Signal Of Need Research Articles

Maternal and paternal sensitivity: Key determinants of child attachment security examined through meta-analysis.

Sensitive caregiving behavior, which involves the ability to notice, interpret, and quickly respond to a child's signals of need and/or interest, is a central determinant of secure child-caregiver attachment. Yet, significant heterogeneity in effect sizes exists across the literature, and sources of heterogeneity have yet to be explained. For all child-caregiver dyads, there was a significant and positive pooled association between caregiver sensitivity and parent-child attachment (r = .25, 95% CI [.22, .28], k = 174, 230 effect sizes, N = 22,914). We also found a positive association between maternal sensitivity and child attachment security (r = .26, 95% CI [.22, .29], k = 159, 202 effect sizes, N = 21,483), which was equivalent in magnitude to paternal sensitivity and child attachment security (r = .21, 95% CI [.14, 27], k = 22, 23 effect sizes, N = 1,626). Maternal sensitivity was also negatively associated with all three classifications of insecure attachment (avoidant: k = 43, r = -.24 [-.34, -.13]; resistant: k = 43, r = -.12 [-.19, -.06]; disorganized: k = 24, r = -.19 [-.27, -.11]). For maternal sensitivity, associations were larger in studies that used the Attachment Q-Sort (vs. the Strange Situation), used the Maternal Behavior Q-Sort (vs. Ainsworth or Emotional Availability Scales), had strong (vs. poor) interrater measurement reliability, had a longer observation of sensitivity, and had less time elapse between assessments. For paternal sensitivity, associations were larger in older (vs. younger) fathers and children. These findings confirm the importance of both maternal and paternal sensitivity for the development of child attachment security and add understanding of the methodological and substantive factors that allow this effect to be observed. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Validating the caregiving experiences questionnaire (CEQ) in a Turkish setting: Understanding attachment and parental care in diverse contexts

Despite the universal significance of secure attachments, differences exist in parental responses to children’s signals of need across cultures. While much research has focused on Western countries, there is a growing recognition of the need to explore cultural variations in parental ideologies and caregiving practices. However, limited assessment tools exist for evaluating caregiving experiences, particularly in non-Western contexts. This present design study aims to explore the Turkish validity of the Caregiving Experiences Questionnaire (CEQ), specifically tailored to assess the self-reported caregiving experiences of parents with young children within the attachment system. The Turkish-CEQ was administered to 339 Turkish mothers with children attending preschools. Confirmatory Factor Analysis was employed to assess the congruence of the Turkish data. The results showed that the CEQ is a relevant construct in Turkish culture. The CEQ successfully adapted to Turkish, resulting in a questionnaire comprising 34 items organized into four factors namely maintaining warm parental bond, suffering from separation concerns, struggling with parenting challenges, and imposing emotional parentification on the child. The internal consistency of each factor demonstrates satisfactory reliability, with Cronbach Alpha coefficients ranging between 0.71 and 0.80. Finally, we assessed the criterion validity of the CEQ by examining its relationships with the Parental Burnout Assessment and Parenting Stress Scale. The results support the criterion validity of the Turkish-CEQ. The study provides Turkish researchers with a new instrument for assessing caregiving experiences and paves the way for future cross-cultural studies on caregiving experiences among parents from diverse backgrounds in Turkey.

Food supply and provisioning behavior of parents: Are small hoopoe nestlings condemned to die?

Parents might use signals of need or of quality to decide food provisioning among their offspring, while the use of one or another signal might depend on food availability. Begging success of nestlings of different quality (i.e., body size) would also depend on food availability, and we here explore the effect of experimental food supply in begging success of nestlings and in provisioning of female hoopoes (Upupa epops), a species with extreme hatching asynchrony and nestlings size hierarchy. We video-recorded food allocation of females, begging success of nestlings of different size, and the social context (i.e., the size category of the other nestlings that were begging for food) during periods when experimental food supply was or was not available in the same nests. We found that when experimental food supplementation was present, begging success of the intermediate, but not that of large or small-sized nestlings, increased. The experiment, however, did not affect the feeding preferences of females toward nestlings of different size. Moreover, when small nestlings were the only ones that were begging for food, their begging success decreased in the experimental period, and females used supplemented prey to feed themselves. Those results, on one hand, confirm the importance of food availability for the begging success of nestlings of particular sizes and, on the other, indicate that females prefer to use extra food for their own rather than for the smallest nestlings. We discuss possible mechanisms explaining the detected experimental effects and the adaptive and nonadaptive explanations of mothers ignoring the small nestlings.

