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98 E. Lekevičius + Gyva tik ekosistema: ne visai tradicinis požiūris į gyvybės evoliuciją Afrikos juodaodžių populiacijose, gyvenančiose ne tokiomis komfortiškomis kaip amerikiečiai sąlygomis ir todėl patiriančiose kur kas galingesnį stabilizuojančiosios …
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4.6. WHITE-TIPPED AND TAIL-LESS DORMICE and normal females: average litter size was 3.87 (n = 31) and 3.88 (n = 148) respectively, and the sex ratio among offspring was very close to 1: 1 in both cases. On average, 56.6% of juveniles were white- tipped …
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148 4. POPULATION STRUCTURE IN M. AVELLANARIUS tions, but usually at a very low frequency. The example of M. avellanarius from study site A mentioned above shows that some- times it is necessary to examine large num- bers of individuals: in the population …
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4.6. WHITE-TIPPED AND TAIL-LESS DORMICE lower than of other females, which also in- dicates lower reproductive success in white- tipped females of M. avellanarius. Reasons for the close correlation between the percentage of white-tipped M. avel- lanarius …
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150 4. POPULATION STRUCTURE IN M. AVELLANARIUS of the broken tail (Fig. 80). Individuals of M. avellanarius with a white hair “whisk” at the tip of the broken tail were caught in Brit- ain (P. Rudlin, unpublished) and Germany (S. Biichner, pers. comm.). …
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4.6. WHITE-TIPPED AND TAIL-LESS DORMICE the tail in July and almost all the remaining part of the tail (1 cm left) in September of the same year. Annual survival rates of tail- less M. avellanarius were inversely related to the length of the lost tail: …
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152 4. POPULATION STRUCTURE IN M. AVELLANARIUS large-island populations of the same spe- cies it was 13-25% (McKee & Adler 2002). Tail autotomy appeared as a common event in the natural history of Proechimys from French Guiana, being found in 6.1-12.7% of …
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4.6. WHITE-TIPPED AND TAIL-LESS DORMICE predation because such a link has not been established yet. According to Jaksic & Greene (1984), tail loss frequencies in lizards are more likely to reflect the inefficiency of predators rather than the intensity of …
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5. Self-regulation in populations of M. avellanarius 5.1. Relationship between population density and reproductive SUCCESS Both intrinsic density-dependent fac- tors and extrinsic density-independent fac- tors, as well as their interactions, play an …
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5.1. POPULATION DENSITY AND REPRODUCTION 0.8 7 Density, ind./ha 0.6 5 0.4 5 O25 —@— density after hibernation —{l—_ f ad density after hibernation 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 —/\— fad density in July Fig. 81. …
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156 5. SELF-REGULATION IN M. AVELLANARIUS Spearman rank correlation: r, = -0.92, p < 0.0001, n= 11 90 85 80 (i Percentage of juveniles in autumnal population 70 65 A 0.1 0.2 0.3 0.4 0.5 0.6 Density of adult females in July, ind./na Fig. 82. Relationship …
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5.1. POPULATION DENSITY AND REPRODUCTION average, one reproducing female produced 3.4 juveniles in 1956 when there were no second litters, and 6.1 juveniles in the next year, which included second litters. The pro- portion of two-year-old and older …
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158 5. SELF-REGULATION IN M. AVELLANARIUS conditions led to intensive breeding. A high proportion of breeding females, an increased number of second litters and breeding by young-of-the-year females were recorded in that year. In consequence, …
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20 Percentage S 5.2. BREEDING BY YOUNG FEMALES May-2 May-3 Jun-1 Jun-2 Jun-3 Jul-1 Jul-2 Jul-3 Aug-1 Aug-2 Aug-3 Sep-1 Sep-2 Sep-3 Fig. 83. Birth time of litters by young-of-the-year females (marked in dark green) among all litters of M. avella- narius (n …
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160 5. SELF-REGULATION IN M. AVELLANARIUS (Juskaitis 2003a, 2008a). According to Wolff (1997), if self-regulation is to occur, it will be mediated through territoriality and repro- ductive suppression, which limit the number of breeding females in a …
