"Amazon Snake Mystery"

Film 4
(one hour HD special)

August 23rd-September 14th 2003

Location of OBA film 4:4
Loreto, Peru

(mouse-over for view of Loreto, Peru)


Eunectes murinus

The Green anaconda (Eunectes murinus) is the largest of the four known species of anacondas*, and although not the longest snake species in the world (that is the S.E.Asian Reticulated python, Broghammerus reticulatus, with a specimen reportedly measuring 33ft (10.0m) being found in Indonesia at the turn of the last century) the green anaconda is most certainly the heaviest and achieves the greatest girths. The maximum length recorded for the green anaconda is around 8.0m while the other anaconda species do not seem to exceed 4.0m.

The reason why green anacondas can achieve much heavier weighs that their large python counterparts is probably because they are boas and therefore ovoviviparous (live-bearing) rather than oviparous (egg-laying) like pythons. All large snakes love water, it supports their weight, but large pythons still have to come onto land to lay their eggs and therefore cannot achieve weights which would make locomotion over land difficult or impossible. Anacondas, being boas, can give birth directly into the water, and since they can also hunt, eat and mate in their aquatic environment, large specimens might not even have to venture onto land and would not be affected by the constraints of terrestrial locomotion that limit weight in pythons.

The quest to find a giant anaconda, or giant snake of any species, is an old one that reaches back to 19th Century "Golden Ages of Exploration" when Europeans and American set out to conquer the world's remotest places and everything that lived within them. Stories of giant snakes were amongst the most popular traveller's tales and almsot replaced the 16th Century sailor's stories of giant marine creatures like the kraken or sea serpents.

Col. Percy Fawcett's book contains vivid tales of giant snakes.
Fawcett disappeared the Amazon in 1925.

The snakes in these stories grew with the telling, but nobody asked for supporting scientific or photographic evidence, such things were not possible or very difficult in those days. Tales of giant snakes entered the travel literature though authors like Up de Graff (1923), Fawcett (1953), Heuvelmans (1958) and Perry (1970) and now inhabit the internet and cycle around repeatedly attached to emails. But many of these stories are gross exagerations of the true maximum sizes recorded for the species concerned (usually green anaconda, reticulated python, and African rock python, Python sebae). One book which dissected many of the earlier giant snake stories was the aptly named Tales of Giant Snakes (Murphy & Henderson 1997). Interest in giant snakes and the desire to find a specimen over 30ft (9.0m) in length peaked with the offer of a reward of $1,000, rising to $5,000 for the skin or skeleton of a 30ft+ snake, made by explorer, big-game hunter and US President Theodore Roosevelt. Other rewards were offered in the United Kingdom and Germany and the New York Zoological Society, now Wildlife Conservation Society, made an offer of $15,000 in 1978, rising to $50,000 in 1980, for a live 30ft snake of any species. This reward was never claimed and has now withdrawn the offer in the interests of conservation.

Yet stories of giant anaconda persist even today, 40ft, 60ft, over 100ft, movies are made about them, books are written about them, and expeditions are mounted to find them. Despite my involvement in such expeditions in the past and my growing scepticism about the validity of any living snake of such gigantic proportions, I was about to embark on another to investigate stories of a giant anaconda called Yacu-Mama (Mother of Waters) said to inhabit a remote Peruvian lake.

Green anaconda, Eunectes murinus


* The anacondas are:
Green anaconda (Eunectes murinus) from throughout northern S.America, east of the Andes, and on Trinidad.
Yellow anaconda (Eunectes notaeus) from Paraguay, northern Argentina and southern Brazil.
De Schauensee's anaconda (Eunectes deschauenseei) Brazil (Ilha Marajo, Pará State, in the mouth of the Amazon & Amapá State) and French Guiana.
Beni River anaconda (Eunectes beniensis) Bolivia (Beni River) - only described in 2002 by Lutz Dirksen, the species looks like a hybrid between a green and yellow anaconda, although Dirksen now rejects this hypothesis.
A fifth species, Barbour's anaconda (Eunectes barbouri) was described from Ilha Marajo (same location as De Schaunsee's anaconda) but is now considered an aberrant green anaconda and no longer a valid species.

Fawcett, P.H. 1953 Exploration Fawcett. Hutchinson, London.
Heuvelmans, B. 1958 On the Track of Unknown Animals. Hill & Wang, New York.
Murphy, J.C. & R.W.Henderson 1997 Tales of Giant Snakes: A Historical Natural History of Anacondas and Pythons. Krieger, Malabar, Fla.
Perry, R. 1970 The World of the Jaguar. Tapinger Publishing, New York.
Up de Graff, F.W. 1923 Head Hunters of the Amazon. Duffield & Co., New York.


Loreto map showing main locations and routes
aircraft & tower = Iquitos main airport, yellow aircraft = rural airstrips
dotted white line = flights
Iquitos-Andoas (fixed-wing), Alianza Cristiana-San Lorenzo (helicopter), San Lorenzo-Iquitos (fixed-wing)
blue line = river boat journey

(click on map for enlarged view)

Facts about Loreto

(sources Wikipedia and others)

Peru it primarily an Andean and west-coast South American country but one third of the country lies in the Upper Amazon Basin, east of the Andes. This region is known as Loreto, at almost 369,000 sq.kms. the largest of Peru's 26 regions, but it is also one of the least populated regions with an average population density of 2.5 persons per, due to the majority of it comprising Amazonian rainforest.

