Use Of Olfaction Research Articles

Social olfaction in marine mammals: wild female Australian sea lions can identify their pup's scent

Historically, anatomical evidence has suggested that marine mammals are anosmic or at best microsmatic, i.e. absent or reduced olfactory capabilities. However, these neuroanatomical considerations may not be appropriate predictors for the use of olfaction in social interactions. Observations suggest that pinnipeds may use olfaction in mother-pup interactions, accepting or rejecting pups after naso-nasal contact. Such maternal-offspring recognition is a favourable area for investigating the involvement of odours in social recognition and selectivity, as females are evolutionarily constrained to direct resources to filial young. However, there is no experimental, morphological or chemical evidence to date for the use of olfaction in social contexts and for individual odour recognition abilities in pinnipeds. Here, we report unequivocal evidence that Australian sea lion (Neophoca cinerea) females can differentiate between the odour of their own pup and that of another, in the absence of any other distinguishing cues. This study demonstrates individual olfactory recognition in a free-ranging wild mammal and is clear evidence of the social function of olfaction in a marine mammal.

Rapid somatic expansion causes the brain to lag behind: the case of the brain and behavior of New Zealand's Haast's Eagle (Harpagornis moorei)

ABSTRACT New Zealand's late Pleistocene and Holocene Haast's eagle (Harpagornis moorei) was the sole predator of the moa (Aves: Dinornithiformes) and the largest eagle so far described. Recent molecular evidence has hypothesised that it evolved from a much smaller Asian/Australian eagle within the past 1.8 my. Osteometry and high-resolution spiral computed tomography of skeletal remains of Haast's eagle were used to determine morphological and functionally significant characteristics of the central and peripheral nervous system and sensory apparatuses and to test these against hypotheses about behavior and evolution based on molecular and external morphology. Compared with other accipitrids, Haast's eagle had a proportionally low endocranial volume for its body weight. There was no anatomical evidence to support the significant use of olfaction by Haast's eagle, as the olfactory bulb size and cross-sectional area of the olfactory nerve foramen were no larger than would be expected for Accipitridae of this body weight. Both the size of the neural canal at the cervicothoracic junction and the brachial spinal quotient (ratio of neural canal area at cervicothoracic and caudal thoracic levels) were low, suggesting that the spinal cord at brachial levels was also small. These data are consistent with the hypothesis that Harpagornis had evolved to large size from a smaller ancestor and that the ancestors of Haast's eagle appear to have undergone rapid expansion of body size and elements of the hindlimb somatic nervous system at the expense of enlargement of the brain and visual, olfactory, and vestibular apparatuses.

Predator-prey dynamics: the role of olfaction

Predator-prey dynamics: the role of olfaction

Blue tits (Cyanistes caeruleus) respond to an experimental change in the aromatic plant odour composition of their nest

Although the use of olfaction by birds is now widely recognised, the olfactory abilities of passerine birds remain poorly explored, for historical reasons. Several studies however suggest that passerines can perceive volatile compounds in several biologically relevant contexts. In Corsica, recent findings suggest that cavity-nesting blue tits may use volatile compounds in the context of nest building and maintenance. Although they build their nests mainly from moss, female blue tits also frequently incorporate fragments of several species of aromatic plants in the nest cup. In field experiments, breeding female blue tits altered their nest maintenance behaviour in response to experimental addition of aromatic plants in their nest. In aviary experiments, captive male blue tits could be trained to detect lavender odour from a distance. Here I report results from a field study aimed to test whether adult blue tits altered their chick-feeding behaviour after an experimental change in nest odour composition. I experimentally added fragments of aromatic plant species that differed from those brought in the nests before the start of the experiment in a set of experimental nests and added moss, the basic nest material, in a set of control nests. Both male and female blue tits hesitated significantly longer entering the nest cavity after addition of new aromatic plant fragments, as compared to moss addition. This response was especially observed during the first visit following the experimental change in nest plant composition. Nest composition treatment had no effect on the time spent in the nest. This study demonstrates that free-ranging blue tits detect changes in nest odour from outside the nest cavity.

