Showing papers in "Behavioral Ecology and Sociobiology in 1977"

Sound transmission and its significance for animal vocalization

Abstract: 1. Sound transmission was measured in open fields, mixed decidous forest with and without leaves and coniferous forest in Dutchess County, New York. Attenuation of white noise and pure tones was measured between one microphone close to a loudspeaker and another microphone 100 m away, at the same height. Graphs of excess attenuation (E.A. in dB/100 m) against frequency were obtained at 0.15, 1, 2, 5, and 10 m above the ground. An analysis of variance was conducted to estimate effects of height, frequency and habitat. 2. Height and frequency affect sound transmission more than habitat. With a sound source close to the ground (15 cm and 1 m) all frequencies were more attenuated than at greater heights. The patterns of E.A. as a function of sound frequency were basically similar in all habitats. At all source heights the lower the frequency the better the sound carried, with the exception that close to the ground, sounds below 2 kHz were excessively attenuated. Comparing open field and forest, trees improved transmission of frequencies below 3 kHz, especially close to the ground. 3. Some general trends can be predicted for maximization of transmission distances of animal sounds in these habitats. For an animal vocalizing higher than 1 m above the ground, the lower the frequency the further the sound travels. Close to the ground, low frequencies are again preferred for maximization of transmission distances, but the frequencies must be pitched above a range of attenuated, low-pitched sounds, the limits of which vary to some extent with habitat, creating the ‘sound window’ of Morton. This ‘window’ of least-attenuated frequencies, only occurring close to the ground, tends to be pitched somewhat lower in forest than in open habitats. However, for an animal producing sounds in the habitats tested, perch height and sound frequency are more important than the habitat in determining how far the sound will carry.

Sound transmission and its significance for animal vocalization: II. Tropical forest habitats

Abstract: Summary1.Attenuation of white noise and pure tones from 350 Hz to 10 kHz was measured at three secondary forest sites in Panama at different stages of maturity. Graphs of excess attenuation (E.A.) versus frequency were obtained near ground level, and at heights of 1, 2, 5, 10, and 12 m in each habitat.2.The pattern of E.A. vs. frequency was similar for all habitats. For all heights other than ground level and 1 m the lower the frequency the better the sound carried. Sounds below 2 kHz were attenuated by a ground effect if the source was 1 m or less from the ground. Consequently there was a minimum of E.A. in all three habitats between 500 Hz and 2 kHz at ground level and 1 m.3.Relevance of the data to assessment of the role of environmental variables in the natural selection of vocalization for long-distance transmission is discussed. Two facts mitigating against Morton's sound “window” as an explanation for lower frequencies in songs of forest as opposed to open country birds are presence of similar “windows” in both habitats and restriction of windows to a zone close to the ground in most habitats.

Social organization and foraging in emballonurid bats

Abstract: 1. Graphical methods are presented for the simultaneous comparisons of group size and territory size (subsumed jointly under the term “social dispersion”), in organisms with exclusive but contiguous territories. The methods are applied to recently published data on five species of neotropical emballonurid bats with particular emphasis on identifying the factors which set maximal limits on group size. The available evidence suggests that population densities, group territory sizes, and group sizes are all limited by components of the food distribution. More particularly, it is argued that minimization of annual foraging ranges is of advantage to these bats and leads to a colony territory size containing one and only one active food site at any given time. Territory size is thus determined by the average distance between successively available food sites, the number of such sites needed per year, and the average size of these sites. Maximal group size is then determined as a result of this territory size minimization and equals average richness of currently used food patches. 2. The model predicts that where food patches are low in richness and close together, social dispersion will be fine-grained; where patches are high in richness and occur far apart, social dispersion will be coarse-grained. Since sites in this study which have many small patches tend to be located in the more stable habitats, the model also predicts that temporal stability in group size and unimodal frequency distributions of group size over space will be associated with fine-grained dispersions. The reverse is predicted for coarse-grained social dispersions. 3. The model only predicts the maximal size colonies can take. Among the many possible factors promoting social aggregation up to the predicted maxima, only a few account for the observed congruence in colony sizes and compositions at the roost and on the foraging grounds. These include information transfer about new food sites, location of roosts centrally to reduce energy costs of transit (Horn, 1968), and stabilization of competition with conspecifics at food sites.

