Ronald E. Thresher, Keith Hayes, Nicholas J. Bax, John Teem, Tillmann J. Benfey, Fred Gould
Genetic control of invasive fish: technological options and its role in integrated pest management
Biological Invasions, April 2013
Genetic options for the control of invasive fishes were recently reviewed and synthesized at a 2010 international symposium, held in Minneapolis/St. Paul, MN, USA. The only option currently available “off-the-shelf” is triploidy, which can be used to produce sterile males for a release program analogous to those widely and successfully used for biological control of insect pests. However, the Trojan Y and several recombinant options that heritably distort pest population sex ratios are technologically feasible, are at or are close to proof-of-concept stage and are potentially much more effective than sterile male release programs. All genetic options at this stage require prolonged stocking programs to be effective, though gene drive systems are a potential for recombinant approaches. They are also likely to differ in their current degree of social acceptability, with chromosomal approaches (triploidy and Trojan Y) likely to be the most readily acceptable to the public and least likely to require changes in legislative or policy settings to be implemented. Modelling also suggests that the efficacy of any of these genetic techniques is enhanced by, and in turn non-additively enhance, conventional methods of pest fish control.
Antonio Vilches, Juan Arizaga, Ixai Salvo, Rafael Miranda, An experimental evaluation of the influence of water depth and bottom color on the Common kingfisher’s foraging performance, Behavioural Processes, Available online 24 April 2013, ISSN 0376-6357, 10.1016/j.beproc.2013.04.012.
To investigate how depth and bottom color affect prey selectivity in Common kingfisher (Alcedo atthis), we developed several experimental procedures using captive birds. We used 20 young kingfishers to test depth (25 or 50 cm) and color (natural gravel or white) effects on foraging behavior. Live freshwater fish were used as target prey. To assess differences resulting from the natural behavior of different fish, we chose bottom-dwelling [Ebro barbel (Barbus graellsii)] and open-water benthopelagic species [Ebro nase (Parachondrostoma miegii) and Pyrenean minnow (Phoxinus bigerri)]. The number of attempts and captures, as well as the effects of hunger and experience, were assessed relative to feeding behavior. The effect of fish behavior, as observed in grouped vs. isolated fish, on the kingfisher’s performance was also tested. The results showed a significant effect of depth, with more attacks and greater success in shallow waters. No significant differences in catch success between natural- and white-colored bottoms were observed. Hunger had no effect on fishing success, but experience had a positive effect in shallow waters and on white bottoms. Both bottom- and open-water species were consumed equally. Kingfishers preyed more often upon grouped prey than upon isolated prey, although capture success did not vary between the two cases. Our results suggest that kingfishers prey upon the most accessible types of prey.
Allan D. McDevitt, Ruth F. Carden, Ilaria Coscia, Alain C. Frantz
European Journal of Wildlife Research, April 2013
Are wild boars roaming Ireland once more?
Wild boars (Sus scrofa) have been increasingly sighted in the wild in Ireland during the last few years, likely due to illegal releases and/or escapees. The species has since been designated an invasive species in Ireland, which is seen as controversial by some because of uncertainties about the historic status of the species in Ireland. However, just as pertinent to the argument is the genetic purity of these individuals currently found in Ireland: are these pure wild boars? We carried out a genetic assessment of 15 wild boars shot in Ireland between 2009 and 2012 using 14 microsatellites and mitochondrial DNA (mtDNA). These were compared to European wild boar, domestic pig breeds and a hybrid population of ‘wild boar’ from England. Microsatellite analysis revealed that almost all the Irish individuals belonged to the ‘domestic pig’ genetic cluster, with only three individuals being classified as hybrids. All but two individuals carried Asian mtDNA haplotypes, indicating a domestic pig origin. It is clear from this study that the individuals currently found in Ireland are not pure wild boars and this result has to be factored into any management/eradication plans.
