Odor preference and social behavior in meadow voles, Microtus pennsylvanicus: seasonal differences

1987 ◽  
Vol 65 (12) ◽  
pp. 2931-2937 ◽  
Author(s):  
Michael H. Ferkin ◽  
Joshua O. Seamon
Keyword(s):  
Social Behavior ◽  
Social Organization ◽  
Breeding Season ◽  
Seasonal Changes ◽  
Microtus Pennsylvanicus ◽  
Odor Preference ◽  
Nonbreeding Season ◽  
Y Maze ◽  
Female Territoriality ◽  
Males And Females

Olfactory cues play a major role in inter- and intra-sexual agonistic behavior for Microtus pennsylvanicus. We show that seasonal changes in odor preference and behavioral interactions coincide with varying patterns of social organization. Odor preference trials were conducted in a Y maze and social behavior was measured in dyadic encounters in a neutral arena. During the breeding season, paired encounters between females contained more agonistic acts than did encounters between males, or those between males and females. Breeding males preferred the odor of females to the odor of conspecific males. In contrast, breeding females preferred their own odor and the odor of males to the odor of other females. The data support female exclusiveness during the breeding season. During the nonbreeding season, paired encounters between females contained fewer agonistic acts than did encounters between males or those between males and females. Nonbreeding females preferred the odor of female conspecifics to their own odor or the odor of male conspecifics. These results are consistent with group nesting and a relaxation of female territoriality during the nonbreeding season. Nonbreeding males did not exhibit a preference for their own odor, the odor of other males, or the odor of female conspecifics. Our results indicate that nonbreeding males are solitary, and overwintering groups are female-biased. Odor preferences may underlie seasonal changes in social organization.

scholarly journals Testicular expression of NGF, TrkA and p75 during seasonal spermatogenesis of the wild ground squirrel (Citellus dauricus Brandt)

2015 ◽  
Vol 59 (3) ◽  
Author(s):  
H. Zhang ◽  
Y. Wang ◽  
J. Zhang ◽  
L. Wang ◽  
Q. Li ◽  
...  
Keyword(s):  
Breeding Season ◽  
Sertoli Cells ◽  
Seasonal Changes ◽  
Ground Squirrel ◽  
Leydig Cells ◽  
Testicular Function ◽  
Nonbreeding Season ◽  
Function Change ◽  
The Mean ◽  
Neuronal Systems

The nerve growth factor (NGF) not only has an essential effect on the nervous system, but also plays an important role in a variety of non-neuronal systems, such as the reproductive system. The aim of this study was to investigate the seasonal changes in<strong> </strong>expression of NGF and its receptors (TrkA and p75) in testes of the wild ground squirrel during the breeding and nonbreeding seasons.<strong> </strong>Immunolocalization for NGF was detected mainly in Leydig cells and Sertoli cells in testes of the breeding and nonbreeding seasons. The immunoreactivity of TrkA was highest in the elongated spermatids, whereas p75 in spermatogonia and spermatocytes in testes of the breeding season. In the nonbreeding season testes, TrkA showed positive immunostainings in Leydig cells, spermatogonia and primary spermatocytes, while p75 showed positive signals in spermatogonia and primary spermatocytes. Consistent with the immunohistochemical results, the mean mRNA and protein level of NGF and TrkA were higher in the testes of the breeding season, and then decreased to a relatively low level in the nonbreeding season. In addition, the concentration of plasma gonadotropins and testosterone were assayed by radioimmunoassay (RIA), and the results showed a significant seasonal change between the breeding and nonbreeding seasons. To conclude, these results of this study provide the first evidence on the potential involvement of NGF and its receptor, TrkA and p75 in the seasonal spermatogenesis and testicular function change of the wild ground squirrel.

Seasonal changes in aggression, hunger, and curiosity in ranch mink

1969 ◽  
Vol 47 (6) ◽  
pp. 1395-1404 ◽  
Author(s):  
R. R. MacLennan ◽  
E. D. Bailey
Keyword(s):  
Breeding Season ◽  
Seasonal Changes ◽  
Environmental Temperature ◽  
Gonadal Hormones ◽  
Corpora Lutea ◽  
Field Situation ◽  
Body Weights ◽  
Males And Females ◽  
And Storage ◽  
Ranch Mink

