Nocturnal Predation by a Black-crowned Night Heron at a Common Tern Colony
Bibliographic record
Abstract
Nocturnal predation by a Black-crowned Night Heron at a Common Tern colony.--Scatteredreports appear in the literature of actual or suspected predation by Black-crowned Night Herons (Nycticorax nycticorax) at Common Tern (Sterna hirundo) colonies.Marshall (1942) reported seeing a single heron eating Common Tern eggs at night in a western Lake Erie colony that all adult terns had temporarily left; he gave no data on numbers of eggs taken or on the duration of observation.Collins (1970) reported the remains of a 2-to 4-day-old Roseate Tern (S. dougallii) chick in the stomach contents of a Black-crowned Night Heron collected at 0700 on 13 July 1968 at Great Gull Island, New York.He suggested that nightherons may also have been responsible for the disappearance of several 1-to 3-dayold Common Tern chicks from the same colony.Nisbet (1975) suggested that most of the nocturnal predation in a Massachusetts Common Tern colony was caused by Great Horned Owls (Bubo virginianus) although he noted footprints of Blackcrowned Night Herons and a raccoon (Procyon lotor) near the colony.This note presents details of nocturnal predation in a Common Tern colony by a Blackcrowned Night Heron and discusses the significance of such predation as a factor influencing the terns' reproductive success.We made these observations at one of several Common Tern colonies near Port Colborne, Ontario, where we have been studying tern reproductive biology for the past 3 years.The ternery was on a concrete shelf forming part of a breakwater at the Lake Erie terminus of the Welland Canal.Egg-laying began in early May 1973 and continued until early August 1973.During the course of recordinghatching and fledging data for approximately 400 marked nests, we noted that numbers of eggs and young chicks disappeared between daily visits for no reason obvious from diurnal observations.In an attempt to assess the possibility of loss July 1976]
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 machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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 | 0.001 | 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".