Does the Siberian chipmunk respond to the snake by identifying it?

Siberian chipmunks were presented with snakes and 4 control animals (tortoises, frogs, eels, quails) in a large outdoor pen to examine whether the snakedirected behavior of the chipmunk is a response to identifying the snake or simply an exploratory behavior toward generally strange objects. The animals were presented to chipmunks in 3 manners; tethered, anesthetized, and in perforated opaque boxes and in wire netting boxes. In “tethered” and “anesthetized”, chipmunks responded significantly more intensively to snakes than to other animals. When the animals were presented in the boxes, that is, when chipmunks could perceive only olfactory stimulus from the animals, they also showed the strongest response to snakes. The results suggest that 1) snake-directed behavior of chipmunks is not a general exploratory response toward strange objects but a response to identifying the snakes, and that 2) olfaction is an important cue for the chipmunks to identify snakes.     

Fleas community in introduced Siberian chipmunks (Tamias sibiricus Laxmann) in Forest of Sénart, France

We examined the fleas community in an introduced population of Siberian chipmunks, Tamias sibiricus, between 2005 and 2007, in the Forest of Sénart (Essonne, France). We collected and identified 383 fleas on 463 chipmunks (total: 1,891 captures on 471 chipmunks). In 2005, 120 fleas were also collected on 65 bank voles, Clethrionomys glareolus, and on 25 wood mice, Apodemus sylvaticus, trapped within the same area. Ceratophyllus sciurorum sciurorum formed 73.6% of the chipmunks' flea community, with an annual prevalence (P) ranging between 8 and 13% and a mean intensity (I) ranging between 1.1 and 1.6 fleas per individual. Among the six other species infecting this Sciurid, Ctenophthalmus agyrtes impavidus constituted 17.2% (P: 1.6-2.2%; I: 1.1-2.6), and Megabothris turbidus 8.1% (P: 0.8-1.9%; I: 1.0-1.4) of the flea community, respectively. These last two species represented respectively 60.8% and 36.6% of the flea community on the bank vole and the wood mouse. Originated from Asia, chipmunks did not import any flea species to Sénart, probably because they were used as pets before their release in the wild. Abundance in C. s. sciurorum increased with adult chipmunk density and with juvenile density in summer. On adult chipmunks C. s. sciurorum tented to decrease with increasing abundance of red squirrels (Sciurus vulgaris]. Moreover, the two other flea species mainly infected young chipmunks during the fall, and their number was not related to chipmunk density. However, the distribution of species within the flea community became more balanced with increase juvenile chipmunk density. Overall, these results indicate that the close phyletic relationship between chipmunks and red squirrels contributed in the acquisition and the spread of fleas by chipmunks. Primary and secondary hosts densities, their habitat use, and more specifically burrowing activities and tree canopy use, also played a role in the spread of fleas on chipmunks.     

An Analysis of Snake-Scent Application Behaviour in Siberian Chipmunks (Eutamias sibiricus asiaticus)

Some rodents assault live snakes by mobbing. Another snake-directed behaviour is shown by Siberian chipmunks, Eutamias sibiricus asiaticus, when encountering a dead snake. They approach the carcass cautiously, gnaw the snake skin, and chew and apply the gnawed bits to their body fur. We have termed this behaviour “Snake-Scent Application” (SSA). SSA behaviour is also elicited by snake urine and feces. Chemicals in snake skin and rectal and cloacal sacs release SSA. Snake urine applied to dead mice tends to suppress ingestion by snakes.     

Observation of marking-like behavior, marking behavior, and growth of the scent gland in young Mongolian gerbils (Meriones unguiculatus) of an inbred strain.

