STRUCTURE AND DYNAMICS OF THE HYBRID ZONE BETWEEN BLACK-CAPPED CHICKADEE (POECILE ATRICAPILLUS) AND CAROLINA CHICKADEE (P. CAROLINENSIS) IN SOUTHEASTERN PENNSYLVANIA

The Auk ◽  
2007 ◽  
Vol 124 (2) ◽  
pp. 463 ◽  
Author(s):  
Matthew W. Reudink ◽  
Stephen G. Mech ◽  
Sean P. Mullen ◽  
Robert L. Curry
Keyword(s):  
Hybrid Zone ◽  
Poecile Atricapillus ◽  
Structure And Dynamics ◽  
Carolina Chickadee

scholarly journals Reproductive Success Across The Black-Capped Chickadee (Poecile Atricapillus) and Carolina Chickadee (P. Carolinensis) Hybrid Zone in Ohio

The Auk ◽  
2005 ◽  
Vol 122 (3) ◽  
pp. 759-772 ◽  
Author(s):  
C. L. Bronson ◽  
Thomas C. Grubb ◽  
Gene D. Sattler ◽  
Michael J. Braun
Keyword(s):  
Reproductive Success ◽  
Hybrid Zone ◽  
Past Century ◽  
Genetic Introgression ◽  
Genetic Composition ◽  
Poecile Atricapillus ◽  
Relative Paucity ◽  
Carolina Chickadee ◽  
The Face ◽  
East West

AbstractBlack-capped Chickadees (Poecile atricapillus) and Carolina Chickadees (P. carolinensis) hybridize in an east-west band from New Jersey to Kansas. Within the past century, the Ohio portion of this hybrid zone and the Carolina Chickadee range to the south have been moving northward, whereas the Black-capped Chickadee range has retracted. In Ohio, we characterized the genetic composition of the hybrid zone using five diagnostic molecular loci. Although there was no evidence of assortative mating in the center of the hybrid zone, we found a relative paucity of genetically intermediate breeding females as compared with breeding males. That suggests viability selection against female hybrids, in line with Haldane’s rule. On the basis of reproductive variables (number of nestlings, reproductive success), we found a decrease in productivity of breeding pairs in the hybrid zone that is significantly and positively related to their probability of producing homozygous offspring at each autosomal or sex-linked locus. We also found that the decrease in productivity was significantly and positively related to the genetic composition of the male of the pair (i.e. pure male chickadees more productive). These data strongly suggest that hybrids are at a selective disadvantage. Because the zone of reduced reproductive success was considerably narrower than the zone of introgression, our results demonstrate that genetic introgression is occurring in the face of substantial selection against hybrids.Éxito Reproductivo a través de la Zona de Hibridación de Poecile atricapillus y P. carolinensis en Ohio

scholarly journals Structure and Dynamics of The Hybrid Zone Between Black-Capped Chickadee (Poecile Atricapillus) and Carolina Chickadee (P. Carolinensis) in Southeastern Pennsylvania

The Auk ◽  
2007 ◽  
Vol 124 (2) ◽  
pp. 463-478 ◽  
Author(s):  
Matthew W. Reudink ◽  
Stephen G. Mech ◽  
Sean P. Mullen ◽  
Robert L. Curry
Keyword(s):  
Hybrid Zone ◽  
Selective Advantage ◽  
Genetic Introgression ◽  
Poecile Atricapillus ◽  
Large Numbers ◽  
Starting Point ◽  
Carolina Chickadee ◽  
Northern Edge ◽  
Historical Accounts ◽  
Carolina Chickadees

AbstractAnalysis of the structure and stability of a hybrid zone can serve as a starting point for examining mechanisms that influence spatial and evolutionary relationships between species. Recent studies of the hybrid zone between Black-capped Chickadee (Poecile atricapillus) and Carolina Chickadee (P. carolinensis) have suggested that genetic introgression is limited to a narrow zone, while also reinforcing the conclusion that the line of contact between these parapatrically distributed species is now shifting northward. We investigated the structure, position, and recent movement of the chickadee hybrid zone in southeastern Pennsylvania. Using selectively neutral microsatellite DNA markers, along with mitochondrial DNA haplotypes, we documented large differences in genetic composition among three populations ≤65 km apart where we sampled large numbers of breeding residents during 1998–2003. Genetic results indicate that the three sites support a population of Carolina Chickadees (Great Marsh), a population in which most individuals exhibit evidence of hybridization (Nolde Forest), and a population comprising mostly Black-capped Chickadees but with evidence of hybridization now taking place (Hawk Mountain). The patterns within the Nolde Forest population suggest that selection against hybrids may not be as strong as has been concluded from studies in other parts of the chickadee hybrid zone. Comparison of mitochondrial and nuclear genotypes between samples collected ≈15 years apart suggest that the northern edge of the hybrid zone shifted by ≈20 km over this interval, with hybridization now occurring as far north as the Kittatinny Ridge and beyond, where only Black-capped Chickadee genotypes were previously detectable. Our data and historical accounts suggest that the hybrid zone, now ≈50 km wide, may have become wider while also shifting northward. These results support the hypothesis that Carolina Chickadees enjoy a selective advantage during hybridization with Black-capped Chickadees, but both the proximate mechanisms and ultimate causes remain to be investigated.Structure et dynamique de la zone d'hybridation entre Poecile atricapillus et P. carolinensis dans le sud-est de la Pennsylvanie

