Protocol 10 - Herpetofauna

Coordinator:
Dr. Teresa Cristina Sauer de Ávila Pires (MPEG) - E-mail: avilapires@museu-goeldi.br
Protocol researchers:
East Pará - Dr. Teresa Cristina Sauer de Ávila Pires (MPEG)
Amapá - MSc. Jucivaldo Dias Lima (IEPA)
West Pará - MSc. Hipócrates de Meneses Chalkidis (UFOPA)
Maranhão - Dr. Larissa Barreto (UFMA)
Mato Grosso - Dr. Marcos André de Carvalho (UFMT)

Groups of interest and diversity of species evaluated per grid: Order Anura (frogs and toads), Caudata (salamanders), Gymnophiona (Caecilians), among the types of amphibians, and Squamata (amphisbaenians, snakes and lizards), among the types of reptiles: 150 species.

Biological role and local diversity of the target-group: Amphibians are present in virtually every environment within the Amazon region. The majority have an aquatic larval stage and a land-based adult stage (arboreal, saxicolous, subterranean, and in some cases, aquatic). This life cycle means that the group is very susceptible to environmental changes, making the group a very useful bioindicator (SEMLITSCH, 2003; YOUNG et al., 2004). The group is a predator of insects and, in some instances, small vertebrates, as well as serving as prey for many larger predators such as spiders, reptiles, birds and mammals. Around 240 species of amphibians are known within the Brazilian Amazon region, distributed into the following orders and families:

Order Anura (frogs and toads), with 224 species: the Allophrynidae, Bufonidae, Centrolenidae, Dendrobatidae, Hylidae, Leptodactylidae, Microhylidae, Pipidae, Pseudidae and Ranidae families.

Order Caudata (salamanders), with 2 species: the Bolitoglossidae family.

Order Gymnophiona (caecilians), with 9 species: Caeciliidae, Rhinatrematidae and Typhlonectidae families (ÁVILA-PIRES et al., 2007).

Squamata (amphisbaenians, snakes and lizards) are also present in almost every Amazonian environment. These can be land-based, fossorial, aquatic or arboreal, or can occupy more than one habitat. They feed on invertebrates such as worms, slugs, insects, spiders and centipedes and even vertebrates, such as fish, amphibians, reptiles, birds and mammals. Around 260 species of Squamata are known in the Brazilian Amazon region at the present time, distributed among the following families: Typhlopidae, Anomalepididae, Leptotyphlopidae, Aniliidae, Boidae, Colubridae, Elapidae, Viperidae, Iguanidae, Gymnophthalmidae, Gekkonidae, Teiidae, Scincidae and Amphisbaenidae (ÁVILA-PIRES et al., 2007).

Collection technique 1. Pitfall traps with drift fence

This is a standardized sampling technique, appropriate for the collection of anura, reptiles, mammals and various types of forest floor invertebrates. It provides quantitative data for comparison between different areas, in which the number and the size of the collection buckets, the distance between them and the design of the traps are explained. Four buckets of 60 litres each will be used at each sampling point, laid out in a straight line or in the form of a letter 'Y', in which the central bucket will be 10 m away from the three peripheral buckets. Each peripheral bucket will be connected to the central bucket by a 50 cm high plastic sheet, the lower extremity being buried in the soil. Each of the three sheets will be separated by an angle of approximately 120° (JONES, 1981; GIBBONS; SEMLITSCH, 1981; CORN, 1994; RIBEIRO-JUNIOR et al., 2008).

The buckets must be visited on a daily basis during the sampling period in order to collect the trapped animals. These buckets must remain closed during the sampling periods, or alternatively, branches must be strategically placed within them in order to facilitate the egress of animals that could fall within. The second option is usually the most efficient due to the difficulty in properly closing the buckets after being buried in the ground.

Due to the efficiency of this method not being restricted to a specific group of fauna, contact with other protocol teams should be sought in order to make full use of all captured animals.

Sampling unit: A pitfall trap set out in letter ‘Y’ format, consisting of four buckets and connected by a drift fence.

Technique 2. Visual search during the day and at night (visual encounter survey, Crump & Scott, 1994).

This method consists of slowly walking along the trails within the grid. An area of 5 meters will be sampled at a height of 3 to 4 meters at each side of the trail. The forest floor debris, decaying trunks, cavities in logs, vegetation, holes in the ground, in addition to other areas that could function as shelter for the herpetofauna, will be inspected.

Sampling design: At least 100 hours of active search should be carried out per period.

Sampling unit: One hour of one observer. Less 100 hours of active search per period.