Use of Olfaction During Prey Location by the Common Vampire Bat (Desmodus rotundus)1

ABSTRACTThe common vampire bat, Desmodus rotundus, feeds on mammalian blood and is a major agricultural pest in Latin America. One way to prevent bats from biting livestock is to understand how the bats locate the livestock. We confirmed the role of olfaction in foraging with a modified cafeteria trial. Bats significantly favored blood meals associated with scent (fur, feces) over meals lacking these olfactory cues. These results confirm earlier observations on the role of olfaction during prey location by this species, and have potential to facilitate eradication measures without extensive loss of other bat species.

Olfactory mate recognition in a sympatric species pair of three-spined sticklebacks

Mate recognition is critical to the maintenance of reproductive isolation, and animals use an array of sensory modalities to identify conspecific mates. In particular, olfactory information can be an important component of mate recognition systems. We investigated whether odor is involved in mate recognition in a sympatric benthic and limnetic species pair of three-spined sticklebacks (Gasterosteus spp.), for which visual cues and signals are known to play a role in premating isolation. We allowed gravid females of each species to choose between water scented by a heterospecific male and water scented by a conspecific male. Benthic females preferred the conspecific male stimulus water significantly more often than the heterospecific male stimulus water, whereas limnetic females showed no preference. These species thus differ in their odor and may also differ in their use of olfaction to recognize conspecific mates. These differences are likely a consequence of adaptation to disparate environments. Differences in diet, foraging mode, habitat, and parasite exposure may explain our finding that odor might be an asymmetric isolating mechanism in these sympatric stickleback species.

Interactions between Steller's jays and yellow pine chipmunks over scatter‐hoarded sugar pine seeds

Summary Sugar pine (Pinus lambertiana Douglas) seeds are dispersed by wind, but yellow pine chipmunks (Tamias amoenus Allen) and Steller's jays (Cyanocitta stelleri Gmelin) gather the seeds and scatter‐hoard them. Chipmunks and jays store seeds in a similar manner, and during cache recovery they appear to compete for stored seeds. A series of aviary studies and radioactive seed studies in the field were used to examine how chipmunks and jays interact over stored seeds. Aviary studies revealed that chipmunks use spatial memory and olfaction to find seeds, including those stored by conspecifics and jays, whereas jays use spatial memory and observational learning, so they usually find only the seeds that they have stored. Use of olfaction makes chipmunks much better pilferers than jays. In the field, both chipmunks and jays have a recovery advantage (they retrieve their own caches 3·6 faster than do pilferers), and chipmunk caches disappear 3·4 faster than jay caches. Steller's jays appear to avoid chipmunk pilferage by caching seeds in closed‐canopy pine forests with little shrub understorey where chipmunks seldom forage, whereas chipmunks cache under shrubs in forest openings. The risk of pilferage by chipmunks appears to force jays to cache in forests. Competition between chipmunks and jays for stored seeds might have indirect effects on sugar pine seedling establishment because seedlings survive better when under shrubs.

Blue tits use selected plants and olfaction to maintain an aromatic environment for nestlings

Animals use the chemical compounds of plants as a defence mechanism against enemies, and sometimes use olfaction to discriminate and select the chemical plant substances. Some birds bring to the nest plant material that has volatile compounds that protect the host and their offspring against parasitic organisms. Here we show that blue tits on the island of Corsica (Parus caeruleus ogliastrae) adorn their nests with fragments of aromatic plants. These plants have chemical compounds that are used by humans to make aromatic house cleaners and herbal medicines. We also show that individual blue tits maintain an aromatic nest environment when offspring are raised, using odour cues to determine the frequency with which they replenish the nest with fresh plant material. We provide an exceptional example of the ecologically relevant use of olfaction by birds under natural conditions. To our knowledge, we present the first experimental demonstration that a free‐ranging animal makes use of smell to maintain an aromatic environment for offspring with plants, supporting predictions of the nest protection hypothesis.

