Diurnal body temperature patterns in free‐ranging populations of two southern African arid‐zone nightjars
Bibliographic record
Abstract
Endotherms allocate large amounts of energy and water to the regulation of a precise body temperature (T b ), but can potentially reduce thermoregulatory costs by allowing T b to deviate from normothermic levels. Many data on heterothermy at low air temperatures (T a ) exist for caprimulgids, whereas data on thermoregulation at high T a are largely absent, despite members of this taxon frequently roosting and nesting in sites exposed to high operative temperatures. We investigated thermoregulation in free‐ranging rufous‐cheeked nightjars Caprimulgus rufigena and freckled nightjars Caprimulgus tristigma in the southern African arid zone. Individuals of both species showed labile T b fluctuating around a single modal T b (T b‐mod ). Average T b‐mod was 39.7°C for rufous‐cheeked nightjars and 39.0°C for freckled nightjars. In both species, diurnal T b increased with increasing T a . At T a ≥ 38°C, rufous‐cheeked nightjar mean T b increased to 42°C, equivalent to 2.3°C above T b‐mod . Under similar conditions, freckled nightjar T b was on average only 1.1°C above T b‐mod , with a mean T b of 40.0°C. Freckled nightjars are one of the most heterothermic caprimulgids investigated to date, but our data suggest that during hot conditions this species maintains T b within a narrow range above T b‐mod , possibly reflecting an evolutionary tradeoff between decreased thermal sensitivity to lower T b but increased sensitivity to high T b . These findings reveal how general thermoregulatory patterns at similar T a can vary even among closely related species.
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) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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".