Eisert, R., Potter, C. W. and Oftedal, O. T. (2013), Brain size in neonatal and adult Weddell seals: Costs and consequences of having a large brain. Marine Mammal Science. doi: 10.1111/mms.12033
Little is known about the ontogeny of brain size in pinnipeds despite potential functional implications of brain substrate (glucose, oxygen) requirements for diving, fasting, growth, and lactation strategies. We measured brain mass (brM) and cranial capacity (CC) in newborn and adult Weddell seals. Neonatal Weddell seals had brM that represented ~70% of adult brM. Weddell seals have the largest neonatal brain, proportional to adult brain, reported for any mammal to date, which is remarkable considering the relatively small size of Weddell seal pups at birth (6%–7% of maternal body mass) compared to neonates of other highly precocial mammals. Provision of sufficient glucose to maintain the large, well-developed brain of the neonatal Weddell seal has a nontrivial metabolic cost to both pup and mother. We therefore hypothesize that this phenomenon must have functional significance, such as allowing pups to acquire complex under-ice navigation skills during the period of maternal attendance.
Baker, J. D., Johanos, T. C., Wurth, T. A. and Littnan, C. L. (2013), Body growth in Hawaiian monk seals. Marine Mammal Science. doi: 10.1111/mms.12035
Body length and axillary girth measurements of more than 600 free-ranging Hawaiian monk seals from 1 to 20 yr old were analyzed. Comparison of fitted von Bertalanffy growth models confirmed there is no evidence of sexual dimorphism in this species. Substantial differences in growth patterns were detected among seven subpopulations representing the species entire geographic range. The age at which seals would be expected to attain a reference length of 180 cm ranged from just over 3 yr up to almost 7 yr at the various sites. Subpopulations exhibiting slower growth have previously been found to also exhibit lower age-specific reproductive rates. Differences in growth of seals among sites likely indicate varying environmental conditions determining growth during the time periods represented in the sampled data.
Zootaxa 3641 (4): 343–370 (26 Apr. 2013)
Trans-Andean Ancistrus (Siluriformes: Loricariidae)
DONALD C. TAPHORN, JONATHAN W. ARMBRUSTER, FRANCISCO VILLA-NAVARRO, C. KEITH RAY
We review the trans-Andean species of Ancistrus from Panama, Colombia and Venezuela. Based on analyses of meristic, morphometric and pigmentation pattern data of preserved specimens, eight of sixteen species reported from this region are considered valid and two new species are described. Here we review Ancistrus chagresi Eigenmann & Eigenmann 1889 from both slopes of central Panama; A. centrolepis Regan 1913 from Pacific slopes of eastern Panama and western Colombia; Ancistrus caucanus Fowler 1943, from the Magdalena River drainage in northern Colombia; Ancistrus martini
Schultz 1944, from the Lake Maracaibo Basin of Venezuela and Colombia. Ancistrus galani Pérez & Viloria 1994, from a cave in the Lake Maracaibo Basin of Venezuela is considered valid but was not examined. Ancistrus tolima new species is described from the upper Magdalena River drainage and Ancistrus vericaucanus new species is described from the upper Cauca River drainage. Ancistrus gymnorhynchus Kner 1854 and A. falconensis Taphorn, Armbruster & Rodriguez-O. 2010 were treated previously. One specimen of A. clementinae Rendahl 1937 from the Pacific coast of Ecuador was examined, it is considered a valid species. A key for identification and geographical ranges are provided.
Laura Williamson, Michael Hudson, Mark O’Connell, Nicholas Davidson, Richard Young, Tatsuya Amano, Tamás Székely
Areas of high diversity for the world’s inland-breeding waterbirds
Biodiversity and Conservation, April 2013
Waterbirds are a globally-distributed, species-rich group of birds that are critically dependent upon wetland habitats. They can be used as ecosystem sentinels for wetlands, which as well as providing ecosystem services and functions essential to humans, are important habitats for a wide range of plant and animal taxa. Here we carry out the first global analysis of inland-breeding waterbird distributions using data from 471 waterbird species in 28 families to identify global areas of high waterbird diversity. First we identify the primary area of high diversity for all inland-breeding waterbird species to be in Eastern Africa. For globally threatened inland-breeding waterbirds, the area of highest diversity is in Eastern China. Second, we show that the current network of protected areas provides poor coverage for threatened waterbirds in Eastern and Central Asia, and Northern India. In contrast, there is a higher protected area coverage in most of Europe and Brazil. Targeting the specific areas that have the highest numbers of species and the poorest coverage of protected areas is vital for both waterbird and wetland conservation.
