Heritability of kinship pheromone in the beaver: How is information about relatedness coded?

We attempted to estimate the narrow-sense heritability of single compounds and whole profile of the anal gland secretion (AGS) with the regression method using several sets of relatives in the beaver (Castor canadensis). We used GC (gas chromatography) and GC-MS (mass spectrometry) to characterize and quantify chemical compounds in beaver AGS. We found that the heritability of single compounds seemed to be low, whereas the heritability of AGS profile appeared to be moderate. We conclude that many compounds might be involved in the coding of genetic relatedness, which was through a combination of analog and digital coding using many compounds

Pheromones in Black-tailed Deer (Odocoileus hem Pheromones in Black-tailed Deer (Odocoileus hemionus columbianus)

Black-tailed deer in captivity and in the field were observed for 3000 hr. The various contexts in which pheromones play a role were determined. For short-range sex, age and individual recognition, the tarsal scent is most important. Gas chromatograms show differences related to sex, age and individuals. Metatarsal scent is discharged in ‘fear-inducing’ situations. Female urine attracts males. Rub-urinating serves as a distress signal in fawns, but as a threat in adult males and females. The home range of deer is marked by rubbing the forehead against dry branch tips. Bioassays were developed for testing fractions of tarsal and metartarsal scents. The active components are being more narrowly defined in both scents

Anal Gland Secretion Codes for Family Membership in the Beaver

We investigated how information about family membership is coded by the individually specific anal gland secretion (AGS) in the beaver, Castor canadensis. Because beavers live in strict family units and relatives share more features in the AGS profile than non-relatives, family members share more AGS features than non-family members. Therefore, family recognition seems to be a natural consequence of the more specific kin recognition. Multivariate statistical analyses revealed two possibilities in coding for family membership using the multi-component AGS: either two (female) to three (male) AGS compounds or many compounds were used, but we were not able to determine which possibility is more likely. Compounds were not equally important in coding family membership information, and the interactions among compounds were complex. We attempted to reconstruct a lineage tree for the relationship among different families using two–three or many compounds. We found there was no significant difference for trees constructed by using few or many compounds in either males or females. However, the trees derived from male compounds and female compounds lacked good congruence

Dispersal pattern and effective population size of the beaver

The dispersal pattern of the beaver (Castor canadensis) was studied by intensive livetrapping, tagging, and observation in Allegany State Park and its vicinity in New York from 1984 to 1996. The majority (74%) of dispersing beavers (n = 46) initiated dispersal in a downstream direction after spring ice-out. Females dispersed significantly farther away from their natal colonies than males (10.15 ± 2.42 (SE) km vs. 3.49 ± 0.86 km). Movements to neighboring sites were common (16 of 46 dispersers), indicating that beavers, especially males, may prefer to disperse to the nearest available sites. Most (64%) natal dispersers were 2-year-olds. Three-year-olds also constituted a considerable proportion (21%) of the dispersers, but 1-year-old dispersers were relatively rare (14%). Many adults underwent secondary dispersal after successful natal dispersal in our study area. Male secondary dispersers were more inclined to take over neighboring sites than were male natal dispersers (10 of 13 vs. 3 of 13). The effective population size in a 250-km2 area was estimated to be 161-228 individuals by the areal method and 267-378 individuals by the 85th percentile method

A Nose for Death: Integrating Trophic and Informational Networks for Conservation and Management

Non-lethal management of wildlife, both problem wildlife and pest species, to protect crops and threatened species is becoming increasingly important as non-human animals and humans come into closer proximity. A particularly promising approach is to apply predator scents to manipulate the cost/benefit ratio that influences the behavioral decisions made by prey and other predators about where to forage or rest. However, such olfactory manipulations are not always successful. Using insights from size-structured food webs, we develop a novel integrative model of the information that animals acquire from eavesdropping on predator and conspecific scents. We show how animals can use the information content in predator scents to derive knowledge of other predators and competitors and thus influence their decision to stay in or leave an area. This model framework clarifies how predator scents can influence all trophic levels, from interference competition directed at smaller predators, to predation and herbivory, and exploits direct and indirect pathways to promote landscapes of fear that influence spatial and temporal patch use in target animals. We illustrate how the application of this conceptual model can focus future research to enhance the use of predator scent-based deterrents in conservation and management. This integrated model shows great promise for addressing wildlife management concerns and for eventually improving the success and efficacy of traditional management techniques