Behavior of Moose Relative to a Road Network

Abstract Roads often negatively affect terrestrial wildlife, via habitat loss or fragmentation, noise, and direct mortality. We studied moose (Alces alces) behavior relative to a road network, in an area with a history of moose-vehicle accidents, to determine when moose were crossing roadways or using areas near roads and to investigate if environmental factors were involved in this behavior. We tracked 47 adult moose with Global Positioning System collars in a study area crossed by highways and forest roads. We hypothesized that moose would avoid crossing roads but would make occasional visits to roadsides to feed on sodium-rich vegetation and avoid biting insects. Further, we expected moose avoidance to be greater for highways than forest roads. We recorded 196,710 movement segments but only observed 328 highway and 1,172 forest-road crossings (16 and 10 times lower than expected by chance). Moose usually avoided road proximity up to ≥500 m on each side but 20% of collared moose made visits to areas within 50 m of highways, which might have resulted from moose searching for sodium in vegetation and roadside salt pools. In fact, vegetation along highways had higher sodium concentrations and was browsed in similar proportions to vegetation in adjacent forest, despite moose avoidance of these zones. Moose, however, did not use areas near roads more during periods of biting insect abundance. Our results supported the hypothesis of scale-dependent selection by moose; avoidance of highways at a coarse scale may confer long-term benefits, whereas selection of highway corridors at finer scales may be part of a strategy to overcome short-term limiting factors such as sodium deficiency. We found a positive relationship between home-range size and the proportion of road axes they contained, suggesting that moose either compensated for habitat loss or made specific movements along highways to gather sodium. The presence of sodium along highways likely increases moose-vehicle accident risks. Removal of salt pools or use of a de-icing salt other than sodium chloride should render highway surroundings less attractive to moose.     

Behavioral Adaptations of Moose to Roadside Salt Pools

Abstract: Sodium has many fundamental physiological functions in animals but is rare in boreal ecosystems where moose (Alces alces) thrive. In Québec (Canada), sodium is readily available in aquatic vegetation and in salt pools that form along highways. We do not know if moose are adopting specific behaviors to access sodium sources or if they simply use the sodium sources they encounter during their movements. We tested the hypothesis that moose modify both space and habitat use to gather sodium from salt pools. We expected moose to use salt pools mostly in spring and early summer, when needs are greatest and before aquatic vegetation has fully developed. We fitted 47 moose with Global Positioning System telemetry collars and collected data for 2 to 36 months between 2003 and 2006. We rarely located moose at salt pools (0.12% among the 95,007 locations collected). As we expected, use of salt pools was highest in late spring and in early summer, and we observed a time lag between peak use of salt pools compared to use of lakes and waterways, indicating moose fulfilled their sodium requirements in salt pools before aquatic vegetation was available. Moose selected salt pools over lakes and waterways when these 2 sodium sources were present in their home range and moved rapidly over large distances to reach them. Our results were consistent with moose using salt pools when they are likely to be sodium deficient. Salt pools were less accessible, required long-distance movements, and were located in habitually avoided areas along highways. Elimination of roadside salt pools should be considered among strategies to reduce cervid-vehicle collision risks in boreal environments.     

