Intermediate Frequencies of Egg Ejection by Northern Mockingbirds (Mimus polyglottos) Sympatric with Two Cowbird Species

The Auk ◽  
2002 ◽  
Vol 119 (3) ◽  
pp. 855-858
Author(s):  
Brian D. Peer ◽  
Spencer G. Sealy
Keyword(s):  
Mimus Polyglottos ◽  
Egg Ejection ◽  
Northern Mockingbirds

Intermediate Frequencies of Egg Ejection by Northern Mockingbirds (Mimus polyglottos) Sympatric with Two Cowbird Species

The Auk ◽  
2002 ◽  
Vol 119 (3) ◽  
pp. 855 ◽  
Author(s):  
Brian D. Peer ◽  
Kevin S. Ellison ◽  
Spencer G. Sealy
Keyword(s):  
Mimus Polyglottos ◽  
Egg Ejection ◽  
Northern Mockingbirds

scholarly journals Intermediate Frequencies of Egg Ejection by Northern Mockingbirds (Mimus polyglottos) Sympatric with Two Cowbird Species

The Auk ◽  
2002 ◽  
Vol 119 (3) ◽  
pp. 855-858 ◽  
Author(s):  
Brian D. Peer ◽  
Kevin S. Ellison ◽  
Spencer G. Sealy
Keyword(s):  
High Frequency ◽  
Previous Evidence ◽  
Mimus Polyglottos ◽  
Egg Ejection ◽  
Molothrus Aeneus ◽  
Study Sites ◽  
Northern Mockingbirds

Abstract We experimentally parasitized Northern Mockingbird (Mimus polyglottos) nests to determine whether that species is more likely to eject immaculate eggs of the Bronzed Cowbird (Molothrus aeneus) or the spotted eggs of the Brown-headed Cowbird (M. ater); the latter species lays eggs that more closely resemble mockingbird eggs. Mockingbirds ejected 69% of model Bronzed Cowbird eggs, indicating that contrary to previous evidence Northern Mockingbirds eject Bronzed Cowbirds eggs at a high frequency. Mockingbirds also ejected 60% of model and real Brown-headed Cowbird eggs. Bronzed Cowbird eggs were ejected faster than Brown-headed Cowbird eggs (1.3 and 2.1 days, respectively). Ejection by mockingbirds may account for the lack of observed parasitism at our study sites in southern Texas, but it is more likely that cowbirds did not parasitize mockingbirds.

Sex differences in defence of eggs and nestlings by northern mockingbirds, Mimus polyglottos

1988 ◽  
Vol 36 (1) ◽  
pp. 62-72 ◽  
Author(s):  
Randall Breitwisch
Keyword(s):  
Sex Differences ◽  
Mimus Polyglottos ◽  
Northern Mockingbirds

Yearly and Situational Changes in the Estimate of Repertoire Size in Northern Mockingbirds (Mimus polyglottos)

The Auk ◽  
1987 ◽  
Vol 104 (2) ◽  
pp. 198-207 ◽  
Author(s):  
Kim C. Derrickson
Keyword(s):  
Social Situation ◽  
Song Type ◽  
Repertoire Size ◽  
Mimus Polyglottos ◽  
Singing Behavior ◽  
The Social ◽  
The One ◽  
Song Types ◽  
Northern Mockingbirds ◽  
Size Estimates

Abstract The singing behavior of 4 male Northern Mockingbirds (Mimus polyglottos) was studied during 1980 and 1981. Over 10,000 song bouts (repetition of a particular song type) were analyzed spectrographically. Between 102 and 412 distinct song types were identified for each male in a given year. Many of these song types (25.8-57.4%) occurred only once in this sample of singing behavior. Repertoire size was estimated by fitting an exponential curve to a cumulative plot of distinct song types as a function of consecutive bouts sampled. The resulting asymptote was the estimate of repertoire size. Sequences of at least 50 consecutive bouts were used in estimating repertoire size. The technique of using consecutive bouts was required because of the high proportion of rare song types. Several estimates were made for each male and resulted in mean repertoire size estimates of 100-200 song types for the four males. Long sequences (125-150 bouts) of consecutive bouts are preferred to estimate repertoire size accurately. In addition, the social situation in which the singing behavior occurred can alter significantly the estimate of repertoire size. For example, estimates produced from singing during patrolling or countersinging were smaller than estimates generated from singing while associating with a female. The repertoire size estimate increased between 1980 and 1981 for 3 of 4 males. The one male not showing an increase spent much time patrolling and interacting with neighboring males before dying early in 1981. These results are consistent with the impression that repertoire size increases with age.

