Site fidelity and the costs of movement among territories: an example from colonial web-building spiders
Bibliographic record
Abstract
Species differ in whether they exhibit strong site fidelity or move readily among sites. To understand the adaptive significance of site fidelity it is necessary to measure the cost of relocating to new sites, but this is very difficult with most species because it entails following individuals during the entire course of their transition. We studied the colonial web-building spider Metepeira incrassata (Araneae: Araneidae), which defends individual orb webs within a large, shared frame web. Colonies are heterogeneous habitats, with more prey but also more predators at the periphery of the colony relative to the central core. We measured relocation costs in this species by breaking them into the following components, (i) searching costs, (ii) establishment costs, and (iii) lost-opportunities costs, or the potential benefits of alternative behaviors that an animal might engage in if it were not relocating. We observed spiders that were in the process of establishing their orb webs at the start of the foraging day and conducted experiments to examine the costs of relocation by transferring spiders between locations within the colony. Transferred spiders had more fights with conspecifics than non-transferred spiders did, and the number of fights was positively correlated with the distance moved. However, searching and establishment costs seem unimportant, as individuals moving within their territories were as active as individuals moving to new sites. Transferred spiders faced greater lost-opportunities costs in the form of time spent on prey-capture orbs, as they significantly delayed orb construction. Lost-opportunities costs seem to be the most important component of relocation costs in this species and are likely to be generally important among species. This study is one of the few to document movement costs through direct observation.
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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 | 0.000 | 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".