Fledging of Leach's Storm-Petrel chicks from Gull Island

We used passive integrated transponder (PIT) tags to track the exact time and date that Leach's Storm-Petrel (Hydrobates leucorhous) chicks fledged from their burrow. The data included here are the last read for each of 123 chicks tracked in 2017, 2018, 2021, and 2022 on Gull Island, Witless Bay Ecological Reserve, Newfoundland and Labrador, Canada. We also include morphometric measurements of each chick that was banded and tagged for this study., Data were collected using a custom-built passive integrated transponder (PIT) system. When a tagged bird passes through the receiver placed in the entrance of the burrow, the system records the date, time, and identification of the bird. Morphometric data including weight and wing chord were collected by researchers at the time of chick banding. Chicks were weighed either on a kitchen scale or with a 100 g Pesola scale. Wing chord was measured with a wing ruler either to the tip of the pin feather or to the end of the skin if chicks did not yet have feathers., , # Fledging of Leach's Storm-Petrel chicks from Gull Island

[https://doi.org/10.5061/dryad.2bvq83bws](https://doi.org/10.5061/dryad.2bvq83bws)

Fledge dates and times of Leach's Storm-Petrel chicks from Gull Island, Witless Bay Ecological Reserve, Newfoundland and Labrador, Canada, were determined using a custom-built passive integrated transponder (PIT) system. 123 chicks were tracked in 2017, 2018, 2021, and 2022. The median fledge date was October 10, and the median fledge time was 1.6 h after sunset. We also examined whether fledging date and time were associated with moon phase and incident illumination. Chicks fledged randomly with respect to moon phase and incident illumination.

## Description of the data and file structure

all\_chicks.csv - the date and time of each detection of a Leach's Storm-Petrel chick in its burrow by the PIT tag system.

* BurrowID: the name of the burrow
* BandNo: the unique number on the steel Canadian Wildlife Service band for the chick
* DateTime: T...