The role of metabolism in understanding the altitudinal segregation pattern of two potentially interacting lizards

Sympatric species from the same ecological guild, that exhibit partial altitudinal segregation, can potentially interact in areas of syntopic occurrence. Besides general species' ecology, physiology can provide important answers about species interactions reflected in altitudinal patterns. Lizards Podarcis muralis and Iberolacerta horvathi exhibit partial altitudinal segregation, while they strongly resemble in overall morphology and ecology (diet, daily and seasonal activity pattern), but show certain degree of physiological dissimilarity. They have similar mean preferred body temperatures and patterns of seasonal and daily variations but differ in the magnitude of seasonal variation. Since an ectotherm metabolism is highly dependent on body temperature, thermoregulation is expected to directly affect their metabolism. We compared metabolic rates of adult males from an area of sympatry, measured under two temperature regimes (20°C and 28°C). Both species increased metabolic rates with temperature in a similar pattern. We also compared electron transport activity from tail tissues which provide values of species' potential metabolic activity (enzymatic capacity). Species clearly differed in potential metabolic activity; I. horvathi attained higher values than P. muralis. No difference was detected in how species exploited this potential (calculated from the ratio of electron transport activity and metabolic rates). However, we observed higher potential metabolic activity I. horvathi which together with the ability to thermoregulate more precisely could represent a higher competitive advantage over P. muralis in thermally more restrictive environments such as higher altitudes. Understanding of metabolism seems to provide valuable information for understanding recent distributional patterns as well as species interactions

The role of natural science collections in the biomonitoring of environmental contaminants in apex predators in support of the EU's zero pollution ambition

The chemical industry is the leading sector in the EU in terms of added value. However, contaminants pose a major threat and significant costs to the environment and human health. While EU legislation and international conventions aim to reduce this threat, regulators struggle to assess and manage chemical risks, given the vast number of substances involved and the lack of data on exposure and hazards. The European Green Deal sets a 'zero pollution ambition for a toxic free environment' by 2050 and the EU Chemicals Strategy calls for increased monitoring of chemicals in the environment. Monitoring of contaminants in biota can, inter alia: provide regulators with early warning of bioaccumulation problems with chemicals of emerging concern; trigger risk assessment of persistent, bioaccumulative and toxic substances; enable risk assessment of chemical mixtures in biota; enable risk assessment of mixtures; and enable assessment of the effectiveness of risk management measures and of chemicals regulations overall. A number of these purposes are to be addressed under the recently launched European Partnership for Risk Assessment of Chemicals (PARC). Apex predators are of particular value to biomonitoring. Securing sufficient data at European scale implies large-scale, long-term monitoring and a steady supply of large numbers of fresh apex predator tissue samples from across Europe. Natural science collections are very well-placed to supply these. Pan-European monitoring requires effective coordination among field organisations, collections and analytical laboratories for the flow of required specimens, processing and storage of specimens and tissue samples, contaminant analyses delivering pan-European data sets, and provision of specimen and population contextual data. Collections are well-placed to coordinate this. The COST Action European Raptor Biomonitoring Facility provides a well-developed model showing how this can work, integrating a European Raptor Biomonitoring Scheme, Specimen Bank and Sampling Programme. Simultaneously, the EU-funded LIFE APEX has demonstrated a range of regulatory applications using cutting-edge analytical techniques. PARC plans to make best use of such sampling and biomonitoring programmes. Collections are poised to play a critical role in supporting PARC objectives and thereby contribute to delivery of the EU's zero-pollution ambition.Non peer reviewe

A review of constraints and solutions for collecting raptor samples and contextual data for a European raptor biomonitoring facility