A marking-like behavior (defined by authors), a marking behavior, and growth of the scent glands were observed in young Mongolian gerbils of an inbred strain. In males and females, a marking-like behavior, in which animals rub their abdominal scent glands on the floor, began to be seen at the age of 19 days and could be seen in almost all the gerbils at 22 days of age during the suckling period. The frequency of this behavior was highest at 60 days of age (males: 17.9/10 min, females: 15.4/10 min) and there was no sex difference. Marking behavior, in which animals rub their abdominal scent glands on small protruding objects, began to be seen at the age of 40 days in males and 50 days in females. The frequency of this behavior tended to increase until 90 days of age in males (13.7/10 min), but the levels were low (2.5-5.0/10 min) in females. The values in the male group therefore tended to be higher than that in the female group. Macroscopic scent gland pads were clearly observed at the age of 30 days in males, but not until 45 days of age in females. At the age of 45-90 days, the length of the scent gland pad in males and females was 2.1-2.8 and 1.6-1.7 cm, respectively and the width was 0.3-0.5 in males and 0.2-0.3 cm in females. During this period, the length and depth of the pads in males were significantly greater than those in females (p < 0.05). Histological examination of the structure of the scent glands after the age of 45 days showed that the development of clusters of acinar cells in females occurred much later than that in males, but the basic structure of these glands was similar in both sexes. These results suggest that the marking-like behavior was manifested although during the period when the scent glands had not yet developed, whereas true marking behavior first occurred when the glands were moderately well developed.     

The Reproductive State of Female Voles Affects their Scent Marking Behavior and the Responses of Male Conspecifics to Such Marks

During the breeding season, the reproductive condition of female mammals changes. Females may or may not be sexually receptive. We conducted a series of experiments to determine whether reproductive condition of female meadow voles affects their scent marking behavior as well as the scent marking behavior of male conspecifics. In expt 1, females in postpartum estrus (PPE females) deposited more scent marks than females that were neither pregnant nor lactating (REF females) or ovariectomized females (OVX females). In expt 2, male voles scent marked more and deposited more over‐marks in areas marked by PPE females than by REF and OVX females. In expt 3, PPE females deposited more scent marks and over‐marks in areas marked by males than did females in the other reproductive states. The results of these experiments showed that male and female voles may vary in the number, type and location of scent marks they deposit in areas scented by particular conspecifics.     

An Unusual Xylotheque with Plant Illustrations from Early Meiji Japan

An Unusual Xylotheque with Plant Illustrations from Early Meiji Japan. Two unusual wood collections, reported previously in the collections of the Botanical Museum at Berlin-Dahlem and the Royal Botanic Gardens, Kew, take the form of framed plant illustrations painted on boards made from the wood of the species illustrated. We present new finds of very similar wood collections in the Economic Botany Collection of the Harvard University Herbaria, a private collection in the U.K. (Loudon collection), and at the Koishikawa Botanical Garden of the University of Tokyo. A stamp on the reverse of the boards links all five collections to Chikusai Kato, an artist working at Tokyo University (now the University of Tokyo) in early Meiji Japan, under the direction of the preeminent nineteenth century Japanese botanist Keisuke Ito. New evidence from contemporary historical accounts indicates that more than 100 boards were ordered in June 1878 by Hiroyuki Katō, the first president of Tokyo University, most likely to support the early teaching of Western-influenced botanical science in Japan. However, while the boards had clear value for teaching, especially about useful plants, their unusual fusion of Western and Japanese influences also made them desirable craft objects that were collected and given as gifts during the early Meiji era.     

Simultaneous Discrimination Learning in Chicks: Spatial Representations and Object Characteristics

Chicks were trained to discriminate (1) between two boxes of the same colour on the basis of their positions; (2) between two boxes of different colours on the basis of their positions or on the basis of their colours. No significant differences between these tasks appeared. Addition of colour and position improved learning when the boxes were entirely coloured but not when differently coloured discs were placed over the lids of two identical boxes. It is argued that in simultaneous discrimination learning chicks rely primarily on the “relative” position of the goal objects (i. e. in relation to each other) and utilize featural information (colour) to segregate the goal objects as distinct perceptual units. Results also stressed the role of “object characteristics” as opposed to the traditional notion of “cues”.     

