Investigating opposing patterns of character displacement in release and advertisement vocalizations of Bufo fowleri and Bufo americanus (Anura; Bufonidae)

2001 ◽  
Vol 79 (9) ◽  
pp. 1577-1585 ◽  
Author(s):  
Christopher J Leary
Keyword(s):  
Hybrid Zone ◽  
Mate Recognition ◽  
Character Displacement ◽  
Dominant Frequency ◽  
Species Group ◽  
Bufo Americanus ◽  
Premating Isolation ◽  
Rapid Release ◽  
Bufo Fowleri

Anuran release vocalizations function to prevent prolonged amplexus between males, whereas advertisement vocalizations potentially act as a premating isolation mechanism. To facilitate rapid release during heterospecific amplexus, selection should favor convergent character displacement in release vocalizations. Conversely, to promote isolation between sympatric congeners, selection should favor divergent character displacement in advertisement vocalizations. I examined properties of release and advertisement vocalizations of Bufo fowleri and Bufo americanus that are important in mate recognition (periodicity and dominant frequency) to determine if the two calls exhibit opposing patterns of character displacement. Release vocalizations showed no pattern of displacement. The periodicity of sympatric advertisement vocalizations differed from that of allopatric vocalizations for B. americanus but not for B. fowleri. However, the results were not consistent with the pattern expected for divergent character displacement because the two species differed in this parameter in allopatry. These results are compared with published reports of char acter displacement in the B. americanus species-group in the context of a possible mosaic hybrid zone for these species.

The Original Descriptions of Bufo fowleri and Bufo americanus

Copeia ◽  
1931 ◽  
Vol 1931 (3) ◽  
pp. 94 ◽  
Author(s):  
George S. Myers
Keyword(s):  
Bufo Americanus ◽  
Bufo Fowleri

A new species of Leptodactylus Fitzinger (Anura, Leptodactylidae) from Serra do Brigadeiro, State of Minas Gerais, Southeastern Brazil

Zootaxa ◽  
2008 ◽  
Vol 1861 (1) ◽  
pp. 44 ◽  
Author(s):  
ULISSES CARAMASCHI ◽  
RENATO N. FEIO ◽  
VINÍCIUS A. SÃO-PEDRO
Keyword(s):  
New Species ◽  
Color Pattern ◽  
Dominant Frequency ◽  
Species Group ◽  
Minas Gerais ◽  
Southeastern Brazil ◽  
Advertisement Call ◽  
Large Size ◽  
O 31 ◽  
A New Species

A new species of Leptodactylus belonging to the L. fuscus species group, and related to the L. mystaceus complex, is described from the Lagoa das Bromélias (20 o 53’S, 42 o 31’W; 1,227 m above sea level), Parque Estadual da Serra do Brigadeiro, Municipality of Ervália, State of Minas Gerais, Southeastern Brazil. Leptodactylus cupreus sp. nov. is characterized by the large size for the group (SVL 50.1–55.1 mm in males) and color pattern. The new species has a non-pulsed advertisement call, with call rate about 12 calls/s and a dominant frequency between 2,800 and 3,058 Hz.

scholarly journals Splendid Hybrids: The Effects of a Tiger Beetle Hybrid Zone on Apparent Species Diversity

2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Mathew L. Brust ◽  
W. Wyatt Hoback ◽  
Stephen M. Spomer
Keyword(s):  
Hybrid Zone ◽  
Biological Diversity ◽  
Biological Indicator ◽  
Species Group ◽  
Cautionary Note ◽  
Tiger Beetle ◽  
Tiger Beetles ◽  
Geographic Regions ◽  
Ecosystem Changes ◽  
Diverse Groups

