scholarly journals Integrating molecular, phenotypic and environmental data to elucidate patterns of crocodile hybridization in Belize

2015 ◽  
Vol 2 (9) ◽  
pp. 150409 ◽  
Author(s):  
Evon R. Hekkala ◽  
Steven G. Platt ◽  
John B. Thorbjarnarson ◽  
Thomas R. Rainwater ◽  
Michael Tessler ◽  
...  
Keyword(s):  
Nuclear Dna ◽  
Molecular Data ◽  
Environmental Data ◽  
Phenotypic Data ◽  
Crocodylus Acutus ◽  
Breeding Habitats ◽  
American Crocodile ◽  
In Captivity ◽  
In The Wild ◽  
Morelet's Crocodile

The genus Crocodylus comprises 12 currently recognized species, many of which can be difficult to differentiate phenotypically. Interspecific hybridization among crocodiles is known to occur in captivity and has been documented between some species in the wild. The identification of hybrid individuals is of importance for management and monitoring of crocodilians, many of which are Convention on International Trade in Endangered Species (CITES) listed. In this study, both mitochondrial and nuclear DNA markers were evaluated for their use in confirming a suspected hybrid zone between American crocodile ( Crocodylus acutus ) and Morelet’s crocodile ( Crocodylus moreletii ) populations in southern Belize where individuals and nests exhibiting atypical phenotypic features had previously been observed. Patterns observed in both phenotypic and molecular data indicate possible behavioural and ecological characteristics associated with hybridization events. The results of the combined analyses found that the majority of suspected hybrid samples represent crosses between female C. acutus and male C. moreletii . Phenotypic data could statistically identify hybrids, although morphological overlap between hybrids and C. moreletii reduced reliability of identification based solely on field characters. Ecologically, C. acutus was exclusively found in saline waters, whereas hybrids and C. moreletii were largely absent in these conditions. A hypothesized correlation between unidirectional hybridization and destruction of C. acutus breeding habitats warrants additional research.

scholarly journals Contributions to the nutrition of the American crocodile Crocodylus acutus (Cuvier, 1807) in captivity

2018 ◽  
Vol 46 (1) ◽  
pp. 15-19 ◽  
Author(s):  
Pablo Hernandez ◽  
Hector Soria ◽  
Olimpia Farnes ◽  
Helios Hernandez ◽  
Rafael Garcia ◽  
...  
Keyword(s):  
Crocodylus Acutus ◽  
American Crocodile ◽  
In Captivity

scholarly journals Tracking a voyager: mitochondrial DNA analyses reveal mainland-to-island dispersal of an American crocodile (Crocodylus acutus) across the Caribbean

2020 ◽  
Vol 131 (3) ◽  
pp. 647-655
Author(s):  
Sergio A Balaguera-Reina ◽  
Juan F Moncada-Jimenez ◽  
Carlos F Prada-Quiroga ◽  
Felipe Hernandez-Gonzalez ◽  
Nacor W Bolaños-Cubillos ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Dna Analysis ◽  
Wildlife Forensics ◽  
Natural Park ◽  
Crocodylus Acutus ◽  
American Crocodile ◽  
In Captivity ◽  
Continental Area ◽  
San Andres ◽  
First Time

Abstract Conservation efforts have allowed American crocodile (Crocodylus acutus) populations to recover to the point that dispersal movements are beginning to be documented. The environmental authority of San Andres Island in Colombia reported, for the first time, the arrival of two C. acutus from unknown localities in 2012 and 2018. The former was sacrificed, and the latter was captured and kept in captivity to determining its potential origin. We used wildlife forensics to establish the origin of the animal that arrived in 2018 based on two mitochondrial genes (COI and Cytb). Additionally, five other samples from Tayrona National Natural Park (TNNP), and Salamanca Island Road Park (SIRP) were sequenced for molecular attribution of these populations to the currently described lineages. Phylogenetic and phylogeographic analyses showed that the American crocodile found in San Andrés belongs to a continental evolutionary lineage endemic to Colombia, showing also a strong genetic similarity with animals from SIRP. Thus, the most likely origin for this individual was not the nearest continental area but somewhere around the central Colombian Caribbean, located ~700 km from the island. We discuss the implication of our findings in the systematics and conservation of the species and the potential of mitochondrial DNA analysis to identify such migrants.

scholarly journals Factors influencing the occurrence of negative interactions between people and crocodilians in Mexico

Oryx ◽  
2021 ◽  
pp. 1-9
Author(s):  
Giovany Arturo González-Desales ◽  
Luis Sigler ◽  
Jesús García-Grajales ◽  
Pierre Charruau ◽  
Martha Mariela Zarco-González ◽  
...  
Keyword(s):  
Anthropogenic Activities ◽  
Biosphere Reserve ◽  
Rigorous Evaluation ◽  
Caiman Crocodilus ◽  
Crocodylus Acutus ◽  
American Crocodile ◽  
Nesting Sites ◽  
The Relationship ◽  
Nesting Season ◽  
Negative Interactions

