Northern Mockingbird

Minus polyglottos

Northern Mockingbirds closely associate with human habitation in Missouri. Most people in the southern portion of the state recognize this vocal "mimic" in their hedgerows or backyard shrubs. Typical yards provide a combination of shrubs for nesting and open areas and fruits appropriate for the species. Mockingbirds frequent brushy pastures in rural areas but apparently avoid large forests. Derrickson and Breitwisch (1992) suggested that Northern Mockingbirds have expanded their range northward since the 19th century. As permanent residents that rely on fruits and berries, they sometimes suffer a massive reduction in population during severe winter weather.

Code Frequency

Mockingbirds are extremely conspicuous both visually and vocally. Therefore, they were likely observed in all blocks where they occurred. Atlasers revisiting these areas usually documented territoriality and occasionally fledglings. While nests are easy to locate, the presence of thorns, chiggers and ticks may have dissuaded Atlasers from the search. Only 18 percent of the records that confirmed breeding resulted from nest observations.

Distribution

Northern Mockingbirds were distributed statewide. They were detected less frequently near the northern edge of their range, especially in northeastern and north central counties. Atlasers also did not record them in many of the more forested blocks of the state. In the Glaciated Plains the frequency of reports decreases from west to east. This species was present in 93 percent of blocks in the Western Natural Section of the Glaciated Plains as compared with 68 percent in the Central, 57 percent in the Eastern, and 50 percent in the Lincoln Hills natural sections. This decrease from west to east may be associated with a decrease in brush land, hedgerows and thickets and the prevalence of forest cover in the Lincoln Hills.

Average Number of Birds / 100 stops

Abundance

Although this species was distributed throughout Missouri, abundance surveys indicated a sharp reduction in numbers northward through the state.

Phenology

Observations of nest and eggs spanned three months for this two-brooded species. Atlasers recorded initial broods between April 26 and May 16, second broods between May 25 and June 23, and an apparent third brood or renesting between July 23 and 27. Observations of nests and young followed appropriately.

Notes

Atlasers noted only two instances of Brown-headed Cowbird parasitism. Ehrlich et al. (1988) considered the Northern Mockingbird to be a rare host.

Breeding Evidence

Reported in 956 (79.2%) of 1,207 blocks

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