Castella, B., Golay, J., Monney, J.-C., Golay, P., Mebert, K. and Dubey, S. (2013), Melanism, body condition and elevational distribution in the asp viper.
Journal of Zoology. doi: 10.1111/jzo.12037
Alternative morphotypes can confer important selective advantages in different habitats, whereas they can be penalized in other circumstances. In ectotherms, such as reptiles, the body colour can have direct effects on numerous aspects of their existence, such as thermoregulation or prey–predator interactions. Darker melanic individuals show lower skin reflectance and consequently heat up more rapidly and maintain optimal body temperatures more easily than lighter coloured individuals. As a consequence, melanistic individuals of diurnal species in cool areas may exhibit higher body condition, growth rate, survival and fecundity than lighter coloured individuals. Such advantages of dark coloration may be counterbalanced by a lower crypsis to predators and a decreased foraging efficiency. We investigated, in two montane populations of asp vipers Vipera aspis, the relationship between (1) colour polymorphism and body condition and length and (2) the coloration of individuals and their elevational distribution. We showed significant relationships between (1) the coloration, body condition and sex of individuals; (2) sexes and reproductive state and morph frequency; and (3) colour morphs that were distributed following an elevational gradient. Hence, colour polymorphism plays an important role in the ecology and evolution of the asp viper and is maintained through differential selective pressures.
Pope, T. L., Morrison, M. L. and Wilkins, R. N. (2013), Woodlands as quality breeding habitat for black-capped vireos. The Journal of Wildlife Management. doi: 10.1002/jwmg.539
Identifying vegetation types that result in the highest quality habitat will help direct management and conservation activities designed to recover endangered species. Shrubland is considered to result in high quality habitat for black-capped vireos (Vireo atricapilla), whereas deciduous and oak-juniper woodlands are considered to result in marginal habitat (i.e., lower quality). We investigated differences in nest and fledgling survival among shrubland and woodland vegetation types. We monitored 302 black-capped vireo nests in 259 territories from 2008 to 2010 in Kerr County, Texas and collected vegetation data at each nest. We also resighted 350 fledglings to estimate individual survival. Nest survival and fecundity did not differ statistically among vegetation types. Although nest-site characteristics differed among vegetation types, none affected nest survival. Nests that were parasitized were less likely to survive and parasitism was the only variable to affect survival of those measured. Parasitism frequency was nearly twice as great in shrubland (22%) than in either woodland type (12% in each) and varied by year (31% in 2008 to 0% in 2010). Vegetation type and proximity of the nest to oak-juniper woodland did not affect fledgling survival. Our results suggest woodlands may result in good quality habitat in areas with large populations of black-capped vireos. Recognizing woodlands as non-typical, yet good quality, habitat will allow managers to incorporate these vegetation types into management plans and make recommendations for conservation incentive programs directed at private landowners.
E. P. Ieshko, B. S. Shul’man, D. I. Lebedeva, Yu. Yu. Barskaya, E. Niemela
Bullhead (Cottus gobio L.) invasion in the Utsjoki River (Northern Finland): Parasitological aspects
Russian Journal of Biological Invasions
January 2013, Volume 4, Issue 1, pp 17-23
The bullhead (Cottus gobio L.) was for the first time recorded in the Utsjoki River (70° N, 27° E), a large tributary of the Teno River (Northern Finland), in 1979 and in subsequent years spread widely within this lake-river system. The studies of 1993 and 2007 allowed the general trends of changes in the bullhead mass parasitic species composition and incidence over the examined time period to be estimated. It was shown that the species diversity of the parasites of this species new to the fish community did not change considerably except for a noticeable increase in the infection rate with larvae of the trematode genera Diplostomum and Apatemon. In general, the incidence rate and distribution of the plerocercoids of Schistocephalus solidus, a mass helminth species, in the bullhead population did not change. The observed increase in the infection rate of the Atlantic salmon parr with Apatemon gracilis metacercariae may be regarded as a consequence of the bullhead invasion.
V. G. Petrosyan, V. V. Golubkov, Z. I. Goryainova, N. A. Zav’yalov, S. A. Al’bov, L. A. Khlyap, Yu. Yu. Dgebuadze
Modeling of the Eurasian beaver (Castor fiber L.) population dynamics in the basin of a small Oka River tributary, the Tadenka River (Prioksko-Terrasnyi Nature Reserve)
Russian Journal of Biological Invasions
January 2013, Volume 4, Issue 1, pp 45-53
A parametric time-discrete model for the beaver population dynamics starting from their invasion (1948) to the present day (2011) in the Tadenka River basin is described. It is shown that the population size tends to a stationary state in the presence of a quasi-periodic component of 14–26 years. Model estimates for the dynamics suggest that the periodic component has a sawtooth shape with the number of beavers increasing from minimum to maximum in each period for 6 years and decreasing from maximum to minimum during the remaining part of the period. The oscillation amplitude of the quasi-periodic component is approximately six individuals and displays a weak trend of increase. It is assumed that further development of this beaver population will depend on many random events influencing the factors that control beaver population size, such as specific geomorphological features of the area, restoration rate of food resources in the abandoned habitats, scale of beaver settlement development, and its rate. Stability analysis of the stationary solution and assessment of the model adequacy suggest that the proposed discrete model is appropriate for quantitatively describing the dynamics of the local beaver populations in other areas depending on the availability of food resources.
