The road effect on small rodent population is investigated at 8 fragmented forest areas in the Baekdudaegan mountain range, South Korea in September 2001. We especially focused on the distribution and body condition o...The road effect on small rodent population is investigated at 8 fragmented forest areas in the Baekdudaegan mountain range, South Korea in September 2001. We especially focused on the distribution and body condition of small rodents near the roads. Korean field mouse (Apodemus peninsulae) seems to be more sensitive to the existence of a road than striped field mouse (Apodemus agrarius). Korean field mouse prefers interior forest area to around road. Striped field mouse is a habitat generalist and has wide distributional range around road, but Korean field mouse is forest-inhabiting species and their distribution is limited in forest area. These results suggest the effect of road is different on each small rodent species and their habitat preferences.展开更多
A number of mechanisms are known to influence coexistence in small mammal communities. However, the role ofbehavioral interactions in promoting species coexistence is under-represented in the literature. We studied th...A number of mechanisms are known to influence coexistence in small mammal communities. However, the role ofbehavioral interactions in promoting species coexistence is under-represented in the literature. We studied the behavioral interactionsof two coexisting small mammals, the Namaqua rock mouse Micaelamys namaquensis (Rodentia) and the Rock sengi Elephantulusmyurus (Macroscelidae), which have high dietary and microhabitat overlap. Using wild-caught individuals, intra- andinterspecific dyadic encounters were staged in tanks on a neutral rocky outcrop. Interspecific dyads displayed significantly moreactive avoidance behavior. There was no support for the prediction that the larger, more specialist species, E. myurus, is behaviorallydominant over M. namaquensis. Intraspecific encounters of E. myurus showed significantly more passive avoidance andamicable behavior, whereas the behavior of M. namaquensis did not differ between intra- and inter-specific encounters, both ofwhich were characterized by low levels of aggression and amicability. Thus, due to the lack of aggression, direct competition appearsweak and instead mutual avoidance may reduce or minimize interspecific interactions, potentially promoting coexistence.展开更多
In hand reared birds and mammals, it is generally considered that the development of hoarding behavior is the result of an interaction between the development and maturation of the nervous system and learning from ind...In hand reared birds and mammals, it is generally considered that the development of hoarding behavior is the result of an interaction between the development and maturation of the nervous system and learning from individual experience. How- ever, few studies have been done on wild animals. We tested differences in hoarding behavior between captive reared and wild individuals of two sympatric small rodents, Korean field mice Apodemus peninsulae and Chinese white-bellied rats Niviventer confucianus. Our aim was to identify if lack of experience from the wild would result in poorly developed hoarding behavior. The Korean field mice perform scatter- and larder-hoarding behaviors whereas Chinese white-bellied rats hoard food in larders only. Within outdoor enclosures we compared seed-hoarding behavior in reared juveniles （RJ, 40-50 d old, pregnant mothers were captured in the wild）, wild juveniles （WJ, as young as the RJ） and wild adults （WA, over-winter animals）. We found that a lack of experience from the wild had significant effects on seed-hoarding behavior for both species. The RJ-group removed and hoarded fewer seeds than the WJ- and WA-groups. The two latter groups hoarded seeds in a similar way. In the Korean filed mouse the ILl-group placed more seeds on the ground surface than other groups. These findings suggest that wild experience is important for the acquisition of an appropriate food-hoarding behavior （especially for scatter-hoarding） in these species展开更多
Abstract Many rodents exhibit inducible defenses when exposed to chemical cues from mammalian predators. These responses may include delays in sexual maturation, smaller adult body size and decreases in litter size an...Abstract Many rodents exhibit inducible defenses when exposed to chemical cues from mammalian predators. These responses may include delays in sexual maturation, smaller adult body size and decreases in litter size and pup weight. We exposed the hybrid juvenile offspring of field-caught and lab-descended house mice Mus musculus to the chemical cues of mouse-fed or chick-fed kingsnakes, Lampropeltis getula, for 20 days after weaning, to examine the effects of ophidian predator cues on prey development. We hypothesized that these cues would elicit inducible defenses such as alteration of growth rates, and/or the timing of reproductive development in mice. Once mature, the reproductive effort of the mice might also be impacted by producing smaller litter sizes or lighter pups or not reproducing at all. We found no effect of kingsnake cues on any of the measures. These findings support the hypothesis that inducible defenses may have evolved as a strategy to deal with specific predators.展开更多
文摘The road effect on small rodent population is investigated at 8 fragmented forest areas in the Baekdudaegan mountain range, South Korea in September 2001. We especially focused on the distribution and body condition of small rodents near the roads. Korean field mouse (Apodemus peninsulae) seems to be more sensitive to the existence of a road than striped field mouse (Apodemus agrarius). Korean field mouse prefers interior forest area to around road. Striped field mouse is a habitat generalist and has wide distributional range around road, but Korean field mouse is forest-inhabiting species and their distribution is limited in forest area. These results suggest the effect of road is different on each small rodent species and their habitat preferences.
