Apodemus Agrarius Research Articles

Ticks, fleas and rodent-hosts analyzed for the presence of Borrelia miyamotoi in Slovakia: the first record of Borrelia miyamotoi in a Haemaphysalis inermis tick

In Slovakia, little knowledge is available on the occurrence, hosts and vectors of Borrelia miyamotoi of the relapsing fever group. In the current study, 2160 questing and rodent-attached ticks of six species (Ixodes ricinus, Ixodes trianguliceps, Dermacentor marginatus, Dermacentor reticulatus, Haemaphysalis concinna and Haemaphysalis inermis), 279 fleas belonging to 9 species (Ctenophthalmus agyrtes, Ctenophthalmus solutus, Ctenophthalmus assimilis, Megabothris turbidus, Amalareus penicilliger, Hystrichopsylla orientalis, Ctenophthalmus uncinatus, Doratopsylla dasycnema and Nosopsyllus fasciatus) and skin biopsies from 245 small mammals belonging to eight species (Apodemus agrarius, Apodemus flavicollis, Apodemus uralensis, Myodes glareolus, Crocidura leucodon, Micromys minutus, Microtus arvalis, Microtus subterraneus) were screened for the presence of B. miyamotoi DNA. The overall prevalence of B. miyamotoi found in questing and rodent-attached ticks was 1.8% (23 positive/1260 examined) and 3.4% (31 positive/900 examined), respectively. Borrelia miyamotoi was detected in questing I. ricinus, rodent-attached I. ricinus and H. inermis ticks, and in one male of the common vole (M. arvalis) in different habitats (mainly rural) in eastern Slovakia. However, B. miyamotoi was not found in any of the tested fleas. Our findings indicate that rural habitats with different species of tick vectors and hosts are appropriate for the occurrence of B. miyamotoi.

Detection of Rickettsia spp. in Fleas Collected from Small Mammals in Slovakia, Central Europe

This survey is aimed at investigation of species composition of fleas removed from small terrestrial mammals captured in rural, suburban, and urban types of habitat and molecular screening of the presence and diversity of Rickettsia species in collected ectoparasites. In total, 279 fleas (Siphonaptera) belonging to 9 species of 2 families, Ceratophyllidae and Hystrichopsyllidae, were collected from 115 (46%) out of 250 trapped small mammals of eight species (Apodemus agrarius, Apodemus flavicollis, Apodemus uralensis, Myodes glareolus, Microtus arvalis, Microtus subterraneus, Crocidura leucodon, and Sorex minutus). Rickettsia spp. were found in 2.5% (7/279) of tested fleas, namely in Ctenophthalmus agyrtes, Ctenophthalmus solutus, Ctenophthalmus uncinatus, Megabothris turbidus, and Amalareus penicilliger. Rickettsia felis, Rickettsia helvetica, and unidentified Rickettsia species were detected in fleas infesting small mammals in Eastern Slovakia. The results of the study suggest that some species of rickettsiae have a different range of arthropod vectors.

Associations between different Laelapidae (Mesostigmata: Dermanyssoidea) mites and small rodents from Lithuania

Associations between species of Laelapidae (Mesostigmata: Dermanyssoidea) mites and small rodents have been studied insufficiently. The aim of this study was to investigate infestation patterns of small rodent species by laelapid mites at six locations in Lithuania. A total of 728 rodents were snap- and live-trapped in various locations during 2013-2016. Eight rodent species were identified, namely Apodemus flavicollis, Apodemus agrarius, Myodes glareolus, Micromys minutus, Mus musculus, Microtus oeconomus, Microtus arvalis and Microtus agrestis. A total of 343 (47.1%) rodents were found to be infested with up to eight species of parasitic mites from the Laelapidae family (n = 1363): Laelaps agilis, Laelaps hilaris, Hyperlaelaps microti, Haemogamasus nidi, Haemogamasus hirsutus, Eulaelaps stabularis, Hirstionyssus sunci and Myonyssus gigas. The dominant species of mite found on rodents was L. agilis (89.1%), found on 43.4% of all hosts. Abundance and mean intensity of infestation with mites varied among species of hosts and were highest for A. flavicollis. We document new geographical and host records for gamasid mites of eight rodent species in Lithuania.