The COST Action ‘European Raptor Biomonitoring Facility’ (ERBFacility) aims to develop pan-European raptor biomonitoring in support of better chemicals management in Europe, using raptors as sentinel species. This presents a significant challenge involving a range of constraints that must be identified and addressed. The aims of this study were to: (1) carry out a comprehensive review of the constraints that may limit the gathering in the field of raptor samples and contextual data, and assess their relative importance across Europe; and (2) identify and discuss possible solutions to the key constraints that were identified. We applied a participatory approach to identify constraints and to discuss feasible solutions. Thirty-one constraints were identified, which were divided into four categories: legal, methodological, spatial coverage, and skills constraints. To assess the importance of the constraints and their possible solutions, we collected information through scientific workshops and by distributing a questionnaire to stakeholders in all the countries involved in ERBFacility. We obtained 74 answers to the questionnaire, from 24 of the 39 COST participating countries. The most important constraints identified were related to the collection of complex contextual data about sources of contamination, and the low number of existing raptor population national/regional monitoring schemes and ecological studies that could provide raptor samples. Legal constraints, such as permits to allow the collection of invasive samples, and skills constraints, such as the lack of expertise to practice necropsies, were also highlighted. Here, we present solutions for all the constraints identified, thus suggesting the feasibility of establishing a long-term European Raptor Sampling Programme as a key element of the planned European Raptor Biomonitoring Facility

Breeding density and altitudinal distribution of the Ural, Tawny, and Boreal Owls in North Dinaric Alps (central slovenia)

Volume: 37Start Page: 55End Page: 6

Habitat selection and patterns of distribution in a hierarchic forest owl guild

Patterns of segregation were studied in a size-structured forest owl guild with the largest Ural Owl Strix uralensis, intermediate Tawny Owl Strix aluco, and the smallest Tengmalms Owl Aegolius funereus, by comparing habitat selection and patterns of dis-tribution. Data on owl territories were collected between 1998 and 2003 on Mt. Krim, North Dinaric Alps, central Slovenia, using the playback method. The Ural Owl was the dominant species, occupying the largest part of its optimal habitat, i.e. its fundamental niche. The Tawny Owl had the widest habitat niche. Due to negative interactions it se-lected refugial areas free of Ural Owls, which were in lowlands only, where human influ-ences prevent Ural Owls from settling. Tengmalms Owl was the most specialised in hab-itat selection. Its territories were on high altitudes, within those of the Ural Owl. They in-habited similar habitats but we found no indications of interactions between them. In con-trast, Tawny and Tengmalms Owls were highly segregated in habitat and in space, due to distinctive negative interactions. Based on these results, we propose the following hy-pothesis: Tengmalms Owl benefits from the presence of Ural Owls, which creates Tawny Owl free areas; this association does not affect the Ural Owl. This could be the first case of positive interactions in a predatory guild, i.e. a specific type of commensalism

Quantifying the intersexual and interspecific morphometric variation in two resembling sympatric lacertids: Iberolacerta horvathi and Podarcis muralis

Podarcis muralis and Iberolacerta horvathi are sympatric, frequently syntopic, lacertids through the entire range of I. horvathi and very similar in their general body size and shape, as well as in most ecological traits. We morphologically compared adults from the area of sympatry using biometric measurements and performed analyses to investigate their sexual size and shape dimorphism. A total of 34 males and 24 females of I. horvathi, and 25 males and 23 females of P. muralis, all adult individuals, were measured. Both species showed sexual size dimorphism with females being longer (snout-vent length, SVL) than males. After SVL correction (ANCOVA), head width, length and height and mass showed to be sexually dimorphic in both species. Males carry relatively wider, longer and higher heads and were heavier than conspecific females. I. horvathi heads were more flattened than those of P. muralis and P. muralis were heavier than I. horvathi. Both species displayed the same pattern of sexual dimorphism regarding body size, head size and shape not only in direction but also in magnitude. All results confirm that both species are very similar in studied biometric characters and, together with their ecological similarities, these suggest in absence of other factors they are likely to interact when living together

Quantifying the intersexual and interspecific morphometric variation in two resembling sympatric lacertids

