An Imperial Beach Hidden Gem and “Dig IB” Bird of the Week, the Loggerhead Shrike
Jan 18, 2018 02:50AM
By Paul Spear
This weekly column provides photos of birds photographed locally in the Tijuana Estuary or on IB's beaches along with background on the bird.
This week’s “Bird of the Week” is the Loggerhead shrike (Lanius ludovicianus), the only
endemic shrike in North America. It is nicknamed the butcherbird after its carnivorous tendencies, as it consumes prey such as amphibians, insects, lizards, small mammals and small birds. Due to its small size and weak talons, this predatory bird relies on impaling its prey upon thorns or barbed wire for facilitated consumption. In open terrain, this predatory songbird watches from a wire or other high perch, then pounces on its prey, often a large insect, and sometimes a small bird or a rodent. During recent decades, numbers have declined in many areas; now essentially gone from the northeast. Reasons for decline are poorly understood, but may be related to pesticides and/or changes in habitat.
Their habitat is in semi-open country with lookout posts; wires, trees, and scrub. They breed in any kind of semi-open terrain, from large clearings in wooded regions to open grassland or desert with a few scattered trees or large shrubs. In winter, they may be in totally treeless country if fences or wires provide hunting perches.
Loggerhead shrikes forage mostly by watching from an exposed perch, then swooping down to take their prey on or near the ground or from low vegetation. They kill their prey by using their hooked bills, and often store uneaten prey by impaling it on a thorn or barbed wire, returning to eat it later.
Their diet consists mostly of large insects, but also on rodents and small birds. Their diet in summer is mainly insects, especially grasshoppers and crickets, but also beetles, wasps. They also eat mice, other rodents, and small birds at all seasons, especially in winter. Also sometimes included in their diet are spiders, snails, frogs, lizards, snakes, crayfish, small fish, and other items.
After mating, females lay 5-6, sometimes 4-8 grayish white to pale buff, with spots of brown and gray often concentrated at large end eggs. Incubation is by females in about 16-17 days. Males feed females during incubation, sometimes bringing them food they have stored on thorns earlier. Both parents feed their nestlings. Young leave their nests at about 17-21 days, and are tended by parents for another 3-4 weeks.
In many regions, nesting begins quite early in the spring. In courtship, males perform short flight displays, and males feed females. Their nests are placed in a dense, and often thorny, tree or shrub, usually 5-30' above the ground, but occasionally higher, in a spot well hidden by foliage. Nests are built by both sexes, and are a solidly constructed but bulky cup of twigs, grass, weeds, strips of bark, lined with softer materials such as rootlets, animal hair, feathers, and plant down.
I spotted this unique species for the first time in the Tijuana Estuary recently perched high in a tree scouting the area for prey. Look for this bird and the many other seasonal visitors while walking or biking on the many trails there. Until next week, good birding!
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