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Yacare Caiman - Caiman yacare
#1
Scalesofanubis: Wrote:Yacare Caiman - Caiman yacare

[Image: Yacar%C3%A9-caiman-head-detail.jpg]

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Crocodilia
Family: Alligatoridae
Genus: Caiman
Species: Caiman yacare

[Image: tumblr_lfwx081F4i1qzpgrno1_500.jpg]

The Yacare caiman (Caiman yacare, Jacaré in Portuguese) is a species of caiman found in central South America, including northeastern Argentina, Uruguay eastern Bolivia, central/south-west Brazil, and the rivers of Paraguay. Approximately 10 million individual Yacare Caiman exist within the Brazilian Pantanal, representing what is quite possibly the largest single crocodilian population on Earth. As a medium-small sized crocodilian, most adult male individuals grow to roughly 2 or 2.5 m (6.6 or 8.2 ft) in length,but do not appear to exceed the 3 meter mark. Females are rather smaller at an average of 1.4 m (4.6 ft). Body mass in this species can range up to 58 kg (130 lb) in males and from 14 to 23 kg (31 to 51 lb) in females. Their relatively smaller size makes them a favorite prey of the jaguar and anaconda. This species diet consists primarily of fish (especially piranha) and birds, with the occasional capybara being taken by larger adults. In general, all species of caiman (the exception being the large black caiman) are incapable of seriously harming or consuming humans.

[Image: Caiman_yacare_Distribution.png]

Ceratodromeus: Wrote:Long distance movements by Caiman crocodilus yacare: implications for management of the species in the Brazilian Pantanal
Abstract:
Movement patterns of caimans were studied over a 16-year period in two areas of the Brazilian Pantanal, one dominated by intermittent rivers and another, adjacent region of many isolated lakes. We marked caimans in 100 lakes (1986–2001) and two rivers (1987–1999). We recaptured 163 adult males, 132 adult females and 237 juveniles. In a two-year interval, hatchlings moved only within the lake area or within the river area and the maximum distance moved was 6.0 km (mean=0.5 km, SD=1.0) in the lake area, and 1.25 km (mean=0.6 km, SD=0.3) in the river area. In a period of one year, females and males larger than 40 cm snout-vent length moved similar distances in both areas (max.=9.8 km). We monitored 47 adult caimans by radio-telemetry in the river area for about a year. The size of the area used by telemetered individuals over periods of 30 to 436 days varied from two to 1649 ha. The areas used by five males in sites subjected to experimental hunting were similar to those used by five other males in areas not subjected to hunting. In periods of 1–5 years, females and males larger than 40 cm SVL moved maximum distances of 16 and 18 km, respectively. Five individuals marked as hatchlings in the lake area were recaptured as adults after intervals of 5–15 years. The extensive long-term and short-term movements by caimans mean that individual ranches should not be considered independent management units for sustained use of caimans in the Pantanal.
http://www.ingentaconnect.com/content/bh...2/art00004

Ceratodromeus: Wrote:Infrasound production by a yacare caiman Caiman yacare in the Pantanal, Brazil
"The social interactions of crocodilians comprise visual, auditory, olfactory  and tactile components, including posturing, vocalizing, producing infrasounds, headslapping, jawslapping, narial geysering, blowing bubbles, and multiple other activities (e.g., Garrick and Lang 1977, Kofron 1991, Thorbjarnarson and Hernandez 1993, Dinets 2013a).  For long distance communication, crocodilians use a combination of vocalizations, headslaps or jawslaps, and infrasound (Dinets 2011a).  Regarding the yacare caiman Caiman yacare (Daudin 1802), Dinets (2011b) reported the roaring display consisted of one to three roars, and with each roar preceded by infrasound.  Infrasound comprises non-vocal vibrations at frequencies below the range of human hearing and that can carry a great distance through the water (Dinets 2011a, 2013b).  Infrasound production can be visually detected by observing water projecting upward into the air above the back of the crocodilian, which Vliet (1989) termed a “water dance.”  The water dance is likely created by Faraday waves produced when the male crocodilian vibrates its lungs at very low frequency (Moriarty and Holt 2011) and with its back submerged just below the surface of the water.  The back of the crocodilian is covered by rough dermal scutes of varying shapes and sizes, some which may project several centimeters outward, and these may direct or focus the Faraday waves.  The production of infrasound expends a great amount of energy (Dinets 2013b)."
[Image: Screenshot_2015-11-06-00-35-48_zpsfpb5pi0x.png]
http://www.biotaxa.org/hn/article/download/10993/14651


Ceratodromeus: Wrote:Growth of Caiman crocodilus yacare in the Brazilian Pantanal
Abstract
We studied growth of the caiman, Caiman crocodilus yacare, in the Brazilian Pantanal for 27 years between 1987 and 2013.We recaptured 647 of 7769 C. c. yacare initially marked in an area of 50 km2, in two ranches. We were able to determine size at age accurately for 24 male and17 female caimans that had been marked at hatching or less than 1 year old, and recaptured over periods of 5 to 24 years. The other 606 caimans were used to evaluate short-term growth rates. Age-size relationships were estimated using growth models from the Richards family of curves (full model, von Bertalanffy and monomolecular). The form of the relationships differed between analyses based on caimans of known age and analyses based on integration of growth rate on size relationships for caimans whose ages were not known. Individuals showed large variation in short-term growth rates, but data on known-age animals indicated little between-individual variability in long-term growth rates. There was evidence of a small effect of rainfall, but not temperature, on short-term growth of small caimans, but most variation in growth rates was unexplained by variables other than age and sex. Data on known-age individuals indicated that female C. c. yacare generally reach sexual maturity between 10 and 15 years of age. Because of the asymptotic relationship between age and size, deviations of observations from the model for age are larger than for size, and estimates of age at a given size have greater errors than estimates of size at a given age. Integration of growth rate on size relationships may be adequate for estimating size from age in many cases, but accurate estimates of age from size require data on known-age individuals over the size range of the species.
[Image: journal.pone.0089363.g001_zpsmorwcabd.png]
Figure 1. Relationship between size and age for known-age female (a) and male (b) Caiman crocodilus yacare (circles) based on the Richards curve (thick continuous line)
http://journals.plos.org/plosone/article...ne.0089363
[Image: wildcat10-CougarHuntingDeer.jpg]
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