Geographic patterns of diversification: an example with ectoparasitic insects

On any spatial scale, the species composition of a taxonomic group often departs from a phylogenetically random subset drawn from the pool of species available on a higher scale. Analysis of the uneven representation of related lineages in different assemblages can reveal the action of various forces shaping their diversification. For any assemblage, unequal diversification among lineages can be estimated using diversity skewness, an index of the balance of a phylogenetic tree whose values increase with increasing differences in diversification rates among tree branches. We tested for geographical patterns in the diversity skewness of flea assemblages parasitic on small mammals in 26 distinct geographic localities from the Palaearctic and 15 from the Nearctic. Overall, diversity skewness of the Nearctic flea assemblage was unexpectedly high compared to that of the global flea fauna, whereas that of the Palaearctic did not depart from the expectations of a null model. On a smaller scale, the diversity skewness of local flea assemblages was sometimes lower, sometimes higher, but, in most of the 41 localities, it did not differ significantly from that of random subsets taken from the species pool available on the larger spatial scale (either the world fauna or that of the biogeographical realm, i.e. Palaearctic or Nearctic). More importantly, among Palaearctic assemblages, diversity skewness increased with increasing latitude and/or decreasing mean air temperatures. The different patterns observed in the Palaearctic and Nearctic may be in part due the fact that flea diversification appears to have been more intense in the former than the latter, and to differences between them in relief and glacial history. Temperature‐driven speciation rates may well explain the latitudinal gradient in diversity skewness in the Palaearctic. The results illustrate the action of various biogeographical processes in shaping the uneven differentiation of flea lineages on different spatial scales. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 807–814.     

Intra‐ and interclonal phenotypic and genetic variability of the trematode Maritrema novaezealandensis

Explaining the origin and maintenance of phenotypic variation remains a central challenge in evolutionary biology. Using the trematode parasite Maritrema novaezealandensis, we examined variability in several morphological, behavioural, and physiological phenotypic traits at the same time as controlling for genotype by using genetically identical parasite clonal lineages. We measured several morphological traits, photoreactive responses, and survivorship to quantify the amount of phenotypic variation within and among 42 clonal parasite lines. Additionally, we tested Lerner's hypothesis that homozygotes are more variable than heterozygotes and assessed correlations between heterozygosity and phenotypic variation among clones. We found substantial differences among clones in morphology, photoreactive behaviour, and survivorship, yet no significant differences among clones in levels of intraclonal phenotypic variability were seen. Although the results demonstrate that conspecific trematode clones have significantly different levels of phenotypic variability, consistent differences over time were not always apparent. Finally, no correlation was found between heterozygosity and phenotypic variation among clones and the pattern of highly variable homozygotes, as observed by Lerner, was not evident in the present study. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 106–116.     

Effectiveness and specificity of a classroom-based group intervention in children and adolescents exposed to war in Lebanon

The purpose of this study was to examine the effectiveness and specificity of a classroom-based psychosocial intervention after war. All students (n=2500) of six villages in Southern Lebanon designated as most heavily exposed to war received a classroom-based intervention delivered by teachers, consisting of cognitive-behavioural and stress inoculation training strategies. A random sample of treated students (n=101) and a matched control group (n=93) were assessed one month post-war and one year later. Mental disorders and psychosocial stressors were assessed using the Diagnostic Interview for Children and Adolescents - Revised with children and parents. War exposure was measured using the War Events Questionnaire. The prevalence of major depressive disorder (MDD), separation anxiety disorder (SAD) and post-traumatic stress disorder (PTSD) was examined pre-war, one month post-war (pre-intervention), and one year post-war. Specificity of treatment was determined by rating teachers’ therapy diaries. The rates of disorders peaked one month post-war and decreased over one year. There was no significant effect of the intervention on the rates of MDD, SAD or PTSD. Post-war MDD, SAD and PTSD were associated with pre-war SAD and PTSD, family violence parameters, financial problems and witnessing war events. These findings have significant policy and public health implications, given current practices of delivering universal interventions immediately post-war.     