The acquisition of rank and the development of reciprocal alliances among free-ranging immature baboons

Abstract: 1. In many Old World monkey species, reproductive benefits accrue to high-ranking males and females. During 15 months' observation of the agonistic interactions of free-ranging juvenile and subadult baboons, most individuals assumed ranks similar to those of their mothers during disputes with their peers. Maternal intervention in the disputes of their offspring appeared to be the primary factor affecting the inheritance of rank. Both the rate and the relative success of maternal aiding behavior were correlated with maternal rank, and therefore tended to perpetuate the existing rank heirarchy across generations. 2. Although the ranks of immature animals depended on the ability of family members to support them successfully when threatened, immature animals formed aggressive alliances primarily with the members of highranking matrilines. In contrast, adult females in the study troop formed alliances primarily with probably related individuals of adjacent rank. A model is presented that attempts to explain ontogenetic changes in alliance formation on the basis of the potential costs and benefits of entering into aggressive alliances with particular indivuduals.

Organizational systems and dominance in feral horses in the Grand Canyon

Abstract: 1. Several aspects of the behavioral ecology of feral horses (Equus caballus) were studied in Grand Canyon, Arizona, USA. Most bands contained three to five horses that included one stallion and his harem. Males that did not obtain a harem remained solitary. Throughout the study bands remained stable in composition. 2. Home ranges for all bands decreased in size in successive warm months, probably due to increased ambient temperature and drought. This resulted in greater utilization of spring areas that led to increased interband confrontation and agonistic display. 3. Territoriality was not observed in individual horses or bands, but bands hierarchial in both inter- and intraband structures. Interband stallion dominance was reinforced through posturing and fighting. Intraband hierarchies, as determined by dominance coefficients, were independent of individual size in three of four bands. 4. Indexes of nervousness (NER), calculated while horses were drinking, showed that stallions were less nervous than mares. A low NER was correlated with individuals leading toward drinking areas, whereas a high NER existed in individuals initiating flight although no single horse acted consistently as a leader. 5. Diurnal activity patterns were correlated with ambient temperatures.

Laboratory analysis of flower constancy in foraging bumblebees: Bombus ternarius and B. terricola

Abstract: 1. We established apparently normal foraging behavior in captive bumblebees utilizing artificial flowers. Syrup rewards of flowers visited were experimentally manipulated to correspond to nectar volumes found in flowers utilized in the field. 2. Bees became >90% flower-constant to either of two flower types (distinguished by color) when rewarded with 1.0 μl 50% sucrose at each visit to flowers of one color, while the others remained unrewarded. 3. Flower-constancy to ‘blue’ was achieved within 50 flower visits, but equal flower constancy to ‘white’ was achieved only after 250 flower visits. 4. While being trained to white flowers the bees increased their percent correct (rewarding) flower choice over consecutive foraging trips during the day, but decreased their performance overnight. 5. Bees trained to blue did not switch to white flowers even when the white were subsequently rewarded with more food than the blue. However, bees trained to white utilized blue flowers. 6. Most bees simultaneously presented with white flowers having six times greater syrup rewards than blue visited both in approximately equal proportions independent of flower density, while some individuals visited primarily blue flowers. 7. The laboratory experiments suggest that bumblebees, once conditioned, are relatively ‘constant’ foragers despite changes in resource availability.

Social organization and foraging in emballonurid bats: IV. Parental investment patterns

Abstract: Summary1.Four species of neotropical emballonurids were contrasted in their demographic profiles and their patterns of parental investment. Species using less seasonal habitats (Rhynchonycteris naso and Saccopteryx leptura) are those most likely to have more than one parturition per year, and parturition periods tend to be relatively asynchronous. Those species utilizing highly seasonal food supplies, Saccopteryx bilineata and Balantiopteryx plicata, show a single synchronous birth period annually.2.In mammals, parental investment costs include not only such features as litter size (in all these species, one), but also the nature of the timing between parturition and food maxima. Where food peaks are synchronized with gestation, the survival of adults will be favored over that of lactating and dispersing offspring. Where food peaks coincide with lactation and dispersal, pregnant females suffer high risks during gestation. In our samples, the two species using seasonal habitats show synchrony between food peaks and lactation and dispersal, while those in stable habitats show synchrony between gestation and maximum food levels.3.Young of both sexes are retained for long periods in S. leptura, a species of stable habitats. Male progeny of S. bilineata tend to settle near to parental units, while female offspring all disperse. In the other two species, both sexes disperse at weaning.4.In S. bilineata, some females pregnant during the lean food season will either resorb or abort offspring. B. plicata females, which also suffer food stress during gestation, either disappear or complete their gestations.5.The two stable habitat species, R. naso and S. leptura, both show a division of female colony members into reproductive and nonreproductive females. The latter are always young females that have never before reproduced. The age of first reproduction is thus later than one year in these species, while it is just one year in the other two species.6.The four species may be ranked with regard to increasing levels of parental costs per parturition as follows: R. naso, S. leptura, S. bilineata, and B. plicata. This ranking is exactly the same as that obtained on the basis of adult female mortality rates or on the basis of habitat seasonality. We suggest that specialization in a particular foraging habitat has led, through differences in seasonality of food supplies, to the observed differences in parental investment patterns in our bat species.

Agonistic aids and kinship in a group of pigtail macaques

Abstract: 1. An analysis of aiding behavior in a group of 49 pigtail macaques (Macaca nemestrina) demonstrated that these animals were very selective in the performance of these aids. 2. Not only did these monkeys discriminate between relatives and nonrelatives, but they also chose to aid relatives of a closer degree of relatedness more often than relatives more distantly related. 3. Kinship, however, was not the only factor that affected the performance and receipt of aids, for age and sex were also relevant. Although females were more active than males in performing acts of aid, neither sex received significantly more aids. While older animals performed more aids than younger animals, younger animals received significantly more aids than did older animals.

Two models for the evolution of polygyny

Abstract: Two models of conditions for the evolution of polygyny are treated axiomatically. Both models assume a social system based on female mate choice in situations in which a female is better off if she mates polygynously with an already mated male on a superior territory than if she selects a bachelor on an inferior territory. One model, the competitive female choice model, assumes that the females of a harem compete for the limited resources of the harem and thus that their fitness decreases as co-wives are added. The cooperative female choice model assumes that, within limits, a female's fitness is improved by the addition of co-wives to her mate's harem, as a result of cooperative interactions within the group. For each model, a sufficient set of independent assumptions is provided. Implications of the models are indicated and methods for testing them are discussed.

Prey recognition and selection by the constant frequency bat, Pteronotus p. parnellii

Abstract: In the laboratory the neotropical bat, Pteronotus p. parnellii of Jamaica W.I., will readily capture free flying and tethered insects. It will also attack a stationary mechanical insect model when its wing-like parts are rapidly moving. On the basis of our observations we conclude that: 1. P. parnellii are attracted to flying insects and recognition of these rather than background objects is dependent on insect wing movements. Insects which are not beating wings are relatively immune from predation. 2. The frequency of the wingbeats of the insects is important in prey recognition. P. parnellii are not attracted to insects or to mechanical models of insects when the wing movements are slow. 3. These bats are selective in the acquisition of their prey and not simply opportunistic. They ignore or reject lampyrid beetles, arctiid and ctenuchid moths and the geometrid moth, Thyrinteina arnobia. They consume a variety of other Lepidoptera, Coleoptera, and insects from other orders. Their prey consists of both large and small insects. 4. In spite of the emission of intense sonar pulses with a constant frequency component of long duration, they can effectively hunt their prey in relatively confined spaces. They can chase their prey among simple arrays of obstacles and they can pursue insects to within several centimeters of large obstacles. 5. Evidence supports the hypothesis that the basis for insect wingbeat detection is the rapid and repetitive pattern of Doppler-shifts which the beating wings impose on the echoes of the constant frequency component of the bat's pulses.

Intra-nest relatedness in the social wasp Polistes metricus - A genetic analysis

Abstract: 1. It was determined that (a) the workers do not produce maledestined egges when foundresses are present, (b) the α foundress shares reproduction with the β foundress; the α foundress produces 78% of the colony's females and 87% of the males, (c) foundresses mate at least twice, using these sperm in a 9:1 ratio, and (d) when the nest's foundresses are dead and the nest successful, two workers lay male-destined eggs, one producing 19 times as many as the other worker. 2. Six nest classes were defined on the basis of combinations of foundress mortality for successful nets which had been derived from one or two foundresses. Using the results summarized above and the time of foundress deaths, a set of intercaste relatedness values was calculated uniquely defining these six nest classes.