M. P. Korablev, N. P. Korablev, P. N. Korablev
Russian Journal of Biological Invasions
January 2013, Volume 4, Issue 1, pp 24-38
Morphophenetic analysis of American mink (Neovison vison) populations from the Caspian-Baltic watershed
The morphological variability of 367 skulls of the American mink from Tver, Pskov, and Novgorod oblasts (Caspian-Baltic watershed) are investigated using quantitative and qualitative traits. Out of the six investigated samplings, five represent feral populations and one represents ranch minks. It is shown that significant morphological differences between feral mink populations exist within a relatively small area (about 250 × 350 km). Differences in the phenotype are determined by different history of the populations and by the degree of affection of escaped ranch animals. The possible consequences of interactions between the feral and ranch mink populations, which may influence the phenotype, are discussed. The morphological differences observed between the feral mink populations are lower than those theoretically expected when taking into account the considerable influence of domesticated animals. Among the possible reasons of morphological stability of skulls of feral populations of the American mink, we specify naturalization of sizes of ranch escapees under pressure of environmental conditions, as well as possible elimination of the first-generation hybrids between feral and domesticated minks owing to outbreeding depression.
Thore J. Bergman, Speech-like vocalized lip-smacking in geladas, Current Biology, Volume 23, Issue 7, 8 April 2013, Pages R268-R269, ISSN 0960-9822, 10.1016/j.cub.2013.02.038.
Recently, we have seen a surge of interest in identifying possible evolutionary links between primate facial communication and human speech (for example). One suggestion is that primate ‘lip-smacking’ — a non-vocal, rhythmic movement of lips usually given in conjunction with affiliative behavior — may have been a precursor to speech. This idea arose because lip-smacking shares several production features with human speech that the vocalizations of non-human primates lack, most notably a 3–8 Hz rhythm. Evidence that non-human primates are indeed able to vocalize while simultaneously producing rhythmic facial movements would lend initial, but important, support to the notion that lip-smacking is a plausible evolutionary step towards speech. Here, I report that a wild primate, the gelada (Theropithecus gelada), makes a derived vocalization (the vocalization is absent in their close relatives, the Papio baboons) that is produced while lip-smacking, called a ‘wobble’. The rhythm of wobbles (6–9 Hz) closely matches that of human speech, indicating that a vocalized lip-smack produces sounds that are structurally similar to speech. Geladas are highly gregarious primates with a relatively large vocal repertoire. Their independent evolution of a speech-like vocalization involving complex facial movements provides initial support for the hypothesis that lip-smacking was a precursor to the emergence of human speech.
Zootaxa 3637 (2): 158–168 (10 Apr. 2013)
A new species of cat snake (Reptilia: Serpentes: Colubridae: Boiga) from dry forests of eastern Peninsular India
GERNOT VOGEL & S.R. GANESH
A new species of cat snake, related to Boiga beddomei (Wall, 1909), is described from the dry forests of eastern Peninsular India. It occupies a large geographic range from Berhampore (type locality), near the River Mahanadi in the northeast to Kaigal near the southern Eastern Ghats in the southwest. The new species is diagnosed by having the following combination of characters: 19 dorsal scale rows at midbody, a high number of ventral scales for the genus Boiga (248–259), a yellowish-green dorsal colouration with numerous faint black bands, an uniform, unpatterned yellow-coloured venter and a relatively short tail (0.180–0.200 of the total length).
Zootaxa 3637 (2): 169–175 (10 Apr. 2013)
Eviota nigramembrana, a new dwarfgoby from the Western Pacific (Teleostei: Gobiidae)
DAVID W. GREENFIELD & TOSHIYUKI SUZUKI
Eviota nigramembrana is described from the Ryukyu Islands, Japan and also recorded from the Philippine Islands. It belongs to the cephalic sensory-pore system pattern group I (complete), has a dorsal/anal fin-ray formula of 8/8, 5th pelvicfin ray absent, some lower pectoral-fin rays branched, five dark internal bands between anal-fin origin and caudal fin, no distinct marking on pectoral-fin base, dark internal rectangular mark above midline of ural centrum, a light spinous dorsal fin, and black pigment on the opercular membrane.