Molecular Epidemiology and Genetic Diversity of Orthohantaviruses in Small Mammals in Western Poland.

Orthohantaviruses are negative-sense, single-stranded RNA viruses harbored by multiple small mammals. Dobrava-Belgrade virus (DOBV) and Puumala virus (PUUV) cause hemorrhagic fever with renal syndrome (HFRS) in Europe. In Poland, serological surveys have demonstrated antibodies against DOBV and PUUV in patients with HFRS. Molecular evidence of DOBV and PUUV has been found in Apodemus flavicollis and Myodes glareolus, respectively, in southeastern Poland, and Seewis virus (SWSV) has been reported in Sorex araneus in central Poland. However, data on the geographic distribution and phylogeny of orthohantaviruses are unavailable for other regions in Poland. To ascertain the prevalence and genetic diversity of orthohantaviruses in western and northern Poland, lung tissues from 106 small mammals were analyzed for the presence of orthohantavirus RNA. DOBV and SWSV were detected in two of 42 (4.8%) Apodemus agrarius and in three of 10 (30%) S. araneus, respectively. Phylogenetic analyses of partial L- and S-segment sequences of DOBV indicated a shared genetic lineage with the Kurkino genotype from Slovakia, Russia, and Hungary, whereas the partial M segment of DOBV clustered with the Kurkino genotype from Germany. Phylogenetic relationships of the SWSV L and S segments showed a geographic lineage with SWSV strains from central Poland, Czech Republic, and Germany. In conclusion, the study provides insights into the molecular prevalence, phylogenetic diversity, and evolutionary relationship of DOBV in A. agrarius and SWSV in S. araneus. This report increases awareness among physicians for HFRS outbreaks in western Poland.

Cascade effects of slope gradient on ground vegetation and small-rodent populations in a forest ecosystem

Abstract In this study, we set out to determine the cascade effects of slope gradient on ground vegetation and small-rodent populations in a forest ecosystem. We focused on two forest-dwelling small rodents with different habitat requirements, the striped field mouse Apodemus agrarius (preferring dense ground vegetation) and the Korean field mouse A. peninsulae (dense forest and woodland). The study area comprised natural deciduous forests and Japanese larch Larix kaempferi plantations in South Korea. The abundance of A. agrarius but not that of A. peninsulae was related to slope gradient. There was a negative effect of slope gradient on ground vegetation coverage and a positive effect of ground vegetation on A. agrarius populations. Our results highlight that the population of A. agrarius was indirectly influenced by the negative effects of slope gradient on ground vegetation. Slope gradient can, therefore, be a limiting factor in the microhabitats occupied by small rodents. This study reveals a critical role for slope gradient since it can modify not only microhabitat conditions, but also small-rodent populations, and this finding can contribute to improved microhabitat management.

Phylogeography of the striped field mouse, Apodemus agrarius (Rodentia: Muridae), throughout its distribution range in the Palaearctic region

To better understand the evolutionary history of oriental wildlife newcomers in Europe, we studied the phylogeography and demographic history of the striped field mouse, Apodemus agrarius, throughout its Palaearctic distribution area. Genetic datasets including cytochrome b gene sequences and microsatellite markers were analysed using a large range of population genetics methodologies, including coalescent models and approximate Bayesian computations. Our results showed high mitochondrial genetic homogeneity among A. agrarius populations throughout the Palaearctic region, but microsatellite markers detected a finer population structure with the genetic differentiation of populations from the Eastern and Western distribution ranges. The Western colonisation likely originated from Far East Russian populations during one of the last interglacials. After their colonisation of the Central Asia and Western regions, the Central Palaearctic populations became isolated from their Eastern relatives. Our coalescent-based approaches suggested a separation between these two distribution ranges around 38 kya or more recently (around 11 kya). Limited gene flow still happened between populations in the two main distribution ranges, mainly from the Eastern to Western populations. Our study, for the first time, provides an overview of the evolutionary and demographic history of the striped field mouse throughout the Palaearctic region. A. agrarius appears to be an Asiatic immigrant and a relatively new member of the European fauna community. This study further confirms the important role of Far East Asian regions as a source of European biodiversity.

