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- Keyword
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- Sexual selection (3)
- Coloniality (2)
- Conspecific brood parasitism (2)
- Fairy-wrens (2)
- Paternity (2)
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- Petrochelidon pyrrhonota (2)
- Social behavior (2)
- Social selection (2)
- Speciation (2)
- Active choice (1)
- American coot (1)
- Aphelocoma insularis (1)
- Asamblea de cortejo (1)
- Atenci ´on visual (1)
- Barn swallow (1)
- Carotenoid (1)
- Cliff Swallow (1)
- Cliff swallow (1)
- Coevolution (1)
- Constraints (1)
- Cooperative breeding (1)
- Corticosterone (1)
- Courtship display (1)
- Despliegue de cortejo (1)
- Directional dispersal (1)
- Ectoparasitism (1)
- Egg rejection (1)
- Endogenous steroid hormones (1)
- Evolutionary relationships (1)
- Experimental (1)
Articles 1 - 27 of 27
Full-Text Articles in Life Sciences
Phenotypic Divergence In Two Sibling Species Of Shorebird: Common Snipe And Wilson’S Snipe (Charadriiformes: Scolopacidae), Tiago M. Rodrigues, Edward H. Miller, Sergei V. Drovetski, Robert M. Zink, Jon Fjeldså, David Gonçalves
Phenotypic Divergence In Two Sibling Species Of Shorebird: Common Snipe And Wilson’S Snipe (Charadriiformes: Scolopacidae), Tiago M. Rodrigues, Edward H. Miller, Sergei V. Drovetski, Robert M. Zink, Jon Fjeldså, David Gonçalves
School of Biological Sciences: Faculty Publications
Natural and social selection are among the main shapers of biological diversity but their relative importance in divergence remains understudied. Additionally, although neutral evolutionary processes may promote phenotypic divergence, their potential contribution in speciation is often overlooked in studies of comparative morphology. In this study, we investigated phenotypic differentiation in two allopatric shorebirds: the Palaearctic Common Snipe Gallinago gallinago and the Nearctic Wilson’s Snipe Gallinago delicata. Specimens of Common Snipe (n = 355 skins, n = 163 skeletons) and Wilson’s Snipe (n = 403 skins, n = 141 skeletons) in natural history collections were examined to quantify differences in skeletal …
Extreme Offspring Ornamentation In American Coots Is Favored By Selection Within Families, Not Benefits To Conspecific Brood Parasites, Bruce E. Lyon, Daizaburo Shizuka
Extreme Offspring Ornamentation In American Coots Is Favored By Selection Within Families, Not Benefits To Conspecific Brood Parasites, Bruce E. Lyon, Daizaburo Shizuka
School of Biological Sciences: Faculty Publications
Offspring ornamentation typically occurs in taxa with parental care, suggesting that selection arising from social interactions between parents and offspring may underlie signal evolution. American coot babies are among the most ornamented offspring found in nature, sporting vividly orange-red natal plumage, a bright red beak, and other red parts around the face and pate. Previous plumage manipulation experiments showed that ornamented plumage is favored by strong parental choice for chicks with more extreme ornamentation but left unresolved the question as to why parents show the preference. Here we explore natural patterns of variation in coot chick plumage color, both within …
Evolutionary Origin And Genetic Diversity Of Ring‐Necked Pheasants In The Upper Midwest United States, Hernán Vázquez-Miranda, Magdalena Jean Olson, Robert M. Zink
Evolutionary Origin And Genetic Diversity Of Ring‐Necked Pheasants In The Upper Midwest United States, Hernán Vázquez-Miranda, Magdalena Jean Olson, Robert M. Zink
School of Biological Sciences: Faculty Publications
We compared mitochondrial cytochrome b sequences of ring‐necked pheasants (Phasianus colchicus) from Midwestern United States (SD and NE, USA) to a molecular phylogeographic hypothesis of pheasants in the native Eurasian range to understand which subspecies are represented by wild and captive released birds. We found that these birds represent 2 Eurasian lineages, which we refer to generally as northern Eurasian (Colchicus group) and eastern China (Torquatus group). These mitochondrial DNA lineages occur in different frequencies in the wild, with the latter being 3 times more common. This suggests that 1) the eastern China lineage is either …
Song Recognition And Heterospecific Associations Between 2 Fairy-Wren Species (Maluridae), Allison E. Johnson, Christina Masco, Stephen Pruett-Jones
Song Recognition And Heterospecific Associations Between 2 Fairy-Wren Species (Maluridae), Allison E. Johnson, Christina Masco, Stephen Pruett-Jones
School of Biological Sciences: Faculty Publications
Although heterospecific associations beneficial to one or both species involved (e.g. commensalisms or mutualisms) are common, it is generally assumed that interactions between species are transient and not particular to individuals. However, long-term interactions between individuals of different species do occur. In such heterospecific social groups, discrimination between heterospecific individuals may be beneficial, allowing individuals to direct beneficial or aggressive behaviors towards appropriate targets. Here, we describe heterospecific groups composed of splendid and variegated fairy-wrens (Malurus splendens and M. lamberti) and provide the first experimental evidence that recognition of heterospecific group members occurs across species. In these species, …
Reproductive Promiscuity In The Variegated Fairy-Wren: An Alternative Reproductive Strategy In The Absence Of Helpers?, Allison E. Johnson, Stephen Pruett-Jones
Reproductive Promiscuity In The Variegated Fairy-Wren: An Alternative Reproductive Strategy In The Absence Of Helpers?, Allison E. Johnson, Stephen Pruett-Jones
School of Biological Sciences: Faculty Publications
Cooperative breeding, in which auxiliary group members help rear related, but nondescendent young, is often explained by kin selection. Reproductive monogamy is predicted in cooperatively breeding systems, as monogamy increases intragroup relatedness and maximizes auxiliary inclusive fitness. While monogamy is observed across many systems, including eusocial insects and cooperatively breeding mammals, some cooperatively breeding birds exhibit high rates of extrapair paternity. Here we quantify paternity and examine the role of auxiliaries on extrapair paternity in the highly cooperative variegated fairy-wren, Malurus lamberti, a species with both male and female auxiliaries. Extrapair paternity occurred in 55.4% of nests, and 39.8% …
Spatially Biased Dispersal Of Acorns By A Scatter-Hoarding Corvid May Accelerate Passive Restoration Of Oak Habitat On California’S Largest Island, Mario B. Pesendorfer, T. Scott Sillett, Scott A. Morrison
Spatially Biased Dispersal Of Acorns By A Scatter-Hoarding Corvid May Accelerate Passive Restoration Of Oak Habitat On California’S Largest Island, Mario B. Pesendorfer, T. Scott Sillett, Scott A. Morrison
School of Biological Sciences: Faculty Publications
Scatter hoarding by corvids (crows, jays, magpies, and nutcrackers) provides seed dispersal for many large-seeded plants, including oaks and pines. When hoarding seeds, corvids often choose nonrandom locations throughout the landscape, resulting in differential survival of seeds. In the context of habitat restoration, such disproportional storing of seeds in areas suitable for germination and establishment can accelerate expansion and recovery of large-seeded tree populations and their associated ecosystems. Here, we investigate the spatial preferences of island scrub jays Aphelocoma insularis during scatter hoarding of acorns (Quercus spp.) on Santa Cruz Island. We use a large behavioral data set on …
The Maintenance Of Phenotypic Divergence Through Sexual Selection: An Experimental Study In Barn Swallows Hirundo Rustica, Rebecca Safran, Yoni Vortman, Brittany R. Jenkins, Joanna K. Hubbard, Matt Wilkins, Rachel J. Bradley, Arnon Lotem
The Maintenance Of Phenotypic Divergence Through Sexual Selection: An Experimental Study In Barn Swallows Hirundo Rustica, Rebecca Safran, Yoni Vortman, Brittany R. Jenkins, Joanna K. Hubbard, Matt Wilkins, Rachel J. Bradley, Arnon Lotem
School of Biological Sciences: Faculty Publications
Previous studies have shown that sexual signals can rapidly diverge among closely related species. However, we lack experimental studies to demonstrate that differences in trait-associated reproductive performance maintain sexual trait differences between closely related populations, in support for a role of sexual selection in speciation. Populations of Northern Hemisphere distributed barn swallows Hirundo rustica are closely related, yet differ in two plumage-based traits: ventral color and length of the outermost tail feathers (streamers). Here we provide experimental evidence that manipulations of these traits result in different reproductive consequences in two subspecies of barn swallow: (H. r. erythrogaster in North …
Displaying To Females May Lower Male Foraging Time And Vigilance In A Lekking Bird, Sarah A. Cowles, Robert M. Gibson
Displaying To Females May Lower Male Foraging Time And Vigilance In A Lekking Bird, Sarah A. Cowles, Robert M. Gibson
School of Biological Sciences: Faculty Publications
Males of many species use courtship behavior to attract mates. However, by doing so males may face the associated costs of increased energetic expenditure, reduced foraging time, and elevated predation risk. We investigated the costs of display in lekking male Sharp-tailed Grouse (Tympanuchus phasianellus). We used lek-wide scan sampling to study how males allocated time among courtship display (‘‘dancing’’), agonism, foraging, and inactivity in relation to female numbers both within and across days. We also addressed the limited attention hypothesis and estimated visual attentiveness by videotaping 13 males and scoring head turns during these different activities. We found that the …
Interspecific Egg Rejection As Ecological Collateral Damage From Selection Driven By Conspecific Brood Parasitism, Bruce E. Lyon, Daizaburo Shizuka, John M. Eadie
Interspecific Egg Rejection As Ecological Collateral Damage From Selection Driven By Conspecific Brood Parasitism, Bruce E. Lyon, Daizaburo Shizuka, John M. Eadie
School of Biological Sciences: Faculty Publications
Distinguishing between interspecific and intraspecific coevolution as the selective driver of traits can be difficult in some taxa. A previous study of an avian obligate brood parasite, the black-headed duck, Heteronetta atricapilla, suggested that egg rejection by its two main hosts (two species of coot) is an incidental by-product of selection from conspecific brood parasitism within the hosts, not selection imposed by the interspecific parasite. However, although both species of coot can recognize and reject eggs of conspecific brood parasites, which closely resemble their own, they paradoxically also accept a moderate fraction of duck eggs (40–60%), which differ strikingly …
Across-Year Social Stability Shapes Network Structure In Wintering Migrant Sparrows, Daizaburo Shizuka, Alexis S. Chaine, Jennifer Anderson, Oscar Johnson, Inger Marie Laursen, Bruce E. Lyon
Across-Year Social Stability Shapes Network Structure In Wintering Migrant Sparrows, Daizaburo Shizuka, Alexis S. Chaine, Jennifer Anderson, Oscar Johnson, Inger Marie Laursen, Bruce E. Lyon
School of Biological Sciences: Faculty Publications
Migratory birds often form flocks on their wintering grounds, but important details of social structure such as the patterns of association between individuals are virtually unknown. We analysed networks of co-membership in short-term flocks for wintering golden-crowned sparrows (Zonotrichia atricapilla) across three years and discovered social complexity unsuspected for migratory songbirds. The population was consistently clustered into distinct social communities within a relatively small area (~ 7 ha). Birds returned to the same community across years, with mortality and recruitment leading to some degree of turnover in membership. These spatiotemporal patterns were explained by the combination of space …
Variable Facial Plumage In Juvenile Cliff Swallows: A Potential Offspring Recognition Cue?, Allison E. Johnson, Steven Freedberg
Variable Facial Plumage In Juvenile Cliff Swallows: A Potential Offspring Recognition Cue?, Allison E. Johnson, Steven Freedberg
School of Biological Sciences: Faculty Publications
Although the ability to recognize related offspring is essential in the evolution of social behavior, the cues that birds use to identify their own offspring are not fully understood. The Cliff Swallow (Petrochelidon pyrrhonota) is a highly social species that nests in large colonies and exhibits a high incidence of both conspecific brood parasitism and extrapair fertilization, behaviors that can potentially lead to parents investing energy and resources in unrelated offspring, which reduces the parents’ genetic fitness. Because parents continue to feed offspring after they leave the nest, parents also risk investing in unrelated offspring by misidentifying their …
Experimental Confirmation That Avian Plumage Traits Function As Multiple Status Signals In Winter Contests, Alexis S. Chaine, Allison M. Roth, Daizaburo Shizuka, Bruce E. Lyon
Experimental Confirmation That Avian Plumage Traits Function As Multiple Status Signals In Winter Contests, Alexis S. Chaine, Allison M. Roth, Daizaburo Shizuka, Bruce E. Lyon
School of Biological Sciences: Faculty Publications
Status signals are thought to reduce costs of overt conflict over resources by advertising social status or an individual’s ability to win contests. While most studies have focused on single badges of status, recent empirical work has shown that multiple status signals may exist. To provide robust evidence for multiple badges of status, an experimental manipulation is required to decouple signals from one another and from other traits linked to fighting ability. Such experimental evidence is lacking for most studies of multiple status signals to date. We previously found that two plumage traits in golden-crowned sparrows, Zonotrichia atricapilla, were correlated …
Melanin Concentration Gradients In Modern And Fossil Feathers, Daniel J. Field, Liliana D’Alba, Jakob Vinther, Samuel M. Webb, William Gearty, Matthew D. Shawkey
Melanin Concentration Gradients In Modern And Fossil Feathers, Daniel J. Field, Liliana D’Alba, Jakob Vinther, Samuel M. Webb, William Gearty, Matthew D. Shawkey
School of Biological Sciences: Faculty Publications
In birds and feathered non-avian dinosaurs, within-feather pigmentation patterns range from discrete spots and stripes to more subtle patterns, but the latter remain largely unstudied. A ,55 million year old fossil contour feather with a dark distal tip grading into a lighter base was recovered from the Fur Formation in Denmark. SEM and synchrotron-based trace metal mapping confirmed that this gradient was caused by differential concentration of melanin. To assess the potential ecological and phylogenetic prevalence of this pattern, we evaluated 321 modern samples from 18 orders within Aves. We observed that the pattern was found most frequently in distantly …
Different Modes Of Evolution In Males And Females Generate Dichromatism In Fairy-Wrens (Maluridae), Allison E. Johnson, J. Jordan Price, Stephen Pruett-Jones
Different Modes Of Evolution In Males And Females Generate Dichromatism In Fairy-Wrens (Maluridae), Allison E. Johnson, J. Jordan Price, Stephen Pruett-Jones
School of Biological Sciences: Faculty Publications
Sexual dichromatism in birds is often attributed to selection for elaboration in males. However, evolutionary changes in either sex can result in plumage differences between them, and such changes can result in either gains or losses of dimorphism. We reconstructed the evolution of plumage colors in both males and females of species in Maluridae, a family comprising the fairy-wrens (Malurus, Clytomias, Sipodotus), emu-wrens (Stipiturus), and grasswrens (Amytornis). Our results show that, across species, males and females differ in their patterns of color evolution. Male plumage has diverged at relatively steady rates, whereas …
Glucocorticoid Hormone Levels Increase With Group Size And Parasite Load In Cliff Swallows, Samrrah A. Raouf, Linda C. Smith, Mary Bomberger Brown, John C. Wingfield, Charles R. Brown
Glucocorticoid Hormone Levels Increase With Group Size And Parasite Load In Cliff Swallows, Samrrah A. Raouf, Linda C. Smith, Mary Bomberger Brown, John C. Wingfield, Charles R. Brown
School of Biological Sciences: Faculty Publications
Animals often cope with adverse events by releasing glucocorticoid hormones, which in turn promote increased energy assimilation. In captive animals, crowding also leads to increased glucocorticoid activity, probably because of increased levels of social competition. We investigated how group size and ectoparasite infestations affected endogenous levels of the glucocorticoid hormone, corticosterone, in colonial cliff swallows, Petrochelidon pyrrhonota, in southwestern Nebraska, USA. Parasites were removed from some colonies by fumigating nests. Baseline levels of corticosterone in breeding adults varied significantly with whether parasites were present, colony size (measured by total number of active nests at a site), and nesting stage. …
Effects Of Endogenous Steroid Hormone Levels On Annual Survival In Cliff Swallows, Charles R. Brown, Mary Bomberger Brown, Samrrah A. Raouf, Linda C. Smith, John C. Wingfield
Effects Of Endogenous Steroid Hormone Levels On Annual Survival In Cliff Swallows, Charles R. Brown, Mary Bomberger Brown, Samrrah A. Raouf, Linda C. Smith, John C. Wingfield
School of Biological Sciences: Faculty Publications
The hormone corticosterone is an important part of animals’ response to environmental stress, modulating short-term adaptive changes in behavior and physiology. The hormone testosterone is also critical, especially for males, in regulating the expression of sexual behavior and parental care. These hormones can have costly consequences, however, and within populations individuals show variation in endogenous levels of both corticosterone and testosterone. We studied how annual survival varied as a function of natural levels of these hormones in colonially breeding Cliff swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, USA, in 2000–2003. We sampled hormone levels of birds caught at colonies …
Testosterone And Group Size In Cliff Swallows: Testing The “Challenge Hypothesis” In A Colonial Bird, Linda C. Smith, Samrrah A. Raouf, Mary Bomberger Brown, John C. Wingfield, Charles R. Brown
Testosterone And Group Size In Cliff Swallows: Testing The “Challenge Hypothesis” In A Colonial Bird, Linda C. Smith, Samrrah A. Raouf, Mary Bomberger Brown, John C. Wingfield, Charles R. Brown
School of Biological Sciences: Faculty Publications
The “challenge hypothesis” states that increases in testosterone levels of male animals during the breeding season are directly related to the extent of intrasexual competition for resources or mates that they experience. Although often tested in territorial species, the challenge hypothesis has not been evaluated for colonial animals that live in groups of different sizes and that thus experience different intensities of intrasexual competition. We measured circulating testosterone levels of male and female cliff swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, where these birds nest in colonies of widely different sizes. Males had significantly higher testosterone levels than females, …
Juvenile And Adult Survival In The Sociable Weaver (Philetairus Socius), A Southern-Temperate Colonial Cooperative Breeder In Africa, Rita Covas, Charles R. Brown, Mark D. Anderson, Mary Bomberger Brown
Juvenile And Adult Survival In The Sociable Weaver (Philetairus Socius), A Southern-Temperate Colonial Cooperative Breeder In Africa, Rita Covas, Charles R. Brown, Mark D. Anderson, Mary Bomberger Brown
School of Biological Sciences: Faculty Publications
We used capture–recapture analyses to describe juvenile and adult survival from 1993 to 2001 in a population of Sociable Weavers (Philetairus socius), a colonial, cooperatively breeding passerine of southern Africa. We examined temporal variation in survival and the role that the breeding season’s length and environmental factors play in determining survival patterns in the population. Annual survival probability (mean ± SE) was 0.66 ± 0.02. In contrast to most passerines, juveniles and adults had similar survival probabilities; survival rates did not vary significantly between years. We found no relationship among temperature, rainfall, and survival. Relatively high survival rates …
A Re-Evaluation Of Hotspot Settlement In Lekking Sage Grouse, Robert M. Gibson
A Re-Evaluation Of Hotspot Settlement In Lekking Sage Grouse, Robert M. Gibson
School of Biological Sciences: Faculty Publications
Recent analyses of avian leks have come to conflicting conclusions concerning the role of male settlement on female traffic hotspots. This issue was re-examined in the sage grouse, Centrocercus urophasianus, using data on prenesting movements of radio-tagged females and the dispersion of lekking males collected during a 10-year field study. As expected with hotspot settlement, leks were preferentially located in areas through which females traveled between wintering and nesting ranges before mating. In addition, the distribution of males among leks was related proximately to variation in numbers of females visiting each lek during the mating period and ultimately to …
Female Choice In Sage Grouse: The Roles Of Attraction And Active Comparison, Robert M. Gibson
Female Choice In Sage Grouse: The Roles Of Attraction And Active Comparison, Robert M. Gibson
School of Biological Sciences: Faculty Publications
Previous studies of female choice in sage grouse Centrocercus urophasianus have implicated both the acoustic quality and repetition rate of the stereotyped strut display as putative cues for female choice. Stages in the choice process at which specific components of male courtship display influence female decisions were investigated using field observations of female premating behavior. Females visited a subset of territorial males and then actively chose one of these as a mate. The order in which males were visited suggested that females searched until an acceptable mate was found, rather than employing a “best-of-n” tactic. Numbers of females visiting a …
Lek Formation In Sage Grouse: The Effect Of Female Choice On Male Territory Settlement, Robert M. Gibson
Lek Formation In Sage Grouse: The Effect Of Female Choice On Male Territory Settlement, Robert M. Gibson
School of Biological Sciences: Faculty Publications
Previous studies of female choice in sage grouse, Centrocercus urophasianus, have identified two processes that could drive the local clustering of male territories at leks: (1) fidelity of females to previous mating sites (“temporal spillover” hypothesis), and (2) “spatial spillover” of matings from an attractive male to his immediate neighbors (“hotshot” hypothesis). The effects of each process on male territory settlement were investigated using observations of the resettlement of vacant territories and of individual site fidelity during a 7-year field study. The frequency with which vacant territories were resettled both within and between seasons increased with mating success of …
The Costs Of Female Choice In A Lekking Bird, Robert M. Gibson, Gwendolyn C. Bachman
The Costs Of Female Choice In A Lekking Bird, Robert M. Gibson, Gwendolyn C. Bachman
School of Biological Sciences: Faculty Publications
We investigated the costs of active female choice in sage grouse, Centrocercus urophasianus, a lekking species in which females make repeated, lengthy visits to leks to assess males before mating. Several potential costs were measured by monitoring changes in hens' ranging behavior, time budgets, and encounter rates with predators when they visited leks. Two costs were identified: hens moved further per day and encountered golden eagles, Aquila chrysaetos, more frequently when visiting leks. However, extra travel due to visiting leks increased predicted daily energetic expenditure by only about 1%, and the risk of predation by golden eagles over …
Mate Choice In Lekking Sage Grouse Revisited: The Roles Of Vocal Display, Female Site Fidelity, And Copying, Robert M. Gibson, Jack W. Bradbury, Sandra L. Vehrencamp
Mate Choice In Lekking Sage Grouse Revisited: The Roles Of Vocal Display, Female Site Fidelity, And Copying, Robert M. Gibson, Jack W. Bradbury, Sandra L. Vehrencamp
School of Biological Sciences: Faculty Publications
In lekking sage grouse (Centrocercus urophasianus), females exhibit relatively unanimous mate choice for particular males, but a satisfactory explanation for this unanimity has been elusive. We present analyses of mating distributions from two leks over 4 years that provide evidence for female choice based on differences in vocal display performance of males, the locations at which hens mated in the previous year, and the choices of other females (copying). The unanimity of female choice varied markedly among leks and years in correlation with changes in the mean numbers of hens that mated at the same time and hence …
Relationships Between Blood Parasites, Mating Success And Phenotypic Cues In Male Sage Grouse Centrocercus Urophasianus, Robert M. Gibson
Relationships Between Blood Parasites, Mating Success And Phenotypic Cues In Male Sage Grouse Centrocercus Urophasianus, Robert M. Gibson
School of Biological Sciences: Faculty Publications
In lek breeding Sage Grouse Centrocercus urophasianus in eastern California, male mating success is strongly correlated with individual differences in lek attendance, and in the rate and acoustic quality of courtship display, suggesting that these provide cues by which females choose mates. Increased lek attendance and high display rates also associated with elevated metabolic expenditure. This paper examines the hypothesis that the ability to commit energy to display is related to the incidence of blood parasites. A single hematozoan genus, Haemoproteus, was found in 37.5% of 184 Sage Grouse sampled over a five year period. Parasitism varied across years and …
Field Playback Of Male Display Attracts Females In Lek Breeding Sage Grouse, Robert M. Gibson
Field Playback Of Male Display Attracts Females In Lek Breeding Sage Grouse, Robert M. Gibson
School of Biological Sciences: Faculty Publications
Recent correlational studies of lekking sage grouse suggest that male vocal display attracts females. To test this hypothesis further, the natural displays of a territorial male were supplemented with the tape-recorded display of another reproductively successful individual. Significantly, more females approached the speaker's location on days when the recording was played, and also on nonplayback days immediately following a playback, than on other nonplayback days. Analysis of male displays indicated that females were responding to the playback itself rather than to changes in male behavior. The "after-response" following a playback suggests that some females present during a playback remembered its …
Foraging Behavior And Switching By The Grasshopper Sparrow Ammodramus Savannarum Searching For Multiple Prey In A Heterogeneous Environment, Anthony Joern
School of Biological Sciences: Faculty Publications
Switching among four alternative grasshopper species by the grasshop- per sparrow (Ammodramus savannarum) through frequency-dependent predation was ex- amined. Grasshoppers were presented against a heterogeneous natural background in an outdoor aviary where total density was held constant but relative density of each grasshopper species varied. Switching among prey, primarily between two of the four species, and inter-bird variability in switching was observed. Species-specific prefer- ences and interactions among the alternative grasshopper species affected the final diet choice as one grasshopper species was always preferentially selected and another disregarded independent of changes in relative density. Attributes of avian foraging behavior, including: …
Sexual Selection In Lekking Sage Grouse: Phenotypic Correlates Of Male Mating Success, Robert M. Gibson, Jack W. Bradbury
Sexual Selection In Lekking Sage Grouse: Phenotypic Correlates Of Male Mating Success, Robert M. Gibson, Jack W. Bradbury
School of Biological Sciences: Faculty Publications
Mate choice cues in sage grouse were reinvestigated by analyzing relationships between male mating success and a range of suggested cues. Display cues were implicated by significant relationships between mating status (whether or not a male mated) and lek attendance, display rate (corrected for effects of female proximity and time of day) and an acoustic component related to temporal and frequency measures of a whistle emitted during the strut display. Although display rate and the acoustic component were intercorrelated, both exerted significant partial effects on mating success in multivariate analyses. These display measures also differed significantly between males. In contrast, …