Developmental and Sex‐Based Variation in Nest Building Among Wild Immature Chimpanzees
Bibliographic record
Abstract
All great apes build nests. Nests in trees or on the ground provide apes with a safe and comfortable place to sleep and rest at night and during the day. Nest building is a necessary skill and form of tool use that individuals learn and practice early in life, but little is known about its development and about the factors affecting the expression of nest building in infancy. We studied the development of daytime nest building of 72 wild immature chimpanzees (Pan troglodytes schweinfurthii) at Ngogo, Kibale National Park, Uganda. We evaluated the effects of age, sex, and maternal parity on the likelihood of infant nest building (presence or absence), as well as on the rates (frequency/hour) and durations (time from start to finish of each nest) with which infants built nests. Compared to the youngest infants (≤ 1 year), older infants were more likely to build nests, and built them at higher rates, consistent with hypotheses that nest building requires learning in early infancy and a threshold of physical development to manipulate tree branches. Female infants were more likely to build nests and built them more often than male infants, corroborating other developmental markers suggesting females attain functional independence at younger ages than males in some chimpanzee populations. Among infants who were seen to build nests at least once, rates and durations were similar, regardless of age, sex, or maternal parity, which indicated that there was little interindividual variation in nest building development once infants started practicing. The observed patterns of prior and subsequent behaviors to nest building suggested that infants > 4 years old built nests more functionally, for resting, than younger infants. This study underscores the value of nest building as a developmental measure in wild great apes. Studying factors that affect the expression of nest building in infancy allows for a better understanding of the ontogeny and evolution of learning and tool use in hominids.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".