My niche: individual spatial niche specialization affects within- and between-species interactions.

Intraspecific trait variation is an important determinant of fundamental ecological interactions. Many of these interactions are mediated by behaviour. Therefore, interindividual differences in behaviour should contribute to individual niche specialization. Comparable with variation in morphological traits, behavioural differentiation between individuals should limit similarity among competitors and thus act as a mechanism maintaining within-species variation in ecological niches and facilitating species coexistence. Here, we aimed to test whether interindividual differences in boldness covary with spatial interactions within and between two ecologically similar, co-occurring rodent species (Myodes glareolus, Apodemus agrarius). In five subpopulations in northeast Germany, we quantified individual differences in boldness via repeated standardized tests and spatial interaction patterns via capture-mark-recapture (n = 126) and automated VHF telemetry (n = 36). We found that boldness varied with space use in both species. Individuals of the same population occupied different spatial niches, which resulted in non-random patterns of within- and between-species spatial interactions. Behavioural types mainly differed in the relative importance of intra- versus interspecific competition. Within-species variation along this competition gradient could contribute to maintaining individual niche specialization. Moreover, behavioural differentiation between individuals limits similarity among competitors, which might facilitate the coexistence of functionally equivalent species and, thus, affect community dynamics and local biodiversity.

Cocirculation of Two Orthohantavirus Species in Small Mammals of the Northwestern Ukraine.

Rodent-borne hantaviruses have been reported in many of the countries surrounding Ukraine; however, to date we have no knowledge of the viral strains circulating in Ukraine within reservoirs such as the striped field mouse (Apodemus agrarius), the yellow-necked field mouse (Apodemus flavicollis), and the bank vole (Myodes glareolus). To determine the prevalence of hantaviruses in Ukraine, we captured 1,261 mammals, of which 1,109 were rodents, in 58 field sites within the province of Volyn in western Ukraine. Foci of the striped field mouse tended to occur in the eastern and southern parts of the province, whereas the bank vole were clustered in western and northern regions. The striped field mouse and bank vole had detectable serum antibodies to Puumala virus (PUUV) or Dobrava virus (DOBV) antigens at 7% or 2%, respectively, using an indirect immunofluorescence assay. Antibody prevalence among the bank vole males and females was equivalent, whereas for the striped field mouse, the prevalence among males was 5% versus 1% for females. In two bank vole specimens, we were able to detect partial nucleotide sequences that showed identity to PUUV. In summary, this study suggests that two human pathogens, PUUV and DOBV, cocirculate in the bank vole and the striped field mouse, respectively, in Ukraine. Future studies will focus on new rodent collections that will enable obtaining the complete genome sequences of the PUUV and DOBV strains circulating in Ukraine to provide guidance on the design of optimal molecular diagnostics that can enable insight into the potential contribution of hantaviruses to human disease in Ukraine.

Innate and adaptive immunity in wild rodents spontaneously and experimentally infected with the tick-borne encephalitis virus