Human sociobiology: Pair-bonding and resource predictability (effects of social class and race)

Abstract: 1. Social class and racial differences in human pair-bonding and heterosexual behavior patterns are considered in an evolutionary perspective. The expected unpredictability of one's future income stream should be an important parameter influencing these variables, according to theoretical considerations. 2. The literature is reviewed relevant to the prediction that those facing more predictable income streams should have a stronger marital pair bond and premarital sexual activities more likely to lead to a strong pair bond, all other things being equal. 3. It is shown that those with high education or high occupational status do have more predictable income streams, and that their pair-bonding activities exhibit the predicted consequences of that fact. A much smaller number of studies comparing different races' sexual patterns are also consistent with the theory. In the extremely few cases that permit it, it is found that a correlate of income predictability is more important in determining the dependent variables than either race or class, as expected. 4. Alternative explanations of the data are briefly examined and found wanting, especially with respect to explaining the patterns of individuals whose parental class differs from their own. Further research is suggested.

The reproductive behavior of Anthidium maculosum (Hymenoptera: Megachilidae) and the evolutionary significance of multiple copulations by females

Abstract: 1. Some males of the megachilid bee Anthidium maculosum establish territories at patches of flowering Monarda and may remain there for up to at least 21 days. The frequency of male-male interactions and territorial takeovers appears partly dependent upon population density. 2. Males that do not hold territories tend to be smaller than territorial individuals. They either visit many territories repeatedly as wandering intruders or occupy a corner of one territory as satellite males. They always flee when challenged by territory owners but often return sooner or later. Although most matings are performed by territory owners, non-aggressive subordinates do occasionally copulate. 3. Females may mate dozens of times in the span of a week. Multiple mating may be an adaptation designed to cope with male harassment while they exploit the food resources in territories. It may save time and energy and reduce foraging interruptions to copulate passively for 30 s rather than to try to evade or repel the large, aggressive males. 4. A male may mate with the same female at intervals of about 6 min and may guard her against intruders during her visit to his territory. These traits may help a territorial male to be the last male to copulate with a female prior to oviposition. If sperm precedence occurs in A. maculosum only this last male is likely to fertilize her egg.

Recruitment behavior, orientation, and the organization of foraging in the carpenter ant Camponotus pennsylvanicus degeer (Hymenoptera: Formicidae)

Abstract: 1. The recruitment process of Camponotus pennsylvanicus initiates and regulates foraging activities. Scout ants recruit nestmates to new food sources with alerting motor displays. Workers subsequently leave the nest and follow a recruitment trail that appears to be composed of hindgut material and poison gland secretion (formic acid) to the food. Hindgut material functions as a long-lasting olfactory orientation cue between the food source and the nest, whereas poison gland secretion makes the recruitment trail highly attractive to stimulated ants. Hindgut trails may also have a recruitment effect. 2. Although hindgut material is an important orientation cue during foraging, because ants make repeated foraging runs they may also make use of visual cues. 3. Mass foraging is organized by the behavioral activities of recruiting ants. Starvation intensifies the recruitment displays of scouts, which releases a strong recruitment response in the colony. The behavior of individual recruiters during the organization of foraging facilitates at first a quick mobilization of nestmates to the food; subsequently recruiter behavior changes. These changes the facilitate food transport to the colony. The amount of food brought into the colony along with the decrease in recruitment behaviors may account for the waning and eventual termination of foraging activity. Only ants of a particular age bracket respond to recruitment signals and participate in foraging, and of this group only a small proportion of workers are consistently active in foraging. 4. When compared to other formicine species, the recruitment behavior of Camponotus pennsylvanicus appears to illustrate some features of chemical mass communication while still retaining characteristics of the group recruitment technique.

