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EUNECTES MURINUS (Green Anaconda). LONGEVITY. Anacondas
and other large reptiles tend to live many years and grow slowly later in life.
However, long-term data on growth rates for wild snakes are in short supply.
Here we report recapture of a Eunectes
murinus after 13 years. These observations were made in the course
of conducting an on-going mark-recapture project (running since 1992) in the
Venezuelan llanos, Distrito Muñoz,
On 27 August 1994 we captured a female (E548, 324 cm SVL, 21 kg). Thirteen years later on 19 March 2007, we caught E548 again and although the scale clipping mark was difficult to read, we were able to identify the individual unequivocally by comparing the subcaudal pattern with our records. Upon recapture E548 measured 366 cm SVL and 25 kg. E548 was wounded, weakened, and had a subcutaneous nematode (possibly Dracunlus sp.) which has been found in other individuals in this population (Calle et al. 1994. J. Zoo. Wild. Med. 25:53-64).
This may be the longest recapture record of any individual snake in the wild. Twelve year recaptures have been reported by Madsen and Shine (2000. J. of Animal Ecology. 69:952-958). It is surprising that in 13 years E548 only grew 42 cm. It is expected that the growth rate of large reptiles will decrease towards older age (e.g. Madsen and Shine, op. cit.), but E548 is still far from the largest size recorded for this region (exceeding 500 cm, Rivas et al. op. cit.) and even further from other records in the literature. Cursory evaluation of our mark/recapture data suggest that anacondas in the wild may take more than a decade to reach 320 cm SVL, so E548 could be in her mid-twenties or perhaps even older.
The harvest of anacondas have
been present for more than two decades driven largely by an demand for luxury
snakeskin products in the global market (Waller et
al. 2007. In
We thank the Wildlife Conservation Society, Zoo de Doue la Fontaine-France, Miami Metro Zoo, Anaconda Investments LLC, COVEGAN, J. and T. Dunbar, and T. Hughes for assistance.
Submitted by JESÚS A. RIVAS, Department of Math and
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