PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Nesting Behavior”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources
PubMed2006

Age-related variation in the adrenocortical response to stress in nestling white storks (Ciconia ciconia) supports the developmental hypothesis.

The post-natal development of the adrenocortical response to stress was investigated in European white storks. Sixty wild nestlings aged 24-59 days old were subjected to a standardized capture and restraint protocol, and the time-course pattern of the response to stress was assessed through determination of circulating corticosterone in blood samples collected at five fixed times during the 45-min period following capture. The time course of the response was best fit to a third-order function of handling time, and showed a strong effect of age. Although age did not affect baseline titers and all birds showed a positive post-capture increase in circulating corticosterone, age had a positive effect on the relative increase from baseline titer, the recorded time to reach maximum level, and the acute concentration after 10 min following capture and restraint. While young nestlings displayed very little response to capture, the response near fledging resembled the typical adrenocortical pattern widely reported in fully developed birds. Our results concur with those found in altricial and semi-altricial species, and suggest that non-precocial birds follow a similar mode of development of the hypothalamic-pituitary-adrenal (HPA) axis. The fact that HPA sensitivity to stress is functional suggests that young storks gradually develop emergency responses of adaptive value and are able to overcome acute perturbations in spite of their parental dependence, at least during the last two-thirds of post-natal development. According to the Developmental Hypothesis, such gradual changes would allow nestlings to respond to perturbations as a function of the specific behavioral and physiological abilities of their age. The potential sources of stress that nestlings have to face during development (i.e., weather conditions, dietary restrictions, and social competition) are discussed according to developmental changes in behavioral and physiological abilities.

Adrenal Cortex↗
PubMedDate not supplied

Baseline and stress-induced levels of corticosterone during different life cycle substages in a shorebird on the high arctic breeding grounds.

After a migratory flight of several thousand kilometers to their high arctic breeding grounds, red knots (Calidris canutus islandica, Scolopacidae) showed high baseline concentrations of plasma corticosterone (58 ng/mL). Such high baseline corticosterone levels may be conditional for the right behavioral and metabolic adjustments to environmental and social stresses that shorebirds experience on arrival in an unpredictable tundra breeding environment. Despite the high baseline levels of corticosterone, red knots still showed a marked stress response during the postarrival period, with corticosterone concentrations increasing significantly during a 60-min period of confinement. Baseline levels of corticosterone declined as the breeding season progressed. Red knots with brood patches, that is, birds that had completed egg laying and commenced incubation, had a reduced adrenocortical response to the stress of confinement compared with red knots with no, or with half-developed, brood patches. This is consistent with the idea that birds breeding in extreme environments with short breeding seasons may exhibit a decreased adrenocortical response to stressful events to prevent high corticosterone concentrations from inducing interruptions of reproductive behavior.

Animal Migration↗
PubMed1997

Feedback control of unsupported standing in paraplegia--part I: optimal control approach.

This is the first of a pair of papers which describe an investigation into the feasibility of providing artificial balance to paraplegics using electrical stimulation of the paralyzed muscles. By bracing the body above the shanks, only stimulation of the plantarflexors is necessary. This arrangement prevents any influence from the intact neuromuscular system above the spinal cord lesion. In this paper, we extend the design of the controllers to a nested-loop LQG (linear quadratic Gaussian) stimulation controller which has ankle moment feedback (inner loops) and inverted pendulum angle feedback (outer loop). Each control loop is tuned by two parameters, the control weighting and an observer rise-time, which together determine the behavior. The nested structure was chosen because it is robust, despite changes in the muscle properties (fatigue) and interference from spasticity.

Biofeedback, Psychology↗
PubMed2004

Comparison of environment and mice in static and mechanically ventilated isolator cages with different air velocities and ventilation designs.