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in the case of the fat dormouse Glis glis when survival rates and breeding patterns of this species were compared across Europe (Lebl 5.3. PROLONGED BREEDING et al. 2011). Comparable studies of M. avel- lanarius populations across Europe are nece- ssary …
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162 5. SELF-REGULATION IN M. AVELLANARIUS Spearman rank correlation: r, = -0.58, p = 0.002, n = 27 T AAA A AA 20 a n ® % ate ° 15 A os & vo o2 £5 10 —- QA o®o on” De = 5 ® 2 ® a 0 A 0.1 0.2 0.3 0.4 0 0.6 Density of adult females in July, ind./ha Fig. 85. …
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tively). In three ten-day periods of August, an obvious trend was observed, namely that overwinter survival of later breeding females decreased compared to earlier breeding fe- males (Fig. 86). However, overwinter sur- vival of females that gave birth in …
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164 5. SELF-REGULATION IN M. AVELLANARIUS To summarise, prolonged breeding in M. avellanarius populations was associated with decreased adult female density in sum- mer, but the abundance of suitable food could also stimulate such breeding. In the south …
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(J control Wi experiment Density, ind./ha 1985 1986 1987 1988 1989 5.4. INFLUENCE OF NESTBOXES 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Fig. 87. Density of adult M. avellanarius in two separate plots of study site A in 1985-1989 and 2000-2009. …
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166 5. SELF-REGULATION IN M. AVELLANARIUS effect was statistically significant both in males (t = 3.12, df = 39, p = 0.003) and fe- males (t = 2.21, df = 24, p = 0.037). 100 m e1-—_—2 => 3 — Fig. 88. Home ranges (minimum convex polygons) of adult M. …
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Nestboxes set up at high densities can be useful for the conservation of M. avel- lanarius where dormice are rare and threat- ened. However, because of their consider- able influence on dormouse population 5.5. SELF-REGULATION IN RODENTS density and other …
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168 5. SELF-REGULATION IN M. AVELLANARIUS Thus, extrinsic factors such as food level may also interact with density in determining the proportion of females entering the breeding population. Prevot-Julliard et al. (1999) found that delayed maturation in …
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hibition of reproduction may be the single most important mechanism regulating and limiting populations of the Peromyscus spe- cies, although a high mortality rate may be associated with increased density too (Chris- tian 1971). Populations of Alpine snow …
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170 5. SELF-REGULATION IN M. AVELLANARIUS of the species distributional range where population densities are comparatively low. In other southern parts of its range where living conditions are more favourable and population densities are higher, different …
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Summary The common dormouse Muscardinus avellanarius (Linnaeus, 1758), also often re- ferred to as the hazel dormouse, is a repre- sentative of the rodent order (Rodentia) and dormouse family (Gliridae). The geographi- cal range of M. avellanarius covers …
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172 SUMMARY ground is about 1 m, and is related to the age and height of young trees and shrubs. In woodlands with high canopy forming trees, most nests of M. avellanarius can be situated in the canopy out of human reach. In all parts of its …
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the soil temperature. Hibernation follows a characteristic pattern: torpor bouts up to 30 days are interrupted by bouts of euthermia lasting several hours. Photoperiod is the principal exogenous factor influencing pan-seasonal activity in M. avellanarius. …
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174 SUMMARY 10-15 ind./ha. However, data on M. avel- lanarius population density may be overes- timated by up to ten-fold in some cases for methodological reasons or may reflect only the densities in small and most favourable plots. In large areas with …
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to 80% of marked animals lost during win- ter (e.g. Likhachev 1966b; Juskaitis 2008a). There is an obvious basic tendency for younger dormice to suffer higher winter mortality rates. Some juveniles born in late summer or early autumn do not accumulate …