Loreto borders Ecuador to the northwest, Colombia to the northeast and Brazil to the east. The capital is Iquitos on the Amazon River. Loreto comprises seven provinces with Iquitos in the largest, Maynas Province in the northeast.

The project location was in Datem del Marañón Province in the west, in its Andoas District, the capital of which is Alianza Cristiana. This remote area, on the Rio Pastaza and Rio Husaga watersheds, is over 11,500 sq.kms. in size but has a population of under 10,ooo, ie. 0.8 persons per



The Film Crew and Expedition Participants

From the UK:
Jon Stephens (Director)
Ann Breeze (Associate Producer)
Mark O'Shea (Presenter)
Mark Stokes (Camera)
Terry Meadowcroft (Sound recordist)

From Germany:
Lutz Dirksen (Contributer and herpetologist)

From Peru:
Deborah McLauchlan (Location manager)
Alex Sandoval (Medical doctor)
Dona Lorenzo (Shaman)
Jose Luis Valles (Guide and translator)
Apu Edwing (Village headman)
Ricardo Cisneros (Local hunter)
José Cisneros (Captain of river boat Nenita)


Mark and the crew:
Terry Meadowcroft (sound) and Mark Stokes (camera) at Peruvian Air Force Base, Iquitos.
Mark and the contributors:
Don Lorenzo (shaman) and Lutz Dirksen (herpetologist) at Alianza Cristiana, Loreto.

The Expedition

I have caught 40 anacondas up to 5.4m (17ft 6in ) and 73kg (11.5 stone/161lb) in Brazil, Venezuela and Guyana but the anaconda we were told dwelled in Panna Cocha would make all those snakes look like earthworms. Apparently not only the people greatly feared this giant snake, all the wildlife had left the area.

Call me "Mr Sceptical" but I have strong views on the possibly maximum sizes for anacondas and whilst I admit we may not have seen the largest specimen yet, I have doubts that they exceed 12m (40ft). The 19th century tales of 50, 60 and even over 120ft long anacondas are exciting yarns but much as I would like to believe in them, I simply cannot take them at face value.

The expedition we were embarking upon was to a very remote region of Amazonian Peru where such a beast was said to exist, one of numerous such stories in the folklore of the Amazon. Would we find the creature in the lake, would we find any anacondas at all ?
Both questions I could not answer at that point, but I generally seek anacondas in the dry season in seasonally flooded savannas, where they are relatively easy to find and fairly safe to capture. This quest was following a period of heavy rain when water-levels were higher, and the region we were visiting was a very different habitat to the Llanos of Venezuela or the Ilha Marajo, Brazil, this was rainforest with large rivers and deep, dark lakes and lagoons, the sort of place a large snake could easily evade detection and where trying to capture one held the additional danger of being drowned in its powerful coils.

The expedition would fly to Andoas in the north of Andoas District, and then travel by boat down the Rio Pastaza and up the Rio Huasaga to Alianza Cristiana, an amerindian settlement that serves as the district headquarters and is located on a large expanse of water called Laguna Anatico. This would be our base for the duration while we visited other sites on the Rio Huasaga, following which we would hitch a ride on a helicopter down to San Lorenzo and then fly by fixed-wing back to Iquitos. That was the plan.

The locations ain Peru visited during filming in 2003 were:

1. Iquitos:
a) Iquitos
b) Around Iquitos
c) Iquitos to Andoas

2. Alianza Cristiana:
a) Andoas to Alianza Cristiana
b) Alianza Cristiana, Rio Huasaga
c) Laguna Anatico, Rio Huasaga
d) Rio Huasaga
e) Union Antioneta, Rio Huasaga
f) Panna Cocha, Rio Huasaga
g) Alianza Cristiana to San Lorenzo

Filming schedule & itinerary:
Saturday 23rd August - Depart UK
Sunday 24th August - Arrive Lima, Peru
Monday 25th August - Arrive Iquitos, Peru
Tuesday 26th August - Iquitos, failed to reach Andoas
Wednesday 27th August - Arrive Andoas
Thursday 28th August - Rio Pastaza, arrive Alianza Cristiana
Friday 29th August - Alianza Cristiana & Panna Cocha
Saturday 3oth August - Alianza Cristiana & Panna Cocha
Sunday 31st August - Alianza Cristiana
Monday 1st September - Alianza Cristiana & Panna Cocha
Tuesday 2nd September - Alianza Cristiana
Wednesday 3rd September - Alianza Cristiana
Thursday 4th September - Alianza Cristiana & Huasaga Cocha
Friday 5th September - Alianza Cristiana
Saturday 6th September - Alianza Cristiana
Sunday 7th September - Alianza Cristiana
Monday 8th September - Depart Alianza Cristiana, Iquitos
Tuesday 9th September - Iquitos
Wednesday 10th September - Iquitos
Thursday 11th September - Iquitos
Friday 12th September - Iquitos
Saturday 13th September - Depart Iquitos
Sunday 14th September - Arrive UK


Expedition Results include a full life-list for the 2003 expedition to the Rio Huasaga, Loreto, Peru.