Abstract Negative interactions between people and crocodilians have increased worldwide, but in Mexico there have been few systematic reports and no rigorous evaluation of this problem. We compiled information on negative interactions between people and the spectacled caiman Caiman crocodilus and American crocodile Crocodylus acutus from the Worldwide Crocodilian Attack Database for 1993–2018, and we investigated interactions in greater depth, through interviews with people in La Encrucijada Biosphere Reserve. We examined the relationship between the occurrence of negative interactions between people and C. acutus and the species' nesting season and abundance, and presence records. In Mexico, the frequency of negative interactions increases when anthropogenic activities occur close to nesting sites (< 30 km) and during the nesting season (February–September). In La Encrucijada, following negative interactions with crocodiles, the local inhabitants killed 30 crocodiles measuring > 2.5 m long in 2011–2012. The frequency of negative human–crocodilian interactions was not correlated with the abundance of crocodilians but was correlated with the number of presence records of crocodiles. Strategies to minimize these interactions include warnings at nesting sites, increased monitoring of anthropogenic activities during the nesting season, and management of nests to prevent them being destroyed by people.

scholarly journals On the modulation and maintenance of hibernation in captive dwarf lemurs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marina B. Blanco ◽  
Lydia K. Greene ◽  
Robert Schopler ◽  
Cathy V. Williams ◽  
Danielle Lynch ◽  
...  
Keyword(s):  
Food Restriction ◽  
Metabolic Disorders ◽  
Biological Rhythms ◽  
Food Ingestion ◽  
Ambient Temperatures ◽  
In Captivity ◽  
In The Wild ◽  
Cheirogaleus Medius ◽  
Save Energy ◽  
Metabolic Strategies

AbstractIn nature, photoperiod signals environmental seasonality and is a strong selective “zeitgeber” that synchronizes biological rhythms. For animals facing seasonal environmental challenges and energetic bottlenecks, daily torpor and hibernation are two metabolic strategies that can save energy. In the wild, the dwarf lemurs of Madagascar are obligate hibernators, hibernating between 3 and 7 months a year. In captivity, however, dwarf lemurs generally express torpor for periods far shorter than the hibernation season in Madagascar. We investigated whether fat-tailed dwarf lemurs (Cheirogaleus medius) housed at the Duke Lemur Center (DLC) could hibernate, by subjecting 8 individuals to husbandry conditions more in accord with those in Madagascar, including alternating photoperiods, low ambient temperatures, and food restriction. All dwarf lemurs displayed daily and multiday torpor bouts, including bouts lasting ~ 11 days. Ambient temperature was the greatest predictor of torpor bout duration, and food ingestion and night length also played a role. Unlike their wild counterparts, who rarely leave their hibernacula and do not feed during hibernation, DLC dwarf lemurs sporadically moved and ate. While demonstrating that captive dwarf lemurs are physiologically capable of hibernation, we argue that facilitating their hibernation serves both husbandry and research goals: first, it enables lemurs to express the biphasic phenotypes (fattening and fat depletion) that are characteristic of their wild conspecifics; second, by “renaturalizing” dwarf lemurs in captivity, they will emerge a better model for understanding both metabolic extremes in primates generally and metabolic disorders in humans specifically.

Performance of a points-based scoring system for assessing species limits in birds

The Auk ◽  
2021 ◽  
Author(s):  
Joseph A Tobias ◽  
Paul F Donald ◽  
Rob W Martin ◽  
Stuart H M Butchart ◽  
Nigel J Collar
Keyword(s):  
Strong Support ◽  
Molecular Data ◽  
Sympatric Species ◽  
Global Scale ◽  
Training Set ◽  
Species Limits ◽  
Phenotypic Data ◽  
Fast Tracking ◽  
Extinction Rates ◽  
Phenotypic Divergence