Influence of predation risk on recruitment and litter intervals in common voles (Microtus arvalis)
M. Jochym, S. Halle
Canadian Journal of Zoology, Published on the web 11 March 2013, 10.1139/cjz-2012-0249
Research on mammals and birds has shown that predation may have indirect effects on prey reproduction. Some of the indirect effects may give prey an adaptive advantage. Females of several vole species respond to the presence of predators from the genus Mustela L., 1758 with suppressed breeding; this response increases females’ chances of survival. However, breeding suppression is observed only in a certain part of the female population; it is unclear whether predation risk affects the remaining females. We investigated this in a capture–mark–recapture experiment on reproductive effort of female common voles (Microtus arvalis (Pallas, 1778)) facing simulated presence of mustelid predators. We measured two parameters: the number of recruits per litter and the litter interval. Compared with control populations, the number of recruits per litter was not affected, but the litter interval was longer in females facing mustelid risk of predation. This indicates that predation risk affects females in a more complex way than originally proposed: it induces breeding suppression in some, but also influences litter frequency in others. Our result suggests that predatory stress deregulates the estrous cycle. Decreased frequency of litters can be a viable antipredatory adaptation in iteroparous organisms.
Trappett, A., Condon, C. H., White, C., Matthews, P., Wilson, R. S. (2013), Extravagant ornaments of male threadfin rainbowfish (Iriatherina werneri) are not costly for swimming. Functional Ecology. doi: 10.1111/1365-2435.12097
Exaggeration of male sexual ornaments should be costly, in terms of metabolic expenditure, resource allocation or even locomotor function. For example, many male ornaments are predicted to affect the aerodynamics, drag or biomechanics of movement and thus inhibit the speed or manoeuvrability of individuals; but empirical support for this is equivocal.We tested the locomotor and metabolic costs of exaggerated male ornaments in the threadfin rainbowfish (Iriatherina werneri), an Australasian native fish characterized by excessively long fin streamers. We predicted that males with greater relative ornamentation would have reduced escape abilities (i.e. burst swim speeds) as well as higher metabolic costs when resting or swimming. Furthermore, we evaluated the benefits of the signal by comparing the preference of females for males with differing amounts of ornamentation.As expected, we found that females spent more time observing (i.e. preferred) males with longer relative fins. We also experimentally reduced threadfin length and found that females continued to show preference for males with longer fins, rather than a preference for particular males.Male I. werneri with longer ornaments had higher resting metabolic rates, but we found no effect of ornament size on metabolic rates during swimming. Males with longer threadfins tended to swim faster, but our manipulation of fin length had no effect on burst swimming speed, indicating swimming abilities are not causally related to threadfin length.Overall, we found no evidence that the extravagant ornaments of male threadfin rainbowfish increase the metabolic or functional costs associated with swimming. Our results are surprising, given the high viscosity of water and the extreme length of I. werneri’s ornaments. We suggest that future work should focus on the fitness costs of threadfin length, relative to reproductive output or survival under more natural conditions.
An example of life history antecedence in the European badger (Meles meles): rapid development of juvenile antioxidant capacity, from plasma vitamin E analogue
K. Bilham, Y.W. Sin, C. Newman, C.D. Buesching, D.W. Macdonald
Ethology Ecology & Evolution
The way organisms cope with oxidative stress, to quench potentially toxic oxygen free radicals while maintaining oxygen species functionality, is crucial in shaping life-history traits. Antioxidant capacity plays an important role in this process. Here we use multi-model inference procedures to examine the age-class-dependent non-enzymatic antioxidant capacity of the European badger (Meles meles), testing non-enzymatic plasma antioxidant capacity and expressing the results as vitamin E analogue (VEA) equivalent units. Despite immaturity (ca 16 weeks old), cubs exhibited plasma antioxidant capacity equivalent to those of prime-age adults (1–5 years old). Compared to individuals aged 6 years and over, cubs exhibited significantly higher non-enzymatic plasma antioxidant capacity. There was no association between plasma antioxidant capacity and sex or other physiological variables, such as body condition or presence of wounding. We consider the adaptive significance of this life-history strategy with respect to pandemic endoparasitoses that affect badger cub survival, as well as a possible link to the free radical theory of ageing. Our finding on the interaction between age and antioxidant defences (linked to immune function) has implications for the controversy surrounding effective badger bovine tuberculosis management strategy in the UK.