The Smell of Nature: Olfaction, Knowledge and the Environment

Olfaction offers unique entry into the non-human world, but Western culture constrains such opportunities because of the dominance of the visual mode of perception. We begin by briefly reviewing philosophical arguments against olfaction as a reliable cognitive input. We then build a biological case for the similarity of non-human and human olfaction. Subsequently, we argue that some contemporary societies still make use of olfaction for organizing themselves in space and time. We end by suggesting that olfaction offers promise for advancing inquiry into the human-nature relationship that is so important to many environmental philosophers, scientists and activists.

The Smell of Nature: Olfaction, Knowledge and the Environment

Abstract Olfaction offers unique entry into the non‐human world, but Western culture constrains such opportunities because of the dominance of the visual mode of perception. We begin by briefly reviewing philosophical arguments against olfaction as a reliable cognitive input. We then build a biological case for the similarity of non‐human and human olfaction. Subsequently, we argue that some contemporary societies still make use of olfaction for organizing themselves in space and time. We end by suggesting that olfaction offers promise for advancing inquiry into the human‐nature relationship that is so important to many environmental philosophers, scientists and activists.

Field observations of the host–parasite relationship associated with the common horse bot fly, Gasterophilusintestinalis

Behavior of Gasterophilus intestinalis (Diptera: Gasterophilidae) was observed in the laboratory and field over a period of 10 years. Mating occurred in a frenzied manner as flies emerged from pupae. Males attempted to copulate with females that had not fully emerged from the pupal case. Mating was never observed in the field or near the horse. Observations suggest that fecal piles of the horse are used as the mating site for the newly hatched flies. Activation of host-seeking behavior was found to occur early and remain throughout the life span of the adult as it sought multiple hosts for oviposition. Evidence is presented supporting the use of olfaction and vision in finding the host. Interest by flies in shadows and linear high-contrast objects was observed. Methods used by the flies to maintain close proximity with the host are discussed including flight with the host and avoidance of host defenses. Recapture methods were successful in determining the time taken to reestablish at the host, and extent of travel to the host. The presence of kairomone(s) within horse secretions is suspected.

Olfaction and predator detection inColeonyx brevis (Squamata: Eublepharidae), with comments on the functional significance of buccal pulsing in geckos

Squamate reptiles rely heavily on two nasal chemical senses in directing most of their behavior: nasal olfaction and vomeronasal function. For most behaviors in most species, the vomeronasal system is the predominant sense. It has been suggested, however, that geckos are unusual in the extent to which they rely on nasal olfaction rather than vomeronasal function. In this study, we use defensive tail display as a behavioral bioassay to examine the context and relative use of olfaction vs. vomeronasal function in a eublepharid gecko, Coleonyx brevis. When presented with appropriate snake-predator skin chemicals in the absence of relevant visual stimuli, C. brevis exhibits a defensive tail display that has been shown to be adaptive in defending against snake predators. We demonstrate that olfactory cues alone are sufficient to provoke the behavior and that geckos precede the display in many cases with “buccal pulsing,” a behavior that we suggest is an olfactory sampling mechanism analogous to mammalian sniffing. Our results support the gecko-olfaction hypothesis and demonstrate that geckos use nasal olfaction to discriminate among potential predator species. We discuss alternative hypotheses for the origin of species-specific, chemosensory predator identification in Coleonyx. © 1996 Wiley-Liss, Inc.