Risking Your Health to Help Others: The Effect of Pandemic Severity on Volunteering

The COVID-19 pandemic affected the provision of voluntary work across the globe. We study informal volunteers who buy and deliver groceries for people in a high-risk group or in quarantine. Using data from a volunteering grocery delivering app in Switzerland that coordinated these volunteers, we are able to track volunteering during the pandemic. Combined with public health data on cases and deaths, we test how the severity of the pandemic affects the provision of voluntary work in the form of neighborhood grocery deliveries. We find a positive effect of the number of deaths on voluntary deliveries. However, in contrast to the literature studying the effect of the severity of the pandemic on giving, this effect is concave. We suggest that this concave effect is due to the signal of risk of infection implied by rising death rates, which is at odds with the signal of need to help others.

Depression and suicidality as evolved credible signals of need in social conflicts

Mental health professionals generally view major depression and suicidality as pathological responses to stress that elicit aversive responses from others. An alternative hypothesis grounded in evolutionary theory contends that depression and suicidality are honest signals of need in response to adversity that can increase support from reluctant others when there are conflicts of interest. To test this hypothesis, we examined responses to emotional signals in a preregistered experimental vignette study involving claims of substantial need in the presence of conflicts of interest and private information about the signaler's true level of need. In a sample of 1240 participants recruited from Amazon Mechanical Turk, costlier signals like depression and suicidality increased perceptions of need, reduced perceptions of manipulativeness, and increased likelihood of support compared to simple verbal requests and crying without further symptoms. The effect of signaling on likelihood of support was largely mediated by the effect of signaling on participants' belief that the signaler was genuinely in need. Our results support the hypothesis that depression and suicidality, apparent human universals, are credible signals of need that elicit more support than verbal requests, sad expressions, and crying when there are conflicts of interest.

Reaching Out for Inaccessible Food Is a Potential Begging Signal in Cooperating Wild-Type Norway Rats, Rattus norvegicus.

Begging is widespread in juvenile animals. It typically induces helpful behaviours in parents and brood care helpers. However, begging is sometimes also shown by adults towards unrelated social partners. Adult Norway rats (Rattus norvegicus) display a sequence of different behaviours in a reciprocal food provisioning task that have been interpreted as such signals of need. The first behaviour in this sequence represents reaching out for a food item the animal cannot obtain independently. This may reflect either an attempt to grasp the food object by itself, or a signal to the social partner communicating the need for help. To distinguish between these two possibilities, we tested in female wild-type Norway rats if the amount of reaching performed by a food-deprived rat changes with the presence/absence of food and a social partner. Focal rats displayed significantly more reaching behaviour, both in terms of number and total duration of events, when food and a potentially helpful partner were present compared to when either was missing. Our findings hence support the hypothesis that rats use reaching behaviour to signal need to social partners that can help them to obtain food.

Honesty of Larval Begging Signals Covaries With Colony Kin Structure in Formica Ants

Social insects live in highly complex societies with efficient communication systems. Begging is one display commonly used by offspring to signal their nutritional state, however begging behavior has received very little attention in social insects. Theory predicts that begging can be either an honest (i.e. honest-signaling strategy) or a dishonest (i.e. scrambling competition) signal of need, with dishonest signals expected to be more likely when relatedness within the group is low. To investigate the presence and honesty of begging, as well as the nature of the involved signals, we used a comparative approach with four species of the ant genus Formica known to differ in the degree of intra-colony relatedness. We investigated the behavior of starved and non-starved larvae of F. aquilonia, F. pressilabris (both low intra-colony relatedness), F. exsecta (intermediate relatedness), and F. fusca (high relatedness). In addition, we assessed the attraction of conspecific workers towards odors extracted from these two classes of larvae and analyzed the larval cuticular hydrocarbon profiles. We found that in F. fusca and F. exsecta, larvae signaled significantly more when starved. In contrast, larvae of F. aquilonia signaled significantly more when they were non-starved, while there was no significant difference in the behavior of starved versus non-starved larvae in F. pressilabris. Our results show that workers were not preferentially attracted to the odor of starved larvae, and we also did not detect any differences between the cuticular hydrocarbon profiles of starved and non-starved larvae. Overall, this study demonstrates among species variation in larval hunger signaling in Formica ants, and encourage further studies for confirming the link between kin structure variation and the honesty of begging signals.