Rohtla, M., Vetemaa, M., Taal, I., Svirgsden, R., Urtson, K., Saks, L., Verliin, A., Kesler, M. and Saat, T. (2013), Life history of anadromous burbot (Lota lota, Linneaus) in the brackish Baltic Sea inferred from otolith microchemistry. Ecology of Freshwater Fish. doi: 10.1111/eff.12057
Strontium to calcium (Sr:Ca) and barium to calcium (Ba:Ca) ratios were quantified in 74 otoliths of brackish water-living burbot Lota lota, collected from two regions in the eastern Baltic Sea. Considerable amount of life history plasticity was observed. Ninety-six per cent of analysed burbot were of freshwater origin; only three specimens displayed signs of hatching in low-salinity (1–2) estuarine environment. Most of the juveniles emigrated from freshwater during late winter and spring the next year after birth, while nine individuals did so at the age of 2–3 months. Age and length at maturity (as determined by first freshwater spawning migration) varied from 2–6 years and 189–540 mm, respectively, with most of burbot maturing during the second or third year of life. It is hypothesised that the bulk juvenile downstream migration is triggered by high-flow conditions as evidenced by Ba:Ca peak around the point of freshwater exit. This study provides new information on burbot life history.
Population Growth in a Wild Bird Is Buffered Against Phenological Mismatch
Thomas E. Reed, Vidar Grøtan, Stephanie Jenouvrier, Bernt-Erik Sæther, and Marcel E. Visser
Science 26 April 2013: 340 (6131), 488-491. [DOI:10.1126/science.1232870]
Broad-scale environmental changes are altering patterns of natural selection in the wild, but few empirical studies have quantified the demographic cost of sustained directional selection in response to these changes. We tested whether population growth in a wild bird is negatively affected by climate change–induced phenological mismatch, using almost four decades of individual-level life-history data from a great tit population. In this population, warmer springs have generated a mismatch between the annual breeding time and the seasonal food peak, intensifying directional selection for earlier laying dates. Interannual variation in population mismatch has not, however, affected population growth. We demonstrated a mechanism contributing to this uncoupling, whereby fitness losses associated with mismatch are counteracted by fitness gains due to relaxed competition. These findings imply that natural populations may be able to tolerate considerable maladaptation driven by shifting climatic conditions without undergoing immediate declines.
Zootaxa 3641 (5): 524–532 (29 Apr. 2013)
Epinephelus geoffroyi (Klunzinger, 1870) (Pisces: Serranidae), a valid species of grouper endemic to the Red Sea and Gulf of Aden
JOHN E. RANDALL, SERGEY V. BOGORODSKY, FRIEDHELM KRUPP, JEAN MICHEL ROSE & RONALD FRICKE
The grouper Epinephelus geoffroyi (Klunzinger), type locality Red Sea, previously regarded as a synonym of E. chlorostigma Valenciennes) is recognized as a valid species. It is ifferentiated from E. chlorostigma by having 25–29 (modally 27) gill rakers vs. 23–26 (modally 24), a more angular anal fin, the dark spots on the abdomen more widely separated, and lacking a clear white margin posteriorly on the caudal fin. The missing holotype of E. geoffroyi was found at the Staatliches Museum für Naturkunde Stuttgart (SMNS 233, 191 mm). Epinephelus chlorostigma is wide-ranging from the
Gulf of Aden and east coast of Africa to Samoa; it is reported from the depth range of 32–280 m. Epinephelus geoffroyi is presently known only from the Red Sea and Gulf of Aden at depths of 3–32 m. Illustrations are provided for three other species of groupers with numerous small dark spots, E. areolatus (Forsskål), E. gabriellae Randall & Heemstra, and E. polylepis Randall & Heemstra, that are, or might be, sympatric with E. geoffroyi.