种内及种间干扰对围栏内花鼠分散贮藏行为的影响

2009 年9 月在黑龙江省带岭区东方红林场10 m ×10 m 半天然围栏内模拟花鼠种内(不同性别) 和种间
(大林姬鼠) 干扰竞争对花鼠分散埋藏红松种子行为的影响。实验分四个处理两个批次进行,依次为单只花鼠对
照实验(雄性7 只,雌性9 只)、种内同性干扰竞争、种内异性干扰竞争和种间干扰竞争。结果表明:(1)花鼠
雌性个体的分散埋藏强度明显高于雄性个体;(2)种间干扰竞争引起花鼠对红松分散埋藏比例明显增加,而种
内干扰对花鼠分散埋藏行为的影响不显著;(3) 种内干扰竞争条件下,同性干扰竞争和异性干扰竞争对花鼠分
散埋藏行为均无显著影响;(4)雄性个体在同性干扰下,埋藏强度不变;而在雌性个体干扰竞争下,埋藏强度
增加;(5)雌性个体在雌性和雄性干扰条件下,花鼠分散埋藏行为均无明显变化。     

Communication impairments in mice lacking Shank1: reduced levels of ultrasonic vocalizations and scent marking behavior

Autism is a neurodevelopmental disorder with a strong genetic component. Core symptoms are abnormal reciprocal social interactions, qualitative impairments in communication, and repetitive and stereotyped patterns of behavior with restricted interests. Candidate genes for autism include the SHANK gene family, as mutations in SHANK2 and SHANK3 have been detected in several autistic individuals. SHANK genes code for a family of scaffolding proteins located in the postsynaptic density of excitatory synapses. To test the hypothesis that a mutation in SHANK1 contributes to the symptoms of autism, we evaluated Shank1(-/-) null mutant mice for behavioral phenotypes with relevance to autism, focusing on social communication. Ultrasonic vocalizations and the deposition of scent marks appear to be two major modes of mouse communication. Our findings revealed evidence for low levels of ultrasonic vocalizations and scent marks in Shank1(-/-) mice as compared to wildtype Shank1(+/+) littermate controls. Shank1(-/-) pups emitted fewer vocalizations than Shank1(+/+) pups when isolated from mother and littermates. In adulthood, genotype affected scent marking behavior in the presence of female urinary pheromones. Adult Shank1(-/-) males deposited fewer scent marks in proximity to female urine than Shank1(+/+) males. Call emission in response to female urinary pheromones also differed between genotypes. Shank1(+/+) mice changed their calling pattern dependent on previous female interactions, while Shank1(-/-) mice were unaffected, indicating a failure of Shank1(-/-) males to learn from a social experience. The reduced levels of ultrasonic vocalizations and scent marking behavior in Shank1(-/-) mice are consistent with a phenotype relevant to social communication deficits in autism.     

同种或异种干扰对花鼠分散贮藏点选择的影响

同种和异种干扰竞争可以增强花鼠(Tamias sibiricus)分散贮食强度,但对其贮藏点选择的影响还不清楚.在半自然围栏内,研究了同种(干扰源为不同性别花鼠)或异种(干扰源为大林姬鼠,Apodemus peninsulae)干扰竞争对花鼠贮藏点选择的影响.结果发现:(1)同种和异种干扰竞争均显著降低了花鼠在高竞争区内的贮藏比例;(2)同种个体存在时,雌性花鼠显著降低了在高竞争区内的贮藏比例,雄性花鼠则显著增加了在中竞争区的埋藏比例.结果表明,花鼠贮藏食物时会避开高竞争区域以降低同种或异种的盗食损失,同时雌雄个体对同种竞争干扰的响应有所差异.     

