Editing Loggerhead shrike

{{Short description|Species of bird}}
{{Speciesbox
| name = Loggerhead shrike
| fossil_range = {{Fossil range|Late Pleistocene|present}}
| image = Shrike Loggerhead JG.jpg
| image_caption = In Florida, USA
| status = NT
| status_system = IUCN3.1
| status_ref = <ref name="iucn status 12 November 2021">{{cite iucn |author=BirdLife International |date=2020 |title=''Lanius ludovicianus'' |volume=2020 |page=e.T22705042A179538598 |doi=10.2305/IUCN.UK.2020-3.RLTS.T22705042A179538598.en |access-date=12 November 2021}}</ref>
| status2 = G4
| status2_system = TNC
| status2_ref = <ref name=NS>{{cite web |title=NatureServe Explorer 2.0 |url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.104527/Lanius_ludovicianus |website=explorer.natureserve.org |access-date=5 November 2022}}</ref>
| genus = Lanius
| species = ludovicianus
| authority = [[Carl Linnaeus|Linnaeus]], 1766
| range_map = Lanius ludovicianus map.svg
| range_map_caption = Approximate distribution range{{leftlegend|#FF7F2A|Breeding}}
{{leftlegend|#7137C8|Year-round}}
{{leftlegend|#5F8DD3|Non-breeding}}
}}

The '''loggerhead shrike''' ('''''Lanius ludovicianus''''') is a [[passerine]] bird in the family [[Laniidae]]. It is the only member of the [[shrike]] family [[Endemic (ecology)|endemic]] to [[North America]]; the related [[northern shrike]] (''L. borealis'') occurs north of its range, however it is also found in Siberia. It is nicknamed the '''butcherbird''' after its carnivorous tendencies, as it consumes prey such as insects, amphibians, lizards, small mammals and small birds, and some prey end up displayed and stored at a site, for example in a tree.<ref name="craig1978">{{cite journal | last1 = Craig | first1 = R | year = 1978 | title = An analysis of the predatory behavior of the Loggerhead Shrike | journal = The Auk | volume = 95 | issue = 2| pages = 221–234 }}</ref> Due to its small size and weak talons, this predatory bird relies on impaling its prey upon thorns or barbed wire for facilitated consumption.<ref name="smith1973">{{cite journal | last1 = Smith | first1 = S | year = 1973 | title = Aggressive display and related behavior in the loggerhead shrike | journal = The Auk | volume = 90 | issue = 2| pages = 287–298 }}</ref> The numbers of loggerhead shrike have significantly decreased in recent years, especially in Midwestern, New England and Mid-Atlantic areas.<ref>{{cite journal | last1 = Lymn | first1 = N | last2 = Temple | first2 = S | year = 1991 | title = Land-use changes in the Gulf coast region: links to declines in Midwestern loggerhead shrike populations | journal = The Passenger Pigeon | volume = 53 | issue = 4| pages = 315–325 }}</ref>

