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1.
Oecologia ; 192(4): 919-928, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32166391

RESUMO

Edible dormice (Glis glis) can remain entirely solitary but frequently share sleeping sites with conspecifics in groups of up to 16 adults and yearlings. Here, we analysed grouping behaviour of 4564 marked individuals, captured in a 13-year study in nest boxes in a deciduous forest. We aimed to clarify (i) whether social thermoregulation is the primary cause for group formation and (ii) which factors affect group size and composition. Dormice temporarily formed both mixed and single-sex groups in response to acute cold ambient temperatures, especially those individuals with small body mass. Thus, thermoregulatory huddling appears to be the driving force for group formation in this species. Huddling was avoided-except for conditions of severe cold load-in years of full mast seeding, which is associated with reproduction and high foraging activity. Almost all females remained solitary during reproduction and lactation. Hence, entire populations of dormice switched between predominantly solitary lives in reproductive years to social behaviour in non-reproductive years. Non-social behaviour pointed to costs of huddling in terms of competition for local food resources even when food is generally abundant. The impact of competition was mitigated by a sex ratio that was biased towards males, which avoids sharing of food resources with related females that have extremely high energy demands during lactation. Importantly, dormice preferentially huddled in male-biased groups with litter mates from previous years. The fraction of related individuals increased with group size. Hence, group composition partly offsets the costs of shared food resources via indirect fitness benefits.


Assuntos
Myoxidae , Animais , Regulação da Temperatura Corporal , Feminino , Cavalos , Masculino , Reprodução , Comportamento Social
2.
Syst Parasitol ; 97(1): 83-98, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31933036

RESUMO

Armadolepis (Armadolepis) spasskyi Tenora & Barus, 1958 is redescribed on the basis of the type-series consisting of the holotype from the garden dormouse Eliomys quercinus (Linnaeus) (type-host) and a paratype from the forest dormouse Dryomys nitedula (Pallas); the occurrence of this species in the fat dormouse Glis glis (Linnaeus) cannot be confirmed due to the lack of specimens from this host species both in the type-series and other studied samples. The main corrections in the diagnostic characters of A. spasskyi are related to the number and length of the rostellar hooks (12 hooks, 12-14 µm long versus 16-19 hooks, 15.3-17.1 µm long in the original description) and the position of the testes in triangle (versus in line as originally described). Specimens originally identified as Hymenolepis myoxi (Rudolphi, 1819) by Genov (1984) from the fat dormouse G. glis from Bulgaria are described as Armadolepis (Bremserilepis) genovi n. sp. The new species differs from the congeners by the presence of a rudimentary rostellum and rudimentary rostellar hooks; the new species differs from the other two species of the subgenus, A. (B.) myoxi and A. (B.) longisoma, by its longer cirrus-sac (196-240 µm), scolex diameter of 180-300 µm (wider than that of A. myoxi and narrower than that of A. longisoma) and wider ovary (220-310 µm). Cestodes previously reported as Hymenolepis myoxi from E. quercinus from Switzerland and France (western and north-western Alps) are now identified as Armadolepis (A.) jeanbaeri Makarikov, 2017. Cestodes from G. glis from Switzerland and Slovakia, previously identified as Hymenolepis sulcata (von Linstow, 1879), are now identified as Armadolepis (B.) myoxi (sensu stricto). The position of Hymenolepis (s.l.) sciurina Cholodkovsky, 1913 as a subspecies of A. myoxi is rejected and it is considered a species inquirenda.


Assuntos
Cestoides/classificação , Myoxidae/parasitologia , Animais , Cestoides/anatomia & histologia , Europa (Continente) , Especificidade de Hospedeiro , Filogenia , Especificidade da Espécie
3.
Cytogenet Genome Res ; 158(3): 145-151, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31234172