Begging behavior as an honest signal of need and parent-offspring association during the postfledging dependency period.

Honest signaling mechanisms can function to appropriate care to hungry offspring and avoid misdirected care of unrelated offspring. Begging, the behavior by which offspring solicit food and parental care, may be an honest signaling mechanism for need, as well as association of parents and offspring. Roseate terns (Sterna dougallii) exhibit prolonged parental care during the postbreeding staging period, offering an ideal system in which to study begging as an honest signaling mechanism. We conducted focal sampling during two premigratory staging seasons (2014 and 2015) at Cape Cod National Seashore, Massachusetts, USA to determine whether postfledging tern begging behavior was an honest signal for need and parent–offspring association. Based on honest signaling theory, we expected begging behavior to be highest during times of high perceived need, and we expected to see a decrease in begging behavior as young terns became increasingly independent of the care‐giving parent. Also, we predicted that young terns would be more likely to beg at parents than nonparents. We found that young roseate terns begged at their parents more often than nonparents; however, they did not always beg at parents. Model predictions of begging probability showed a linear relationship between begging and time of day and date of season, such that begging increased with time of day and decreased with date of season, respectively. Our results provide evidence for honest parent–offspring interactions and are inconsistent with parent–offspring conflict theory but suggest that begging may play a complex role in postfledging parent–offspring interactions.OPEN RESEARCH BADGES This article has been awarded Open Data, Open materials Badges. All materials and data are publicly accessible via the Open Science Framework at https://doi.org/10.5281/zenodo.2656718.

Condition-Dependent Begging Elicits Increased Parental Investment in a Wild Bird Population.

The coevolution of parental supply and offspring demand has long been thought to involve offspring need driving begging and parental care, leaving other hypotheses underexplored. In a population of wild birds, we experimentally tested whether begging serves as a negatively condition-dependent signal of need or a positively condition-dependent signal of quality. Across multiple years, we supplemented nestling house wrens with food shortly after hatching and simultaneously manipulated corticosterone levels to simulate the hunger-induced increase in glucocorticoids thought to mediate begging. This allowed us to also test whether begging is simply a proximate signal of hunger. Days after supplementation ended, food-supplemented nestlings were in better condition than nonsupplemented nestlings and begged for food at an increased rate; their parents, in turn, increased provisioning to a greater extent than parents of nonsupplemented young, as begging positively predicted provisioning. Food-supplemented nestlings therefore attained above-average condition, which predicted their recruitment as breeding adults in the local population. Glucocorticoids increased begging in the short term, but this transient effect depended on satiety. Thus, glucocorticoids promoted begging as a proximate response to hunger, whereas the longer-term changes in nestling condition, begging, and food provisioning suggest that begging ultimately signals offspring quality to elicit increased investment, thereby enhancing offspring survival.

One problem, too many solutions: How costly is honest signalling of need?

The “cost of begging” is a prominent prediction of costly signalling theory, suggesting that offspring begging has to be costly in order to be honest. Seminal signalling models predict that there is a unique equilibrium cost function for the offspring that results in honest signalling and this cost function must be proportional to parent’s fitness loss. This prediction is only valid if signal cost and offspring condition is assumed to be independent. Here we generalize these models by allowing signal cost to depend on offspring condition. We demonstrate in the generalized model that any signal cost proportional to the fitness gain of the offspring also results in honest signalling. Moreover, we show that any linear combination of the two cost functions (one proportional to parent’s fitness loss, as in previous models, the other to offspring’s fitness gain) also leads to honest signalling in equilibrium, yielding infinitely many solutions. Furthermore, we demonstrate that there exist linear combinations such that the equilibrium cost of signals is negative and the signal is honest. Our results show that costly signalling theory cannot predict a unique equilibrium cost in signalling games of parent-offspring conflicts if signal cost depends on offspring condition. It follows, contrary to previous claims, that the existence of parent-offspring conflict does not imply costly equilibrium signals. As an important consequence, it is meaningless to measure the “cost of begging” as long as the dependence of signal cost on offspring condition is unknown. Any measured equilibrium cost in case of condition-dependent signal cost has to be compared both to the parent’s fitness loss and to the offspring’s fitness gain in order to provide meaningful interpretation.

When Saying "Sorry" Isn't Enough: Is Some Suicidal Behavior a Costly Signal of Apology? : A Cross-Cultural Test.