==Taxonomy==
In 1760 the French zoologist [[Mathurin Jacques Brisson]] included a description of the loggerhead shrike in his ''Ornithologie'' based on a specimen collected in [[Louisiana]] in the United States. He used the French name ''La pie-griesche de la Louisiane'' and the Latin ''Lanius ludovicianus''.<ref name=brisson>{{ cite book | last=Brisson | first=Mathurin Jacques | author-link=Mathurin Jacques Brisson | year=1760 | title=Ornithologie, ou, Méthode contenant la division des oiseaux en ordres, sections, genres, especes & leurs variétés | volume=2 | language=fr, la | place=Paris | publisher=Jean-Baptiste Bauche | pages=162–164, Plate 15 fig 2 | url=https://biodiversitylibrary.org/page/36011386 }} The two stars (**) at the start of the section indicates that Brisson based his description on the examination of a specimen.</ref> Although Brisson coined Latin names, these do not usually conform to the [[binomial nomenclature|binomial system]] and are not recognised by the [[International Commission on Zoological Nomenclature]].<ref name=allen>{{cite journal |last=Allen | first=J.A. | author-link=Joel Asaph Allen | year=1910 | title=Collation of Brisson's genera of birds with those of Linnaeus |journal=Bulletin of the American Museum of Natural History |volume=28 | pages=317–335 | hdl=2246/678 }}</ref> When in 1766 the Swedish naturalist [[Carl Linnaeus]] updated his ''[[Systema Naturae]]'' for the [[12th edition of Systema Naturae|twelfth edition]], he added 240 species that had been previously described by Brisson.<ref name=allen/> One of these was the loggerhead shrike. Linnaeus included a brief description, adopted the [[binomial name]] ''Lanius ludovicianus'' (identical to Brisson's Latin name) and cited Brisson's work.<ref>{{cite book | last=Linnaeus | first=Carl | author-link=Carl Linnaeus | year=1766 | title=Systema naturae : per regna tria natura, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis | edition=12th | volume=1, Part 1 | publisher=Laurentii Salvii  | place=Holmiae (Stockholm) | language=la | page=134 | url=https://biodiversitylibrary.org/page/42946330 }}</ref> The [[Specific name (zoology)|specific name]] ''ludovic'' is [[Late Latin]] for "Louis" and the epithet "-ianus" is to describe something being of another or possessed by it. When translated, its scientific name means something alongside the lines of "Louis’ butcher".<ref name=hbwkey>{{cite web | last=Jobling | first=J.A. | year=2018 | title= Key to Scientific Names in Ornithology | editor1-last=del Hoyo | editor1-first=J. | editor2-last=Elliott | editor2-first=A. | editor3-last=Sargatal | editor3-first=J. | editor4-last=Christie | editor4-first=D.A. | editor5-last=de Juana | editor5-first=E. | work=Handbook of the Birds of the World Alive | publisher=Lynx Edicions | url=https://www.hbw.com/dictionary/definition/ludoviciana-ludovicianus | access-date=21 June 2018 }}</ref>  "Loggerhead," a similar word to "blockhead," refers to the unusually large head to body ratio of this bird.<ref>{{cite web| url= https://www.allaboutbirds.org/guide/Loggerhead_Shrike/overview| title= Loggerhead Shrike| website= allaboutbirds.org| publisher= Cornell University| date= 2019| access-date= August 19, 2021}}</ref>

There are seven recognized [[subspecies]]:<ref name=ioc>{{cite web| editor1-last=Gill | editor1-first=Frank | editor1-link=Frank Gill (ornithologist) | editor2-last=Donsker | editor2-first=David | year=2018 | title=Shrikes, vireos, shrike-babblers | work=World Bird List Version 8.1 | url= http://www.worldbirdnames.org/bow/shrikes/ | publisher= [[International Ornithologists' Union]] | access-date=21 June 2018 }}</ref>

* ''L. l. excubitorides'' [[William Swainson|Swainson]], 1832 – central Canada, central and west USA
* ''L. l. migrans'' Palmer, W, 1898 – east North America
* ''L. l. ludovicianus'' Linnaeus, 1766 – coastal southeast USA
* ''L. l. anthonyi'' [[Edgar Alexander Mearns|Mearns]], 1898 – [[Channel Islands (California)|Channel Islands]] (off south California, southwest USA)
* ''L. l. mearnsi'' [[Robert Ridgway|Ridgway]], 1903 – [[San Clemente Island]] (off south California, southwest USA)
* ''L. l. grinnelli'' [[Harry C. Oberholser|Oberholser]], 1919 – extreme south California and north Baja California (northwest Mexico)
* ''L. l. mexicanus'' [[Alfred Brehm|Brehm, CL]], 1854 – west and central Mexico, south Baja California (northwest Mexico)