RESUMO

Classical cytogenetics and mapping of 18S-28S rDNA and (TTAGGG)n sequences by fluorescence in situ hybridization (FISH) was performed on Graphiurus platyops (GPL) and Graphiurus ocularis (GOC) metaphases with the aim to characterize the genomes. In both species, inverted DAPI karyotypes showed the same diploid number, 2n = 46, and hybridization of the (TTAGGG)n probe revealed interstitial telomeric sequences (ITSs) at the centromeres of almost all bi-armed chromosomes. FISH with the rDNA probe localized nucleolus organizer regions (NORs), at the terminal ends of the p arms of the subtelocentric pairs 16 and 17 in both species and detected additional signals on GPL8 and GOC18, 19, and 22. The species have similar karyotypes, but their chromosome pairs 18-22 differ in morphology; these are acrocentric in G. platyops, as also confirmed by C-banding, and subtelocentric in G. ocularis. These differences in pairs 18-22 were also highlighted by hybridization of the telomeric probe (TTAGGG)n, which showed the small p arms in G. ocularis enriched with ITSs. FISH of rDNA probes detected multiple NOR loci in G. ocularis, underlining the intense evolutionary dynamics related to these genes. Although the Graphiurus species analyzed have similar karyotypes, the results on the repetitive sequences indicate a complex pattern of genomic reorganization and evolution occurring in these phylogenetically close species.


Assuntos
Cromossomos de Mamíferos/genética , DNA Ribossômico/genética , Myoxidae/genética , RNA Ribossômico 18S/genética , RNA Ribossômico 28S/genética , Animais , Sequência de Bases , Bandeamento Cromossômico , Hibridização in Situ Fluorescente , Cariótipo , Masculino , África do Sul
4.
Sci Rep ; 8(1): 13881, 2018 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-30224823

RESUMO

Small hibernators are long-lived for their size because seasonal dormancy greatly reduces predation risk. Thus, within a year, hibernators switch between states of contrasting mortality risk (active season versus hibernation), making them interesting species for testing the predictions of life-history theory. Accordingly, we hypothesized that, with advancing age and hence diminishing reproductive potential, hibernators should increasingly accept the higher predation risk associated with activity to increase the likelihood of current reproductive success. For edible dormice (Glis glis) we show that age strongly affects hibernation/activity patterns, and that this occurs via two pathways: (i) with increasing age, dormice are more likely to reproduce, which delays the onset of hibernation, and (ii) age directly advances emergence from hibernation in spring. We conclude that hibernation has to be viewed not merely as an energy saving strategy under harsh climatic conditions, but as an age-affected life-history trait that is flexibly used to maximize fitness.


Assuntos
Envelhecimento/fisiologia , Hibernação/fisiologia , Myoxidae/fisiologia , Reprodução/fisiologia , Animais , Feminino , Masculino , Estações do Ano
5.
J Exp Biol ; 221(Pt 20)2018 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-30127077

RESUMO

Entire populations of edible dormice (Glis glis) can skip reproduction in years without mast seeding of deciduous trees (particularly beech or oak seed), because juveniles require high-calorie seeds for growth and fattening prior to hibernation. We hypothesized that, in mast failure years, female dormice may be forced to spend larger amounts of time foraging for low-quality food, which would increase their exposure to predators, mainly owls. This may lead to chronic stress, i.e. long-term increased secretion of glucocorticoids (GC), which can have inhibitory effects on reproductive function in both female and male mammals. We monitored reproduction in free-living female dormice over 3 years with varying levels of food availability, and performed a supplemental feeding experiment. To measure stress hormone levels, we determined fecal GC metabolite (GCM) concentrations collected during the day, which reflect hormone secretion rates in the previous nocturnal activity phase. We found that year-to-year differences in beech mast significantly affected fecal GCM levels and reproduction. However, contrary to our hypothesis, GCM levels were lowest in a non-mast year without reproduction, and significantly elevated in full-mast and intermediate years, as well as under supplemental feeding. Variation in owl density in our study area had no influence on GCM levels. Consequently, we conclude that down-regulation of gonads and reproduction skipping in mast failure years in this species is not caused by chronic stress. Thus, in edible dormice, delayed reproduction apparently is profitable in response to the absence of energy-rich food in non-mast years, but not in response to chronic stress.