scholarly journals The conservation status of the Socorro MockingbirdMimodes graysoniin 1993–1994

1996 ◽  
Vol 6 (3) ◽  
pp. 271-283 ◽  
Author(s):  
Juan E. Martínez-Gómez ◽  
Robert L. Curry
Keyword(s):  
Habitat Degradation ◽  
Conservation Status ◽  
Small Region ◽  
High Elevation ◽  
Territory Size ◽  
Sheep Grazing ◽  
Nest Failure ◽  
Mimus Polyglottos ◽  
Socorro Island ◽  
Northern Mockingbirds

SummaryThe Socorro MockingbirdMimodes graysoniis endemic to Socorro Island, Mexico, and has declined dramatically in this century. Study of its population size, distribution, and structure is currently under way to help assess its conservation status. In 1993 and 1994 215 Socorro Mockingbirds were ringed; a modified Lincoln index yielded a population estimate of 353 ± 66 individuals in 1994. Most of the birds observed occupied a small region at high elevation that covered less than 10% of the island's area. Average territory size was 1.48 ± 0.71 ha,n= 11. Of the 86 birds banded in 1993 67% were adults and 33% subadults. Of the 170 birds detected in 1994, including new captures and ringed individuals from the previous year, 44% were adults and 56% subadults. In 1993 62% were male and 38% female; in 1994 56% were male and 44% were female. The sex ratio of the population was similar to that of other undisturbed Mimid populations, which argues against the possibility that cats might prey disproportionately on incubating females. Moreover, the presence of young birds in both years indicates that successful reproduction was occurring and that the population was not suffering catastrophic nest failure, as might be caused by cat predation on nestlings or fledglings. Northern MockingbirdsMimus polyglottos, which first arrived on Socorro in the 1970s, occupied mainly open areas produced by sheep grazing, which suggests that the Socorro Mockingbird is not being competitively displaced. Our observations indicate that habitat degradation by sheep is the most probable cause of the Socorro Mockingbird's decline.

Seasonal patterns of vocal mimicry in northern mockingbirds Mimus polyglottos

2014 ◽  
Vol 45 (6) ◽  
pp. 545-550 ◽  
Author(s):  
David E. Gammon
Keyword(s):  
Seasonal Patterns ◽  
Mimus Polyglottos ◽  
Vocal Mimicry ◽  
Northern Mockingbirds

Development of the Corticosterone Stress Response in Young Northern Mockingbirds (Mimus polyglottos)

2000 ◽  
Vol 119 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Christopher G. Sims ◽  
Rebecca L. Holberton
Keyword(s):  
Stress Response ◽  
Mimus Polyglottos ◽  
Northern Mockingbirds

scholarly journals Numerical Discrimination by Wild Northern Mockingbirds

The Condor ◽  
2006 ◽  
Vol 108 (4) ◽  
pp. 953-957 ◽  
Author(s):  
George L. Farnsworth ◽  
Jennifer L. Smolinski
Keyword(s):  
Food Reward ◽  
Optimal Foraging Theory ◽  
Optimal Choice ◽  
Urban Habitat ◽  
Limited Capacity ◽  
Free Living ◽  
Mimus Polyglottos ◽  
Numerical Discrimination ◽  
The One ◽  
Northern Mockingbirds

Abstract Abstract Optimal foraging theory predicts that birds, when faced with alternative foraging options, will choose the one that provides the greatest rate of return. We tested if wild, free-living Northern Mockingbirds (Mimus polyglottos) could solve a novel foraging problem to attain food rewards with the least amount of effort. We introduced five subjects to experimental feeders in their winter territories in an urban habitat. Feeders contained different numbers of bamboo sticks at each of two ends. Birds could access a food reward (Tenebrio larvae) by removing all sticks from either end; therefore, the optimal choice was to remove sticks from the end with fewer sticks. Each subject was tested in repeated trials to determine if it preferentially chose the end with fewer sticks. All five birds successfully discriminated between one stick and six sticks as well as between two sticks and five sticks. However, all five birds failed to discriminate between three sticks and four sticks. Wild Northern Mockingbirds thus appear to have a limited capacity to solve novel foraging problems by minimizing the number of obstacles to be removed.

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