"Single-capture" rodents: vagrants or just newly weaned young?

Abstract

The reliability of the estimation of residency time of the bank vole Clethrionom ys glareolus (Schreber, 1780) and the yellow-necked mouse Apodem us flavicollis (Melchior, 1834) in open populations was assessed by halving the 6-w eek intervals between trapping sessions. The status of " single-capture" individuals was identified to estimate the probability that they are native young rather than adult invaders. W e found that the majority of " single-session" individuals constituted true transients that were present in the study plot for a short time only. They were young, immature rodents with a small body mass and a small number o f captures. The probability that the " single-session" individuals stay on the plot for a longer time was 0 .35 and 0.37 for voles and mice, respectively. These ostensible transients were trap-prone, fully-grown, mature adults, that revealed their presence on the plot already at the beginning of each trapping session. W e found that " single-capture" individuals were mainly young, immature rodents that were not retrapped. The probability that the single-capture rodents are mature individuals, with a longer residency tim e, was 0 .10 and 0 .18 for voles and mice, respectively.

Body mass and sex, but not breeding condition and season, influence open‐field exploration in the yellow‐necked mouse

“…As a prominent example, a recent meta‐analysis suggested that in the wild, individuals expressing greater risky behaviors live longer (Moiron et al, 2020). While contrary to predictions, our results on exploration vs. body mass might be linked to age‐specific patterns of exploration and dispersal in rodents (Gliwicz, 1988; Macrı̀ et al, 2002; Rajska‐Jurgiel & Mazurkiewicz, 2000), and the influence of sex on exploration in the open field conforms to long‐standing theoretical notions (Palanza, 2001a). Finally, the presence of strong and highly consistent interindividual differences in exploration tendency suggests the existence of individuals strategies (“behavioral types”) that go beyond the effects of body mass and sex.…”

“…As a prominent example, a recent meta-analysis suggested that in the wild, individuals expressing greater risky behaviors live longer (Moiron et al, 2020). While contrary to predictions, our results on exploration vs. body mass might be linked to agespecific patterns of exploration and dispersal in rodents (Gliwicz, 1988;Macrı̀ et al, 2002;Rajska-Jurgiel & Mazurkiewicz, 2000),…”

“…During this period, risk taking and exploration of novel environments might be selectively favored (Macrì et al, 2002 ). In support of this line of reasoning, subadults are overrepresented among dispersers in the yellow‐necked mouse (Gliwicz, 1988 ; Rajska‐Jurgiel & Mazurkiewicz, 2000 ). We note, however, that in our study, the highest exploration occurred in animals that weighed almost 30 g, whereas dispersers in field studies of yellow‐necked mice typically weigh only about 20 g (Gliwicz, 1988 ; Rajska‐Jurgiel & Mazurkiewicz, 2000 ).…”

Is the matrix really inhospitable? Vole runway distribution in an experimentally fragmented landscape

“…Third, if the focal species is competitively inferior to a species occurring primarily on larger patches, the focal species might occur in large numbers on small patches because of exclusion from large patches (Diffendorfer et al 1996). Fourth, if small patches represent sub‐optimal habitat or are smaller than an individual's home range, they would have a continually changing population of vagrants (or newly weaned young, Rajska‐Jurgiel and Mazurkiewicz 2000) and thus appear to have higher population densities than large patches (Foster and Gaines 1991, Diffendorfer et al 1995a). A fifth but not mutually exclusive explanation, considered in this paper, is that some mammals use the matrix as an integral part of their home ranges, so densities on small patches are thus overestimated because they are typically calculated using only the patch area.…”

The home-range concept in rodents revised

“…This thesis was later developed in an analysis that has come to be regarded as a classic by Lidicker (1975), as well as by Stenseth and Lidicker (1992), and in the studies made on this issue by Hansson (1977). Most recently, Rajska-Jurgiel and Mazurkiewicz (2000), and Rajska-Jurgiel (2001) have presented research results on this matter that are very debatable from the point of view of interpretation.…”