Assuntos
Corticosterona/metabolismo , Dieta/veterinária , Glucocorticoides/metabolismo , Myoxidae/fisiologia , Reprodução , Estresse Fisiológico , Animais , Áustria , Suplementos Nutricionais/análise , Feminino
6.
Mol Phylogenet Evol ; 127: 712-722, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29906609

RESUMO

We used the fat dormouse (Glis glis), a species from a monotypic genus of family Gliridae, as a model to promote the understanding of patterns of cryptic diversification along the ancient Hyrcanian Forests, one of the old-growth relicts of the temperate deciduous forests worldwide. Mitochondrial Cytb data was used to investigate the phylogenetic status of two geographically-different populations of G. glis along the Hyrcanian Forests among all the worldwide known lineages of the species. Regarding phylogenetically informed partitioning of occurrence data, we then used two analytically different ENMs (i.e. environmental-space and geographic-space) to address whether niche divergence conforms G. glis diversification over the study area. Phylogenetic reconstruction showed significant heterogeneity between other fat dormouse lineages and those belonging to the Hyrcanian Forests as well as within the two hypothesized cryptic groups in the study area. Quantifying niche differences using the two ENM frameworks additionally confirmed divergence between the two cryptic lineages by indicating niche conservatism. The integration of phylogeny and ENM in this study confirms the development of distinct cryptic species and suggests that the Hyrcanian Forests, a well-known Pleistocene refugium, might contain multiple cryptic refugia for small forest-dwelling species during paleontological oscillations.


Assuntos
Ecossistema , Modelos Teóricos , Filogenia , Refúgio de Vida Selvagem , Animais , Teorema de Bayes , Variação Genética , Haplótipos/genética , Irã (Geográfico) , Myoxidae/classificação , Filogeografia , Análise de Componente Principal , Fatores de Tempo
7.
Elife ; 72018 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-29458711

RESUMO

Dormice born late in the year start to prepare for winter sooner than mice born earlier in the year.


Assuntos
Hibernação , Myoxidae , Torpor , Animais , Fertilidade , Camundongos , Estações do Ano
8.
Elife ; 72018 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-29458712

RESUMO

For hibernators, being born late in the active season may have important effects on growth and fattening, hence on winter survival and reproduction. This study investigated differences in growth, fattening, energetic responses, winter survival and fecundity between early-born ('EB') and late-born ('LB') juvenile garden dormice (Eliomys quercinus). LB juveniles grew and gained mass twice as fast as EB individuals. Torpor use was low during intensive growth, that are, first weeks of body mass gain, but increased during pre-hibernation fattening. LB juveniles showed higher torpor use, reached similar body sizes but lower fat content than EB individuals before hibernation. Finally, LB individuals showed similar patterns of hibernation, but higher proportion of breeders during the following year than EB dormice. These results suggest that torpor is incompatible with growth but promotes fattening and consolidates pre-hibernation fat depots. In garden dormice, being born late in the reproductive season is associated with a fast life history.


Assuntos
Fertilidade , Hibernação , Myoxidae/fisiologia , Sobrevida , Torpor , Ganho de Peso , Animais , Myoxidae/crescimento & desenvolvimento , Estações do Ano , Fatores de Tempo
9.
J Comp Physiol B ; 188(3): 553-563, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29299670

RESUMO

Hibernation is the most effective way to reduce thermoregulatory costs during periods of unfavourable environmental conditions. In preparation to hibernation, fat-storing hibernators accumulate large quantities of body fat, which increases their locomotor costs and also the risk of predation. As a consequence, there should be a strong selective pressure to restrict pre-hibernation fattening to a short-time period before the onset of hibernation. The edible dormouse (Glis glis) is characterized by having adapted its whole life history to the irregularly occurring mast-seeding pattern of the European beech (Fagus sylvaticus). Thus, the question arises how this small endotherm copes with huge differences in food availability between years. Therefore, we investigated body mass and thermal energetics of edible dormice during high and low food years. Our results demonstrate that during periods of low food availability, edible dormice enter an energy-saving mode with reduced body temperature (Tb) and resting metabolic rate (RMR), and high torpor frequencies. During irregularly occurring short events of high food availability in mast years, however, Tb was higher, torpor did not occur, and RMR was drastically elevated possibly due to an enlarged digestive tract and the heat increment of feeding associated with a dietary switch to high-quality food and an increase in the amount of food ingested. This physiological flexibility allows edible dormice to efficiently accumulate body fat reserves under extremely different situations of food availability.