Miller, in 1931, suggested that the wing-chord-to-tail-length ratio was an important indicator for distinguishing between subspecies.<ref name="miller1931"/> 
''Lanius ludovicianus migrans'', found in eastern North America, can be distinguished from the western subspecies, ''L. l. excubitorides'' by wing length, tail length, and colour. ''L. l. migrans'' have a paler forehead than the top of the head.<ref name="chabot1994"/>
According to Mundy et al.’s 1997 study, there is a substantial genetic difference between the island subspecies ''L. l. mearnsi'' and the mainland subspecies ''L. l. gambeli'' due to a gene flow barrier between the two species.<ref name="mundy1997">{{cite journal | last1 = Mundy | first1 = N. |last2= Winchell |first2= C.| last3= Burr |first3= T.| last4= Woodruff |first4= D. | year = 1997 | title = Microsatellite variation and microevolution in the critically endangered San Clemente Island loggerhead shrike (Lanius ludovicianus mearnsi) | journal = [[Proceedings of the Royal Society of London B]] |publisher= [[Royal Society of London]] | volume = 264 | issue = 1383| pages = 869–875 | doi=10.1098/rspb.1997.0121| pmc = 1688432| bibcode = 1997RSPSB.264..869M }}</ref>

==Description==
[[Image:Loggerhead Shrike florida RWD6.jpg|right|thumb|In Florida]]

The loggerhead shrike is a medium-sized passerine.<ref name="chapman1904">{{cite book| last= Chapman |first= F.| year= 1904| title= Handbook of birds of eastern North America| edition= 6th | place= New York, New York| publisher= Appleton and Company| isbn= }}</ref> "Loggerhead" refers to the relatively large size of the head as compared to the rest of the body. The wing and tail length are about {{cvt|3.82|in|cm|sigfig=3}} and {{cvt|3.87|in|cm|sigfig=3}} long, respectively.<ref name= "chapman1904"/> It weighs on average {{cvt|50|g|sigfig=2|order=flip}}, with a range of {{cvt|45|–|60|g|sigfig=2|order=flip}} for a healthy adult shrike.<ref>{{cite journal | last1 = Craig | first1 = R | last2 = DeAngelis | first2 = D | last3 = Dixon | first3 = K | year = 1979 | title = Long- and short-term dynamic optimization models with application to the feeding strategy of the loggerhead shrike | doi = 10.1086/283363 | journal = The American Naturalist | volume = 113 | issue = 1| pages = 31–51 | bibcode = 1979ANat..113...31C }}</ref>

;Measurement ranges<ref>{{Cite web|title=Loggerhead Shrike Identification, All About Birds, Cornell Lab of Ornithology |url= https://www.allaboutbirds.org/guide/Loggerhead_Shrike/id|access-date=2020-09-27|website= allaboutbirds.org|language=en}}</ref>
* '''Length''': {{cvt|7.9|–|9.1|in|cm|sigfig=2}}
* '''Weight''': {{cvt|1.2|–|1.8|oz|g|sigfig=2}}
* '''Wingspan''': {{cvt|11.0|–|12.6|in|cm|sigfig=3}}