Foraging behavior of ants: Experiments with two species of myrmecine ants

Abstract: 1. Experiments presented in this paper for two species of ants confirm the predictions of models based upon the hypothesis that the animals maximize the net rate of energy intake while foraging. 2. Solenopsis geminata in the laboratory recruited at higher rates to patches of sugar solution when the distance to a patch decreased, the diameter of a patch increased, or the sugar concentration increased. 3. Pogonomyrmex occidentalis in its natural setting recruited at higher rates to patches of seeds mixed with pebbles when the distance to a patch was decreased, the size of the patch was increased (when recruitment was already at a high level), the density of seeds was increased, or seed size was increased. When presented with a uniform distribution of seed sizes within a patch, this species tended to choose intermediate-sized seeds, but there was no tendency to choose a narrower range of seed sizes as the distance to the patch increased. This last finding was the only one inconsistent with a model based on maximization of net rate of energy intake. 4. The tendency for Solenopsis to respond to sugar concentration and for Pogonomyrmex to respond to seed size refutes the predictions of models based on minimization of the average time required to obtain each food item. 5. Increased temperature increases running speed. Thus, when the temperature increased during an experimental session for Pogonomyrmex, a particular rate of recruitment to a patch was maintained by a decrease in the total number of recruits on the trail to the patch. 6. Further analysis of the Pogonomyrmex results reveals that different levels of response to variable changes in the various experiments can be explained in terms of the model. This indicates that interference among recruits to a patch is always important to the level of response.

Behavioral ecology of the social wasp, Mischocyttarus mexicanus

Abstract: 1. The social biology of the polistine wasp Mischocyttarus mexicanus was studied in southern Florida at the Archbold Biological Station (January–May 1975=‘winter-spring’; November–December 1975 and January 1976=‘fall’). Nests were initiated by from one to twenty females (foundresses). The mean foundress-group size varied with season; most nests were founded by one female in winter-spring and by larger groups in the fall (Fig. 1). The females in a group were derived from one natal nest and were thus closely related. During the period between nest initiation and daughter emergence (predaughter phase) groups were stable in terms of membership. Approximately two months after nest initiation daughters began emerging; they remained on the nest, all as active foragers. Toward the end of the colony cycle future queens and males were produced. These gradually dispersed from their natal nests, the females leaving to found new nests. Mating probably occurred away from the nest. 2. Nest productivity (number of cells) at the end of the predaughter phase varied with the number of nest foundresses (Fig. 2). The number of cells/foundress was smaller in larger groups. 3. Survivorship of nests during the predaughter phase varied with group size, one-foundress nests suffering greater mortality than multiple-foundress nests (Table 3). Nests failed either when they were abandoned or when attacked by birds. Wasps sometimes renested or repaired the damaged nest. Larger nests were more likely to survive because these nests continued to be active after the disappearance of one female; this was impossible for single-foundress nests. 4. The number of queens (egg-layers) in a colony at any given time varied with group size and with season, one in winter-spring nests, and several in most fall nests. Among foundresses there were parallel hierarchies of dominance, defined in terms of degree of aggression (bitting frequency), ovarian development, and foraging frequency (Table 6). Away-from-the nest mortality rates of foraging foundresses (cofoundresses) and of lone-nesting females were greater than those of queens (Table 7). 5 Non-egg-laying foundresses were capable of laying eggs, because when queens were removed from nests, they were replaced by one of the cofoundresses. The replacement queen was in all cases the β-individual in the hierarchy previous to queen removal. 6. Mortality rates of foragers were lower in winter-spring than in fall. Many nestmates in large fall nests did no foraging but solicited others frequently. Durations of foraging trips for arthropods and nectar were longer in fall than in winter-spring because sources of prey and nectar were less available to wasps in fall. 7. Some possible effects of certain environmental factors (predation, abundance of food) on the foraging and social behavior of Mischocyttarus mexicanus are discussed.

Measurement of nest cavity volume by the honey bee (Apis mellifera)

Abstract: 1. Honey bee swarms exercise considerable care when selecting a nest site. One nest site variable evaluated by bees is cavity volume. 2. The volume distribution of natural nests (Fig. 1) has a wide range (12 to 4431 observed), but most nest volumes are clustered in the 20- to 100-1 subrange. The modal volume is approximately 351. This distribution reflects a process of volume selection among potential nest cavities when a swarm chooses its nest site. For example, swarms prefer 40-1 to 10 and 100-1 nest cavities. In nature, the volume-selection process operates primarily by rejecting undersized cavities, but also by rejecting oversized cavities. 3. The observed limit in resolution power of volume perception was discrimination between cubes differing by 151. 4. A swarm's preference in nest cavity volume is independent of swarm size. 5. A scout bee's inspection of a nest site spans approximately 40 min. During this time a scout spends, most of her time at the nest site, engaged in numerous brief inspections inside and outside the nest cavity. When inside a cavity, a scout's principal behavior is rapid walking about the cavity's inner surfaces. The pattern of walking movements over successive interior inspections shows (1) a general progression from walking mostly near the entrance to walking deeper inside the cavity, and (2) a tendency to traverse different regions of the cavity's interior surface on different inspections. 6. Honey bees can measure cavity volume if at least one of two conditions is fulfilled: (1) the cavity interior is well illuminated, or (2) the cavity's inner surfaces can be completely traversed by walking. The natural conditions for volume perception are probably low (<0.5 lux) cavity illumination, but traversable inner surfaces. The importance of walking to volume perception was demonstrated by manipulating scout bees' perceptions of a cavity's volume by varying the amount of walking required to move between points inside the cavity. The hypothesis is presented that scouts measure the volumes of dimly illuminated cavities by integration information on the distances and directions of walking movements made inside the cavity.

