Nesting habitat and diet studies of sandhill cranes (Grus canadensis) from the central and north coast of British Columbia

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dc.contributor.author Roessingh, Krista
dc.date.accessioned 2012-08-24T21:38:10Z
dc.date.available 2012-08-24T21:38:10Z
dc.date.copyright 2012 en_US
dc.date.issued 2012-08-24
dc.identifier.uri http://hdl.handle.net/1828/4168
dc.description.abstract The purpose of this study was to document the occurrence, habitat, and diet of sandhill cranes that breed in coastal British Columbia, a population believed to belong to the subspecies rowani. Specific objectives were to: 1) locate cranes and their nests in selected coastal areas of the central and north coasts (5138’N, 12805’W - 5400’N, 13037’W) and foster observer expertise in conducting aerial crane surveys; 2) describe sandhill crane nest habitat using a range of stand- and site-level characteristics; and, 3) identify diet content of breeding cranes from faecal samples. Helicopter surveys were conducted within 1.5 km of the coastline during May 2007 and 2008. Twenty nest sites were visited in 2008 to collect data on nest habitat characteristics. Satellite imagery was used to measure stand-level and landscape features for 29 nests. Faecal samples were collected at 6 nest and roost sites. During the 2008 survey, 104 cranes and 19 nests were counted over a 430 km2 area (average survey effort = 2.0 km2/min.). Crane nests were located in bog habitat, while cranes frequented bogs, shorelines, and marshes. Nests were in bog pools under 0.5 ha in size with the exception of one that occured in a 1.2 ha beaver-dammed pond (median = 0.10 ha, inter-quartile range (IQR) = 0.037 – 0.17 ha, n = 29), and had median water depth of 56 cm around nest islets (IQR = 49 – 77 cm, n = 21). Bog pools were in forest or woodland bog openings with median distance from the pool edge to the nearest treeline of 46 m (IQR – 24 – 160 m, n = 25) and median forest buffer width of 150 m (IQR = 93 – 260 m, n = 25). Forested habitat may serve as a corridor for cranes with pre-fledged young connecting bog nest and roost sites with shoreline foraging areas. Median distance from nest to shoreline was 400 m (IQR = 200 – 500 m, n = 28). Food items characteristic of faecal samples (n = 138) included mussel (Mytilus edulis), periwinkle (Littorina littorea) and limpet shells, insects, sedge (Carex spp.) and crowberry (Empetrum nigrum), plant remains, and crab remains. Changes in the probability of observing periwinkle and limpet in samples were observed between sites, while the frequency of occurrence of insects differed between time periods and that of sedge, crowberry, and mussels differed between time periods and sites. Sandhill cranes were sparsely distributed on inner and outer coastal islands with bog nesting habitat and sheltered intertidal foraging habitat. en_US
dc.language English eng
dc.language.iso en en_US
dc.subject sandhill crane en_US
dc.subject habitat en_US
dc.subject British Columbia en_US
dc.subject aerial survey en_US
dc.title Nesting habitat and diet studies of sandhill cranes (Grus canadensis) from the central and north coast of British Columbia en_US
dc.type Thesis en_US
dc.contributor.supervisor Smith, Daniel J.
dc.contributor.supervisor Jelinski, Dennis E.
dc.degree.department Dept. of Geography en_US
dc.degree.level Master of Science M.Sc. en_US
dc.rights.temp Available to the World Wide Web en_US
dc.identifier.bibliographicCitation Roessingh, K. A., and B. Penn. 2010. Sandhill cranes of coastal British Columbia: results of helicopter surveys and preliminary observations of habitat use. Proceedings of the North American Crane Workshop 11:1-8 en_US
dc.description.scholarlevel Graduate en_US

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