The adult plumage of the loggerhead shrike is grey above with a white to pale grey breast and black tarsi and feet. The bird possesses a black mask that extends across the eyes to its bill. The wings are black with a distinct white patch on the [[Flight feather|primaries]]. The tail is black edged with white and the irises are brown.<ref name="chabot1994">{{cite book| last= Chabot |first= A.| year= 1994| title= Habitat selection and reproductive biology of the loggerhead shrike in eastern Ontario and Quebec| place= Montreal |publisher= McGill University Libraries}}</ref> The beak is short, black, and hooked, and contains a tomial tooth to help tear into prey.<ref name="miller1931">{{cite journal | last1 = Miller | first1 = A | year = 1931 | title = Systematic revision and natural history of the American shrikes (Lanius) | journal = University of California Publications in Zoology | volume = 38 | issue = 2| pages = 11–242 }}</ref> It is difficult to sex an adult loggerhead shrike in the field as they are sexually monochromatic.<ref name="sustaita2014">{{cite journal | last1 = Sustaita | first1 = D | last2 = Owen | first2 = C | last3 = Villarreal | first3 = J | last4 = Rubega | first4 = M | year = 2014 | title = Morphometric tools for sexing loggerhead shrikes in California | journal = The Southwestern Naturalist | volume = 59 | issue = 4| pages = 562–569 | doi=10.1894/ekl-06.1}}</ref> However, several studies have reported [[sexual dimorphism]] in plumage and size traits.<ref name="miller1931" /><ref name="sustaita2014" /><ref name="collister1996">{{cite journal | last1 = Collister | first1 = D | last2 = Wicklum | first2 = D | year = 1996 | title = Intraspecific variation in Loggerhead Shrikes: sexual dimorphism and implication for subspecies classification | journal = The Auk | volume = 113 | issue = 1| pages = 221–223 | doi=10.2307/4088949| jstor = 4088949 | doi-access = free }}</ref> Juveniles possess a paler gray plumage that is subtly [[Vermiculation|vermiculated]].<ref name="natgeo">{{cite book | title=National Geographic Field Guide to the Birds of North America | first1=Jon Lloyd |last1=Dunn|first2= Jonathan K.|last2= Alderfer |publisher= National Geographic Books| year= 2006 | page= 312 | isbn = 9780792253143 | url= https://books.google.com/books?id=gA-rfkTZi1YC&pg=PA312 }}</ref>

The loggerhead shrike can be distinguished from the [[northern shrike]] by its smaller size, darker grey plumage, and larger black face mask that covers the eye completely. It also has a shorter bill with less prominent hook. Their calls are similar.<ref name=natgeo/>

===Vocalization===
[[File:LoggerheadShrike-21DEC2017.jpg|alt=Loggerhead Shrike in Yolo County, California|thumb|In Yolo County, California.]]
Their vocal range is broad and varied, and has been described as harsh and jarring.<ref>{{cite journal | last1 = Frost | first1 = E | year = 1885 | title = The loggerhead shrike in New Hampshire | journal = The Auk | volume = 2 | issue = 4| page = 379 | doi=10.2307/4625312| jstor = 4625312 }}</ref> The shrike's notes include squeaky whistles, shrill trills, and guttural warbles.<ref name="chapman1904"/> The trills sung by males during breeding season vary in rhythm and pitch. When alarmed, a shrike will produce a "schgra-a-a" shriek while spreading out its tail feathers. A distinctive alarm call is often given when threats from above are detected. Nestlings will make "tcheek" and "tsp" sounds shortly after hatching.<ref name="soendjoto1995">{{cite book| last= Soendjoto |first= M.| year= 1995| title= Vocalization behavior of captive loggerhead shrikes (Lanius ludovicianus excubitorides)| place= Montreal | publisher= McGill University Libraries}}</ref> During courtship feedings, females may ask for food with "mak" begging notes; conversely, males emit "wuut" or "shack" sounds to offer food.<ref>{{cite journal | last1 = Cade | first1 = T | year = 1992 | title = Hand-reared loggerhead shrikes breed in captivity | journal = Condor | volume = 94 | issue = 4| pages = 1027–1029 | doi=10.2307/1369306| jstor = 1369306 }}</ref> The male emits a territorial, harsh shriek, while the female's song is pitched lower and softer than the male's. Generally, the male is far more vocal than the female.<ref name="chabot1994"/><ref name="soendjoto1995"/>

==Distribution and habitat==
[[File:Loggerhead Shrike Gary Leavens.jpg|thumb|In Tatum, Florida]]
Loggerhead shrikes were once widely distributed across southern Canada, the contiguous USA and Mexico.<ref name="miller1931" /> However, their populations have heavily declined since the 1960s.<ref name="collister1996" /> Four subspecies reside in southern coastal California: ''mearnsi, gambeli, grinnelli'' and ''anthonyi''.<ref>Patten M, Campbell K. 2008. Typological thinking and the conservation of subspecies: the case of the San Clemente Island loggerhead shrike. Diversity and Distributions. 6(4): 177–188.</ref> ''L. l. mearnsi'' is only found on San Clemente Island in California, whereas ''L. l. gambeli'' breeds on the mainland and ''L. l. anthonyi'' breeds on the Channel Islands.<ref name="mundy1997" /> ''L. l. excubitorides'' is found in central North America, whereas the non-migrating ''L. l. ludovicianus'' resides in southeastern North America.<ref name="collister1996" /> The distribution of ''L. l. migrans'' ranges from north to eastern North America; however, its range has been diminishing since the 1940s.<ref name="chabot1994" />
   
