Wednesday, April 29, 2015

Student Guest Post: Loggerhead Shrike by Jordan Nevius

Loggerhead Shrike (Lanius ludovicianus)

  • Kingdom - Animalia
 Phylum - Chordata
   Class - Aves
     Order - Passeriformes
       Family - Laniidae
         Genus - Lanius
           Species - L. ludovicianus
  • Geographic Range – The Loggerhead shrike ranges throughout most of North America from southern Canada to southern Mexico, but their range is decreasing at an alarming rate. It is believed that this species does not have any breeding populations in Pennsylvania and other New England States because of the conversion of forests and pastures to farmlands and increased urbanization.
  • Habitat— Loggerhead shrikes live in open country grasslands with short vegetation and small shrubs or low trees. Shrikes tend to build their nests in thick trees or shrubs with thorns in order to serve as protection. Some examples include agricultural fields, pastures, desert scrublands, savannas, prairies, golf courses, and cemeteries. Loggerhead Shrikes are often seen along mowed roadsides with access to fence lines and telephone poles.
  • What they eat— Loggerhead shrikes are amazing hunters. They consume insects, small mammals, songbirds, snakes, frogs, and lizards. Shrikes hunt from perches like fence posts and telephone wires high above their habitat to look for prey. When shrikes have spotted their prey, they aerial dive to pounce on it to kill it. In addition shrikes lack talons, so they have a tendency to use thorns and other sharp objects to impale their prey. They use these sharp objects as a placeholder for their prey while they feed on them.

  • This species tends to be an early breeder from the month of February until about July. The female will lay a clutch with about 1 to 9 brown spotted eggs and will incubate them for 2 weeks until they hatch. During this time the male will be the sole provider, hunting and bringing back food to the mother. Shrikes may possible have 2 to 3 clutches a year. After the eggs have hatched, the chicks will remain in the nest for 2 to 3 weeks in which they will begin to become independent and “fly the coop”. A year after birth is when shrikes become reproductively mature and are able to breed.
  • Exact threats of the Loggerhead Shrike are unknown. It is believed that their decline is attributed by factors of deforestation, conversion of pastures to agricultural crops, and the use of pesticides in which are negatively affecting their nesting habitat. Along with deforestation, the removal of shrubs and hedges, which support their nests, have been cleared in the process. This eliminates the number of breeding sites for shrikes. An additional cause of shrike decline is due to collisions with cars since their habitat is frequently found near highways.  
  • According to the IUCN the Loggerhead shrike is at the status of Least Concern. Measures are still being taken to ensure that its nesting and breeding habitats are conserved. This includes retaining pasture habitats and other suitable trees and shrubs that shrikes tend to build nests in. In Pennsylvania, the recent shrike population is noticeably declining, so their areas of breeding are being taken into consideration so that they are not completely eradicated from the area. In Canada, the Eastern Loggerhead Shrike Recovery Program is restoring its habitat, monitoring its populations, and undertaking a captive breeding program by releasing captive-bred individuals into the wild. The results have so far been positive, with the wild population now increasing.
References/ Works Cited
  5. Brittingham, M.C. , Maret, T.J. , Merritt, J.F. , Steele, M.A. 2010. Terrestrial Vertebrates of Pennsylvania: A Complete Guide to Species of Conservation Concern. 123-126. “Loggerhead Shrike.” The John Hopkins University Press.


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Loggerhead Shrike


  1. "It is believed that this species does not have any breeding populations in Pennsylvania and other New England States because of the conversion of forests and pastures to farmlands and increased urbanization."

    Urbanization may be a factor, but there has been immense reforestation in the Northeast over the last century. See: It strikes me that the better explanation for Loggerhead Shrike declines is the decline of tradition agricultural practices, and subsequent reversion of agricultural land into forest.

  2. I totally agree; should have been the conversion of pasture to forest and crop land. Pastures are good - corn and soy, not so good.