Two dominant species of wild small rodents trapped in Novosibirsk region, South-Western Siberia, Russia differed in their susceptibility to the tick-borne encephalitis virus (TBEV) infection. TBEV RNA average detection rate for Northern red-backed vole Myodes rutilus (Pallas, 1779) (82.2 ± 5.8% blood samples and 63.1 ± 2.7% organ samples) significantly exceeded the corresponding values for the striped field mouse Apodemus agrarius (Pallas, 1771) (47.0 ± 8.7% blood and 24.5 ± 2.8% organ samples) (p <0.001). Innate immunity may be one of possible reasons of the differences. Th1 cytokine gene expression distinguished between M. rutilus (12.5 ± 8.5%) and A. agrarius (66.6 ± 11.4%), whereas Th2 cytokine frequencies were statistically similar (81.8 ± 12.2% and 100.0%, respectively). Polarization indexes (PI) of the innate immunity calculated as ratio of Th2 to Th1 cytokine RNA detection rates for both M. rutilus (6.5) and A. agrarius (1.5) suggested Th2 mainly humoral immune response against persistent TBEV in natural mammalian hosts. Therefore, the TBEV-induced antibodies were analyzed by ELISA and hemagglutination inhibition (HI) tests. The TBEV-specific antibodies were detected in 74.8 ± 4.3% sera of M. rutilus and 67.3 ± 6.8% of A. agrarius. Among them HI antibodies were found in 4.8 ± 2.1% of the same analyzed sera of M. rutilus and in 6.0 ± 3.4% blood samples of A. agrarius only.To model the TBEV persistence both M. rutilus and A. agrarius were infected with the suspensions of the TBEV-infected ticks with further observations during 4 subsequent months. Detection rate of the TBEV RNA and antigen E remained high during the whole period, however, pathogenic for laboratory suckling mice virus was isolated up to 8 days postinfection. At late stages of the persistent infection (1–4 months) the TBEV RNA detection rate in northern red-backed voles remained high 70.6 ± 7.9% whereas in striped field mice significantly declined to 26.7 ± 9.2% (p < .001). Comparative analysis of the innate immunity of the wild rodents in 2 months postinfection showed similar frequencies of Th2 cytokine gene expression for M. rutilus (77.8 ± 10.1%) and A. agrarius (71.4 ± 12.5%) (p > .05) but Th1 cytokine mRNA detection rates were different (44.4 ± 12.5% and 85.7 ± 9.7%, respectively) (p < .05). In 2 months PI decreased from 6.5 until 1.75 for M. rutilus and from 1.5 until 0.83 for A. agrarius. Nevertheless, Th2 mainly humoral immune response was confirmed by direct detection of the TBEV-specific antibodies. HI and neutralizing antibodies were revealed in blood sera of the small rodents of both studied species in 30 days postinfection and remained at detectable levels during 4 months of observations. Accordingly, Th2 polarized innate immunity of small rodents might facilitate the TBEV intracellular persistence in the presence of HI and neutralization antibodies.

Dynamics of Mouse-Like Rodent Communities in Anthropogenically Disturbed Territories of the Southeast of Western Siberia (Kemerovo Region, Russia)

We studied the dynamics of mouse-like rodent communities in the area of self-growing vegetation, which had undergone deforestation. The research is based on the results of continuous monitoring conducted from 1978 to 2019. Pitfall traps was the method of catching small mammals during the monitoring period. We used Simpson’s Diversity Index to quantify species diversity. The community similarity was evaluated by the percentage of species through Czekanowski-Sørensen Index. The studies were carried out near the “Azhendarovo” Biological Station (54°45ʹ N, 87°01ʹ E). The results of the studies showed that natural primeval communities of the taiga zone before deforestation were characterized by a multidominant structure. The dominant group included the Alexandromys oeconomus Pallas, 1776, and codominant species are represented by the genus Clethrionomys. A characteristic feature of the small mammals’ population of taiga forests is the preponderance of the Apodemus peninsulae (Thomas, 1907) over the Apodemus agrarius Pallas, 1771. On meadowlands, the genus Microtus voles prevailed. These were largely the Al. oeconomus, which accounted for 43% of all mouse-like rodents. After the deforestation, the structure changed. In the early stage of deforestation, the dominant species among rodents was the Al. oeconomus. The composition of dominant species in the recovering areas of cut-down taiga began to approach to the original state 40 years after the deforestation. Meadow communities followed the path of transformation, having no analogs in the initial period and were characterized by a significant amount of ruderal vegetation.

Документальное подтверждение обитания пятнистого оленя, дальневосточного лесного кота и полевой мыши на территории национального парка «Бикин»

In 2018-2019 three new mammal species were reliably registered on the territory of the Bikin National Park (Primorsky Krai, Russia): the sika deer Cervus nippon, the Amur leopard cat Prionailurus bengalensis euptilura and the striped field mouse Apodemus agrarius. For the first time, the habitats of these species were documented in the basin of the middle and upper reaches of the Bikin River (Primorsky Krai). The sika deer is included in the Red Book of the Russian Federation (Danilov-Danil’yan 2001) and the Red Book of Primorsky Krai (Kostenko 2005), and the Amur leopard cat is included in the Red Book of Primorsky Krai (Kostenko 2005).

