Burrow Entrance Attrition Rate in Wedge-tailed Shearwater Puffinus Pacificus Colonies on Rottnest Island, Western Australia

�ANCROFT, W.J., RO�ERTS, J.D. & GARKAKLIS, M.J. �005.�u���w e�������e ������i��i�� ����e i� Wedge-���iled She��w���e� Puffinus pacificus ��l��ies� �� R������es��� Is�l��d, Wes���e�� Aus�����li�.Marine Ornithology ��: ��-�6.She��w���e�s� (Puffinus s�pp.)�ppe�� ��� s�ele��� bu���w-�es��� s�i��es� ��� mi�imis�e ��he �is�k �� bu���w ��ll�ps�e ��d ��e k��w� ��� �le�� ��d �e-ex��v���e d�m�ged bu���ws�, ye�� empi�i��l evide��e �� ��he i��ide��e �� bu���w ��ll�ps�e is� l��ki�g.We p��vide p�elimi���y d���� �� ����es� �� bu���w e�������e ��ll�ps�e i� � ��l��y �� Wedge-���iled She��w���e�s� (P.pacificus) �� R������es��� Is�l��d, Wes���e�� Aus�����li�.E�������es� ��� 67.8% �� bu���ws� ��h��� we�e ����ive du�i�g ��he l�yi�g ph�s�e �� ��he �00�/0� b�eedi�g s�e�s��� h�d ��ll�ps�ed by ��he begi��i�g �� ��he �ex�� s�e�s���.The ������i��i�� ����e w�s� li�e�� �ve� ��ime, ��d ��ll�ps�ed p����i��s� h�d � me�� le�g��h �� 17.9 ± �.7 �m (s�����d��d e����).�u���w e�������es� �ve�l�i� wi��h s�h�ll�w-�����ed, ���u�l pl����s� (89.7% ��ll�ps�e ����e) we�e m��e ��h�� ��wi�e �s� likely ��� ��ll�ps�e �s� ��h�s�e l�����ed be�e���h deepe�-�����i�g, pe�e��i�l s�h�ubs� (40.9% ��ll�ps�e ����e).Th�ee qu����e�s� �� ��ll�ps�ed e�������es� we�e �e-ex��v���ed ��he ��ll�wi�g s�e�s���, ��d ��� le�s��� 11.5 �� h� -1 y� -1 (8.5 m � h� -1 y� -1 ) �� s��il w�s� dis�pl��ed ��h��ugh ��his� p���es�s�.O� m��ke� p�s���s� ��h��� we�e pl��ed ��� ��he e�������es� �� bu���ws� i� 199� (� = �64), ��% we�e ��u�d i� �00�.O� ��he p�s���s� ��h��� we�e ��u�d, 19% �em�i�ed �s�s���i���ed wi��h � bu���w e�������e.We ���s�ide� ��h��� m�s��� e�������e ��ll�ps�es� i� ��his� s���udy �e�le��� �b��d��me��� �� bu���ws� by ��he bi�ds�.Ou� d���� p�edi��� ��h���, i� � �u��e��� i���e�s�e i� s�h�ll�w-�����ed vege�����i�� i� ��l��y ��e�s� �����i�ues�, ��he ����e �� e�������e ��ll�ps�e ��d ��l��y e��s�i�� will i���e�s�e.Al��h�ugh we did ���� �����emp�� ��� qu����i�y ��he e��e��� ��h��� bu���w e�������e ��ll�ps�e h�s� �� ��he �ep��du���ive bi�l�gy �� ��he s�he��w���e�s�, we h�pe ��h��� �u� w��k will �����lys�e �u��u�e i�ves���ig���i�� i� ��his� �ield.