00000nam 2200000za 4500 9.850201 CaOODSP 20241203113641 cr ||||||||||| 180117s1988 oncd||||o f000 0 eng d CaOODSP eng n-cn--- CW69-9/172E-PDF Gaston, A. J. The use of knock-down tags to detect changes in occupancy among burrow-nesting seabirds [electronic resource] : what is an adequate sample size? / by A.J. Gaston and B.T. Collins. [Ottawa] : Canadian Wildlife Service, 1988. 4 p. : charts Progress notes ; no. 172 "January 1988." Digitized edition from print [produced by Environment and Climate Change Canada]. Issued also in French under title: Utilisation de marqueurs de présence pour déterminer les variations du taux d'occupation de colonies d'oiseaux de mer nichant dans des terriers : calcul de la taille appropriée de l'échantillon. Includes bibliographical references. "A major problem in taking a census of burrow-nesting seabirds is to decide what proportion of burrows is actually occupied. Where burrows are long, it may be necessary to dig one or more access tunnels to find the nest chamber and determine whether it is occupiect by a bird, egg or chick. The disturbance thus created may cause birds to desert and may alter the structure of the breeding habitat. In either case this affects the chances of future occupation. If the census is being conducted to detect population trends, such disturbances will reduce the validity of subsequent observations. Hence, there is a definite need for a method of determining burrow occupancy with minimum disturbance"--Introd. gccst Aquatic birds gccst Population Collins, B. T., 1949- Canada. Environment Canada. Canadian Wildlife Service. Utilisation de marqueurs de présence pour déterminer les variations du taux d’occupation de colonies d’oiseaux de mer nichant dans des terriers (CaOODSP)9.860830 Progress notes (Canadian Wildlife Service) no. 172 (CaOODSP)9.504439 PDF 251 KB https://publications.gc.ca/collections/collection_2018/eccc/CW69-9-172-eng.pdf