Lethal and nonlethal suicidal behaviors are major global public health problems. Much suicidal behavior (SB) occurs after the suicide victim committed a murder or other serious transgression. The present study tested a novel evolutionary model termed the Costly Apology Model (CAM) against the ethnographic record. The bargaining model (BRM) sees nonlethal suicidal behavior as an evolved costly signal of need in the wake of adversity. Relying on this same theoretical framework, the CAM posits that nonlethal suicidal behavior can sometimes serve as an honest signal of apology in the wake of committing a severe transgression, thereby repairing valuable social relationships. To test this hypothesis, the CAM was operationalized into a set of variables, and two independent coders coded 473 text records on suicidal behavior from 53 cultures from the probability sample of the Human Relations Area Files. The results indicated that in ethnographic accounts of suicidal behavior, transgressions, punishment, and shame were relatively common, supporting the CAM, but explicit motives to apologize and evidence of forgiveness were rare, contrary to the CAM. The theoretical variables of the CAM nevertheless formed a cluster distinct from the BRM, and a subset of cases of suicidal behavior were largely related to transgressions and other CAM variables rather than BRM or other variables. Support for the CAM varied widely across cultures, but there was evidence for it in every major geographical region. Exploratory analyses suggested that the CAM is potentially more likely to occur in response to severe conflicts concerning transgressions committed against nonkin. Furthermore, in text records that involved transgressions, male suicidal behavior was most frequently associated with murder, whereas female suicidal behavior was most frequently associated with sexual transgressions. In conclusion, the results provided mixed support for the hypothesis that some instances of suicidal behavior function to send a costly signal of apology to those harmed by a transgression.

Parent-absent begging and the risk of nest predation

Despite the fact that parent-absent begging (PAB) has been studied as a communication tool during competition between nestlings for food or as a signal of need, its role in nest predation has been poorly investigated. In this study we examined whether the natural level of Common Cuckoo (hereafter “Cuckoo”) PAB increases the risk of artificial nest predation (n = 48) by using three types of experimental playback of parent-present begging (PPB) which differ in the presence or absence of additional PPB, PAB or periods of silence. Contrary to our predictions, we did not find a significant difference in daily survival rates between PPB + PAB vs. PPB + PPB nests or between PPB + PAB vs. PPB + silence nests, indicating that the natural level of Cuckoo PAB did not influence nest vulnerability to predation. Moreover, we did not find a significant difference between nests with any of the types of playback and completely silent control nests, suggesting that not only PAB, but also begging behaviour itself, does not present an important predation cost for nestlings, at least not in cases when nestlings beg at the natural level used in our experiment. As we filmed all experimental nests during their exposure to predators, we were able to show that eight of 20 filmed nest-predation events were caused by predators that never or rarely predate upon passerine nests. Excluding predation events by these unlikely predators, however, did not change our original results. Nonetheless, we advocate direct identification of nest predators to strengthen the interpretation of future studies on the predation cost of begging.

The influence of environmental variance on the evolution of signaling behavior

A recent meta-analysis has indicated that environmental quality and variability can influence whether offspring begging and parental responses to these signals are motivated by offspring need or offspring quality. We create a model to verify and apply evolutionary logic to this hypothesis. We determine the ecological and social conditions under which species signal and respond to need in favorable environments and quality in poor environments. The environmental conditions that favor this shift are widest when signaling costs and differences in quality between offspring are moderate. Low relatedness between siblings coupled with high signaling costs, as well as moderate relatedness between siblings coupled with low signaling costs, allow for the shift between signals of need and signals of quality to occur in more volatile environments. Furthermore, only species whose offspring are highly dependent on parents for survival are not expected to use both signals of need and of quality. Ultimately, this shift between signaling need and signaling quality is the result of high-quality offspring benefiting more from meager amounts of parental provisioning, whereas low-quality offspring have most to gain when parents can contribute more substantially. We show that this differential benefit of resources depends substantially upon offspring fitness as functions of parental investments, a variable which lacks both diversity and biological realism in previous theoretical approaches. We then use this work to reassess previous theory on signals of need and of quality.