Assuntos
Regulação da Temperatura Corporal , Comportamento Alimentar , Myoxidae/fisiologia , Animais , Metabolismo Basal , Temperatura Corporal , Peso Corporal , Fagus , Masculino , Consumo de Oxigênio , Sementes , Temperatura
10.
J Comp Physiol B ; 188(2): 359-371, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28756562

RESUMO

The oxygen delivery system is one major determinant of the performance of vertebrates and responds sensitively to a variety of internal and environmental factors. To understand physiological mechanisms underlying variations of fitness, we investigated effects of demanding conditions associated with certain life-history events, food availability, and population density on the oxygen delivery system in free-ranging edible dormice (Glis glis). We sampled blood (n = 248) and urine (n = 319), performed an erythrocyte haemogram and visually determined the presence of haemoglobinuria. Reproduction leads to increased mortality in edible dormice and our study now reveals severe haematological impairments during reproduction that were associated with nutrient and energy deficits and stress. These effects were even more pronounced in subsequent reproductive years, indicating prolonged physiological impairment. Under limited food availability, the rate of erythrocyte generation was reduced. This seems to be part of an energy saving strategy instead of representing a poor body condition as survival probability in this species is high in years of low food availability. A high prevalence ratio of haemoglobinuria (up to 85%) at the end of the active season indicated amplified erythrocyte destruction through haemolysis. This may be the result of a preparative mechanism to avoid massive oxidative damage during the long hibernation period. Most ecophysiological studies so far focus on single erythrocyte parameters on a short time scale, which could be misleading. Our results clearly highlight that a wide-array RBC approach is a powerful tool for investigating mechanisms underlying physiological performance and fitness, also for other vertebrate taxa.


Assuntos
Índices de Eritrócitos , Hibernação/fisiologia , Myoxidae/sangue , Myoxidae/fisiologia , Animais , Feminino , Masculino , Reprodução/fisiologia , Estações do Ano
11.
Syst Parasitol ; 95(1): 65-79, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29168150

RESUMO

Two new species of hymenolepidid cestodes belonging to the genus Armadolepis Spassky, 1954 are described from dormice (Gliridae) from the southern East European Plain and the northwestern Caucasus, Russia. Armadolepis (Bremserilepis) longisoma n. sp., with a rudimentary, unarmed rostellar apparatus is described from the fat dormouse Glis glis (Linnaeus) from the Republic of Adygeya, Russia. Additionally, A. (Armadolepis) dryomi n. sp., characterised by a well-developed rostellar apparatus and armed rhynchus is described from the forest dormouse Dryomys nitedula Pallas from Rostov Oblast', Russia. Armadolepis (Bremserilepis) longisoma n. sp. differs from A. (Bremserilepis) myoxi (Rudolphi, 1819) in having a substantially longer strobila and cirrus-sac, wider scolex and ovary and larger rostellar pouch and testes. Armadolepis (Armadolepis) dryomi n. sp. is distinguishable from A. (Armadolepis) spasskii Tenora & Barus, 1958, A. (Armadolepis) jeanbaeri Makarikov, 2017 and A. (Armadolepis) tenorai Makarikov, 2017 in having a substantially longer and wider strobila, and larger rostellar pouch and cirrus-sac. Furthermore, A. dryomi n. sp. can be distinguished from its congeners by the number and size of rostellar hooks and the arrangement of the testes. Phylogenetic affinities of Armadolepis were studied for the first time using partial sequences of the nuclear ribosomal 28S DNA gene. Phylogenetic analysis strongly supported the status of Armadolepis as a separate genus belonging to the "Rodentolepis clade".


Assuntos
Cestoides/classificação , Myoxidae/parasitologia , Filogenia , Animais , Cestoides/anatomia & histologia , Cestoides/genética , RNA Ribossômico 28S/genética , Federação Russa , Especificidade da Espécie
12.
J Comp Physiol B ; 187(5-6): 803-814, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28321493

