Stock composition of juvenile salmon taken by an abundant, pursuit-diving seabird in the coastal waters of British

We determined the stock composition of the juvenile salmon delivered to offspring by a pursuit-diving seabird, the Rhinoceros Auklet (Cerorhinca monocerata) on five breeding colonies in British Columbia, in 2012-2014. We obtained 778 meals (bill-loads) in 11 colony-years, of which 215 (28%) included salmon, and estimated stock composition for 126 pink, 101 sockeye, and 113 chum. The number, species, and stock composition of salmon taken by the birds varied markedly among colonies and years. On the two southernmost colonies there was a dramatic increase in the amount of Fraser River sockeye in diets in 2012, the offspring of the exceptionally large run up the river in 2010. The biennial cycle in pink salmon was also evident: individuals from Puget Sound stocks featured prominently in diets on colonies in 2012 and 2014, but were virtually absent in 2013 and replaced by pinks from more northerly stocks. Salmon generally comprise a minor proportion of Rhinoceros Auklet diets, but our result..., , , # Data from: Stock composition of juvenile salmon taken by an abundant, pursuit-diving seabird in the coastal waters of British

[https://doi.org/10.5061/dryad.xd2547dtg](https://doi.org/10.5061/dryad.xd2547dtg)

## Description of the data and file structure

Composition of food loads (number of fish species) delivered to rhinoceros auklet nestlings on breeding colonies in British Columbia Canada in 2012-2014

### Files and variables

#### File: Rhinoceros_Auklet_Food_loads_British_Columbia_2012-2014.csv

**Description:** Food loads delivered to rhinoceros auklet nestlings on colonies in British Columbia from 2012 to 2014

##### Variables

* Colony name (column A)
* Year of sampling (column B)
* Observers initials (column C)
* Date of sampling (column D)
* Food load number (column E)
* Number of individual items of fish species (columns F to T including an Other column)

## Code/software

Excel
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