Relative inclusive fitness in the social wasp Polistes metricus

Abstract: 1. The average between-foundress relatedness for foundresses of Polistes metricus was estimated as 0.63. Both foundresses were assumed to be derived from the same nest. 2. The relative probability of producing a successful nest for two foundress: one foundress nests was estimated as 1.38, SE=0.022. 3. The relative reproductive success observed for two foundress: one foundress nests was 2.25, SE=0.35. 4. The inclusive fitness of an α foundress relative to its expected fitness if it and the β foundress act alone is 1.83±0.57. The inclusive fitness of a β foundress relative to its expected fitness if it and the α foundress act alone is 1.39±0.44. 5. The β foundresses who may have the option of founding their own nests would not appear to decrease their inclusive fitness by becoming a subordinated foundress on the nest of a foundress from their own nest even though they give up a substantial portion of reproduction and increase their chance of death. Thus the results presented in this paper are in accord with those expected for kin selection theory.

Refraction and the spitting behavior of the archerfish (Toxotes chatareus)

Abstract: 1. Archerfish (Toxotes chatareus) spit droplets of water at aerial insect prey, knocking them onto the water surface to be eaten. Since the fish's eyes remain completely below the water surface during sighting and spitting the fish must deal with potentially severe refraction effects at the air-water interface. High speed (200 f.p.s.) motion picture films of 480 spitting sequences were analyzed to determine the magnitude of the refraction effect and to suggest how the fish compensate for it. 2. T. chatareus do not shoot from a position directly below the prey, but can correctly set their spitting angle to compensate for the refraction unique to a variety of positions (Fig. 6). The fish can correct (Fig. 14) for large refraction effects on the prey's apparent elevation (Fig. 12) or apparent height (Fig. 13). They may be enabled to do so by a rather precise linear relationship between the real elevation of the prey from the nose and the apparent elevation from the eye which exists during sighting (Fig. 15) and spitting. However, spitting accuracy decreases with increasing prey height (Fig. 7) or range (Fig. 8). 3. The archerfish must also correct for significant curvature of the water droplet's trajectory (Fig. 10). Since shot velocity is relatively constant (Fig. 9) the fish must make this correction via their spitting angle, but the stage in the spitting process at which this occurs is unknown.

The contributions of kinship and conditioning to nest recognition and colony member recognition in a primitively eusocial bee, Lasioglossum zephyrum ( Hymenoptera: Halictidae )

Abstract: 1. In the primitively social halictine bee, Lasioglossum zephyrum, colony unity is maintained through an interplay of both nest recognition and nest mate recognition, using odor cues. 2. Nests have odors which are attractive to members of their colonies and also to bees from other colonies. Bees are, however, usually able to distinguish between their own nest and a foreign nest if given a choice. 3. Bees from colonies which are relatively homogeneous genetically and in which the bees share a common larval environment recognize their own nest with less difficulty than bees from genetically heterogenous colonies in which a common early environment is lacking among member bees. 4. A significant component of nest recognition behavior is based on genetic homogeneity, and/or larval conditioning, perhaps a form of imprinting to chemical cues. 5. Recognition of nestmates by guards, essential for intraspecific nest defense, seems not to be based on the aphrodisiac secreted by females. 6. Guards apparently learn individual odors of residents or a combination of the odors of several residents, providing a mechanism for distinguishing between nest mates and intruders attempting to enter the nest. 7. Though adult learning is important in nest mate recognition, an overriding contribution from genetic similarity or early conditioning also occurs.