Note types and coding in parid vocalizations. III: The chick-a-dee call of the Carolina chickadee (Poecile carolinensis)

2005 ◽  
Vol 83 (6) ◽  
pp. 820-833 ◽  
Author(s):  
Laurie L Bloomfield ◽  
Leslie S Phillmore ◽  
Ronald G Weisman ◽  
Christopher B Sturdy
Keyword(s):  
Acoustic Communication ◽  
Comparative Studies ◽  
Individual Recognition ◽  
Poecile Atricapillus ◽  
Poecile Carolinensis ◽  
Carolina Chickadee ◽  
Carolina Chickadees

Species of the genus Poecile Kaup, 1829 (the chickadees) are well suited to comparative studies of acoustic communication because their songs and calls occur in similar contexts and are acoustically similar. Here we provide careful, reliable descriptions and spectrographic exemplars for seven note types observed in the chick-a-dee calls of the Carolina chickadee, Poecile carolinensis (Audubon, 1834). The note types include A, C, and D notes similar to those found in the chick-a-dee calls of the black-capped chickadee, Poecile atricapillus (L., 1766), a complex of three B-note subtypes (B1, B2, and B3) and a rare note type previously identified as high-tee-chick. In common with black-capped chickadees, the organization of note types in Carolina chickadees follows a stringent syntax; the position of note types within a call is fixed. In contrast with black-capped chickadees, the chick-a-dee call syntax of the Carolina chickadee includes a B-note complex composed of three acoustically distinct subtypes of B notes, and follows a strict syntax: A→(B1→B2→B3)→C→D. Analysis of call variability suggests that the B-note complex (in particular, the most commonly sung note, B2) and the D note may provide reliable cues for species and individual recognition.

scholarly journals Limited movement of a hybrid zone in relation to regional variation in magnitude of climate change

2021 ◽  
Author(s):  
Alana Alexander ◽  
Mark Robbins ◽  
Jesse Holmes ◽  
Robert Moyle ◽  
Townsend Peterson
Keyword(s):  
Climate Change ◽  
Reproductive Isolation ◽  
Hybrid Zone ◽  
Parental Species ◽  
Range Shifts ◽  
Hybrid Zones ◽  
Poecile Atricapillus ◽  
Temperature Trends ◽  
Additional Reference ◽  
Western Portion

Hybrid zones can provide clear documentation of range shifts in response to climate change and identify loci important to reproductive isolation. Using a deep temporal (36-38 years) comparison of the black-capped (Poecile atricapillus) and Carolina (P. carolinensis) chickadee hybrid zone, we investigated movement of the under-sampled western portion of the zone (western Missouri) as well as investigating whether loci and pathways underpinning reproductive isolation were similar to those from the eastern portion of the hybrid zone. Using 92 birds sampled along the hybrid zone transect in 2016, 68 birds sampled between 1978 and 1980, and 5 additional reference birds sampled from outside the hybrid zone, we generated 11,669 SNPs via ddRADseq. We used these SNPs to interpolate spatially and assess the movement of the hybrid zone interface through time, and to assess variation in introgression among loci. We demonstrate that the interface has moved approximately 5-8 km to the northwest over the last 36-38 years, i.e., at only one-fifth the rate at which the eastern portion of the hybrid zone (e.g. Pennsylvania, Ohio) has moved. Temperature trends across the last 38 years reveal that eastern areas have warmed 50% more than western areas in terms of annual mean temperature, possibly providing an explanation for the slower movement of the hybrid zone in Missouri. Using genomic cline analyses, we detected four genes that showed restricted introgression in both Missouri and Pennsylvania, including Pnoc, a gene involved in metabolism, learning and memory, concordant with previous physiological and behavioral findings on hybrids and the parental species.