Identification and investigation of Calodium hepaticum in rodents and insectivores from wuhan section of the yangtze river in China

Objective: To investigate the prevalence of Calodium hepaticum (C. hepaticum) in rodents and insectivores from Wuhan section of the Yangtze River in China, and to provide evidence for the prevention and treatment of hepatic Calodium infection. Methods: Rodents and insectivores were captured from three selected Yangtze River beaches using mousetraps. The three survey sites were divided into six areas according to natural conditions, with 60 mousetraps placed in each area. The liver lesions in the captured rodents were observed by the naked eye and the eggs in the liver tissue were observed by microscopic examination. Results: A total of 1 080 mousetraps were placed, and 1 075 mousetraps were retrieved, with the retrieve rate as 99.5%. A total of 101 Apodemus agrarius, 12 Rattus norvegicus, and 9 Crocidura attenuata were caught. The average density of rodents and insectivores was 10.5% and 0.8%, respectively. DNA of egg nodules from infected rodents showed 98% similarity with that of C. hepaticum 18S rRNA (LC425008.1). One Rattus norvegicus was infected with C. hepaticum, with an infection rate of 3.23% in the Erqi river beach; the other two beaches did not show the incidence of C. hepaticum. Conclusions: The monitoring of C. hepaticum in the Yangtze River beaches should be strengthened to reduce the risk of human C. hepaticum infection.

Первая находка полевой мыши — Apodemus agrarius Pallas, 1771 на территории Норского заповедника

Первая находка полевой мыши — Apodemus agrarius Pallas, 1771 на территории Норского заповедника

The striped field mouse (Apodemus agrarius) as a host of fleas (Siphonaptera) and tapeworms (Cestoda) in suburban environment of Lublin (eastern Poland)

The striped field mouse, Apodemus agrarius, is one of the most abundant species among small rodents in Poland. It occurs commonly across the whole country inhabiting diverse ecological niches as meadows, farmlands, enclaves of natural habitats in cities. Wide range of ecological tolerance of this species makes it often the host, reservoir and vector of many pathogens: viruses, bacteria, protozoa, helminths and arthropods. The aim of the present study was to carry out a qualitative and quantitative analysis of the fleas community and intestinal tapeworms of A. agrarius in suburban environment of Lublin (eastern Poland).&#x0D; In studied population three species of Siphonaptera class i.e. Ctenophthalmus agyrtes, Nosopsyllus fasciatus, Hystrichopsylla talpae and one intestine Cestoda species Hymenolepis diminuta were identified. The results of our researches confirmed role of A. agrarius as the reservoir for tapeworms and host for fleas in urban environment. High level of the prevalence of fleas and tapeworms in rodents indicates the significant degree of contamination and can cause an epidemiological threat for human’s health.