Evolutionary trends in body size of parasitic flatworms

Evolutionary trends in body size have been identified within several lineages, but not all have followed Cope's rule, which states that average body size within a taxon tends to increase over time. In organisms such as parasites, space constraints may have shaped the evolution of body sizes, favouring small-bodied taxa capable of exploiting new niches. Here, the average adult body sizes of families in three groups of parasitic flatworms, the Digenea and two clades of Monogenea (Monopisthocotylea and Polyopisthocotylea), are related to their clade rank. Clade rank reflects the number of branching events, and thus the total path length, between an extant family and the root of the phylogenetic tree. Among families of Digenea, all of which are endoparasites of vertebrates, there was no trend in body size evolution. In contrast, the Monopisthocotylea and Polyopisthocotylea, which are (with the exception of Polystomatidae and Sphyranuridae) ectoparasites of fish, revealed significant negative relationships between family body size and clade rank, suggesting an evolutionary trend of decreasing size. In addition, an analysis of body size distributions in monogenean families also provides support, albeit weak, for this trend. From an ancestor parasitic on the skin of fishes, monogeneans have diversified by colonizing other microhabitats on their hosts, including such space-limited sites as the gaps between secondary gill lamellae. Using a conservative likelihood ratio test, however, a random walk, or null model of evolution could not be discarded in favour of the directional trends mentioned above. Nevertheless, these results suggest that body size has taken different evolutionary paths in endo- and ectoparasitic flatworms.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 85 , 181–189.     

Ten polymorphic microsatellite loci for the trematode Gymnophallus sp.

Ten polymorphic loci were isolated and characterized from the intertidal New Zealand trematode Gymnophallus sp., a common parasite of the abundant local bivalve Austrovenus stutchburyi. Observed heterozygosities ranged from 0.17 to 0.96, and three to 23 alleles were detected in 24 trematode metacercariae. These loci are currently being used to investigate the molecular ecology of this species within the bivalve host.     

Interspecific allometry of morphological traits among trematode parasites: selection and constraints

Developmental constraints and selective pressures interact to determine the strength of allometric scaling relationships between body size and the size of morphological traits among related species. Different traits are expected to relate to body size with different scaling exponents, depending on how their function changes disproportionately with increasing body size. For trematodes parasitic in vertebrate guts, the risk of being dislodged should increase disproportionately with body size, whereas basic physiological functions are more likely to increase in proportion to changes in body size. Allometric scaling exponents for attachment structures should thus be higher than those for other structures and should be higher for trematode families using endothermic hosts than for those using ectotherms, given the feeding and digestive characteristics of these hosts. These predictions are tested with data on 363 species from 13 trematode families. Sizes of four morphological structures were investigated, two associated with attachment (oral and ventral suckers) and the other two with feeding and reproduction (pharynx and cirrus sac). The scaling exponents obtained were generally low, the majority falling between 0.2 and 0.5. There were no consistent differences within families between the magnitude of scaling exponents for different structures. Also, there was no difference in the values of scaling exponents between families exploiting endothermic hosts and those using ectotherms. There were strong correlations across families between the values of the scaling exponents for the oral sucker, the ventral sucker and the pharynx: in families where the size of one trait increases relatively steeply as a function of body size, the same is generally true of the other traits. These results suggest either that developmental constraints link several morphological features independently of their specific roles or that similar selection pressures operate on different structures, leading to covariation of scaling exponents. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96 , 533–540.     

Persistence and colonisation as measures of success in bog restoration for aquatic invertebrates: a question of detection

1. van Duinen et al. (Freshwater Biol., 2006) raise an interesting point regarding Mazerolle et al.’s (Freshwater Biol., 2006, 51 , p. 333) conclusion on the ability of invertebrates, especially sedentary species, to colonise newly created bogs pools. We wish to clarify that Mazerolle et al. (2006) targeted large arthropods and the absence of smaller sedentary species was purely a result of sampling design. 2. van Duinen et al. (2006) postulate that colonisation rates by bog specialists should be higher in Canada than in the Netherlands, given the extensive amount of intact peatlands in Canada. Here, we emphasise the importance of taking the regional context into account when assessing restoration success as our study site occurs in a landscape where most bog pools have been drained. 3. An evaluation of restoration efforts should focus on both sedentary and vagile invertebrates, to resolve the importance of persistence and colonisation. Such patterns are difficult to interpret, however, when sampling designs and analyses do not account for the probability of detection: an absence may be due to non‐detection or true absence. We strongly urge investigators to directly estimate detection probability in addition to the parameters of interest (e.g. presence, abundance) to provide the best information possible regarding restoration success.