Carnivore olfactory bulb size: allometry, phylogeny and ecology

Olfactory bulb size was measured in 146 species of Carnivora in order to examine whether recently observed functional patterns for overall brain size were similar for component parts of the brain. Comparative measures were analysed in relation to various allometric characters (body, brain and skull size), phylogeny, behaviour and ecology. Olfactory bulbs are significantly and positively correlated with all allometric variables, but indices of skull size correlate slightly more closely than other variables. This probably relates to functional aspects of skull size, facial proportions, and anterior elements of the brain. Phylogenetic associations were examined by two comparative methods: the method of independent contrasts and phylogenetic autoregression. Both revealed similar phylogenetic correlation at generic and familial levels. Using calculated values from either method, relative olfactory bulb size only correlates with zonation among seven behavioural and ecological variables; aquatic otters have smaller bulb sizes than carnivores of other zonal types. This agrees with discussion about the diminution of olfactory communication in aquatic environments. Also, olfactory bulb size correlates with home range size, which is consistent with a recent model on the use of olfaction for foraging in designated home ranges. Generally, comparative differences in olfactory bulb size in carnivores do not associate with functional variables found in other comparative studies. Nevertheless, future analyses of specific brain components in mammals may be more useful than overall brain size for testing evolutionary hypotheses of mammalian brain size.

The Use of Olfaction in Food Location by Frugivorous Bats

The Use of Olfaction in Food Location by Frugivorous Bats

A Field Test on the Use of Olfaction in Homing by Testudo hermanni (Reptilia: Testudinidae)

A Field Test on the Use of Olfaction in Homing by Testudo hermanni (Reptilia: Testudinidae)

Olfaction—a link with the past

The article emphasizes the similarities between man and other mammals in the use of olfaction for communication with conspecifics. It is based on the author's experience gained during prolonged studies of the role of olfaction in the behaviour of the European wild rabbit, Oryctolagus cuniculus and an carlier literature dealing with smell in humans. There is experimental proof that in all animals olfaction plays a very significant role in the functioning of territoriality, species specificity, pair and group formation, dominance heirarchy, class distinction, sexual differentiation and many other phenomena which form the basis of social behaviour. The same phenomena underly the behaviour of man. Olfaction becomes involved consciously or subconsciously to reinforce them. Man is well equipped to produce and perceive olfactory signals but it appears that this dependence on olfaction is deliberately repressed in childhood. There are many observations which suggest a connection or interdependence between sex and smell in man. The sense of smell has been suggested to play a role in the recognition of mothers by babies and in the establishment of sexual identity in children. Odour may be involved in courtship. Olfactory signals were found to effect the menstrual cycles of women. Odours are involved in the appreciation of the state of pleasantness or unpleasantness and hence in shaping mood. Smell is often exploited nowadays commercially to affect the decision of consumers.

HOMING AND OLFACTION IN SALMONIDS: A CRITICAL REVIEW WITH SPECIAL REFERENCE TO THE ATLANTIC SALMON

Summary(1) Based on data from the literature, the phenomenon of homing in salmonids is examined with special reference to the Atlantic salmon. Wild, native fish demonstrate an excellent homing ability, judged from percent return to the home river (1–3 %) and straying to non‐native watersheds (less than 3 % of returning fish).(2) The homing ability in wild fish is shown to be closely related to the existence of reproductively isolated populations between and within watersheds, as demonstrated by data from salmonid ecology and biochemical genetics.(3) Two main hypotheses have dominated the literature on salmonid homing during recent years: (a) An ‘imprinting’ hypothesis based on a process of learning of stream odours during seaward migration, coupled with sun‐orientation for open sea navigation, (b) A ‘pheromone’ hypothesis related to odours from fish and based on inheritance and the seasonal migrating schedules of discrete populations.(4) The olfactory sense has been demonstrated as mandatory for salmonids, both in near range and open sea navigation. According to genetic, sensory and ecological aspects of homing, the pheromone hypothesis is therefore concluded to be the most appropriate.(5) Fish produced from artificially fertilized eggs, released within native systems or transplanted, demonstrate a reduced homing ability. Since hatchery‐raised fish demonstrate a survival in sea equivalent to that of wild fish, a genetic disturbance of navigational ability has been suggested, resulting from the production of population hybrids by man.(6) Studies made in the fields of behaviour, electrophysiology and chemistry strongly suggest that population‐specific fish odours are involved in home‐stream recognition by salmonids.(7) An evaluation of ‘imprinting’ experiments related to artificial organic compounds reveals that: (a) the odorant properties of the applied chemicals must be questioned, (b) imprinting related to olfaction may be based on a weak theoretical foundation, (c) returns obtained in census experiments may be adequately explained through ecological interpretations, and (d) behavioural preferences obtained from exposure to non‐natural compounds may be founded on mechanisms not associated with homing.(8) A logical link between the use of olfaction and the role of genetics in salmonid homing is emphasized, together with its practical implications for salmonid management.