Phenotypic evidence for an extensive mosaic hybrid zone between two species of columbine, Aquilegia flavescens and A. formosa

Botany ◽  
2020 ◽  
Vol 98 (8) ◽  
pp. 459-467
Author(s):  
Jeffrey S. Groh ◽  
Quentin C.B. Cronk
Keyword(s):  
Hybrid Zone ◽  
Elevational Gradient ◽  
Hybrid Population ◽  
Clinal Variation ◽  
Hybrid Zones ◽  
Contact Zones ◽  
Structure And Dynamics ◽  
Ecological Selection ◽  
Herbarium Collections ◽  
Lineage Diversification

Describing the structure and dynamics of hybrid zones has important consequences for our understanding of lineage diversification. Herbarium collections constitute an extensive, though often underutilized, morphological resource that can potentially be leveraged to identify and describe hybrid zones. We demonstrate the use of herbarium collections to describe the structure of a hybrid zone between two North American columbines, Aquilegia flavescens S. Watson and A. formosa Fisch. ex DC. Hybrid indices were calculated from floral morphology measurements and mapped using geolocation data, revealing an extensive and consistent pattern of floral intermediacy in several contact zones. Population phenotype samples from contact zones corroborate these findings and strongly suggest introgression. At one locality with a confirmed hybrid population, floral phenotypes show clinal variation in parental-type morphology along an elevational gradient, in the direction predicted by the divergent elevational distributions of these taxa. We argue that these patterns together reflect a habitat-associated mosaic hybrid zone, consistent with divergent ecological selection maintaining the structure of the hybrid zone.

Haemosporidian prevalence and community composition vary little across a chickadee hybrid zone

The Auk ◽  
2021 ◽  
Author(s):  
Ari A Rice ◽  
Robert L Curry ◽  
Jason D Weckstein
Keyword(s):  
Community Composition ◽  
Breeding Season ◽  
Hybrid Zone ◽  
Host Species ◽  
Leading Edge ◽  
Parasite Prevalence ◽  
Molecular Methods ◽  
Hybrid Zones ◽  
Poecile Atricapillus ◽  
Bird Parasite

Abstract Within animal hybrid zones, parasites may determine competitive outcomes between host species and thus affect hybridization dynamics. We addressed this hypothesis by evaluating haemosporidian prevalence and community composition in a rapidly moving hybrid zone between Black-capped Chickadees (Poecile atricapillus) and Carolina Chickadees (P. carolinensis). Using molecular methods, we screened for haemosporidians in multiple chickadee populations across the hybrid zone and investigated whether parasite prevalence varied as a function of admixture among these birds. We identified 36 parasite lineages from 3 haemosporidian genera (Plasmodium, Haemoproteus, and Leucocytozoon) but found no genera or lineages more likely to infect any particular chickadee taxon. Instead, haemosporidian prevalence varied across sites and seasons: Leucocytozoon was more prevalent during chickadees’ breeding season, whereas Haemoproteus prevalence peaked during nonbreeding periods. Leucocytozoon infected proportionally fewer birds at the leading edge of the hybrid zone than near its center. However, haemosporidian communities were similar among chickadee populations, and evidence for parasite exchanges between chickadee taxa was lacking. These results underscore the complexity of bird–parasite relationships and suggest that haemosporidians are unlikely to play a major role in the ongoing movement of this hybrid zone.

Nucleosome dynamics

2006 ◽  
Vol 73 ◽  
pp. 109-119 ◽  
Author(s):  
Chris Stockdale ◽  
Michael Bruno ◽  
Helder Ferreira ◽  
Elisa Garcia-Wilson ◽  
Nicola Wiechens ◽  
...  
Keyword(s):  
High Resolution ◽  
Chromatin Structure ◽  
Current Knowledge ◽  
Dynamic Properties ◽  
Structure And Dynamics ◽  
Nucleosome Dynamics ◽  
Sharp Focus ◽  
Recent Advances ◽  
Insight Into ◽  
Chromatin Structure And Dynamics

In the 30 years since the discovery of the nucleosome, our picture of it has come into sharp focus. The recent high-resolution structures have provided a wealth of insight into the function of the nucleosome, but they are inherently static. Our current knowledge of how nucleosomes can be reconfigured dynamically is at a much earlier stage. Here, recent advances in the understanding of chromatin structure and dynamics are highlighted. The ways in which different modes of nucleosome reconfiguration are likely to influence each other are discussed, and some of the factors likely to regulate the dynamic properties of nucleosomes are considered.

Sign in / Sign up

Export Citation Format

Share Document