The bird requires an open habitat with an area to forage, elevated perches, and nesting sites.<ref name="brooks1990" /> They are often found in open pastures or grasslands and appear to prefer red-cedar and hawthorn trees for nesting.<ref name="chabot2001">{{cite journal | last1 = Chabot | first1 = A | last2 = Titman | first2 = R | last3 = Bird | first3 = D | year = 2001 | title = Habitat use by Loggerhead Shrikes in Ontario and Quebec | journal = Canadian Journal of Zoology | volume = 79 | issue = 5| pages = 916–925 | doi=10.1139/z01-039| bibcode = 2001CaJZ...79..916C }}</ref> The hawthorn's thorns and the cedar's pin-like needles protect and conceal the shrike from predators.<ref>Gawlick D, Bildstein K. 1990. Reproductive success and nesting habitat of Loggerhead Shrikes in north-central South Carolina. Wilson Bulletin. 102(1): 37–48.</ref> It may also nest in fence-rows or hedge-rows near open pastures and requires elevated perches as lookout points for hunting.<ref name="brooks1990">Brooks B, Temple S. 1990. Habitat availability and suitability for loggerhead shrikes in the upper midwest. The American Midland Naturalist. 123(1): 75–83.</ref><ref name="chabot2001" /> Open pastures and grasslands with shorter vegetation are preferred by loggerhead shrikes, as they increase the bird's hunting efficiency. Longer vegetation often requires more time and energy to be spent searching for prey, so these birds gravitate towards areas of shorter vegetation.<ref>{{cite journal | last1 = Yosef | first1 = R | last2 = Grubb | first2 = T | year = 1992 | title = Territory size influences nutritional condition in nonbreeding loggerhead shrikes (Lanius ludovicianus): a ptilochronology approach | journal = Conservation Biology | volume = 6 | issue = 3| pages = 447–449 | doi=10.1046/j.1523-1739.1992.06030447.x| bibcode = 1992ConBi...6..447Y }}</ref>

==Behavior==
===Diet===
Loggerhead shrikes have been repeatedly observed killing prey larger than themselves by spearing the neck or head of the animal and twisting. The speed at which this occurs causes a [[whiplash (medicine)|whiplash]] injury to the animal. The neck strength of the shrikes compensates, making their talon weakness inconsequential.<ref>{{cite news |title=Head-turning violence helps tiny songbirds kill big prey: study |url=https://www.afp.com/en/news/2265/head-turning-violence-helps-tiny-songbirds-kill-big-prey-study-doc-18u9wy1 |work= AFP.com| publisher= Agence France-Presse |date=5 September 2018 |archive-url= https://web.archive.org/web/20180905060159/https://www.afp.com/en/news/2265/head-turning-violence-helps-tiny-songbirds-kill-big-prey-study-doc-18u9wy1 |archive-date= 5 September 2018 |language=en}}</ref>