基金provided by the National Research Foundation (Grant number:2069110)the University of the Witwatersrand
文摘A number of mechanisms are known to influence coexistence in small mammal communities. However, the role ofbehavioral interactions in promoting species coexistence is under-represented in the literature. We studied the behavioral interactionsof two coexisting small mammals, the Namaqua rock mouse Micaelamys namaquensis (Rodentia) and the Rock sengi Elephantulusmyurus (Macroscelidae), which have high dietary and microhabitat overlap. Using wild-caught individuals, intra- andinterspecific dyadic encounters were staged in tanks on a neutral rocky outcrop. Interspecific dyads displayed significantly moreactive avoidance behavior. There was no support for the prediction that the larger, more specialist species, E. myurus, is behaviorallydominant over M. namaquensis. Intraspecific encounters of E. myurus showed significantly more passive avoidance andamicable behavior, whereas the behavior of M. namaquensis did not differ between intra- and inter-specific encounters, both ofwhich were characterized by low levels of aggression and amicability. Thus, due to the lack of aggression, direct competition appearsweak and instead mutual avoidance may reduce or minimize interspecific interactions, potentially promoting coexistence.
文摘In hand reared birds and mammals, it is generally considered that the development of hoarding behavior is the result of an interaction between the development and maturation of the nervous system and learning from individual experience. How- ever, few studies have been done on wild animals. We tested differences in hoarding behavior between captive reared and wild individuals of two sympatric small rodents, Korean field mice Apodemus peninsulae and Chinese white-bellied rats Niviventer confucianus. Our aim was to identify if lack of experience from the wild would result in poorly developed hoarding behavior. The Korean field mice perform scatter- and larder-hoarding behaviors whereas Chinese white-bellied rats hoard food in larders only. Within outdoor enclosures we compared seed-hoarding behavior in reared juveniles （RJ, 40-50 d old, pregnant mothers were captured in the wild）, wild juveniles （WJ, as young as the RJ） and wild adults （WA, over-winter animals）. We found that a lack of experience from the wild had significant effects on seed-hoarding behavior for both species. The RJ-group removed and hoarded fewer seeds than the WJ- and WA-groups. The two latter groups hoarded seeds in a similar way. In the Korean filed mouse the ILl-group placed more seeds on the ground surface than other groups. These findings suggest that wild experience is important for the acquisition of an appropriate food-hoarding behavior （especially for scatter-hoarding） in these species
文摘Abstract Many rodents exhibit inducible defenses when exposed to chemical cues from mammalian predators. These responses may include delays in sexual maturation, smaller adult body size and decreases in litter size and pup weight. We exposed the hybrid juvenile offspring of field-caught and lab-descended house mice Mus musculus to the chemical cues of mouse-fed or chick-fed kingsnakes, Lampropeltis getula, for 20 days after weaning, to examine the effects of ophidian predator cues on prey development. We hypothesized that these cues would elicit inducible defenses such as alteration of growth rates, and/or the timing of reproductive development in mice. Once mature, the reproductive effort of the mice might also be impacted by producing smaller litter sizes or lighter pups or not reproducing at all. We found no effect of kingsnake cues on any of the measures. These findings support the hypothesis that inducible defenses may have evolved as a strategy to deal with specific predators.
