Editing Loggerhead shrike (section)

==Conservation status==
Loggerhead shrike populations have been decreasing in North America since the 1960s. Reasons behind the decline remain unclear, although suggestions include habitat loss, pesticide contamination, and human disturbance.<ref name="collister1996"/> The eastern loggerhead shrike (''L. l. migrans'') is critically endangered in Canada, with fewer than 35 known breeding pairs in Canada.<ref>{{cite book| publisher= Committee on the Status of Endangered Wildlife in Canada| year= 2000| title= Assessment and update status report on the loggerhead shrike migrans subspecies, Lanius ludovicianus migrans in Canada| place= Ottawa| pages= viii + 13 pp}}</ref> The San Clemente Island shrike, ''L. l. mearnsi'', is critically endangered, with a population as low as 5–10 individuals during 1983–1988.<ref name="mundy1997"/> Although only this island subspecies is legally listed as endangered in the United States, the species is declining continent-wide and no longer occurs in most of the northeastern U.S.; it is [[extirpated]] from every state in [[New England]], as well as [[New Brunswick]] and [[Nova Scotia]].<ref name=NS/><ref>{{cite web| last= Yosef| first= Reuven| year= 1996| url= http://bna.birds.cornell.edu/bna/species/231 |title= Loggerhead Shrike (''Lanius ludovicianus'')| work= The Birds of North America Online| editor-first= A.| editor-last= Poole | place= Ithaca| publisher= Cornell Lab of Ornithology| via= bna.birds.cornell.edu}}</ref> A captive population was established at the [[Toronto Zoo]] and [[McGill University]] in 1997. In 2001, an experimental field breeding and release program managed by [[Wildlife Preservation Canada]] was established. "Field breeding" refers to moving captive pairs from their wintering cages at the Toronto Zoo and McGill to large enclosures within shrike habitat in Ontario where the pairs nest and raise their young. The young then are released to the wild when they'd naturally disperse from their parents. Since 2004, over 90 young have been released annually and between 2% and 6.5% of young released have successfully migrated and returned to breed in the subsequent year.<ref>{{cite web |title= Conservation > Birds |publisher= Toronto Zoo  |website= torontozoo.com |url= http://www.torontozoo.com/conservation/birds.asp |access-date  = 2009-09-22 |archive-url= https://web.archive.org/web/20100206003504/http://torontozoo.com/Conservation/birds.asp |archive-date = 2010-02-06 |url-status= dead}}</ref><ref>{{cite web| url= http://wildlifepreservation.ca/species-in-need/canadian-species/species-9/| archiveurl= https://web.archive.org/web/20140408123725/http://wildlifepreservation.ca/species-in-need/canadian-species/species-9/ |archivedate= April 8, 2014| title= Eastern Loggerhead Shrike| publisher= Wildlife Preservation Canada| website= wildlifepreservation.ca| date= | access-date= August 19, 2021}}</ref>