Dating furniture and coopered vessels without waney edge – Reconstructing historical wood-working in Austria with the help of dendrochronology

In the present study, 208 furniture and 168 coopered vessels from three Austrian museums were examined. Dendrochronology was used to date objects and to extract further information such as the necessary time for seasoning, wood loss through wood-working and methods of construction. In most cases sampling was done by sanding the cross section and making digital photographs using a picture frame and measuring digitally.The dendrochronological dates of the sampled furniture range between 1524 and 1937. The group of furniture includes cupboards, chests, tables, benches, commodes and beds. In many cases furniture was artfully painted and sometimes even shows a painted year. With the help of dendrochronology it was proved that some objects had been painted for some time after construction, or had been over-painted. Most furniture, however, was painted immediately after completion. In this case, the seasoning and storage time of the boards and the wood loss due to shaping can be verified. As an average value, 14 years have passed between the dendrochronological date of the outermost ring and the painting. The time span includes time of seasoning and storage and the rings lost by wood-working. This leads, on the one hand to a short storage time of less than 10 years and on the other hand to very little wood loss due to manufacturing. Those boards being less shaped turned out to be back panels of cupboards, therefore they are recommended to be sampled for dating.Coopered vessels were dated between 1612 and 1940. There was evidence that staves were split and not sawn in many cases. The staves were often split out of the outermost part of the tree and hardly any wood was worked away which was proved by the close dendrochronological dates of the single staves of a vessel.Since there is a short time of storage and only little wood loss through wood-working, dating of objects without a waney edge becomes reasonable.     

Discrimination by male ring-tailed Lemurs (Lemur catta) between the scent marks of male and those of female conspecifics

Olfaction plays an important role in the social communication of all prosimians. (The experiment reported in this paper forms part of an intensive chemobehavioral study of olfaction in Lemur catta (ring-tailed lemur) being carried out in this laboratory.) Five male Lemur cattawere tested on their behavioral responses to paired scent stimuli. Responses measured were (1) total investigation time, (2) arm-marking, (3) ABO/BO rubbing, and (4) flehmen. Males showed a strong discrimination between the scent stimuli,giving higher levels of response to female scent on measures 1, 3, and 4. This response suggests an olfactory-related preference by males for female scent under controlled conditions. This preference may be a consequence of the females’ dominance over males and the brevity of estrus in L. catta,both of which would favor such choice behavior.     

Olfactory Enrichment in California Sea Lions (Zalophus californianus): An Effective Tool for Captive Welfare?

In the wild, California sea lions (Zalophus californianus) are exposed to a wide variety of sensory information, which cannot be replicated in captive environments. Therefore, unique procedures are necessary for maintaining physiological and psychological health in nonhuman animals in captivity. The effects of introducing natural scents to captive enclosures have been investigated in a variety of species, yet they have not been examined in marine mammals. This project explored the behavioral effect of scent added to the environment, with the goal of improving the welfare of sea lions in captivity. Two scent types were introduced: (a) natural scents, found in their native environment, and (b) non-natural scents, not found in their native environment. This study examined not only scent enrichment but also the possible evolutionary underpinnings of pinniped olfaction. Scent enrichment was found to significantly impact sea lion behavior as demonstrated by a reduction in pattern swimming, an increase in habitat utilization, and a reduction in stereotypical behavior. However, there were no differences in behavior between natural and non-natural scent conditions.     

Urinary behavior of female domestic dogs (Canis familiaris): influence of reproductive status,location, and age

The urinary behavior of adult domestic dogs (Canis familiaris) is sexually dimorphic with respect to the posture (males lift a leg and females squat), frequency of urination (males urinate more frequently than females), and tendency to direct urine at specific objects in the environment (males are more likely than females to direct their urine). Such behavioral differences have led to the belief that urination functions largely, or exclusively, in elimination in female dogs, while having the additional function of scent marking in male dogs. In this study, we observed urinary behavior of six spayed and six non-estrous intact female Jack Russell Terriers during walks on and off their home area. The females ranged in age from 0.4 to 11.2 years. Frequency of urination was positively correlated with age, and females four or more years old directed the majority of their urinations at objects in the environment. Overall, females urinated more frequently and directed more of their urinations when walked off their home area than when walked within their home area. Spayed females were more likely than non-estrous intact females to ground-scratch following defecation; we detected a similar trend for ground-scratching after urination. There was, however, considerable variation among spayed females in the tendency to display ground-scratching behavior. Overall, the most common posture displayed by females while urinating was the squat-raise. Other postures, in order of their frequency of occurrence included squat, arch-raise, combination, and handstand. Females used the squat-raise and arch-raise postures more when off their home area than when on their home area. Overall, there was substantial individual variation among females in the postures used while urinating. Our data indicate that female urinary behavior varies with location and reproductive status, and that substantial individual differences exist among females for some patterns of behavior. Additionally, the large percentages of directed urinations by spayed (60.8%) and non-estrous intact females (56.7%) in our study suggest that urination in female dogs does not function solely in elimination, but that it also has a significant role in scent marking, even when females are not in estrus.     

Homing Strategy of the Eastern Chipmunk,Tamias striatus (Mammalia: Rodentia): Validation of the Critical Distance Model

Fifteen eastern chipmunks, Tamias striatus, were displaced and released 500m away from their nest sites, and their eventual behavior was monitored by means of radio-assisted surveillance. As a rule (allowing for some interindividual variability), the chipmunks left the release site area along a relatively straight course, made a U-turn at a median 60 m from the release site, returned closer to the latter and initiated a pattern of systematic search based on relatively straight forays from and back to the release site area. This overall strategy is consistent with the critical distance model of homing, which was originally proposed on the basis of the homing behavior of another sciund, the red squirrel, Tamiasciurus hudsonicus.     

Better safe than sorry: The response to a simulated predator and unfamiliar scent by the European hare

Predator presence can create a “landscape of fear,” which is defined as the spatially explicit distribution of perceived predation risk as seen by prey. Prey species can alter their behavior and space use as a response to increased predation risk, which might be traded off with energetic requirements. Thus, whether or not an anti-predator behavior is performed might depend on the perceived risk. In this study, we investigated the behavioral and spatial response of the European hare (Lepus europaeus) toward the presence of a predator scent, using red fox (Vulpes vulpes) scat, an unfamiliar control scent (butyric acid), and a true control (no scent). We collected data on hare activity times and behavior using 50 camera trap locations and spatial data using GPS telemetry (30,481 GPS positions of 12 hares). Hares showed spatial anti-predator behaviors within their home range, for example, the local avoidance of areas treated with scent and remaining further from field edges, in response to sympatric predator scent and partly also in response to unfamiliar butyric acid. Conversely, more costly anti-predator behaviors, that is, increased vigilance at the expense of foraging, were only shown in response to the predator scent. Our results suggest that prey species respond flexibly toward scent cues, utilizing less costly anti-predator behaviors independent of the perceived threat, whereas costly anti-predator responses are only used in the presence of “real” threat. Further, our findings emphasize that a combination of camera trap and GPS data can provide detailed information on animal behavior and space use, and caution that interpretation of one data source alone might lead to incomplete conclusions.     

Whole-genome single nucleotide polymorphism and mating compatibility studies reveal the presence of distinct species in sub-Saharan Africa Bemisia tabaci whiteflies