RESUMO

Measuring T b during the active season can provide information about the timing of reproduction and the use of short bouts of torpor and may be used as a proxy for the locomotor activity of animals (i.e., maximum T b). This kind of information is especially important to understand life-history strategies and energetic costs and demands in hibernating mammals. We investigated T b throughout the active season in edible dormice (Glis glis), since they (i) have an expensive arboreal life-style, (ii) are known to show short bouts of torpor, and (iii) are adapted to pulsed resources (mast of beech trees). We show here for the first time that maximum T b's in free-living active dormice (during the night) increase regularly and for up to 8 h above 40 °C, which corresponds to slight hyperthermia, probably due to locomotor activity. The highest weekly mean maximum T b was recorded 1 week prior to hibernation (40.45 ± 0.07 °C). At the beginning of the active season and immediately prior to hibernation, the mean maximum T b's were lower. The time dormice spent at T b above 40 °C varied between sexes, depending on mast conditions. The date of parturition could be determined by a sudden increase in mean T b (plus 0.49 ± 0.04 °C). The occurrence of short torpor bouts (<24 h) was strongly affected by the mast situation with much higher torpor frequencies in mast-failure years. Our data suggest that locomotor activity is strongly affected by environmental conditions, and that sexes respond differently to these changes.


Assuntos
Temperatura Corporal/fisiologia , Locomoção/fisiologia , Myoxidae/fisiologia , Torpor/fisiologia , Animais , Feminino , Masculino , Reprodução , Estações do Ano
13.
Artigo em Inglês | MEDLINE | ID: mdl-28105489

RESUMO

Dormouse numbers are declining in the UK due to habitat loss and fragmentation. We know that dormice are nocturnal, arboreal, and avoid crossing open spaces between habitats, yet how they navigate around their canopy is unknown. As other rodents use whisker touch sensing to navigate and explore their environment, this study investigates whether Hazel dormice (Muscardinus avellanarius) employ their whiskers to cross between habitats. We analysed high-speed video footage of dormice exploring freely in flat and climbing arenas in near darkness and using infrared light illumination. We confirm that, like rats and mice, dormice move their whiskers back and forth continuously (~10 Hz) in a motion called whisking and recruit them to explore small gaps (<10 cm) by increasing the amplitude and frequency of whisking and also the asymmetry of movement between the left and right whisker fields. When gaps between platforms are larger than 10-15 cm, dormice spend more time travelling on the floor. These findings suggest that dormice can actively and purposively move their whiskers to gather relevant information from their canopy at night. As this species is vulnerable to threats on the ground, we also provide evidence that joining habitat patches between dormouse populations is important for promoting natural behaviours and movement between patches.


Assuntos
Ecossistema , Comportamento Exploratório/fisiologia , Myoxidae/fisiologia , Tato/fisiologia , Árvores , Vibrissas/fisiologia , Animais , Feminino , Masculino , Gravação em Vídeo/métodos
14.
Ecohealth ; 14(Suppl 1): 106-116, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-26957436

RESUMO

The success of any population translocation programme relies heavily on the measures implemented to control and monitor the spread of disease. Without these measures, programmes run the risk of releasing immunologically naïve species or, more dangerously, introducing novel infectious agents to native populations. As a precaution, a reintroduction programme for the common or hazel dormouse, Muscardinus avellanarius, in England screens dormice before release following captive breeding. Using PCR sequencing of a range of genes, we tested whether the same species of tapeworm(s) were present in captive and free-living dormice. Whilst only Rodentolepis straminea were identified in free-living dormice, cestode ova found in a captive individual produced a molecular match closely related to Hymenolepis microstoma and a previously unrecorded Rodentolepis species. To prevent putting at risk the free-living population, we recommended the continued treatment of dormice showing tapeworm infection before release. Our work demonstrates how molecular techniques can be used to inform reintroduction programmes, reduce risk from disease and increase chances of reintroduction success.


Assuntos
Cestoides/patogenicidade , Myoxidae/parasitologia , Animais , Cestoides/genética , Inglaterra , Parasitos , Reação em Cadeia da Polimerase
15.
J Comp Physiol B ; 187(1): 253-263, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27480769