Evgenia A. Markova, Nikolay G. Smirnov, Tatyana P. Kourova, Yuliya E. Kropacheva, Ontogenetic variation in occlusal shape of evergrowing molars in voles: An intravital study in Microtus gregalis (Arvicolinae, Rodentia), Mammalian Biology – Zeitschrift für Säugetierkunde, Available online 28 April 2013, ISSN 1616-5047, 10.1016/j.mambio.2013.03.004.In order to reveal patterns of ontogenetic change in occlusal shape of evergrowing molars in arvicolines, an intravital tooth printing method was applied to 20 individuals of Microtus gregalis born in captivity. Complexity patterns of the first lower molar were assessed by morphotype analysis of the anteroconid complex. Morphotype dental patterns were monitored using tooth prints at 0.5, 1, 2, 3 months of age, and postmortem. Ontogenetic changes in molar complexity and bilateral symmetry among right and left molars of the same individual during the process of tooth wear were assessed. Our results suggested that morphotype dental patterns could not be clearly established in half-month old animals due to presence of juvenile characters. For animals of 1 month and older, age differences in morphotype dental patterns were non-significant and negligible compared to among-individual variation. Within-individual differences among right and left molars, when present, were not related to age of an animal suggesting that bilateral asymmetry of morphotype dental pattern could be regarded as inherent characteristic of an individual persisting during post-juvenile tooth wear.
Daniel J. Twedt
Foraging Habitat for Shorebirds in Southeastern Missouri and its Predicted Future Availability
Wetlands, April 2013
Water management to protect agriculture in alluvial floodplains often conflicts with wildlife use of seasonal floodwater. Such is the case along the Mississippi River in southeastern Missouri where migrating shorebirds forage in shallow-flooded fields. I estimated the current availability of habitat for foraging shorebirds within the New Madrid and St. Johns Basins based on daily river elevations (1943–2009), under assumptions that shorebirds forage in open habitat with water depth <15 cm and use mudflats for 3 days after exposure. The area of shorebird foraging habitat, based on replicated 50-year random samples, averaged 975 ha per day during spring and 33 ha per day during fall. Adjustments to account for habitat quality associated with different water depths, duration of mudflat exposure, intra-seasonal availability, and state of agricultural crops, indicated the equivalent of 494 ha daily of optimal habitat during spring and 11 ha during fall. Proposed levees and pumps to protect cropland would reduce shorebird foraging habitat by 80 %: to 211 ha (108 optimal ha) per day during spring and 9 ha (<3 optimal ha) per day during fall. Alternative water management that allows natural flooding below a prescribed elevation would retain nearly all existing shorebird foraging habitat during fall and about 60 % of extant habitat during spring. Are spotted skunks conspicuous or cryptic?
T. Caro, T. Stankowich, C. Kiffner, J. Hunter
Ethology Ecology & Evolution
Vol. 25, Iss. 2, 2013
Aposematism and crypticity are viewed as mutually exclusive antipredator defense strategies with skunks being a classic example of the former. Skunks can spray noxious anal secretions and many species (Conepatus and Mephitis spp.) have bold blocks of white fur on black pelage, but spotted skunks (Spilogale sp.) have white spots and lines on a black coat suggesting an additional function. We tested the possibility that spotted skunks are conspicuous at close range but cryptic at a distance. Using quantitative measures of colouration extracted from photographs of taxidermied western spotted skunk, bobcat and striped skunk mounts taken at ≤ 5 m, we found that spotted skunk colouration was significantly more conspicuous than the cryptic bobcat but not than the striped skunk. Differences between mount and background colouration were significantly greater for spotted skunks than for bobcats but not for striped skunks. Both sets of results indicate that spotted skunks match their background poorly when viewed close up. In poor light, human observers found it easy to see a striped skunk mount when standing 40–145 m away but difficult to see a bobcat mount. Spotted skunk mounts were more difficult to see than a striped skunk but easier than a bobcat mount during evening watches, and no easier to see than a bobcat during early morning watches, results of which were broadly confirmed using dyed spotted skunk mounts. Therefore naturally coloured spotted skunks are relatively cryptic under certain lighting conditions when viewed from afar by human observers. Finally, across skunk species, spottedness is associated with small size, living in closed habitats, and being arboreal, similar to some other small cryptic carnivore species. Our analyses provide preliminary support for spotted skunks being cryptic at a distance but conspicuous close up, adding to a small but growing list of species utilizing two formerly distinct antipredator defense strategies. Share on facebookShare on twitterMore Sharing Services0