Aggression, hunger, and curiosity of ranch mink (Mustela vison) were examined. The animals were divided into socialized animals (those visually isolated at 1 year of age) and unsocialized animals (those visually isolated at 10 weeks of age).Aggression was measured by placing two mink in a special cage and measuring the time until a fight or confrontation occurred. The effects of 0, 24, and 48 hours of food deprivation were measured in summer, fall, and winter. The number of trips made by each mink up a vertical cage to get food was used as an indicator of hunger. Levels of curiosity were determined by measuring the speed and pattern of exploration of a novel open-field situation. The breeding behaviors of experienced and inexperienced male mink were compared.Aggression in mink consisted of at least two offensive threats and, as in other animals, fighting was ritualized to a great extent. All young mink showed some adult aggressive patterns by 20 weeks of age. Aggression in males reached a peak at breeding season (March) and declined throughout the summer and fall, to a low point in November. Socialized males had lower aggressive levels than unsocialized males. Aggression in female mink reached a peak after the breeding season and declined to a low in winter. These cycles were likely caused by gonadal hormones in males and hormones from the corpora lutea in females.Both consumption and storage of food must be considered in determining hunger in mink. Hunger varied inversely with environmental temperature, reaching a peak in the winter and a low point in the summer. Immature animals had lower hunger drives than adult animals. Changes in body weights of mink centered around the breeding season.Curiosity decreased from summer to fall as did aggression. Unsocialized males had higher levels of curiosity than socialized males and females. Immature mink showed incomplete exploratory behavior and had lower curiosity scores than adult animals.

Elimination marking behavior in feral horses

1981 ◽  
Vol 59 (8) ◽  
pp. 1561-1566 ◽  
Author(s):  
J. W. Turner Jr. ◽  
A. Perkins ◽  
J. F. Kirkpatrick
Keyword(s):  
Social Organization ◽  
Breeding Season ◽  
High Frequency ◽  
Seasonal Changes ◽  
Behavior Pattern ◽  
Behavior Patterns ◽  
Feral Horses ◽  
Reproductive Patterns ◽  
Feral Horse ◽  
Time Of Year

It was the goal of this study to develop a reliable behavioral endpoint for use in studying patterns of reproduction and methods for regulating reproduction in feral horses. Several characteristic stallion behavior patterns associated with harem activities were examined. The only behavior which occurred with high frequency and was readily observable and quantifiable was stallion elimination marking behavior in which stallions marked eliminations (urinations–defecations) of other horses with their own urine and feces. Elimination marking behavior was not exhibited by mares or immature animals and stallions rarely marked eliminations made by immatures. Stallion response to eliminations by mature mares varied markedly with time of year, averaging 93% and 89% in May and June, the peak of the breeding season, and 1% from November through February. Thus, seasonal changes in elimination marking behavior were well correlated with the breeding season. The completeness of the behavior pattern showed an annual pattern similar to that for frequency. The possible significance of this behavior in relation to feral horse social organization and its use as a behavioral correlate in studying reproductive patterns is discussed.

Sexually dimorphic spatial learning in meadow voles Microtus pennsylvanicus and deer mice Peromyscus maniculatus.

1996 ◽  
Vol 199 (1) ◽  
pp. 195-200 ◽  
Author(s):  
L A Galea ◽  
M Kavaliers ◽  
K P Ossenkopp
Keyword(s):  
Breeding Season ◽  
Spatial Learning ◽  
Water Maze ◽  
Microtus Pennsylvanicus ◽  
Group Differences ◽  
Deer Mice ◽  
Sexually Dimorphic ◽  
Meadow Voles ◽  
Spatial Performance ◽  
Males And Females

A number of studies examining developmental, neural and hormonal aspects of sexually dimorphic spatial learning (Morris water-maze) in meadow voles (Microtus pennsylvanicus) and deer mice (Peromyscus maniculatus) are described. We found that, in adult deer mice, female spatial performance decreased during the breeding season relative to the non-breeding season, whereas the reverse pattern was observed in male performance. There was a sex difference favouring males in spatial learning during the breeding season, but not during the non-breeding season. In adult meadow voles, females with low levels of oestradiol and males performed better in the water-maze than females with high levels of oestradiol. Postweaning voles (20 and 25 days after birth) acquired the water-maze task more quickly than preweaning voles (day 10). No sex difference in water-maze performance was evident at any of these juvenile ages. When these same voles were tested again as adults to investigate retention and re-acquisition of the water-maze, both males and females from male-biased litters re-acquired the task better than males and females from female-biased litters. Together, the results of these studies indicate that sexually dimorphic spatial ability is dependent on the organization (in utero) and activational effects of gonadal hormones. These studies provide the first demonstration of the influence of natural changes in reproductive status on spatial learning of deer mice and meadow voles. The results also demonstrate that spatial performance of males and females is differentially affected by changes in reproductive status and that group differences in the laboratory are associated with group differences in space utilization in the wild. These findings help to clarify previous apparently contradictory findings about sex differences in spatial ability.