The effect of olfactory deprivation by nasal tubes upon homing behavior in pigeons

Abstract: 1. As a test of the importance of olfaction to the navigational system of homing pigeons, a method of olfactory deprivation, the insertion of plastic tubes through the nostrils, has been employed. Birds wearing the tubes, and untreated controls, were singly released from two sites: a familiar one west of the loft, from which the birds had been released without tubes eight times previously, and an unfamiliar site south of the loft. 2. From the unfamiliar site anosmatic birds showed drastically impaired homing ability, both in terms of vanishing bearings and homing success (only 6 of 33 homing on the day of release vs. 33 of 36 controls). From the familiar site, tube-equipped birds showed homing performance which was only marginally poorer than that of controls. 3. The latter experiment shows that the effect of olfactory deprivation on homing is not a general behavioral influence on, for example, homing motivation, but is a consequence of the central importance of olfactory cues in determining home direction from unfamiliar territory. Anosmatic birds do home from familiar sites, presumably using an auxiliary pilotage mechanism relying on visual landmarks or other local cues.

How nepotistic is the brain worm

Abstract: The evolution of altruism does not necessarily require an extreme amount of kinship. This point is illustrated with an analysis of altruistic behavior in the Trematode parasite Dicrocoelium dendriticum, which apparently can evolve even when the parasites of the host are derived from as many as five different parents.

Play behavior and exercise in young ponies (Equus caballus L.)

Abstract: Play behavior of young ponies accounted for two-thirds of total running exercise and over 95% of all high-speed turns in ten animals from birth to age six weeks. The classical supposition, never previously demonstrated, that most exercise of young mammals occurs in play, is confirmed in these subjects.

Social dynamics of mixed-species groups of Jamaican reef fishes

Abstract: 1. Observation of coral reef fish in Jamaica revealed a continuous and erratic series of fluctuations in both individual and species group size. 2. No apparent trend existed between group size or species composition with any subsequent changes in the group. However, solitary striped parrots did, eventually, join conspecifics and very large groups fragmented. Other species (i.e., redtail parrot, ocean surgeon, blue tang, spotted goatfish, and foureye buttefly fish) did join the striped parrot groups for brief periods and tended to be solitary for long periods of time. 3. The rapid compositional changes were attributed to the different foraging strategies of the component species. Two basic strategies were identified; the striped parrot and the stoplight parrot strategies. Both herbivores and carnivores occurred in each strategy. 4. Species utilizing the striped parrot strategy (e.g., striped parrot, blue tang, ocean surgeon, and spotted goatfish) fed in open areas of sand, grass, and/or small rubble. The feeding behavior consisted of rapid, consecutive nips at the substrate with little time invested searching for food once the animal settled to the substrate. 5. Species utilizing the stoplight parrot strategy (e.g., stoplight parrot, redtail parrot, and the foureye butterfly fish) appeared to carefully search the crevices or the surfaces before making a nip. Multiple nips usually contained search time between each nip. 6. The species utilizing the striped parrot strategy formed and disbanded in the open areas and appeared to forage on a homogenuous resource. An individual joined others already engaged in foraging and fed only within its immediate area of settlement. Once food was exhausted, it left the group and joined another or began foraging on its own. 7. The species using the stoplight parrot strategy moved from one patchy resource to another and joined groups mainly as they passed through the open areas. 8. The mixed-species groups were products of seemingly random encounters between species having different foraging strategies.

Incompatibility and assortative mating in the Midas cichlid

Abstract: 1. The Midas cichlid Cichlasoma citrinellum of Nicaragua is a polychromatic fish. In some populations about 10% of the adults of both sexes are colored as the common goldfish. To explore differential effects of coloration on pair success, all four combinations of sex and color were observed, first separated by a transparent screen, then together. The normal size relation was used, i.e., the female about 85% the weight of the male. 2. Time to spawn showed no difference according to pair types with or without the screen, but the pairs that formed without the screen spawned more quickly than those with it. Failure to pair due to the male attacking the female, without the screen, occurred faster in pairs with normal than in those with gold females. The combination least able to form a pair was gold male x normal female. 3. Mixed-color pairs were then tested with the females half or equal to the weight of the males. Equal-sized mates in gold male x normal female pairs resulted in pair success comparable to “normal” levels. Other studies indicate that gold color inhibits aggression. Apparently the combination of larger size and gold color makes the gold male too intimidating for the normal female, while making the female as large as the male compensates for the male's gold color.