In sub-Saharan Africa cassava growing areas, two members of the Bemisia tabaci species complex termed sub-Saharan Africa 1 (SSA1) and SSA2 have been reported as the prevalent whiteflies associated with the spread of viruses that cause cassava mosaic disease (CMD) and cassava brown streak disease (CBSD) pandemics. At the peak of CMD pandemic in the late 1990s, SSA2 was the prevalent whitefly, although its numbers have diminished over the last two decades with the resurgence of SSA1 whiteflies. Three SSA1 subgroups (SG1 to SG3) are the predominant whiteflies in East Africa and vary in distribution and biological properties. Mating compatibility between SSA1 subgroups and SSA2 whiteflies was reported as the possible driver for the resurgence of SSA1 whiteflies. In this study, a combination of both phylogenomic methods and reciprocal crossing experiments were applied to determine species status of SSA1 subgroups and SSA2 whitefly populations. Phylogenomic analyses conducted with 26 548 205 bp whole genome single nucleotide polymorphisms (SNPs) and the full mitogenomes clustered SSA1 subgroups together and separate from SSA2 species. Mating incompatibility between SSA1 subgroups and SSA2 further demonstrated their distinctiveness from each other. Phylogenomic analyses conducted with SNPs and mitogenomes also revealed different genetic relationships among SSA1 subgroups. The former clustered SSA1-SG1 and SSA1-SG2 together but separate from SSA1-SG3, while the latter clustered SSA1-SG2 and SSA1-SG3 together but separate from SSA1-SG1. Mating compatibility was observed between SSA1-SG1 and SSA1-SG2, while incompatibility occurred between SSA1-SG1 and SSA1-SG3, and SSA1-SG2 and SSA1-SG3. Mating results among SSA1 subgroups were coherent with phylogenomics results based on SNPs but not the full mitogenomes. Furthermore, this study revealed that the secondary endosymbiont—Wolbachia—did not mediate reproductive success in the crossing assays carried out. Overall, using genome wide SNPs together with reciprocal crossings assays, this study established accurate genetic relationships among cassava-colonizing populations, illustrating that SSA1 and SSA2 are distinct species while at least two species occur within SSA1 species.     

Personality predicts ectoparasite abundance in an asocial sciurid

Parasitism is a consequence of complex interactions between host, parasite, and their shared environment, and host behavior can influence parasite risk. Animal personality (i.e., consistent behavioral differences that are repeatable across time and context) can influence parasitism with more explorative individuals typically hosting greater parasite loads. Host “sociality” is known to impact parasite risk with more social individuals typically at higher risk of acquiring or transmitting parasites, but other behaviors could also be important. We quantified personality in least chipmunks (Tamias minimus), including repeatability of behavioral traits, and determined whether these personality traits affected ectoparasite prevalence and abundance. We measured personality using standardized hole‐board tests and quantified ectoparasitism of 39 least chipmunks over 2 years at a site in southeastern Manitoba, Canada. We found that activity and exploration were repeatable within the context of the hole‐board test for least chipmunks, which suggests that these traits reflect personality. More exploratory individuals hosted a greater abundance of ectoparasites compared to less exploratory individuals. Our results are consistent with past studies implicating personality as a factor in host–parasite dynamics and suggest that exploration may be an important behavioral correlate of parasite acquisition.     

`Little Chipmunk' Syndrome? Male Body Size and Dominance in Captive Yellow‐Pine Chipmunks (Tamias amoenus)

In mammals, large males are often assumed to have higher mating success because they have greater success at contest competition. This relationship is often used to explain the prevalence of male-biased sexual size dimorphism in mammals. However, in many small vertebrates, large individuals are not always dominant. Using staged dyadic encounters, we examined the relationship between male body size and social dominance in captive male yellow-pine chipmunks ( Tamias amoenus ), a species with female-biased sexual size dimorphism. The yellow-pine chipmunk has a mating system in which males participate in mating chases and dominant males may have an advantage in acquiring matings with oestrous females. Captive male chipmunks were aggressive in only 28% of 144 paired encounters; however, several lines of evidence indicated that smaller chipmunks were dominant over large chipmunks: (1) small males were dominant in more dyads than large males; (2) within dyads, dominant males were smaller than subordinate males; and (3) small males performed more aggressive behaviour than large males. These results are not consistent with the prediction that large males are typically dominant. If large chipmunks are able to gain matings with females because of qualities other than dominance (such as the ability to successfully find and/or chase receptive females), then the costs of aggression to large chipmunks may outweigh any potential benefits. Small males, but not large males, may improve their mating success by being aggressive.