Comparison of methods to estimate grey seal pup production at different colonies / M.O. Hammill ... [et al.].: Fs70-5/2017-041E-PDF

“Aerial surveys were flown in January and February 2016 to estimate grey seal pup abundance on Sable Island, along coastal Nova Scotia and in the Gulf of St Lawrence (GSL). Owing to a combination of circumstances (absence of ice in the GSL) and opportunities, different platforms were used to obtain counts of pups on different island colonies. The methods included the use of visual counts, oblique photography from low altitude helicopter flights, photographs using an unmanned aerial vehicle (UAV) and a large format aerial photographic camera. Images from the large format camera were the easiest to count, but this option was the most expensive and presented logistic challenges in coordinating positioning of the aircraft within the four week optimum time for photography of the colonies in the different regions. Images from the UAV were easy to count; the UAV was easy to deploy and did not disturb animals, but flights were limited in some cases by high wind speeds. Images from oblique photographs were suitable for counting, but also provided challenges in ensuring coverage of a colony, particularly if the colony was flat and without obvious landmarks. If only a few pups were present, visual counts were suitable, but at large colonies visual counts underestimated abundance"--Abstract, p. iii.

Permanent link to this Catalogue record:

Publication information
Department/Agency Canada.Department of Fisheries and Oceans.
Canadian Science Advisory Secretariat.
Title Comparison of methods to estimate grey seal pup production at different colonies / M.O. Hammill ... [et al.].
Series title Canadian Science Advisory Secretariat (CSAS), research document, 1919-5044 ; 2017/041, Quebec Region
Publication type Series - View Master Record
Language [English]
Format Electronic
Electronic document

Archived Content

Archived information is provided for reference, research or recordkeeping purposes. It is not subject to the Government of Canada Web Standards and has not been altered or updated since it was archived. Please contact the authoring department to request a format other than those available.

Note: The URLs contained in this/these document(s) may no longer be functional
Having trouble opening this document?
Note(s) Cover title.
“August 2017.”
Includes bibliographical references (p. 8-9).
Includes abstract in French.
Publishing information Ottawa : Fisheries and Oceans Canada, Canadian Science Advisory Secretariat, 2017.
Author / Contributor Hammill, M. O.(Michael O.)
Description iv, 19 p. : col. ill., map
Catalogue number
  • Fs70-5/2017-041E-PDF
Subject terms Seals, Animal populations, Wildlife management

Date modified: