The time of day of egg laying by the Brown-headed Cowbird and other icterines

1991 ◽  
Vol 69 (8) ◽  
pp. 2093-2099 ◽  
Author(s):  
David M. Scott
Keyword(s):  
Molothrus Ater ◽  
Time Of Day ◽  
Egg Laying ◽  
Agelaius Phoeniceus ◽  
Brood Parasite ◽  
Dendroica Petechia ◽  
Cardinalis Cardinalis ◽  
Vireo Olivaceus ◽  
Molothrus Bonariensis ◽  
Dumetella Carolinensis

I present data on the time of day of oviposition for 16 species of icterines to evaluate the idea that laying exceptionally early in the morning by the brood parasite, the Brown-headed Cowbird (Molothrus ater), is a specialization for parasitism. This cowbird, the earliest known layer among icterines, typically lays before sunrise (sunrise −9.14 ± 2.52 (SE) min, n = 36). Another brood parasite, the Shiny Cowbird (Molothrus bonariensis), also sometimes lays before sunrise. The best-known nonparasitic icterines, the Red-winged Blackbird (Agelaius phoeniceus) and the Common Grackle (Quisacalus quiscula), lay shortly after sunrise. Fragmentary records show that several other icterines lay within an hour or so after sunrise. Data are inadequate to conclude that early laying by Brown-headed Cowbirds has arisen as an adaptation for parasitism. The Brown-headed Cowbird at London, Ontario, lays earlier than most local passerines, as is shown by new data on oviposition by seven host species arranged in order of increasing lateness of oviposition: Agelaius phoeniceus, Dendroica petechia, Melospiza melodia, Cardinalis cardinalis, Vireo olivaceus, Dumetella carolinensis, and Turdus migratorius.

Reactions of Four Passerine Species To Threats of Predation and Cowbird Parasitism: Enemy Recognition or Generalized Responses?

Behaviour ◽  
1992 ◽  
Vol 123 (1-2) ◽  
pp. 84-105 ◽  
Author(s):  
Spencer G. Sealy ◽  
Diane L. Neudorf
Keyword(s):  
Host Species ◽  
Molothrus Ater ◽  
Egg Laying ◽  
Agelaius Phoeniceus ◽  
Bombycilla Cedrorum ◽  
Cowbird Parasitism ◽  
Dumetella Carolinensis ◽  
Passerella Iliaca ◽  
Enemy Recognition ◽  
Defensive Behaviours

AbstractFour host species of the parasitic brown-headed cowbird (Molothrus ater) were exposed to taxidermic mounts of a female cowbird, fox sparrow (Passerella iliaca), and common grackle (Quiscalus quiscula) at their nests during their egg-laying or nestling stage. Red-winged blackbirds (Agelaius phoeniceus), a species that accepts cowbird eggs laid in their nests, responded more aggressively to cowbird models early in their nesting cycle, indicating that they recognized the unique threat the cowbird posed. Gray catbirds (Dumetella carolinensis), northern orioles (Icterus galbula), and cedar waxwings (Bombycilla cedrorum) can remove cowbird eggs from their nests and for the most part they responded similarly to cowbird models and the "nonthreatening control," i.e. a fox sparrow. Cedar waxwings were nonaggressive to all the models and may rely on concealment to protect their nests from enemies. Removal of cowbird eggs by puncture ejection is more risky than grasp ejection. Despite this, orioles and waxwings (puncture ejectors) were not significantly more aggressive to cowbird models at egg laying than catbirds (grasp ejectors). Responses of the three rejector species toward the cowbird model did not change over the nesting cycle, indicating further that they do not recognize cowbirds as a unique threat. Rejector species may not recognize cowbirds because they have little experience with them. With the exception of waxwings, all of the hosts recognized the grackle as an enemy and increased their levels of defence from the laying to nestling stages. Three of the host-species did not simply respond in a generalized manner to any intruder at their nests but indeed recognized specific enemies. Considerable interspecific variability exists amongst the four species in defensive behaviours, which may reflect their different nesting habitats.

Tests of two functions of alarm calls given by yellow warblers during nest defence

2003 ◽  
Vol 81 (10) ◽  
pp. 1685-1690 ◽  
Author(s):  
Sharon A Gill ◽  
Spencer G Sealy
Keyword(s):  
Molothrus Ater ◽  
Egg Laying ◽  
Nest Defence ◽  
Alarm Calls ◽  
Potential Danger ◽  
Dendroica Petechia ◽  
Yellow Warblers ◽  
Avian Nest ◽  
Nest Predators

During nest defence, yellow warblers (Dendroica petechia) give "seet" and "chip" calls. Seet calls are given preferentially toward brood parasitic brown-headed cowbirds (Molothrus ater) during the yellow warblers' egg-laying period, whereas chip calls are given toward mammalian and avian nest predators throughout the nesting period. In this study, we investigated two possible functions of seet and chip calls during nest defence by playing alarm calls to nesting yellow warblers. We tested whether nest owners give seet and chip calls during defence to alert their offspring and their mates about nest threats and, in the latter case, whether the alarm calls differ in function depending on nesting stage. In response to playbacks, nestlings remained inactive for a significantly longer period when chip calls were played than when seet calls were played. Female yellow warblers returned to their nesting areas more quickly when seet calls were played than when chip calls were played, but pairs were equally likely to return to the nesting area in response to both call types. These findings suggests that both seet and chip calls alert mates but that only chip calls function to alert nestlings of potential danger.

scholarly journals Conflicting Temporal Changes in the Frequency and Intensity of Cowbird Parasitism on Four Common Hosts in Ontario over 130 Years

The Condor ◽  
2006 ◽  
Vol 108 (1) ◽  
pp. 238-242
Author(s):  
Celia M. McLaren ◽  
Todd J. Underwood ◽  
Spencer G. Sealy
Keyword(s):  
Molothrus Ater ◽  
Past Century ◽  
Cardinalis Cardinalis ◽  
Vireo Olivaceus ◽  
Song Sparrows ◽  
Limited Support ◽  
Before And After ◽  
Cowbird Parasitism ◽  
Northern Cardinals ◽  
Spizella Passerina

AbstractWe tested the hypothesis proposed by Friedmann (1963) that multiple parasitism (nests with more than one parasitic egg) by Brown-headed Cowbirds (Molothrus ater) is a recent phenomenon associated with increased densities of cowbirds. We used Ontario Nest Records Scheme data to quantify frequencies of parasitism and multiple parasitism on four common host species over the last 130 years. Frequency of multiple parasitism significantly increased over all decades only in Chipping Sparrows (Spizella passerina). We also analyzed data separately before and after 1970 because at about this time cowbird abundance began to stabilize and then decline. Pre-1970, multiple parasitism significantly increased on Chipping Sparrows and Song Sparrows (Melospiza melodia), but neither had significant trends post-1970. There were no significant trends in multiple parasitism on Red-eyed Vireos (Vireo olivaceus) or Northern Cardinals (Cardinalis cardinalis). For all time periods analyzed, there were no significant trends in overall frequency of parasitism on any species. Our results provide limited support for the hypothesis that temporal variation in parasitism patterns has followed changes in cowbird density over the past century.

scholarly journals Sora (Porzana carolina) Parasitism of Red-winged Blackbird (Agelaius phoeniceus) Nests

2018 ◽  
Vol 131 (4) ◽  
pp. 312-316
Author(s):  
Lawrence D. Igl
Keyword(s):  
North Dakota ◽  
Agelaius Phoeniceus ◽  
Brood Parasite ◽  
Nest Sites ◽  
Porzana Carolina

Sora (Porzana carolina) is a conspecific brood parasite that also occasionally parasitizes nests of other species. Sora parasitism in nests of passerines is rare. Of 129 Red-winged Blackbird (Agelaius phoeniceus) nests found in North Dakota in 2009 and 2010, two (1.6%) were parasitized by Soras. The conditions favouring this rare parasitic behaviour may include competition for nest sites and high Sora density.

scholarly journals Seasonal Patterns of Singing Activity Vary With Time of day in The Nightingale (Luscinia Megarhynchos)

The Auk ◽  
2004 ◽  
Vol 121 (1) ◽  
pp. 110-117 ◽  
Author(s):  
Valentin Amrhein ◽  
Hansjoerg P. Kunc ◽  
Marc Naguib
Keyword(s):  
Seasonal Pattern ◽  
Time Of Day ◽  
Egg Laying ◽  
Breeding Cycle ◽  
Seasonal Patterns ◽  
Singing Behavior ◽  
The Social ◽  
Luscinia Megarhynchos ◽  
Singing Activity ◽  
Late Stages

Abstract Seasonal patterns of singing activity of male birds have been thoroughly studied, but little is known about how those patterns vary with time of day. Here, we censused mated and unmated male Nightingales (Luscinia megarhynchos) at four different hours of the day throughout the breeding cycle. In unmated males, singing activity increased until the young hatched in their neighborhood, and the seasonal variation was similar at each of the four hours of the day. In mated males, however, the seasonal patterns of singing activity differed between hours of the day. In morning (about the hour of egg-laying) and during the dusk chorus, the singing activity of mated males was strongly influenced by the females' reproductive state: singing activity was low before egg-laying and during incubation, but high during the egg-laying period. In the dawn chorus, however, singing activity showed a similar seasonal pattern in mated and unmated males and was high until late stages of the breeding cycle. Our results suggest that the social context influences singing behavior to a varying degree across the season, and that this variation also depends on time of day. The hour of data collection thus is an important but often neglected factor when seasonal changes of singing activity are studied.

scholarly journals Costs of Egg Punctures and Parasitism by Shiny Cowbirds (Molothrus Bonariensis) at Creamy-Bellied Thrush (Turdus Amaurochalinus) Nests

The Auk ◽  
2006 ◽  
Vol 123 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Andrea A. Astié ◽  
Juan C. Reboreda
Keyword(s):  
Reproductive Success ◽  
Hatching Success ◽  
Nest Survival ◽  
Egg Laying ◽  
Chick Survival ◽  
Egg Survival ◽  
Lower Survival Rate ◽  
Molothrus Bonariensis ◽  
Primary Determinant ◽  
The Cost

AbstractMost studies on cowbird parasitism have focused on its effects on parasitized nests, whereas few have considered the costs at nests that cowbirds visit but at which they do not lay eggs. Shiny Cowbirds (Molothrus bonariensis) peck and puncture host eggs both in nests where they lay eggs and in unparasitized nests. We analyzed the effect of egg punctures in unparasitized and parasitized nests of a large host, the Creamy-bellied Thrush (Turdus amaurochalinus; hereafter “thrush”), as well as the costs of Shiny Cowbird eggs and chicks in this host’s nests. We determined thrush egg survival, hatching success, and chick survival in successful nests, and nest survival during the egg and nestling stages. Frequency of parasitism was 60%, and its intensity 1.6 ± 0.1 eggs nest−1. Number of host eggs punctured was positively associated with intensity of parasitism. The host’s eggs were frequently punctured in parasitized nests (71%) and in unparasitized nests (42%). Egg punctures reduced the number of eggs at hatching in 23% and 49% of unparasitized and parasitized nests, respectively. Nests with egg punctures had a lower survival rate than nests without them, but nest survival was not associated with parasitism. Presence of a Shiny Cowbird egg was associated with a decrease in the hatching success of host eggs, but presence of a Shiny Cowbird chick did not have any detrimental effect on either the survival and growth rate of host chicks in successful nests or the survival of the whole nest. Our results show that egg punctures were the primary determinant of thrush reproductive success. Consequently, comparison of unparasitized and parasitized nests gives an incomplete estimation of the effects of Shiny Cowbirds on host reproductive success, because the cost of egg punctures is also important in nests where there is no Shiny Cowbird egg laying.Costos de la Perforación de Huevos y el Parasitismo por Molothrus bonariensis en Nidos de Turdus amaurochalinus

scholarly journals Variations in Calcium Use by Birds During the Breeding Season

The Condor ◽  
2001 ◽  
Vol 103 (3) ◽  
pp. 592-598 ◽  
Author(s):  
André A. Dhondt ◽  
Wesley M. Hochachka
Keyword(s):  
Breeding Season ◽  
High Frequency ◽  
Molothrus Ater ◽  
Egg Laying ◽  
Surprising Result ◽  
Very High Frequency ◽  
Cyanocitta Cristata ◽  
Egg Formation ◽  
Calcium Sources ◽  
Very High

Abstract During the breeding season birds need increased amounts of dietary calcium during egg laying and nestling rearing. Passerines acquire calcium shortly before and during laying and do not store calcium for egg formation. Many passerines need to eat extraneous calcium in the form of snail shells or calcareous grit to acquire the element. However, very little is known about variation in the dependency of birds on extraneous calcium, and where this calcium is acquired. Using reports from volunteers who provided extraneous calcium sources at feeder sites across North America we documented that (1) the use of extraneous calcium varied during the breeding season; (2) the location in which species preferentially took the calcium varied with typical feeding location, aside from swallows which, somewhat surprisingly, favored calcium offered on the ground; (3) Brown-headed Cowbirds (Molothrus ater) did not visit calcium sites more often than other blackbirds; (4) calcium use varied among species with thrushes, wrens, and woodpeckers taking calcium only rarely, and swallows, pigeons, and corvids taking calcium frequently. The most surprising result perhaps was the very high frequency of calcium use in jays; Blue Jays (Cyanocitta cristata) may hoard calcium in the fall. Variaciones en el Uso de Calcio por Aves durante la Época Reproductiva Resumen. En la época reproductiva, las aves necesitan incrementar la cantidad de calcio en la dieta durante el período de postura de huevos y cría de los pichones. Las aves paserinas adquieren calcio poco antes y durante la postura y no lo almacenan para la formación de los huevos. Muchas aves paserinas necesitan ingerir calcio de fuentes externas como conchas de caracoles o cascajo calcáreo para adquirir este elemento. Sin embargo, se sabe muy poco sobre la variación en el grado de dependencia de las aves de calcio externo y sobre dónde adquieren este calcio. Con base en reportes de voluntarios que suministraron fuentes externas de calcio en comederos a través de Norteamérica, documentamos que (1) el uso de calcio externo varió durante la época reproductiva; (2) el sitio en donde las especies tomaron el calcio preferencialmente varió de acuerdo al sitio típico de alimentación, con excepción de las golondrinas, que de manera algo sorprendente, prefirieron el calcio ofrecido en el suelo; (3) Molothrus ater no visitó sitios con calcio con más frecuencia que otros ictéridos; (4) el uso de calcio varió entre especies: los túrdidos, troglodítidos y carpinteros muy rara vez tomaron calcio, mientras que las golondrinas, palomas y córvidos lo hicieron frecuentemente. Quizás el resultado más sorprendente fue la muy alta frecuencia de uso de calcio en Cyanocitta; C. cristata podría acumular calcio durante el otoño para uso futuro.

Opposite Changes in Plasma Testosterone and Corticosterone Levels Following a Simulated Territorial Challenge in Male Great Tits

Behaviour ◽  
2004 ◽  
Vol 141 (4) ◽  
pp. 451-467 ◽  
Author(s):  
Rianne Pinxten ◽  
Lutgarde Arckens ◽  
Els van Duyse ◽  
Marcel Eens ◽  
Veerle Darras
Keyword(s):  
Parus Major ◽  
Time Of Day ◽  
Behavioural Response ◽  
Egg Laying ◽  
Plasma Testosterone ◽  
Breeding Cycle ◽  
Territorial Defence ◽  
Breeding Stage ◽  
Simulated Territorial Intrusion ◽  
Territorial Intrusion

AbstractThe apparent ability of plasma testosterone (T) and corticosterone (B) levels to fluctuate rapidly in response to agonistic interactions, suggests that these hormones may play an important role in an animal's acute behavioural response during such interactions. In the present study, free-living male great tits, Parus major, were subjected to a simulated territorial intrusion (STI) during the egg laying, incubation and nestling stage of first broods. Plasma T and B levels of challenged males were compared to those of control males matched for breeding stage, day in breeding stage, and time of day. Plasma B levels were significantly higher in challenged males compared to control males during the egg laying and incubation stage but not during the nestling stage. On the other hand, challenged males had significantly lower plasma T levels than control males throughout the breeding cycle. While having low plasma T and elevated plasma B levels, challenged males showed a vigorous and unrelenting territorial response to the STI. Plasma T and B levels of challenged males did not correlate with the intensity of the behavioural response to the STI. These findings do not agree with the predictions of the 'challenge hypothesis' that males exposed to a territorial challenge while having breeding baseline T levels will respond with an increase in T or that T correlates with the intensity of aggression during a challenge. Together, our findings suggest a role for B rather than T in the regulation of territorial defence in male great tits.

Sign in / Sign up

Export Citation Format

Share Document