Podarcis muralis and Iberolacerta horvathi are sympatric, frequently syntopic,lacertids through the entire range of I. horvathi and very similar intheir general body size and shape, as well as in most ecological traits. We morphologically compared adults from the area of sympatry using biometric measurements and performed analyses to investigate their sexual size and shapedimorphism. A total of 34 males and 24 females of I. horvathi, and 25 males and 23 females of P. muralis, all adult individuals, were measured. Bothspecies showed sexual size dimorphism with females being longer (snout-vent length, SVL) than males. After SVL correction (ANCOVA), head width, length and height and mass showed to be sexually dimorphic in both species. Males carry relatively wider, longer and higher heads and were heavier than conspecific females. I. horvathi heads were more flattened than those of P. muralis and P. muralis were heavier than I. horvathi. Both speciesdisplayed the same pattern of sexual dimorphism regarding body size, head size and shape not only in direction but also in magnitude. All results confirm that both species are very similar in studied biometric characters and, together with their ecological similarities, these suggest in absence of other factors they are likely to interact when living together

Data from: Towards a functional understanding of species coexistence: ecomorphological variation in relation to whole-organism performance in two sympatric lizards

1. We examined intra- and interspecific variation in functional morphology and whole-organism performance in a sympatric lizard species pair, Iberolacerta horvathi and Podarcis muralis, in the area with a high potential for competition. 2. The biggest variation between species was found in two functional traits, bite force and climbing speed, linked with corresponding morphological traits. 3. The species with larger and taller heads, P. muralis, exhibited correspondingly stronger bite forces. The other species exhibited smaller and flatter head. Both traits may potentially promote segregation between species in trophic niche (stronger bites relate to harder prey) and in refuge use (flatter heads allow using narrower crevices, hence, influencing escaping from common predators). Stronger bites and larger heads also provide one species with a dominant position in interspecific agonistic interactions. 4. Females had longer trunks that impacted negatively on climbing speed, which may lower anti-predator escape abilities of the more trunk-dimorphic species, but positively influence reproductive effort. 5. Our results exemplify how the joint examination of morphological and functional traits of ecologically similar and sympatric species can provide a mechanistic background for understanding their coexistence, namely syntopic populations that are frequent in the study area. 6. The identified roles of functional morphology in this system of sympatric rock lizards support the contribution of functional diversification for the complexity of community structure via coexistence

Ecophysiological dissimilarities of two sympatric lizards

The lizards Podarcis muralis and Iberolacerta horvathi display an overall similarity in morphology and ecology. Although they are widely sympatric in part of their distribution range of Slovenia, areas of altitudinal segregation have been observed. Ecophysiological traits such as preferred body temperatures (T p ) and rates of evaporative water loss (EWL) are some of the factors likely to be subjacent to this pattern. We expect the species that is more abundant in higher altitudes to have lower T p and higher EWL (due to lower environmental temperatures at higher elevations) than the species that is more abundant in lowlands. We conducted lab experiments to determine whether intra- and interspecific variation in these two physiological traits exists. Contrary to expectations, the means of T p were similar between the species, but their seasonal dynamics differed, which indicates that thermal accuracy might be more important. Species differed in seasonal (and daily) variation of T p , rising from spring to summer more in P. muralis than in I. horvathi. Comparing instantaneous EWL, our results showed interspecific differences with higher values in P. muralis than in I. horvathi. Throughout a 12-h period, the accumulative EWL was also always higher for P. muralis than for I. horvathi, with the greatest differences occurring after 9–12 h of the experiment. Further studies should focus on investigating if these divergent physiological characteristics of both species are associated with their habitat use (in terms of thermal and water environment) and species interaction.Funding for research was provided by a PTDC/BIA–BEC/101256/2008 project award from Fundação para a Ciência e a Tecnologia (FCT, Portugal). EG-M was supported by a postdoctoral grant from FCT (SFRH/BPD/72806/2010), and AZ was supported by Ph.D. grant from FCT (SFRH/BD/81324/ 2011). We thank L. Kastelic, M. Kavšček, B. Rakar, T. Delié, T. Romih, P. Raspor, D. Osojnik, and A. Kastelic, who helped during sampling, and Z. Žagar for constructing the terraria for photogradient experiments. Lizards were collected under two special licenses 35601–32/2010– 6 and 35601–47/2011–6 issued by the Slovenian Environment Agency. We thank J. Harris for the English language review.publishe