RESUMO

Juvenile hibernators have to allocate energy to both growth and fattening, to survive winter, and to avoid possible disadvantages during their first reproductive season. Being born late in the active season may have important effects on growth and fattening. This study aimed at determining potential differences in rates and maximal level of growth, and in pre-hibernation body fat mass between early and late-born juvenile garden dormice (Eliomys quercinus), and kept in outdoor enclosures with ad libitum food and water. We first assessed mean pup mass in early and late-born litters (n = 31) from birth to their early weaning phase, at which time body composition was determined. Then, growth and body mass of early and late-born individuals (six males and six females, for each group) were measured weekly until hibernation onset (n = 24). We also assessed fat content in a group of juveniles during pre-hibernation fattening (n = 16) and after their first winter hibernation (n = 18). During the pre-weaning phase, young from early and late litters mainly grew structurally and gained mass at similar rates. After weaning, late-born juveniles grew and gained mass twice as fast as early born individuals. Body mass was positively associated with fat content during pre-hibernation fattening. Late-born females reached similar structural sizes, but had lower pre-hibernation fat reserves than early born females. Conversely, late-born males showed lower maximal size and pre-hibernation body fat content, compared with early born males. Thus, individuals born late in the season cannot fully compensate the lack of available time before the winter onset.


Assuntos
Myoxidae/crescimento & desenvolvimento , Animais , Composição Corporal , Tamanho Corporal , Feminino , Hibernação , Lactação , Masculino , Myoxidae/fisiologia , Desmame
16.
Acta Parasitol ; 62(1): 1-21, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28030358

RESUMO

In present study the systematic and taxonomic position of hymenolepidids parasitizing rodents of the family Gliridae from Europe and Central Asia is discussed. Hymenolepis myoxi is redescribed on the basis of the type material from the fat dormouse Glis glis deposited in the collection of the Museum für Naturkunde, Berlin, Germany. Significant corrections of morphologically distinctive characters attributable to H. myoxi include: (1) recognition of a rudimentary rostellar apparatus; (2) absence of rostellar hooks and spination on the suckers; and (3) tissues of the scolex and neck filled with numerous "firm elements". Hymenolepis sulcata was recognised as a synonym of H. myoxi (sensu stricto). The generic allocation of true H. myoxi and validity of the genus Armadolepis is clarified. Specimens from Eliomys quercinus originally designated as H. myoxi by Baer (1932) are described as a new species, Armadolepis jeanbaeri n. sp. The taxonomy has potentially been confused as Spassky (1954) designated misidentified specimens of H. myoxi sensu Baer (1932) as the type species of the genus Armadolepis. In the current article, this error is corrected and A. jeanbaeri n. sp. is fixed as the type of the genus Armadolepis. An additional new species of Armadolepis, A. tenorai n. sp., is described from Dryomys nitedula from Almaty Province, Kazakhstan. The generic diagnosis of Armadolepis is amended. Armadolepis (sensu stricto) is subdivided into two subgenera; the nominotypical subgenus includes species having well developed rostellar apparatus armed by rostellar hooks and A. (Bremserilepis) n. subgen. includes species with rudimentary and unarmed rostellar apparatus.


Assuntos
Cestoides/classificação , Himenolepíase/veterinária , Myoxidae , Doenças dos Roedores/parasitologia , Animais , Cestoides/isolamento & purificação , Himenolepíase/parasitologia , Especificidade da Espécie
17.
Behav Processes ; 135: 25-28, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27908663

RESUMO

Communal nesting has been described in many rodents including some dormouse species. In this study, we report the existence of this reproductive strategy in the garden dormouse Eliomys quercinus. Data was recorded by checking natural nests and nest-boxes from 2003 to 2013 in SE Spain. Pups and adults dormice found in nests were captured and marked. Overall, 198 nests were found: 161 (81.31%) were singular nests and 37 (18.69%) were communal nests. Communal nests were composed by different combinations of one up to three females together with one up to three different size litters. The number of communal nests varied from year to year in accordance with the number of singular nests and no seasonal differences were observed. In at least one case, an adult female and her adult daughter were found sharing the same nest-box. The hypothesis that communal nesting was encouraged by a lack of favourable nesting sites was rejected. Litters protection from predators or conspecifics seems the most likely hypothesis to explain communal nesting in our garden dormouse population.