The purpose of this study was to compare environmental conditions and mice in cages with four different mechanical ventilation designs and a static isolator cage. Environmental conditions (air velocity, temperature, relative humidity, bedding weight change, airborne dust, NH3, and CO2) were compared for each cage type (n = 5 per cage). Bedding type was chipped hardwood. Mouse response in each cage type was evaluated by body weight, feed consumption, water intake, location of specific behaviors, and building of bedding mounds. Commercial polycarbonate mouse caging units (29.2 x 19.1 x 12.7 cm shoebox style, stainless-steel round wire bar lids, and 7-cm-deep isolator cage filter tops) were modified to fit the mechanical ventilation cage types and were used for the static isolator cages. Mechanically ventilated cages were fitted with forced air inlets centered 5 cm above the cage floor on the 19.1 cm-side of the cage. Inlet air velocity was either 40 or 200 feet/min (n = 10 cages each), and the air volume exchange rate was 9.3 L/min. In half of the mechanically ventilated cages, the exhaust air was forced through a filter in the isolator cage top, whereas in the remaining mechanically ventilated cages, the air was forced through a single exhaust port fixed in the narrow side of the cage top directly above the air inlet. Inlet air velocity but not exhaust design affected intracage air velocity distribution. Other environmental conditions were similar between the four mechanical ventilation designs. Relative to the mechanically ventilated cages, the static isolator cages had lower air velocities, higher relative humidities, higher NH3 levels, higher CO2 levels, lower body weight gain, and lower water consumption; temperatures, particulate levels, and feed consumption rates did not differ significantly between cage types. Locations of bedding mounds and behaviors were similar in all cage treatments.

Air↗
PubMed1993

Conditioned defeat in the Syrian golden hamster (Mesocricetus auratus).

When singly housed under laboratory conditions, male Syrian golden hamsters routinely attack novel conspecific intruders introduced into their home cages. As we report here, after being repeatedly defeated by a larger, more aggressive intruder, such normal territorial aggression on the part of the resident hamsters is replaced by defensive behavior and flight. We have found that such conditioned defeat (CD) can be reliably induced by a series of 5-min trials with an aggressive intruder whether these trials are spread over 4 days or are all given on the same day. A useful behavioral criterion for the appearance of CD during acquisition is the first occurrence of anticipatory flight (AF), i.e., the first time the resident flees from the next aggressive intruder before being attacked. CD shows generalization: Animals trained to the AF criterion (AF Group) subsequently show defensive behavior toward, and even flee from, intruders which show absolutely no sign of aggressiveness. Animals in the AF Group persisted in such defense behavior for two test sessions; animals given three additional defeat trials beyond the appearance of AF (AF + 3 Group) showed a greater magnitude and persistence of defense and flight. A comparison of CD-trained animals which met a non-aggressive intruder (NAI) every day for 5 days to similarly trained animals which met the intruder only on the fifth day after acquisition suggests that CD diminishes passively as a function of time and not as the consequence of repeated encounters with a nonaggressive stimulus animal. We also found that near ideal NAIs could be prepared by treating nonaggressive hamsters with high doses of diazepam: animals so treated locomote more or less continuously around the cage virtually ignoring the subject. An unexpected observation was that subjects in the AF Group tended to closely follow these diazepam-treated, rapidly locomoting NAIs around the cage. Following may be an example of the "risk assessment" activities directed toward a potential threat. The development of a rapid and reliable technique for inducing CD in hamsters sets the stage for further physiological and pharmacological work on this interesting phenomenon.

Aggression↗
PubMed1977

Development of odor-guided behavior in Wistar and Sprague-Dawley rat pups.

The odor of home-cage shavings attracts Sprague-Dawley and Wistar pups 3-4 days old. Attraction increases during postnatal week one in both strains. Lemon odor repels Sprague-Dawley pups 3 and 8 days old equally, while Wistar aversion to lemon increases during the first postnatal week. Shavings from the nests of strange litters 4 or 8 days old attract Sprague-Dawley pups 4 but not 8 days old equally. Sensory changes appear to underlie Sprague-Dawley response development, while locomotor and sensory changes may mediate Wistar response ontogeny.

Age Factors↗
PubMed1999

Estrogen implants in the lateral habenular nucleus do not stimulate the onset of maternal behavior in female rats.