P. Waldeck, K. Larsson, Effects of winter water temperature on mass loss in Baltic blue mussels: Implications for foraging sea ducks, Journal of Experimental Marine Biology and Ecology, Volume 444, June 2013, Pages 24-30, ISSN 0022-0981, 10.1016/j.jembe.2013.03.007.
Water temperature may through its effects on body mass, reproductive output and recruitment of bivalves also influence organisms higher up the food chain. The small sized Baltic blue mussel (Mytilus trossulus × Mytilus edulis) is a dominant key species in the Baltic Sea food web and it is an important food source for sea ducks such as the common eider (Somateria mollissima) and the long-tailed duck (Clangula hyemalis) and for some species of fish. Possible links between winter water temperature and the quality of blue mussels as food for wintering sea ducks were investigated by measuring the soft body mass loss of mussels during winter in an experimental set-up and in the field. demonstrated that warmer water temperatures in winter had a significant negative effect on soft body mass of Baltic blue mussels. Analysed mussels, on average 15mm in length, kept in experimental aquaria between January and March and exposed to a 3.6°C elevated water temperature regime corresponding to conditions during mild winters, had about 11% smaller tissue dry mass in March than mussels exposed to a water temperature regime corresponding to conditions in cold winters. At two field study areas, the body mass loss of mussels from October to March in a mild winter was significant and more pronounced (15% and 19%, respectively) than in a cold winter (11% and 4% respectively). This difference is of importance because in winter and spring, sea ducks build up energy stores for the subsequent breeding season by consuming large quantities of blue mussels and the energy gain of the birds per dive will be affected by the soft body tissue content of the mussels. The results improve our possibilities to predict the seasonal and yearly variation of the quality of the main food of sea ducks and help us to better understand the causes for the variable reproductive success and the present population declines of sea ducks. The results may also improve our possibilities to model the effects on Baltic Sea food webs of possible future increases in water temperature.
Wickström, H. and Sjöberg, N. B. (2013), Traceability of stocked eels – the Swedish approach. Ecology of Freshwater Fish. doi: 10.1111/eff.12053
Stocking of eels is one of the management measures in the eel regulation (EC No 1100/2007) to recover the stock. The Swedish Eel Management Plan doubles the numbers stocked to 2.5 million eels per year. Whether stocked eels contribute to the spawning stock or not has been questioned: stocked eels might not migrate as successful as wild recruited eels. The EIFAAC/ICES Working Group on Eel (2011) recommended ‘that all stocked eel should be marked and thereby separable from wild eel in subsequent sampling’. Since 2009, eels stocked in Sweden have been bathed in a strontium (Sr) solution, which gives a detectable mark in their otoliths. So far, 5.5 million eels have been marked in Sweden; Finland imports eels for stocking via Sweden, and these 0.6 million eels were marked by two Sr rings. We present results on marking success and recapture rates and also from marking with alizarin complexone and PIT tags in combination with Sr. If all eels stocked in the Baltic are marked, their contribution to the spawning run can be estimated. Using different combinations of marks in different regions, the relative contribution from separate stocking programmes can be evaluated. To increase the set of suitable marks, barium was tested as an additional tracer.
Pagano, A. M., Peacock, E. and McKinney, M. A. (2013), Remote biopsy darting and marking of polar bears. Marine Mammal Science. doi: 10.1111/mms.12029
Remote biopsy darting of polar bears (Ursus maritimus) is less invasive and time intensive than physical capture and is therefore useful when capture is challenging or unsafe. We worked with two manufacturers to develop a combination biopsy and marking dart for use on polar bears. We had an 80% success rate of collecting a tissue sample with a single biopsy dart and collected tissue samples from 143 polar bears on land, in water, and on sea ice. Dye marks ensured that 96% of the bears were not resampled during the same sampling period, and we recovered 96% of the darts fired. Biopsy heads with 5 mm diameters collected an average of 0.12 g of fur, tissue, and subcutaneous adipose tissue, while biopsy heads with 7 mm diameters collected an average of 0.32 g. Tissue samples were 99.3% successful (142 of 143 samples) in providing a genetic and sex identification of individuals. We had a 64% success rate collecting adipose tissue and we successfully examined fatty acid signatures in all adipose samples. Adipose lipid content values were lower compared to values from immobilized or harvested polar bears, indicating that our method was not suitable for quantifying adipose lipid content.
Clint E. Collins, Jessica D. Self, Roger A. Anderson, Lance D. McBrayer, Rock-dwelling lizards exhibit less sensitivity of sprint speed to increases in substrate rugosity, Zoology, Available online 8 April 2013, ISSN 0944-2006, 10.1016/j.zool.2013.01.001.
