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To gain support, children use signals to communicate their needs and wants to parents. Infant signals of need, particularly infant cries, have been extensively studied in diverse populations. However, the full range of potential child signals of need, which extend beyond cries, has rarely been investigated in a single study of children of all ages. To help fill this gap, we collected mother and other primary caregiver reports of three common types of child signaling from 131 families with 263 children on Utila, a small island off the coast of Honduras. In exploratory analyses, we found that child signaling was common in both sexes and across all ages, although it decreased with age and neighborhood quality and increased with the frequency of conflict between children and caretakers. Consistent with signaling theory, children who were sad more frequently were perceived as needier within the household and were more likely to receive investment. Caregivers were less likely to respond positively in situations of family conflict or child transgressions, and more likely for injuries and illness. Our results suggest that evolutionary theories of signaling can help explain patterns of child sadness, crying, and temper tantrums. 

Animals that occupy stable home ranges tend to unevenly exploit different areas in their efforts to find fitness-limiting resources, while also reducing the risks of intergroup conflict. Most analyses of these extrinsic forces identify their effects on movement paths and home range geometry, but not on the interaction of these responses or how movements might be centrally constrained as a result of competition with neighbors. The range utilization slope is a measure of central tendency and consists of space use plotted against distance from the center of the range. Slopes tend to be linear, concave-up, or concave-down and are predicted to change as a function of feeding competition from neighbors. To test this prediction and determine the spatio-temporal scales over which the central tendency might vary, we calculated utilization slopes and an index of range overlap for grey-cheeked mangabeys (Lophocebus albigena), blue monkeys (Cercopithecus mitis), and red-tailed monkeys (C. ascanius) in Uganda, which consume similar diets but experience varying intensities of intergroup conflict. As predicted, we find variation in utilization slopes across and within species, which corresponds with the extent of range overlap among conspecific groups.