. Wong, Zulfahmi, Cryptic mammals caught on camera: Assessing the utility of range wide camera trap data for conserving the endangered Asian tapir, Biological Conservation, Volume 162, June 2013, Pages 107-115, ISSN 0006-3207, 10.1016/j.biocon.2013.03.028.
The loss and fragmentation of substantial areas of forest habitat, in combination with rampant hunting, has pushed many of Southeast Asia’s megafauna species to the verge of extinction. However, the extent of these declines is rarely quantified, thereby weakening lessons learned and species-based management. This need not be the case as a proliferation of camera trap surveys for large-bodied mammals across Southeast Asia, which use a standardized sampling technique, presents a rich yet under-utilized wildlife data set. Furthermore, advances in statistical techniques for assessing species distribution provide new opportunities for conducting comparative regional analyses. Here, we focus on one of Southeast Asia’s least known species of megafauna, the Endangered Asian tapir (Tapirus indicus), to investigate the performance of a camera trap-based spatial modeling approach in conducting a range-wide species assessment. Detection data were collectively collated from 52,904 trap days and 1,128 camera traps located across 19 study areas drawn from the Asian tapir’s entire range. Considerable variation in tapir occurrence was found between study areas in: Malaysia (0.52–0.77); Sumatra, Indonesia (0.12–0.90); Thailand (0.00–0.65); and, Myanmar (0.00–0.26), with generally good levels of estimate precision. Although tapirs were widespread (recorded in 17 of the 19 study areas), their occurrence was significantly and negatively correlated with human disturbance. Thus, this study extends the previously known applicability of camera traps to include a threatened and cryptic species by identifying where and how tapirs persist (including new records of occurrence), where future surveys should be conducted and providing a benchmark for measuring future conservation management efforts.
Sally Macdonald, Oliver Schülke, Julia Ostner
The Absence of Grooming for Rank-Related Benefits in Female Assamese Macaques (Macaca assamensis)
International Journal of Primatology, May 2013
Seyfarth’s model of social grooming proposes that by grooming females higher ranking than themselves, females can gain access to important rank-related benefits, such as agonistic support. This, in turn, produces a distinctive pattern of grooming in which females direct their grooming up the female dominance hierarchy and compete for access to the highest ranking individuals. We aimed to test to what extent the grooming behavior of female Assamese macaques (Macaca assamensis) fits the assumptions and predictions of Seyfarth’s model. During two 1-yr sampling periods (October 2007–September 2008, May 2010–April 2011) we collected >2100 focal hours of data from a single wild group in their natural habitat at Phu Khieo Wildlife Sanctuary, Thailand. Subjects included all adult female group members (N = 12 in 2007/8; N = 15 in 2010/11). We collected detailed data on grooming interactions, approaches, and departures as well as all aggressive and submissive behaviors between all subjects. We found no evidence that grooming was exchanged for rank-related benefits. In line with this we found no evidence that the grooming of female Assamese macaques fits the pattern predicted by Seyfarth’s model. These results are surprising given that such deviations from Seyfarth’s model are relatively rare among macaques. We propose that our findings are best explained as a lack of a need for rank-related benefits by females in this group.
WOODFORD, J. E., MACFARLAND, D. M. and WORLAND, M. (2013), Movement, survival, and home range size of translocated american martens (Martes americana) in wisconsin. Wildlife Society Bulletin. doi: 10.1002/wsb.291
We translocated and released a total of 90 (55 F and 35 M) wild American martens (Martes americana) from Minnesota to northern Wisconsin, USA, during 2008–2010. Our objective was to evaluate the short-term results of this translocation project by comparing marten dispersal, time to residency, and survival by release method, sex, and age categories. On average, translocated martens took 18 days (range = 1–64 days) and traveled 4.6 km (range = 0.4–45.7 km) from release sites before establishing residency. Although survival probabilities for adults and males were 0.84 and 0.79 and juveniles and females were 0.66 and 0.71, respectively, they were not statistically different. Translocated adult and juvenile survival was similar to resident adult and juvenile survival reported in Wisconsin and elsewhere. Predation (primarily by other carnivores) was the main cause (85%) of observed mortality for translocated animals, but it did not appear to be a major limiting factor for adults or juveniles. Contrary to some studies, we found no significant difference between release methods for any analyzed parameter, but we observed increased injuries to slow-released individuals. We concluded there was no benefit resulting from slow-release or an acclimation period for translocation of American martens and that long-term monitoring of the population is needed to evaluate species recovery in Wisconsin.