NEW FINDINGS OF CHIGGER MITES (ACARIFORMES: TROMBICULIDAE) IN THE REPUBLIC OF KARELIA AND THE ARKHANGELSK REGION

The article provides information on the occurrence of chigger mites (Acariformes, Trombiculidae), obtained as a result of long-term studies of the ectoparasite fauna of small mammals from 1992 to 2018 in Karelia, Murmansk Region (2015), Arkhangelsk Region (2007) and Finland (1999, 2007). A total of 6154 specimens of small mammals of the orders Rodentia (Myodes glareolus, M. rutilus, M. rufocanus, Microtus agrestis, M. oeconomus, Arvicola terrestris, Sicista betulina, Micromys minutus, Apodemus agrarius, A. flavicollis) and Eulipotyphla (Sorex araneus, S. caecutiens, S. isodon, S. minutus, Neomys fodiens) were examined and 878 chiggers were collected. Hirsutiella zachvatkini (Schluger 1948) and Neotrombicula (Digenualea) uliginosa Kudryashova 1998 were found. Their prevalences were 0.84 % and 0.16 %, respectively. H. zachvatkini (parasite associated with the bank vole) was found only in southern Karelia and south-western Arkhangelsk Region. The northernmost record of this species in Karelia comes from the Kizhi Archipelago (Medvezhjegorsky District), where after long-term monitoring and with a large number of host individuals examined, chiggers were found only on Malyi Lelikovsky Island (N61.989°; E35.15°). A high relative abundance of H. zachvatkini was observed in the south-west of Karelia, in the Lahdenpohsky District. The second species, N. uliginosa, was noted only in the north-west of Karelia (Voknavolok, N65.046857°; E30.603793°) on Microtus agrestis, Myodes glareolus and Neomys fodiens. Its prevalence and abundance were 12.3 % and 0.86 spm., respectively. This paper is the first report on the fauna of chiggers on small mammals in Karelia. Further focused studies of this group of arthropods may expand the list of species.

Three‐year surveillance (2016–2018) of chigger mites vector for tsutsugamushi disease in the Hwaseong‐Si area of Gyeonggi‐Do, Republic of Korea

AbstractOwing to climate change, the global resurgence of vector‐borne infectious diseases has emerged as a critical public health issue. Orientia tsutsugamushi is the etiological agent of tsutsugamushi disease (scrub typhus) a mite‐borne acute febrile disease occurring in the Asia‐Pacific region. We investigated the prevalence of tsutsugamushi disease transmitted by chigger mite vectors living on rodents. Using sticky‐type chigger traps for three months during 2016–2018, 1,057 chigger mites were collected (chigger mite index, 1.31) from four locations in the Hwaseong‐si area of Gyeonggi‐do, Republic of Korea. Five species distributed among three genera were identified. In addition, 94 rodents were captured (collection rate: 7.83%) using Sherman live traps over the course of three months (April, October, and November) during 2016–2017. Three rodent species were captured and identified and the striped field mouse (Apodemus agrarius) was the dominant rodent host species in the surveyed area. A total of 10,469 ectoparasitic chigger mites were recovered from the 94 rodents, from which 13 species distributed among four genera were identified. Of the 5,250 chigger mites examined, Leptotrombidium pallidum was most abundant (n = 2,558), followed by L. orientale, L. scutellare, L. zetum, Euschoengastia koreaensis, L. subintermedium, and Neotrombicula tamiyai. Of the examined chigger mites, no groups recovered from rodent hosts tested positive for O. tsutsugamushi. This study provides fundamental regional information on vector‐borne disease data collection in the Hwaseong‐si area, Gyeonggi‐do, and will further contribute to formulating disease control and prevention strategies.

Comparative analysis of peroxidase in digestive system of Apodemus agrarius and A. peninsulae

Comparative analysis of peroxidase in digestive system of Apodemus agrarius and A. peninsulae

Temporal Dynamics of Two Pathogenic Hantaviruses Among Rodents in Hungary.

Hantaviruses are worldwide pathogens, which often cause serious or even fatal diseases in humans. Hosts are predominantly in the form of rodents and soricomorphs; however, bats are also described as an important reservoir. In Hungary, representatives of two human pathogenic species of the genus Orthohantavirus are present: the Dobrava-Belgrade orthohantavirus and Puumala orthohantavirus. In Hungarian forests, the dominant rodent species are Apodemus flavicollis, Apodemus agrarius, Apodemus sylvaticus, and Myodes glareolus, all of which are natural reservoirs comprising different hantaviruses. The aim of the study was to survey the prevalence of hantaviruses among rodent populations and examine the potential relationship regarding population densities, years, sex, and seroprevalence. Rodents were trapped at 13 sampling plots in a forest reserve located in the Mecsek Mountain range, Hungary, from March to October between 2011 and 2014. Rodent serum samples were tested for IgG antibodies against Dobrava-Belgrade virus and Puumala virus by enzyme-linked immunosorbent assay (ELISA) using a recombinant nucleocapsid protein. During the 4-year sampling period, 2491 specimens were tested and 254 (10.2%) proved seropositive for orthohantaviruses. In 2011, the seroprevalence among Apodemus spp. and M. glareolus was 17.2% (114/661) and 3.9% (3/77), respectively, although this rate had reversed itself in 2014. Seropositivity was substantiated in 18.4% (12/65) of Myodes voles, while only 3.6% (13/359) of the tested Apodemus rodents were found to be IgG positive. Seroconversion was observed in 58 cases, while seroreversion was only detected in 3 individual cases. A significant difference among the number of infected males and females was identified in the first 2 years of our study. Winter survival with respect to rodents was not negatively affected due to the hantavirus infection. Hantavirus seroprevalence was not directly influenced by host abundance. Consequently, we assume that high rodent density alone does not lead to an increased risk of hantavirus infection among the rodent host population.