Supplementary techniques:

Active auditory search: This will occur by listening to the sounds (songs) of the Order Anura (day and night), with emphasis on close proximity collection in and around bodies of water (ponds, lakes, streams etc.). The sounds made by the Anura will be recorded as and when possible. Even though no specific sampling design exists for this particular technique, investment should still be made, on an equal basis, into the different types of habitats found within the grid.

Sampling unit: A recording of a vocal sound.

Rat glue traps

A method used for providing information in addition to data already collected through pitfall traps; glue traps mainly capture arboreal lizard specimens, i.e. animals that are very rarely captured in the pitfall traps (BAUER; SADLIER, 1992; RIBEIRO-JÚNIOr et al., 2006). These traps must be set out at a distance of 50 m from the pitfall traps, laid out on fallen logs and within a number of standing trees, at a height of around 0.5 to 2 meters.

Sampling unit: A glue trap.

Observations: It is necessary to take into account the variation of amphibian and reptile seasonal activity, with collections ideally taking place during different seasons throughout the year, each taking around 15-20 days.

Environmental variables: The following environmental variables may be utilized in the area designated for sampling, as applicable: air humidity, temperature (air, soil and water), rainfall, type of soil and the extent of the canopy opening.

Fixation and preservation of material: The date, area of capture, method of capture and the season identification number must be recorded for all captured specimens. The substrate where the animal was originally found must also be recorded for all active collections (including the height, diameter and the distance from the water or from the edge of a clearing that the animal was found, in addition to any other relevant information for each individual case), including the time of collection. All of the captured species must be photographed, whenever possible. The collected individuals will then be sacrificed by a lethal dose of an appropriate anesthetic.

Before fixation, (1) a tissue sample should be removed (either muscle of liver), then preserved in P.A. Ethanol for future molecular studies (this procedure aiming to maximize utilization of the collected material); (2) weighing and measuring should then take place (snout-vent length, limb length and, where applicable, length of the tail) of each specimen; and (3) notes taken regarding animal coloration while still alive, as applicable.

All data will be recorded in a field notebook, linked by a common field number, for example.

Amphibians and reptiles will be fixed in 4% formaldehyde (one 40% formaldehyde portion for nine portions of water) and then preserved in 70% alcohol. The collected samples must be deposited for use as future reference specimens in PPBIO linked scientific collections.

Referências

ÁVILA-PIRES, T. C. S.; HOOGMOED, M. S.; VITT, L. J. Herpetofauna da Amazônia. In: Nascimento, L.; Oliveira, E. (Eds.). Herpetologia no Brasil II. Belo Horizonte: Sociedade Brasileira de Herpetologia, 2007. p. 13-43.

BAUER, A. M.; SADLIER, R. A. The use of mouse glue traps to capture lizards. Herpetological Review, v. 23, p. 112-113, 1992. 

CORN, P. S. Straight line drift fences and pitfall traps. In: HEYER, W. R. M. et al. (Eds.). Measuring and monitoring biological diversity: standard methods for amphibians. Washington: Smithsonian Institution Press, 1994. p. 109-117.

CRUMP, M. A.; SCOTT JR., N. J. Visual Encounter Surveys. In: HEYER, W. R.; DONNELLY, M. A.; MCDIARMID, R. W. L.; HAYEK, C.; FOSTER, M. S. (Eds.). Measuring and monitoring biological diversity: standard methods for amphibians. Washington: Smithsonian Institution Press, 1994. p. 84-92.

GIBBONS, J.; SEMLITSCH, R. D. Terrestrial drift fences with pitfall traps: an effective technique for quantitative sampling of animal populatuions. Brimleyana, v. 7, p. 1-16, 1981. 

JONES, K. B. Effects of grazing on lizard abundance and diversity in western Arizona. Southwestern Naturalist, v. 26, p. 107-115, 1981.

RIBEIRO-JR, M. A.; GARDNER, T. A.; ÁVILA-PIRES T. C. S. Evaluating the effectiveness of herpetological sampling techniques across a gradient of habitat change in a tropical forest landscape. Journal of Herpetology, v. 42, n.4, p. 733-749, 2008.

RIBEIRO-JR., M. A.; GARDNET, T. A.; AVILA-PIRES, T.C. The effectiveness of glue traps to sample lizards in a tropical rainforest. South American Journal of Herpetology, v. 1, n. 2, p. 131-137, 2006.

SEMLITSCH, R. (Ed.). Amphibian Conservation. Washington: Smithsonian Books, 2003. p. 1-324.

YOUNG, B. E.; STUART, S. N.; CHANSON, J. S.; COX, N. A.; BOUCHER, T. M. Disappearing Jewels: The Status of New World Amphibians. Arlington: NatureServe, 2004. p. 1-54.