Observation on the breeding biology of Polypedates teraiensis (Dubois, 1987) (Amphibia: Rhacophoridae)

2017 ◽  
Vol 17 (1) ◽  
pp. 25-32
Author(s):  
Jacinta Lalchhanhimi ◽  
Lalremsanga H.T.
Keyword(s):  
Sexual Dimorphism ◽  
Breeding Season ◽  
Sound Production ◽  
Reproductive Function ◽  
Breeding Biology ◽  
Tree Frog ◽  
University Campus ◽  
Morphometric Measurements ◽  
Advertisement Calls ◽  
Males And Females

The breeding biology of tree frog, Polypedates teraiensis was studied during the breeding season at Mizoram University Campus. It was found that sound production by male during the breeding season was primarily a reproductive function and advertisement calls attract females to the breeding areas and announce other males that a given territory is occupied. The aim of this study was to provide the detailed information on the breeding behaviour and the advertisement calls of Polypedates teraiensis. The morphometric measurements of the amplecting pairs (males and females) for sexual dimorphism along with clutch sizes were also studied.

Winter coexistence of voles in spruce forest: relevance of seasonal changes in aggression

1975 ◽  
Vol 53 (8) ◽  
pp. 1004-1011 ◽  
Author(s):  
Brian N. Turner ◽  
Michael R. Perrin ◽  
Stuart L. Iverson
Keyword(s):  
Microtus Pennsylvanicus ◽  
Meadow Vole ◽  
Breeding Period ◽  
Spruce Forest ◽  
Vole Population ◽  
Reproductive Condition ◽  
Interspecific Aggression ◽  
Meadow Voles ◽  
Nonbreeding Season ◽  
Short Period

Beginning in November 1973, numerous meadow voles (Microtus pennsylvanicus) moved onto a spruce forest grid occupied by red-backed voles (Clethrionomys gapperi). A resident meadow vole population resulted, the two species coexisting until April 1974, when most meadow voles disappeared from the grid during a relatively short period. Interspecific aggression levels, as determined from voles temporarily removed from the populations and tested in paired encounters in a laboratory arena, were low during the winter, but increased when males of both species entered reproductive condition in the spring. Microtus was generally dominant in early breeding period encounters, but this dominance declined concurrently with the meadow voles' disappearance from the forest. It is argued that meadow voles did not leave the forest to breed, or because the snow cover melted, since this species will live and reproduce in forest in the absence of Clethrionomys. The results are interpreted as support for an earlier hypothesis that competitive habitat exclusion varies seasonally with reproduction-related aggression. Thus, these species apparently may coexist in either of their preferred habitats when interspecific aggression is low (the nonbreeding season), but this relationship terminates when interspecific aggression levels increase with the resumption of breeding in the spring.

Stature at Tikal, Guatemala: Implications for Ancient Maya Demography and Social Organization

1967 ◽  
Vol 32 (3) ◽  
pp. 316-325 ◽  
Author(s):  
William A. Haviland
Keyword(s):  
Social Organization ◽  
Classic Maya ◽  
Ancient Maya ◽  
Ruling Class ◽  
Late Classic ◽  
Class Division ◽  
Lower Status ◽  
Simple Class ◽  
Males And Females ◽  
Maya Site

AbstractThis paper presents an analysis of stature of the prehistoric population from the Maya site of Tikal, Guatemala. From this analysis, based on 55 skeletons from the Tikal burial series, three important conclusions emerge with respect to ancient Maya demography and social organization. (1) Tikal was settled by people of moderate stature, and this remained relatively stable over several centuries. A marked reduction in male stature in Late Classic times may be indicative of a situation of nutritional stress, which may have had something to do with the collapse of Classic Maya civilization. (2) Stature differences between those buried in tombs and others at Tikal suggest that, in the last century B.C., a distinct ruling class developed at Tikal. This simple class division of rulers and commoners may have become more complex in Late Classic times. (3) There was a marked sexual dimorphism in stature between males and females at Tikal. This is probably partially genetic and partially a reflection of relatively lower status for women as opposed to men in Maya society.

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