Nonexpert citizen groups are being used to monitor species to track ecosystem changes; however, challenges remain for proper identification, especially among diverse groups such as beetles. Tiger beetles,Cicindelaspp., have been used for biological diversity monitoring because of their diversity and the ease of recognition. The finding of an apparent hybrid zone amongCicindela denverensisCasey,Cicindela limbalisKlug, andCicindela splendidaHentz in central Nebraska prompted a detailed study of the biogeography of this species group within Nebraska, a test of characteristics that could be used by citizen scientists, and limited breeding experiments. This study suggests that whileC. denverensisappears to hybridize with bothC. limbalisandC. splendidawithin the hybrid zone, all three species maintain their integrity across most of their ranges, largely occupy unique geographic regions, and at leastC. denverensisandC. splendidacooccur in many areas with no evidence of hybridization. Evidence of hybridization betweenC. limbalisandC. splendidawas found at only two sites. Furthermore, breeding experiments with virginC. splendidaandC. denverensisshowed that they are capable of producing hybrid larvae in the laboratory. The presence of morphological intergrades serves as a cautionary note when using biological indicator species.

Mating call characteristics of hybrid toads (Bufo americanus × B. fowleri) at Long Point, Ontario

1982 ◽  
Vol 60 (12) ◽  
pp. 3293-3297 ◽  
Author(s):  
David M. Green
Keyword(s):  
Pulse Rate ◽  
Dominant Frequency ◽  
Pulse Number ◽  
Bufo Americanus ◽  
Call Duration ◽  
Mating Call ◽  
Intermediate Morphology ◽  
Laryngeal Cartilages ◽  
Northern Shore ◽  
The Relationship

The mating calls of the toads Bufo americanus, B. fowled, and their natural hybrids were recorded in May 1981 at Long Point, Ontario, on the northern shore of Lake Erie. The calls of the two species differed substantially in pulse rate and call duration but much less so in terms of dominant frequency. The numbers of pulses per call were not significantly different. Calls of hybrids were intermediate in character. Values for pulse rate, call duration, and dominant frequency agreed with those previously described. The relationship between pulse rate and call duration is hyperbolic as pulse number appears to be relatively constant. The differences in the calls of B. americanus and B. fowled appear to be fundamentally due to mechanical properties of the pulse modulating apparatus of the larynx. The characteristics of the calls of the hybrids may be due to intermediate morphology of the laryngeal cartilages that modulate the pulses of a call.

scholarly journals Reproductive character displacement generates reproductive isolation among conspecific populations: an artificial neural network study

2006 ◽  
Vol 273 (1592) ◽  
pp. 1361-1368 ◽  
Author(s):  
Karin S Pfennig ◽  
Michael J Ryan
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Artificial Neural Network ◽  
Artificial Neural Networks ◽  
Reproductive Isolation ◽  
Mate Recognition ◽  
Character Displacement ◽  
Reproductive Character Displacement ◽  
Reproductive Character ◽  
Artificial Neural

When interactions with heterospecifics prevent females from identifying conspecific mates, natural selection can promote the evolution of mating behaviours that minimize such interactions. Consequently, mating behaviours may diverge among conspecific populations in sympatry and in allopatry with heterospecifics. This divergence in conspecific mating behaviours—reproductive character displacement—can initiate speciation if mating behaviours become so divergent as to generate reproductive isolation between sympatric and allopatric conspecifics. We tested these ideas by using artificial neural networks to simulate the evolution of conspecific mate recognition in populations sympatric and allopatric with different heterospecifics. We found that advertisement calls diverged among the different conspecific populations. Consequently, networks strongly preferred calls from their own population to those from foreign conspecific populations. Thus, reproductive character displacement may promote reproductive isolation and, ultimately, speciation among conspecific populations.

scholarly journals POSITIVE FEEDBACK BETWEEN ECOLOGICAL AND REPRODUCTIVE CHARACTER DISPLACEMENT IN A YOUNG AVIAN HYBRID ZONE

Evolution ◽  
2011 ◽  
Vol 66 (4) ◽  
pp. 1167-1179 ◽  
Author(s):  
Niclas Vallin ◽  
Amber M. Rice ◽  
Richard I. Bailey ◽  
Arild Husby ◽  
Anna Qvarnström
Keyword(s):  
Hybrid Zone ◽  
Positive Feedback ◽  
Character Displacement ◽  
Reproductive Character Displacement ◽  
Reproductive Character
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