The natural onset of maternal behavior in the rat is hormonally mediated. Estrogen, progesterone, and prolactin administered to ovariectomized females in amounts and sequences that produce circulating levels similar to those found during pregnancy stimulate the onset of maternal behavior. In fact, maternal behavior can be stimulated by estrogen alone, administered either peripherally or by implant in the central nervous system. The lateral habenula (Lhb), which is a necessary component in the neural circuit that supports maternal behavior, contains a subset of neurons with estrogen receptors. The present study investigated whether estradiol implants directly in the Lhb are sufficient to stimulate maternal behavior. Female rats, hysterectomized and ovariectomized on day 16 of pregnancy, received estrogen implants in the Lhb or, as a positive control, in the medial preoptic area (MPOA). An additional control group received cholesterol implants in the Lhb. All females were tested for pup retrieval, nest building, crouching behavior, locomotor activity, and carrying behavior. Estradiol implants into the Lhb did not stimulate the onset of maternal behavior. Females with estrogen implants in the Lhb scored significantly lower in pup retrieval and crouching behavior compared to females with implants in the MPOA and were not significantly different from females with cholesterol implants in the Lhb. There were also no significant differences in overall activity or carrying behavior among the groups.

Animals↗
PubMed1993

Reproductive behavior, endocrine state, and the distribution of GnRH-like immunoreactive mast cells in dove brain.

Previous studies indicate that there is an increase in the number of detectable mast cells expressing gonadotropin-releasing hormone-like immunoreactivity (GnRH-ir) in the medial habenular region of the brain in ring doves after a period of 2 hr of courtship. In the present experiment the overall distribution of GnRH-ir mast cells in the brain is described, and the influence of behavioral and endocrine state on brain mast cell distribution and detectable mast cell number is explored. Four groups of male birds were studied: (1) paired with a female and displaying courtship behavior, (2) paired with a squab and displaying aggressive behavior, (3) visually isolated from other doves, and (4) long-term castrates housed communally. In all four groups, GnRH-ir mast cells were observed in the following areas: the medial habenula, circumventricular organs, organum vasculosum lamina terminalis and organum subseptale, the pia mater, and blood vessels. Cell counting revealed differences among groups in numbers of habenular mast cells. Courted doves had the most habenular mast cells, followed by doves paired with squabs, and then visually isolated doves, while castrates had the fewest. One-way ANOVA indicates significant differences among groups. All pairwise comparisons show that the courting animals had significantly more detectable mast cells in the habenular area than did visually isolated and castrated groups. These results suggest that the appearance and/or detectability of GnRH-ir mast cells in the habenula is related to the behavioral state and possibly to the endocrine state of the animal and suggest a novel mechanism for interactions among the nervous, endocrine, and immune systems.

Aggression↗
PubMed1985

Orienting and freezing responses in incubating ptarmigan hens.

Behavior studies and telemetric recordings of heart and respiration rates were performed on five wild and two captive, incubating, willow ptarmigan hens (Lagopus lagopus lagopus) and on four wild, incubating, Svalbard ptarmigan hens (Lagopus mutus hyperboreus). Sounds and sight of approaching humans, egg predators, or dogs near the nests elicited behavior in the hens which we have interpreted as an orienting response (OR) followed by freezing behavior. During both types of behavioral responses, heart rate was reduced from 204 +/- 39 (mean +/- SE) to 119 +/- 26 beats per minute and respiration from 25 +/- 2 to 12 +/- 3 breaths per minute. In wild incubating willow ptarmigan, further approach led to tachycardia and increased respiration. Some birds maintained freezing behavior, while others became restless before flying off. Two of the four incubating Svalbard ptarmigan hens showed the OR followed by freezing behavior accompanied by decreased heart and respiration rates. The other two birds showed flight response, restless behavior accompanied by increased heart and respiration rates. Flight behavior was also typical for willow ptarmigan incubating in captivity. Repeated auditory provocation of incubating hens caused progressive decrement in behavioral and cardiac responses that is interpreted as habituation of the OR.

Animals↗
PubMedDate not supplied

Changes of auditory-evoked potentials in response to behaviorally meaningful tones induced by acute ethanol intake in altricial nestlings at the stage of formation of natural behavior.