Seasonal Movements of Mexican Freetail Bats Tadarida brasiliensis mexicana Banded in the Great Plains

Records of band recoveries from 170,000 bats banded in northern Oklahoma between 1952 and 1968 are summarized to present an account of the migratory habits of the Great Plains population of this species. Winter range lies between 20° and 29°N, and between the Gulf of Mexico and the interior of the Mexican Plateau. Maximum recorded distance from banding site to point of recovery is 1,840 km. One bat was recovered in its natal cave after making eight migra- tory circuits. A theory regarding the use of olfaction in long-range navigation is presented. The Mexican freetail bat has been known since 1956 to be a migratory species (Villa, 1956; Glass, 1958, 1959; Villa and Cockrum, 1963). Since the first discovery of long-range migration, Constantine (1967) has summarized his data on activity patterns and recorded numerous records of movements to and from Carlsbad Cavern. Cockrum (1969) summarized data he obtained in northwestern Mexico and southern Arizona. He recognzied four discrete populations, those in California and western Arizona which perform only local or short-range movements, and those of the intermontane desert and the Great Plains, which perform long migratory flights. The Arizona-New Mexico population migrates south along the Sierra Madre Occidental and the west coast of Mexico at least as far as the state of Sinaloa; the Great Plains population moves southward through Texas and along the Sierra Madre Oriental into eastern and south-central Mexico. Cockrum recorded two instances of movement of banded bats from Carlsbad to Arizona and northern Sonora, and Constantine recorded three recoveries of his Carlsbad bands in Arizona and one in Sinaloa. These records constitute the only evi- dence of intermixing between the Great Plains and Interior Desert populations. Between 1952 and 1968 the author and his graduate students banded approximately 170,000 of these bats in western Oklahoma. In the early years bats were banded without regard to age, but from 1962 to 1968, about 120,000 neonates were banded, males and females in about equal numbers. The bats came from four caves less than 80 km apart, whose populations constantly intermingle. These four caves constitute the northernmost nursery aggregation of freetail bats in the Great Plains and collectively con- tain an estimated >3 million fledged bats in late summer when all neonates are fully capable of flight. By using a different-colored band each year, with colors being repeated only at 5-year intervals, it was possible to recognize our bats, as opposed to bats banded elsewhere, and to recognize year classes, without capturing bats to read the numbers. From 329 bands actually read, and many hundreds more seen and recognized as ours, it appears that a large part of the population returns each year to its natal area. However, numerous summer records (Fig. 9) indicate that many bats of both sexes

Experience and selection behavior in the food habits of Peromyscus: use of olfaction.

AbstractFeeding behavior in young and adult Peromyscus maniculalus and P. lcucopus was studied by examining the extent to which food habit could be modified by prior experience and by decribing the pattern of feeding behavior used by the mice in a three-choice situation. Modifiability of food preferences was investigated by providing mice with specific food-cue experience and testing their subsequent preferences. The food preferences of young and adult P. leucopus and young P. m. baiudi were significantly affected by the food-cue conditioning and the effect persisted for at least 30 days. Adult P. m. bairdi food preferences were not affected by the prior experience. Automatic monitoring devices were used to describe the patterning of feeding behavior with three choices present. Analyses showed that; (1) young mice were less flexible initially than adult mice; (2) adult P. leucopus switched feeding sites more frequently than any other group; and (3) young P. m. bairdi avoided a novel food-cue stimulus whereas the other test groups ate readily from this source. The principal conclusion was that P. leucopus exhibited more flexibility in feeding behavior than P. m. bairdi. Food habits and flexibility of feeding behavior were discussed in relation to the habitat distributions of these two species of mice.