AbstractSpecies are fundamental to biology, conservation, and environmental legislation; yet, there is often disagreement on how and where species limits should be drawn. Even sophisticated molecular methods have limitations, particularly in the context of geographically isolated lineages or inadequate sampling of loci. With extinction rates rising, methods are needed to assess species limits rapidly but robustly. Tobias et al. devised a points-based system to compare phenotypic divergence between taxa against the level of divergence in sympatric species, establishing a threshold to guide taxonomic assessments at a global scale. The method has received a mixed reception. To evaluate its performance, we identified 397 novel taxonomic splits from 328 parent taxa made by application of the criteria (in 2014‒2016) and searched for subsequent publications investigating the same taxa with molecular and/or phenotypic data. Only 71 (18%) novel splits from 60 parent taxa have since been investigated by independent studies, suggesting that publication of splits underpinned by the criteria in 2014–2016 accelerated taxonomic decisions by at least 33 years. In the evaluated cases, independent analyses explicitly or implicitly supported species status in 62 (87.3%) of 71 splits, with the level of support increasing to 97.2% when excluding subsequent studies limited only to molecular data, and reaching 100% when the points-based criteria were applied using recommended sample sizes. Despite the fact that the training set used to calibrate the criteria was heavily weighted toward passerines, splits of passerines and non-passerines received equally strong support from independent research. We conclude that the method provides a useful tool for quantifying phenotypic divergence and fast-tracking robust taxonomic decisions at a global scale.

scholarly journals Previously unknown behavior in parasitic cuckoo females: male-like vocalization during migratory activity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Swetlana G. Meshcheryagina ◽  
Alexey Opaev
Keyword(s):  
Vocal Communication ◽  
Harmonic Spectrum ◽  
Common Cuckoo ◽  
Neck Extension ◽  
Migratory Activity ◽  
Call Production ◽  
In Captivity ◽  
In The Wild ◽  
Combined Features ◽  
Female Call

Abstract Background In the last decade, enigmatic male-like cuckoo calls have been reported several times in East Asia. These calls exhibited a combination of vocal traits of both Oriental Cuckoo (Cuculus optatus) and Common Cuckoo (Cuculus canorus) advertising calls, and some authors therefore suggested that the enigmatic calls were produced by either Common × Oriental Cuckoo male hybrids or Common Cuckoo males having a gene mutation. However, the exact identity of calling birds are still unknown. Methods We recorded previously unknown male-like calls from three captive Oriental Cuckoo females, and compared these calls with enigmatic vocalizations recorded in the wild as well as with advertising vocalizations of Common and Oriental Cuckoo males. To achieve this, we measured calls automatically. Besides, we video-recorded captive female emitting male-like calls, and compared these recordings with the YouTube recordings of calling males of both Common and Oriental Cuckoos to get insight into the mechanism of call production. Results The analysis showed that female male-like calls recorded in captivity were similar to enigmatic calls recorded in the wild. Therefore, Oriental Cuckoo females might produce the latter calls. Two features of these female calls appeared to be unusual among birds. First, females produced male-like calls at the time of spring and autumn migratory activity and on migration in the wild. Because of this, functional significance of this call remained puzzling. Secondly, the male-like female call unexpectedly combined features of both closed-mouth (closed beak and simultaneous inflation of the ‘throat sac’) and open-mouth (prominent harmonic spectrum and the maximum neck extension observed at the beginning of a sound) vocal behaviors. Conclusions The Cuculus vocalizations outside the reproductive season remain poorly understood. Here, we found for the first time that Oriental Cuckoo females can produce male-like calls in that time. Because of its rarity, this call might be an atavism. Indeed, female male-like vocalizations are still known in non-parasitic tropical and apparently more basal cuckoos only. Therefore, our findings may shed light on the evolution of vocal communication in avian brood parasites.

scholarly journals Reintroduction of the Golden Conure (Guaruba guarouba) in Northern Brazil: Establishing a Population in a Protected Area

Diversity ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 198
Author(s):  
Marcelo Rodrigues Vilarta ◽  
William Wittkoff ◽  
Crisomar Lobato ◽  
Rubens de Aquino Oliveira ◽  
Nívia Gláucia Pinto Pereira ◽  
...  
Keyword(s):  
Power Lines ◽  
Food Supplementation ◽  
Territorial Disputes ◽  
Amazon Forest ◽  
Nest Boxes ◽  
In Captivity ◽  
Viable Population ◽  
In The Wild ◽  
Northern Brazil ◽  
Native Foods

Brazil has the highest number of parrots in the world and the greatest number of threatened species. The Golden Conure is endemic to the Brazilian Amazon forest and it is currently considered as threatened by extinction, although it is fairly common in captivity. Here we report the first reintroduction of this species. The birds were released in an urban park in Belem, capital of Para State, where the species was extinct more than a century ago. Birds were trained to recognize and consume local food and to avoid predators. After the soft-release, with food supplementation and using nest boxes, we recorded breeding activity in the wild. The main challenges before the release were the territorial disputes within the aviary and the predation by boa snakes. During the post-release monitoring the difficulties were the fast dispersion of some individuals and the dangers posed by anthropic elements such as power lines that caused some fatalities. Released birds were very successful at finding and consuming native foods, evading predators, and one pair reproduced successfully. Monitoring continues and further releases are programmed to establish an ecologically viable population.

Sign in / Sign up

Export Citation Format

Share Document