Acute ethanol's influence on field L auditory-evoked potentials (AEP) was studied in 4-7-days-old altricial nestlings of the pied flycatcher. Nestlings were presented with behaviorally meaningful tone pips (2.0 and 5.0 kHz) and control tone pips (3.0 kHz). Ethanol ingestion was found to reduce the N1 amplitude and maturity index (MI) of the AEP in response to "behavioral" but not to control frequencies. This effect was first observed on day 5, when the nestlings' behavior became more complex (their eyes opened and defence behavior appeared), and when previously formed feeding behavior was undergoing modifications. The MI increase during the early postembryonic ontogeny was probably due to the selective involvement of neurons with newly formed behavioral specializations into the subserving of new behavioral patterns, while the decrease of the MI under alcohol was due to the depression of activity in these neurons.

Animals↗
PubMed1989

Testosterone-induced inhibition of incubation in the spotted sandpiper (Actitis mecularia).

The spotted sandpiper (Actitis macularia) is characterized by intense female intrasexual competition and predominantly male parental care. Females often are polyandrous. Incubating males were implanted with testosterone (T)-filled Silastic tubes. Plasma T levels were significantly elevated by T implants while prolactin (Prl) remained unchanged. Birds implanted with T deserted clutches (30%) or exhibited reduced incubation constancy (50%) while controls incubated normally. The T implants appeared to heighten sexual receptivity and hence reduce incubation constancy. Variation in male incubation behavior may have been further influenced by the degree to which males were exposed to courting females.

Animals↗
PubMed2001

Self-referent phenotype matching: theoretical considerations and empirical evidence.

In most birds and mammals, young are raised in family groups. The phenotypes of nestmates and parents are thus reliable cues for recognition of conspecifics and kin. However, in some species, young develop alone, or in broods of mixed relatedness (e.g. because of multiple paternity or maternity), or among heterospecifics or unrelated conspecifics (brood parasites). Under these circumstances, the best referent (model) for discriminating close from distant kin and heterospecifics from conspecifics might be one's own self. This recognition process is known as self-referent phenotype matching. Here we review recent experimental evidence of self-referencing and suggest that behavioral neuroscience can provide new tools and insights into how it works (its proximate mechanistic and ontogenetic bases) and why it exists (its adaptive significance).

Animals↗
PubMed2004

Environmental color affects Nile tilapia reproduction.

We investigated the effects of environmental color on the reproductive behavior of Nile tilapia, Oreochromis niloticus. Two environmental colors were tested by covering the aquarium (60 x 60 x 40 cm) with white (12 groups) or blue (13 groups) cellophane and observing reproductive behavior in groups of 2 males (10.27 +/- 0.45 cm) and 3 females (10.78 +/- 0.45 cm) each. After assignment to the respective environmental color (similar luminosity = 100 to 120 Lux), the animals were observed until reproduction (identified by eggs in the female's mouth) or up to 10 days after the first nest building. Photoperiod was from 6:00 h to 18:00 h every day. Food was offered in excess once a day and water quality was similar among aquaria. Daily observations were made at 8:00, 11:00, 14:00 and 17:00 h regarding: a) latency to the first nest, b) number of nests, c) gravel weight removed (the male excavates the nest in the bottom of the aquarium), d) nest area, and e) mouthbrooding incubation (indication of reproduction). The proportion of reproducing fish was significantly higher (6 of 13) in the group exposed to the blue color compared the group exposed to the white color (1 of 12; Goodman's test of proportions). Moreover, males under blue light removed significantly larger masses of gravel (blue = 310.70 +/- 343.50 g > white = 130.38 +/- 102.70 g; P = 0.01) and constructed wider nests (blue = 207.93 +/- 207.80 cm(2) > white = 97.68 +/- 70.64 cm(2); P = 0.03) than the control (white). The other parameters did not differ significantly between light conditions. We concluded that reproduction in the presence of blue light was more frequent and intense than in the presence of white light.

Animals↗
PubMed1988

Influence of the odorization of the rearing environment on the development of odor-guided behavior in rat pups.