Although loggerhead shrikes are [[passerines]], they are a predatory species that hunt during the day. They primarily eat insects, but also consume arachnids, reptiles, amphibians, rodents, [[bat]]s and small birds.<ref>{{cite journal|last1=Mikula|first1=P.|last2=Morelli|first2=F.|last3=Lučan|first3=R. K.| last4= Jones| first4=D. N.|last5=Tryjanowski|first5=P.| display-authors= 3| year= 2016| title=Bats as prey of diurnal birds: a global perspective |journal= [[Mammal Review]] |volume= 46| issue= 3|pages=160–174|doi=10.1111/mam.12060}}</ref><ref>{{cite journal | last1 = Sustaita | first1 = D | last2 = Rubega | first2 = M | year = 2014 | title = The anatomy of a shrike bite: bill shape and bite performance in Loggerhead Shrikes | journal = [[Biological Journal of the Linnean Society]] | volume = 112 | issue = 3| pages = 485–98 | doi=10.1111/bij.12298| doi-access = free }}</ref> They have even eaten venomous snakes such as the [[water adder]]. The size of prey ranges from {{cvt|0.001|g}} insects to {{cvt|25|g|sigfig=2}} mice or reptiles.<ref name= "craig1978"/>
[[File:Desert Iguana imported from iNaturalist photo 13241876 on 3 December 2024.jpg|thumb|[[Desert iguana]] pinned to a [[Krameria bicolor|white rhatany]] shrub by a loggerhead shrike. In California.]]
They are not true birds of prey, as they lack the large, strong talons used to catch and kill prey.<ref name="smith1973"/> Instead, they are sit-and-wait hunters that stalk prey by [[hawking (birds)|hawking]] and diving from elevated perches. By scanning their vicinity from a perch instead of flying, the shrike does not exhaust its energy during the search. Preferred perches are approximately {{cvt|13|ft|m|sigfig=2}} off the ground, and are usually outer branches of trees or telephone wires.<ref name="craig1978"/><ref>{{cite journal | last1=Atkinson |first1=Eric C. | last2=Cade | first2=Tom J. |year= 1993 |title= Winter foraging and diet composition of Northern Shrikes in Idaho |journal= [[Condor (journal)|Condor]] |volume= 95| issue=3| pages= 528–35 | url= https://sora.unm.edu/sites/default/files/journals/condor/v095n03/p0528-p0535.pdf | doi=10.2307/1369596|jstor=1369596 }}</ref> In winter, prey availability is low due to the shrike's preference for insects and [[poikilotherm]]ic prey; during this time, shrikes may be energetically stressed and underweight.<ref name="craig1978"/> Insects are consumed in mid-flight, but vertebrates usually require more handling time and therefore more energy.<ref name="smith1973"/> Due to the shrike's small size in proportion to the size of its prey, it must rely on specialized adaptations to facilitate its hunting. The powerful, hooked beak of the loggerhead shrike allows it to sever the neck of a small vertebrate. Larger prey are subjected to impaling, in which they are pushed down into a sharp projection, such as a thorn or barbed wire. The bird can then tear off flesh by using the projection as an anchor.<ref name="smith1973"/> The shrike may also use the thorn to fasten and store its food to return to at a later time.<ref name= "craig1978"/>

The motion of impalement appears to be instinctive, as parent shrikes do not demonstrate the behavior to their nestlings. However, a young shrike must experience impaling prey upon an actual projection during a critical developmental period; otherwise, it will not learn to use the instinctive impaling action upon an actual projection.<ref>{{cite journal| last= Smith |first= S.| year= 1972| title= The ontogeny of impaling behaviour in the Loggerhead Shrike, Lanius ludovicianus L.| journal= [[Behaviour (journal)|Behaviour]]| volume= 42| number= 3| pages= 232–46|doi= 10.1163/156853972X00284}}</ref> [[Kleptoparasitism]] has also been observed in nature, in which the shrike chased down another bird and stole its recently-caught prey.<ref>{{cite journal | last1 = Etterson | first1 = M | last2 = Howery | first2 = M | year = 2001 | title = Kleptoparasitism of soil-foraging passerines by loggerhead shrikes | journal = [[Journal of Field Ornithology]] | volume = 72 | issue = 3| pages = 458–461 | doi=10.1648/0273-8570-72.3.458}}</ref>

===Reproduction===
[[File:Loggerhead Shrike nest site.jpg|thumb|In Napanee, Ontario]]

