Description

The following publication includes data from two coastal aerial surveys in Atlantic Canada in 2017: a spring breeding survey for Common Eiders (Somateria mollissima dresseri) and Black Guillemots (Cepphus grylle), and a summer moult survey for Common Eiders. Counts of individuals and groups were made around shorelines, islands, and exposed ledges. Surveys were conducted with 3 observers from a fixed-wing aircraft flying between 400 and 800 feet above sea level. Common Eiders: During the spring breeding survey, counts were made of individuals and groups of adult males on the water around coastlines and potential breeding islands. Timing of survey (mid-May) is intended to count breeding birds (males only) shortly after peak egg-laying when females initiate incubation and males begin dispersal from their breeding sites. Therefore, counts represent general numbers of breeding males for the region, but locations of bird groups do not necessarily reflect breeding sites/islands. For the summer moult survey, large flocks of flightless eiders were searched for on coastal areas along the Bay of Fundy (New Brunswick) and Nova Scotia. Large flocks of moulting males were seldom observed, and small groups of females with young of the year were also recorded. Black Guillemots: Counts were made of individuals and groups of Black Guillemots on the water around coastal areas and islands. Counts included birds flushed from islands which are likely to be breeding sites. Counts of individuals are intended to represent numbers of breeding birds prior to egg laying. However, ideal survey timing for counts of pre-breeding (courtship) pairs is during the last week of April or first week of May, prior to egg laying. Given the timing of this survey (mid-May) and uncertainties of timing of breeding in Nova Scotia, these counts may not accurately represent estimates of breeding individuals. Moreover, low counts (or absence of birds) were observed around some islands where breeding colonies were expected, therefore, we believe these counts are underestimates of breeding birds. Nonetheless, where > 10 birds were observed on or adjacent to islands, these may represent minimum estimates of breeding individuals at these sites. Accompanying files include, flight tracklines, survey conditions, and bird sightings.

Resources

Name	Format	Description	Link
View ECCC Data Mart (English) for the English Data Mart URL, and View ECCC Data Mart (French) for the French URL	HTML		https://data-donnees.az.ec.gc.ca/data/species/protectrestore/CWS-Atlantic-COEI-and-BLGU-Surveys-2017?lang=en
Voir le Dépôt de données d'ECCC (Anglais) for the English Data Mart URL, and Voir le Dépôt de données d'ECCC (Français) for the French URL	HTML		https://data-donnees.az.ec.gc.ca/data/species/protectrestore/CWS-Atlantic-COEI-and-BLGU-Surveys-2017?lang=fr

Tags

Topics

Categories