The give and take of food sharing in Sumatran orang-utans, Pongo abelii, and chimpanzees, Pan troglodytes

Proximate factors of primate food sharing, in contrast to its evolutionary explanations, have received little attention. Active food sharing is considered prosocial, since possessors may benefit others by spontaneously passing food or by reacting to ‘signals of need’. However, in contrast to passive sharing, active food sharing is rare in most nonhuman primates. Surprisingly, previous research showed that captive Sumatran orang-utans actively share food more frequently than chimpanzees and bonobos, and hence, appear more prosocial. Yet these comparisons with the two Pan species were relying on previously published studies, which differed with regard to methods and food types used. Here we used the identical procedure and food type to compare the food-sharing behaviour of 10 captive Sumatran orang-utans and 18 chimpanzees, in situations where individuals could monopolize a sharable food source. We focused on communicative behaviours used to initiate food transfers, and assessed whether and how much food was transferred in response to these initiation attempts. In both species, most transfers were initiated by taking the food, resulting in passive sharing, while active sharing by offering food or after requesting it occurred only rarely. However, orang-utans differed from chimpanzees in several aspects. Because the food was mostly monopolized by the adult male, orang-utans attempted to initiate food transfers more frequently, resisted more to taking attempts, and were less likely to transfer whole food items. In both species, requests were less likely to result in food transfers, indicating that in situations involving access to food, they do not necessarily respond to ‘signals of need’. We argue that in addition to instances of active sharing, other factors such as the degree of food monopolization, response rates to ‘signals of need’, and the quality and quantity of transferred food need to be considered to gain a more detailed picture of prosociality across species.

Responsiveness to siblings’ need increases with age in vocally negotiating barn owl nestlings

In animal societies, individuals should optimize the way they behave in relation to the behavior displayed by their conspecifics. This social competence, i.e., the ability to adjust behavior to the social context, can vary between individuals, but also improve with age and experience. This aspect, although important, has rarely been studied. We tested whether the ability to adjust behavior to siblings develops with age in barn owl nestlings (Tyto alba). In this species, young siblings show intense social interactions referred to as “sibling negotiation.” Indeed, because parents bring a single indivisible food item at each visit to the nest, all the effort invested in sibling competition is only paid back in the nestling that is able to monopolize the food item. Therefore, before the arrival of parents, siblings vocally inform each other about their relative hunger level so that they can optimally invest in sibling competition, with the most vocal, and hence hungry, nestling momentarily deterring its siblings from competing. This process implies that siblings have the ability to adjust their behavior in relation to the behavior of their siblings, a process that could change with age. In a series of experiments, we examined how nestlings of different ages respond to the vocal behavior of siblings. We show here that older nestlings adjusted their vocal behavior more finely than younger nestlings in relation to the behavior of their siblings. Elders also more readily refrained from eating in front of a hungry sibling. These patterns could arise because owlets’ social competence develops with age or because they adopt different competitive and cooperative strategies according to their age. In sibling barn owls, competition for food brought by parents is settled by vocalization. Highly vocal owlets induce their siblings to call less and to let them eat in priority once parents are back with a prey item, a process referred to as “sibling negotiation.” Nestling barn owls adjust their investment in sibling competition according to two parameters: their hunger level and the vocal behavior of their siblings. We analyzed the relative importance of these two parameters in differently aged owlets. Younger owlets adjusted the intensity of vocalizing primarily in relation to their own hunger level, which was efficient in modifying older nestlings’ behavior, as older nestlings readily withdrew from vocal contest and refrained from eating in front of highly vocal siblings. Hence, social adjustment changed with age in owlets, older ones being more sensitive to the signals of need of their siblings.

Female begging calls reflect nutritional need of nestlings in the hen harrier Circus cyaneus

BackgroundMost birds exhibit bi-parental care with both sexes providing food for their young. Nestling signal food needs through begging. However, for some species, males rarely visit the nest, so have limited opportunity for gaining information directly from the chicks. Instead, females beg when males deliver food. We tested whether this calling signalled nutritional need and specifically the needs of the female (Breeder Need hypothesis) or that of their chicks (Offspring Need hypothesis).ResultsWe observed begging and provisioning rates at 42 nests of hen harrier (Circus cyaneus) in Scotland, explored the factors associated with variation in begging rate and the relationship between begging and provisioning. We also tested the impact of food on begging and provisioning through a feeding experiment. Female begging rate increased up to a chick age of 3 weeks and then tailed off. In addition, begging increased when broods were large.ConclusionsOur data provided support for the Offspring Need hypothesis. At nests where adlib food was provided females reduced their begging rate. These patterns suggested that female begging was an honest signal of need. However, begging continued even with adlib food and was only weakly associated with greater provisioning by males, suggesting that these calls may also play an additional role, possibly reflecting sexual or parent-offspring conflict.