Sound localization by monkeys: A field experiment

Abstract: Characteristic responses shown by free ranging mangabeys to playback of species-specific vocalizations allow field measurement of their sound-localizing abilities. The median error of localization of single 10 to 15 s calls heard through several hundred meters of tropical forest was only 6°.

Die rolle des taschendrüsenpheromons beim Hochzeitsflug der Bienenkönigin

Abstract: 1. Es wird eine Methode beschrieben die es erlaubt, sowohl die Wirkung der 9-Oxodecensaure als auch die des Taschendrusensekretes der Bienenkonigin auf die Drohnen quantitativ zu erfassen und klar voneinander zu trennen. 2. Fur die Anlockung der Drohnen aus groβerer Entfernung bis zu 50m und mehr ist, wie schon Butler 1971 zeigen konnte die 9-Oxodecensaure verantwortlich. 3. Das Pheromon der Taschendrusen ist dagegen nur im Nahbereich der Konigin wirksam, hier aber uberwiegt seine Attraktivitat, die der 9-Oxodecensaure deutlich. Es erhoht auβerdem die Kopulationsbereitschaft der Bienenmannchen: Drohnen, die mit Taschendrusensekret benetzten Objekten von geeigneter Form und Groβe nahekommen, versuchen in jedem Fall sie zu erfassen und sich damit zu verpaaren. Verwendet man Papierrollchen von etwa 3 mm Durchmesser, kopulieren die Drohnen fast ausnahmslos schon nach wenigen Minuten damit.

Die Bedeutung des Sekretes der Tergittaschendrüsen für die Attraktivität der Bienenkönigin gegenüber jungen Arbeiterinnen

Abstract: 1. Die biologische Bedeutung des Sekrets der Tergittaschendrusen der Bienenkonigin wurde mit Hilfe neu entwickelter quantitativ auswertbarer Verhaltenstests untersucht. 2. Das Sekret der Taschendrusen wirkt stark anlockend auf junge Arbeits-bienen. Es entfaltet seine volle Wirksamkeit allerdings nur gemeinsam mit dem Mandibeldrusensekret: Das Sekret der Mandibeldrusen wirkt anlockend uber eine Distanz von mehreren Zentimetern, das Produkt der Taschendrusen nur dann, wenn die Arbeitsbienen Fuhlerkontakt mit dem Duftstofftrager aufnehmen konnen (Kontaktchemorezeption). Das Taschendrusensekret scheint die “Hofstaatbildung” zu stabilisieren. 3. Chemische Untersuchungen ergaben, daβ im Taschendrusensekret ahnlich wie im Sekret der Mandibeldruse mehrere Pheromone zusammen fur die Lockwirkung verantwortlich sind. 9-Oxodecensaure ist im wirksamen Pheromonkomplex der Taschendrusen nicht enthalten.

Aggregation pheromone in Hypogastrura viatica (Collembola)

Abstract: An animal of the collembolan Hypogastrura viatica isolated on a substrate previously contaminated by individuals of the same species behaves as if it were part of an aggregate. The basic activity decreases by an amount equal to the constant of aggregation. This decrease is due to the response to a stimulus caused by a substance that is discharged onto the substrate by aggregating organisms. This substance seems to be an aggregation pheromone.

Geotropism of hornet comb construction under persistent acceleration

Abstract: 1. The effect of persistent acceleration on comb construction by Oriental hornet (Vespa orientalis) workers was assessed experimentally within breeding boxes of various sizes, and shapes. Groups of hornets in the building phase were subjected to a centrifugal and gravitational force whose resultant ranged between 26° and 45°. The comb construction within such boxes was compared to that within control boxes under ordinary gravitational pull. 2. It was found that: (a) juvenile hornets (1–2 days of age) placed in quasi-rectangular boxes built in the direction of the resultant force; (b) juvenile and adult hornets (3–7 days of age) placed in spherical-shaped containers also built in the direction of the resultant force; (c) adult hornets who had spent their first days of life in a stationary rectangular box, ‘tried’ to build in the direction of the gravitational force when exposed to a centrifugal force; (d) adult hornets made to spin in quasi-rectangular boxes tilted in the direction of the calculated resultant, built in the direction of the resultant. 3. Only the roof of the breeding box gives geometric cues of critical importance.