Loggerhead shrikes are monogamous birds. However, males are known to begin second nesting attempts with a second female before his first clutch has fledged. They begin breeding during their first spring.<ref name="chabot1994"/> During this time, the male performs a [[courtship ritual]] that occurs in flight. He dances erratically in the air, flying rapidly up and down and occasionally chasing the female. He presents himself to his potential mate by fanning out his tail and fluttering his wings.<ref name="smith1973"/><ref name="miller1931"/><ref>{{cite book| last= Bent | first= A.| year= 1950| chapter= Loggerhead shrike| title= Life histories of North American wagtails, shrikes, vireos and their allies| place= New York | publisher= Dover Publications, Inc.| isbn= }}</ref>  Females may respond to the fluttering display with begging notes, similar to those of juveniles begging for food; this encourages the male to feed her.<ref name="smith1973"/>

The bird breeds in semi-open areas in [[southern Ontario]], [[Quebec]], and the Canadian prairie provinces, south to [[Mexico]]. It nests in isolated or small clusters of dense trees and shrubs from near ground level to over 4m in height. There is an increase in average [[avian clutch size|clutch size]] as latitude increases. Shrikes begin incubation after laying the second to last egg, resulting in asynchronous hatching. Incubation, on average, lasts 16 days. The female lays 4 to 8 eggs in a bulky cup made of twigs and grass. Once hatched, nestlings are fed by both the male and female parent. Average fledging period is about 19 days. Young may then remain nearby and dependent on adults for 3 to 4 weeks. After that, they begin to forage independently. Oftentimes, nestlings do not survive long past hatching. In the case of dead nestlings, adult shrikes may eat or discard their bodies or else feed them to their remaining young.<ref>{{cite journal| last= Kridelbaugh |first= A.| year= 1983| title= Nesting ecology of the loggerhead shrike in central Missouri| journal= The Wilson Bulletin| volume= 95| number= 2| pages= 303–08}}</ref> The oldest recorded age of a loggerhead shrike was 12 years and 6 months.<ref>{{cite book| editor-last1= Podulka | editor-first1= S| editor-last2= Rohrbaugh | editor-first2= R| editor-last3= Bonney | editor-first3= R| year= 2004| title= Handbook of Bird Biology| place= Princeton, New Jersey| publisher= Cornell Lab of Ornithology| edition= | isbn= }}</ref>

==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>

==References==
{{Reflist}}

==External links==
{{Commons category|Lanius ludovicianus|Loggerhead Shrike}}
{{Wikispecies|Lanius ludovicianus}}
*[http://busbee.freehostia.com/science/ontogeny.html The Ontongeny of Cricket and Mouse Killing in the Loggerhead Shrike]
*[http://busbee.freehostia.com/science/dieldren.html The Effects of Dieldren on the Behavior of Young Loggerhead Shrikes]
*[http://www.birds.cornell.edu/AllAboutBirds/BirdGuide/Loggerhead_Shrike.html Loggerhead Shrike Species Account] – Cornell Lab of Ornithology
*[http://www.mbr-pwrc.usgs.gov/id/framlst/i6220id.html Loggerhead Shrike – ''Lanius ludovicianus''] – USGS Patuxent Bird Identification InfoCenter
*{{usurped|1=[https://web.archive.org/web/20020114062505/http://www.bird-stamps.org/cspecies/17601300.htm Stamps]}} (for [[Mexico]]) with Range Map at bird-stamps.org
* {{InternetBirdCollection|loggerhead-shrike-lanius-ludovicianus|Loggerhead Shrike}}
* [https://web.archive.org/web/20121009142144/http://www.flmnh.ufl.edu/wwwsounds/birds/hardy66sh.wav Recording of its call]
* {{VIREO|Loggerhead+Shrike|Loggerhead Shrike}}
* {{IUCN_Map|22705042/179538598|Lanius ludovicianus}}

{{Laniidae}}
{{Taxonbar|from=Q430863}}
[[Category:Birds described in 1766]]
[[Category:Endemic birds of North America]]
[[Category:Extant Late Pleistocene first appearances]]
[[Category:Lanius]]
[[Category:Taxa named by Carl Linnaeus]]