The city changes the daily activity of urban adapters: Camera-traps study of Apodemus agrarius behaviour and new approaches to data analysis

Abstract As a result of the widespread use of camera-traps, the analysis of the daily activity of animals based on field data has become a common practice, which is addressed in ecological studies. The more frequent consideration of this issue in ecological research, however, has not led to any advancement in the techniques of analysis of these activity patterns. In this work, we have two main aims: ecological and methodological. Firstly, using camera-traps in the winter period, we examine the differences in the daily activity of wild small mammal populations, which are affected or unaffected by urbanization; we treated changes in daily activity as indicators of species adaptation to urban conditions. Secondly, we test four different approaches to data analysis regarding the determination and comparison of activity patterns, which are not based on the traditional methods that have been used to date, such as particle swarm optimization (PSO), neural networks, decision trees and cluster analysis. We found that the urbanized environment modifies the daily activity patterns of the mammals studied. Animals from the urban population have a longer active period than their rural counterparts and can forage under more favourable thermal conditions, so that the energetic cost of foraging is lower. PSO and neural networks allow for a more detailed analysis of patterns of daily activity than traditional methods, and their results correspond well with each other. Daily activity analysis shows great potential in the application of new statistical approaches that could supplement and enrich the traditionally used methods (e.g. the kernel density estimation). Our approach may help researchers to gain a broader perspective during their analysis of daily activity patterns and lead to a better description of the ecology of the species or even to more balanced wildlife management decisions.

Native generalist consumers interact strongly with seeds of the invasive wild cucumber (Echinocystis lobata)

When alien plant species arrive in a new environment, they develop novel interactions with native biota that can range from negative to positive. Determining the nature and strength of these interactions is integral to understanding why some aliens are suppressed and others become highly invasive pests. For introduced terrestrial plants, seed and seedling interactions with native biota are crucial, because most nascent populations start from seed. Herein, we explored interactions between native generalist rodent and bird consumers and seeds of the invasive wild cucumber Echinocystis lobata by conducting seed-offering experiments in Poland. We also evaluated how interspecific competition from native plants and intraspecific competition from clustering of E. lobata seed (clustering resembling consumer seed caching) affected survival of seedlings and young plants. Native consumers interacted strongly with E. lobata seeds, with rodents removing 98% of seeds from ground locations and birds removing 24% of elevated seeds. Camera and live traps indicated that striped field mice Apodemus agrarius were the predominant rodent removing seeds. Camera traps and visual observations indicated that great tits Parus major and European jays Garrulus glandarius were the primary bird species removing elevated seeds. While some level of seed removal was likely attributable to seed predation, as indicated by seed coat remains, we also observed evidence that rodents may cache E. lobata seeds and Garrulus glandarius are known to cache and disperse seeds. Monitoring of seedlings indicated that increasing cover of native plants and clustering of E. lobata seedlings both reduced survival of seedlings and young plants due to inter- and intraspecific competition, respectively. Hence, caching by generalist consumers may disperse E. lobata seeds, which are heavy and lack dispersal adaptations, but such caching may also reduce individual seedling survival rates. Fully understanding invasion success of the E. lobata will require evaluating the net effects of generalist consumers on its recruitment and dispersal.