The study describes a phenomenon in which attraction of rat pups to artificial odors disappeared after the first week of life. In experiment 1, pups were continually exposed to either: (1) the normal odors present in the litter or (2) the same odors enriched with one of four artificial odors present in the dam's food. Pups were tested daily with the odors of normal or adulterated soiled shavings from their nests. The results show that attraction to the normal test shavings lasted throughout the testing period (PN 1-7). However, pups raised on odorized shavings exhibited an attraction to the artificial odor until day 6 only, not on day 7. In experiment 2, pups were tested with dam's artificially adulterated food. The results show that the artificial odor, and not the food odor, was responsible for the lack of attraction on day 7. Experiment 3 was carried out to determine whether the date on which attraction to artificial odors changed might be specific to postnatal day 7 or whether the duration of odor exposure in test conditions was the important factor. The results suggest that the age of pup is the more important variable.

Aging↗
PubMed2006

Elevated 11-ketotestosterone during paternal behavior in the Bluebanded goby (Lythrypnus dalli).

The relationship between androgens and paternal behavior is not straightforward, potentially because of the diversity of tasks a male must undertake to maximize reproductive success, notably alternating between courtship, aggression, and offspring care. In some species, these events are separated in time, but in others they are coincident. The endocrine profiles of species that simultaneously court, parent, and defend a nest, such as male bluebanded gobies (Lythrypnus dalli), are not well understood. We sampled a potent fish androgen, 11-ketotestosterone (KT), at different life history stages (experienced parenting males, experienced males not actively parenting, inexperienced males with their first clutch, and females), to examine this relationship. We found that experienced parenting L. dalli males have the highest KT levels of any group, while none of the other groups differed significantly. Males showed elevated KT levels when they had eggs compared to when they did not. Our data suggest that KT facilitates at least some aspects of parental care in L. dalli.

Animals↗
PubMed1999

Steroid hormones and paternal care in the plainfin midshipman fish (Porichthys notatus).

The present study investigated the relationship between plasma steroid hormone levels and the expression ofpaternal behavior in the plainfin midshipman fish (Porichthys notatus), where males may simultaneously care for multiple clutches in different stages of development. Blood samples were collected from free-living parental males during that part of the breeding season when males may be found in various stages of parental care. Plasma 11-ketotestosterone levels were significantly higher in males with empty nests and nests containing only eggs than in males with nests containing embryos. All males with nests containing embryos had undetectable testosterone levels, whereas testosterone levels were detectable in many males with empty nests or nests containing only eggs. Estradiol levels were detectable in only a few males from nests with no eggs or nests containing only eggs. Cortisol levels were not correlated with stage of paternal care or with handling time. These results follow the frequently reported vertebrate pattern of declining androgen levels over the course of the breeding season or during the period of parental care. However, many male midshipman guarding nests containing only eggs had androgen levels similar to those of males whose nests contained no offspring. Thus the pattern of androgen levels exhibited by reproductively active parental male midshipman may reflect a compromise between investment in paternal care versus courtship and/or territoriality.

Animals↗
PubMed1998

Ultrasonic vocalizations by infant laboratory mice: a preliminary spectrographic characterization under different conditions.

During the first 2 to 3 weeks of life, isolated neonatal mice emit ultrasonic vocalizations, with various conditions such as hypothermia or olfactory or tactile stimulation eliciting this behavior. Although it is known that pup vocalizations stimulate prompt expression of maternal behavior, the communicative role of infant ultrasonic calls is still a matter of investigation. A fine-grained spectrographic analysis of ultrasonic calls emitted by pups exposed to different conditions was performed. Forty 8-day-old outbred CD-1 mice (Mus musculus) were isolated from their mothers and littermates and randomly exposed to one of the following conditions: (a) odor from the nest, (b) social isolation, (c) low temperature-isolation, (d) tactile stimulation, or (e) odor from a conspecific adult male. Upon consideration of the spectrogram typology and emission frequency interval, it appears that the conditions under which vocalizations are emitted influence the sound characteristics of call production.

Analysis of Variance↗