Effectively moving across variable substrates is important to all terrestrial animals. The effects of substrates on lizard performance have ecological ramifications including the partitioning of habitat according to sprinting ability on different surfaces. This phenomenon is known as sprint sensitivity, or the decrease in sprint speed due to change in substrate. However, sprint sensitivity has been characterized only in arboreal Anolis lizards. Our study measured sensitivity to substrate rugosity among six lizard species that occupy rocky, sandy, and/or arboreal habitats. Lizards that use rocky habitats are less sensitive to changes in substrate rugosity, followed by arboreal lizards, and then by lizards that use sandy habitats. We infer from comparative phylogenetic analysis that forelimb, chest, and tail dimensions are important external morphological features related to sensitivity to changes in substrate rugosity.
Hampton, P. M. (2013), Feeding in natricines: relationships among feeding morphology, behavior, performance and preferred prey type. Journal of Zoology. doi: 10.1111/jzo.12029
The diversity of feeding mechanisms among predators reflects phenotypic modifications that may improve feeding performance on a preferred prey type. I compared trophic morphology, feeding performance (time and upper-jaw walks) and behavior (initial bite and ingestion directions) among three species of natricine snakes that were fed fish and frogs over a broad range of relative prey sizes. Feeding behavior was influenced by prey type but did not differ among the snake species. Both bite and ingestion directions influenced the number of upper-jaw movements (lateral excursions and protractions) required to consume fish, but only initial bite position significantly affected the number of upper-jaw movements required to ingest frogs. Within snake species, feeding performance did not differ between fish and frogs for Nerodia fasciata and Nerodia rhombifer; however, Thamnophis proximus consumed fish with fewer upper-jaw movements. Feeding time differed significantly among snake species when fed both fish and frogs. Trophic morphology did not significantly affect ingestion costs for fish but did influence ingestion when fed frogs. In general, differences in trophic morphology among the three species are not correlated to handling and ingestion performance.
Helena R. Batalha, Jaime A. Ramos, Gonçalo C. Cardoso, A successful avian invasion occupies a marginal ecological niche, Acta Oecologica, Volume 49, May 2013, Pages 92-98, ISSN 1146-609X, 10.1016/j.actao.2013.03.003.
Biological invasions often threaten biodiversity, yet their ecological effects are unpredictable and in some cases may be neutral. Assessing potential interactions between invasive and native species is thus important to understand community functioning and prioritize conservation efforts. With this purpose, we compared the ecological niche and occurrence of a successful avian invader in SW Europe, the common waxbill (Estrildidae: Estrilda astrild), with those of co-occurring native passerine species. We found that common waxbills occupy a marginal niche relative to the community of native passerines, with a larger average ecological distance to the remaining species in the community compared to the native species amongst themselves, and a nearest-neighbour ecological distance identical to those of native species. Furthermore, ecological similarity did not predict co-occurrence of waxbills with other bird species. This is consistent with the invasion using a vacant niche in unsaturated communities, which is likely related to invading waxbills occupying partly human-modified habitats. Similar explanations may apply to other biological invasions of human-modified environments. Results also suggest that detrimental ecological effects due to interspecific competition with native passerines are unlikely. Notwithstanding, the ecological nearest-neighbour of common waxbills was the reed bunting (Emberiza schoeniclus), whose SW European subspecies are endangered, and may justify conservation attention regarding possible interactions between these two species.
Jin, Y. T., Li, J. Q. and Liu, N. F. (2013), Elevation-related variation in life history traits among Phrynocephalus lineages on the Tibetan Plateau: do they follow typical squamate ecogeographic patterns?. Journal of Zoology. doi: 10.1111/jzo.12042
We examined body size, litter size and evidence for Bergmann’s and Rensch’s rules among eight closely related viviparous Phrynocephalus (Agamidae) lineages from the Qinghai-Xizang (Tibetan) Plateau. Mean snout-vent length and (relative) abdomen length was greater in females than males, whereas absolute and relative mean head size, fore – and hindlimb length was larger in males. These patterns suggest that body size may reflect sexual evolutionary conservatism. The lizards are smaller at higher elevations or in colder climates, representing the converse of Bergmann’s rule. Absolute differences in female body size among taxa are not equal to the male differences among taxa. This results in a slope less than one when male size is regressed on female size, which allows rejection of Rensch’s rule for this group. The female body size elevation-related cline was steeper than the corresponding male cline. Litter sizes were both smaller and less variable at higher elevations. These elevational clines remained after application of phylogenetic comparative methods, indicating that ecological processes play a more important role than phylogeny in shaping patterns of size and reproductive variation in these lizards. It is suggested that seasonal activity and temperature are important environmental factors that contribute to the converse Bergmann’s cline, while fecundity selection in females and sex-specific differential-plasticity likely explain why patterns do not conform to Rensch’s rule.