Tadpole begging reveals high quality

Parents can benefit from allocating limited resources nonrandomly among offspring, and offspring solicitation (i.e. begging) is often hypothesized to evolve because it contains information valuable to choosy parents. We tested the predictions of three 'honest begging' hypotheses - Signal of Need, Signal of Quality and Signal of Hunger - in the tadpoles of a terrestrial frog (Oophaga pumilio). In this frog, mothers provision tadpoles with trophic eggs, and when mothers visit, tadpoles perform a putative begging signal by stiffening their bodies and vibrating rapidly. We assessed the information content of intense tadpole begging with an experimental manipulation of tadpole condition (need/quality) and food deprivation (hunger). This experiment revealed patterns consistent with the Signal of Quality hypothesis and directly counter to predictions of Signal of Need and Signal of Hunger. Begging effort and performance were higher in more developed and higher condition tadpoles and declined with food deprivation. Free-living mothers were unlikely to feed tadpoles of a nonbegging species experimentally cross-fostered with their own, and allocated larger meals to more developed tadpoles and those that vibrated at higher speed. Mother O.pumilio favour their high-quality young, and because their concurrent offspring are reared in separate nurseries, must do so by making active allocation decisions. Our results suggest that these maternal choices are based at least in part on offspring signals, indicating that offspring solicitation can evolve to signal high quality.

Sibling conflict and dishonest signaling in birds

Offspring survival can often depend on successful communication with parents about their state of need. Theory suggests that offspring will be less likely to honestly signal their need when they experience greater competition from either a greater number of nestmates or less-related nestmates. We found support for this hypothesis with a comparative analysis, examining data from across 60 species of birds. We found that offspring are less honest about their level of need when (i) they face competition from current siblings; (ii) their parents are likely to breed again, and so they are in competition with future siblings; and (iii) parental divorce or death means that they are likely to be less related to future siblings. More generally, these patterns highlight the sensitivity of communication systems to conflict between signaler and receiver while also suggesting that when there is little conflict, natural selection favors the honest.

Incubating females signal their needs during intrapair vocal communication at the nest: a feeding experiment in great tits

Parental care is a key factor of breeding success and parents face evolutionary trade-offs between investment in current offspring and future reproduction and survival. Incubation in birds is energetically costly and the balance between parental and offspring's energetic needs is especially challenging when only one sex incubates, generally the female. In that case, males can contribute indirectly to incubation effort by feeding their mate and females may use begging behaviours to signal their needs to their visiting partner. The great tit, Parus major , is a good model species to test whether females use acoustic communication from the nest to signal their needs to their mate outside because females interact vocally with their mate during incubation. To test whether females use these vocal exchanges to communicate how hungry they are, great tit pairs were recorded on 2 days during incubation: 1 day with a feeder of mealworms in the nestbox and 1 day with an empty feeder. First, food supplementation increased females' nest attentiveness, revealing a decrease in foraging activity and consequently in females' needs. Second, females signalled their need for food both during their male's visits inside the nest but also during the vocal exchange immediately preceding the male's entrance by calling more and by modifying the frequency spectrum of their calls. So females' calling behaviour is an honest signal of need not only during their male's visits, but also before his entrance in the nest.

Information warfare in avian families: sex-specific begging responses to need and social environment in canary nestlings

Begging behaviour is a crucial component of parent–offspring communication. It is used by offspring to trigger the transfer of parental resources while at the same time allowing parents to access cryptic information about their offspring's need. But in a brood of more than one, offspring may gain indirect fitness benefits from responding to the need of its (related) siblings, not to withdraw all resources, especially if these are needier and would possibly contest more vigorously. Thus each offspring is thought to adjust its begging behaviour to its own intrinsic need as well as to its social environment, which is also shaped by the parents potentially having control over the distribution of resources. Here, we experimentally satiated the heaviest nestling within canary broods, Serinus canaria, in order to analyse: (1) whether nestlings honestly communicate their intrinsic hunger level; (2) whether nestlings adjust their begging behaviour to the need of their siblings; and (3) how parents respond to these begging strategies. Only female nestlings responded honestly, begging significantly less when satiated. Male nestlings, by contrast, did not alter their begging according to the level of satiation. Nestlings only weakly responded to the need of their siblings, and again only female nestlings did so. Thus female nestlings appear to be more sensitive to both intrinsic need and changes in their social environment, potentially owing to their lower competitiveness. Parents preferentially fed needier nestlings irrespective of the observed sex differences in begging strategies. They appear to control food distribution according to (cryptic) signals of need, which is important to take into account when studying the adaptive significance of any begging behaviour and strategy.