Assuntos
Myoxidae/fisiologia , Comportamento de Nidação/fisiologia , Reprodução/fisiologia , Animais , Feminino , Espanha
18.
Sci Rep ; 6: 36856, 2016 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-27883035

RESUMO

Telomere shortening is thought to be an important biomarker for life history traits such as lifespan and aging, and can be indicative of genome integrity, survival probability and the risk of cancer development. In humans and other animals, telomeres almost always shorten with age, with more rapid telomere attrition in short-lived species. Here, we show that in the edible dormouse (Glis glis) telomere length significantly increases from an age of 6 to an age of 9 years. While this finding could be due to higher survival of individuals with longer telomeres, we also found, using longitudinal measurements, a positive effect of age on the rate of telomere elongation within older individuals. To our knowledge, no previous study has reported such an effect of age on telomere lengthening. We attribute this exceptional pattern to the peculiar life-history of this species, which skips reproduction in years with low food availability. Further, we show that this "sit tight" strategy in the timing of reproduction is associated with an increasing likelihood for an individual to reproduce as it ages. As reproduction could facilitate telomere attrition, this life-history strategy may have led to the evolution of increased somatic maintenance and telomere elongation with increasing age.


Assuntos
Hibernação/genética , Myoxidae/genética , Roedores/genética , Homeostase do Telômero/genética , Encurtamento do Telômero/genética , Telômero/genética , Envelhecimento/genética , Animais , Feminino , Longevidade/genética , Masculino , Reprodução/genética
19.
J Exp Biol ; 219(Pt 16): 2469-74, 2016 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-27535986

RESUMO

We studied the impact of hibernation and food supply on relative telomere length (RTL), an indicator for aging and somatic maintenance, in free-living edible dormice. Small hibernators such as dormice have ∼50% higher maximum longevity than non-hibernators. Increased longevity could theoretically be due to prolonged torpor directly slowing cellular damage and RTL shortening. However, although mitosis is arrested in mammals at low body temperatures, recent evidence points to accelerated RTL shortening during periodic re-warming (arousal) from torpor. Therefore, we hypothesized that these arousals during hibernation should have a negative effect on RTL. Here, we show that RTL was shortened in all animals over the course of ∼1 year, during which dormice hibernated for 7.5-11.4 months. The rate of periodic arousals, rather than the time spent euthermic during the hibernation season, was the best predictor of RTL shortening. This finding points to negative effects on RTL of the transition from low torpor to high euthermic body temperature and metabolic rate during arousals, possibly because of increased oxidative stress. The animals were, however, able to elongate their telomeres during the active season, when food availability was increased by supplemental feeding in a year of low natural food abundance. We conclude that in addition to their energetic costs, periodic arousals also lead to accelerated cellular damage in terms of RTL shortening. Although dormice are able to counteract and even over-compensate for the negative effects of hibernation, restoration of RTL appears to be energetically costly.


Assuntos
Abastecimento de Alimentos , Hibernação/fisiologia , Myoxidae/fisiologia , Telômero/metabolismo , Animais , Temperatura Corporal/fisiologia , Comportamento Alimentar/fisiologia , Estações do Ano , Homeostase do Telômero
20.
PLoS One ; 11(1): e0146142, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26789632

RESUMO

The development of appropriate wildlife survey techniques is essential to promote effective and efficient monitoring of species of conservation concern. Here, we demonstrate the utility of two rapid-assessment, non-invasive methods to detect the presence of elusive, small, arboreal animals. We use the hazel dormouse, Muscardinus avellanarius, a rodent of conservation concern, as our focal species. Prevailing hazel dormouse survey methods are prolonged (often taking months to years to detect dormice), dependent on season and habitat, and/or have low detection rates. Alternatives would be of great use to ecologists who undertake dormouse surveys, especially those assessing the need for mitigation measures, as legally required for building development projects. Camera traps and footprint tracking are well-established tools for monitoring elusive large terrestrial mammals, but are rarely used for small species such as rodents, or in arboreal habitats. In trials of these adapted methods, hazel dormice visited bait stations and were successfully detected by both camera traps and tracking equipment at each of two woodland study sites, within days to weeks of installation. Camera trap images and footprints were of adequate quality to allow discrimination between two sympatric small mammal species (hazel dormouse and wood mouse, Apodemus sylvaticus). We discuss the relative merits of these methods with respect to research aims, funds, time available and habitat.


Assuntos
Ecossistema , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Myoxidae/fisiologia , Animais
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