59; natrix maura defence behaviour
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Great Chaco. Phyllomedusa 5, 149–157. Morello, J. & Adámoli, J. (1974). Vegetación y ambiente de la Provincia del Chaco. INTA. Serie Fitogeográfica 13. 130 pp. Scrocchi, G.J., Moreta J.C & Kretzchmar, S. (2006). Serpientes del Noroeste Argentino. Fundación Miguel Lillo, Tucumán, Argentina. 176 pp. IGOR BERKUNSKY 1 and FEDERICO P. KACOLIRIS 2 1 Laboratorio de Ecología y Comportamiento Animal. Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Pabellón II. Ciudad Universitaria (C1428EHA), Ciudad Autónoma de Buenos Aires. Argentina. 2 Laboratorio de Herpetología, Departamento de Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata. Paseo del Bosque s/n. (B1900FWA), La Plata. Buenos Aires. Argentina. NATRIX MAURA (Viperine snake): DEFENCE BEHAVIOUR. The ways in which animals respond to a perceived threat are varied and depend on many factors, for example the size of the predator, its body temperature, its size or sex or the nature of the terrain where the encounter takes place. Snakes employ a variety of defence behaviours in response to predators. Included in this array is `balling`, a behaviour that is perhaps most commonly seen in the small boid Python regius, but this has also been observed in the viperine snake Natrix maura in Spain (Hailey & Davies, 1986). The present note describes the behaviour in N. maura in the Vendee region of France and gives a photographic example. On June 23 rd , 2007 at the southern end of the village of Chasnais in the Vendee region of western France, a male N. maura (s.v. length 37cm) was captured whilst basking next to a drainage ditch. The snake was in the process of ecdysis (Figure 1) and this probably enabled the close approach and relatively easy capture as usually the snakes rapidly flee into water when approached. The weather was sunny at the time with an air temperature 23°C. After a few minutes handling, to enable the taking of photographs, the snake adopted the behaviour shown in Figure 2. As can be seen, the head is hidden and in the centre of the `ball` with the tail raised above, which could represent a tail lure where a less valuable part of the body is offered as a diversionary tactic. According to Arnold & Ovenden (2002), N. maura may attain total lengths of 100cm and hence this individual was at the smaller end of the size range. Hailey & Davies (1986) found that the behaviour was more frequently employed by smaller V. maura due perhaps to their lower endurance and suggested that static defence may reduce the feeding stimulus of a predator and adopted when fasting or where performance capacity was reduced, for example low body temperature. It may be that in the present instance ecdysis was also a contributing factor. However, it should be noted that here the behaviour was apparently used as a last resort and adopted after flight and then musk release had failed. Biting has also been cited as a defence response in N. maura (Arnold & Ovenden, 2002) but was not observed in this snake nor in any of the N. maura captured in this area – perhaps there are regional differences. Roth & Johnson (2004) attribute an absence of biting in certain snakes to the potential danger of reducing the distance between predator and snake and hence the vulnerability of the head and neck region to injury. 42 Herpetological Bulletin [2008] - Number 104 Natural History Notes Figure 1. Natrix maura, just after capture. As can be seen the snake was in the process of ecdysis, as indicated by the cloudy eye condition. © R. Meek. Figure 2. Natrix maura employing ‘balling’ behaviour. Herp. Bulletin 104.qxd 21/08/2008 09:05 Page 42
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Transcript of 59; natrix maura defence behaviour
Great Chaco. Phyllomedusa 5, 149–157. Morello, J. & Adámoli, J. (1974). Vegetación y
ambiente de la Provincia del Chaco. INTA. SerieFitogeográfica 13. 130 pp.
Scrocchi, G.J., Moreta J.C & Kretzchmar, S. (2006).Serpientes del Noroeste Argentino. FundaciónMiguel Lillo, Tucumán, Argentina. 176 pp.
IGOR BERKUNSKY1 and FEDERICO P.
KACOLIRIS2
1 Laboratorio de Ecología y ComportamientoAnimal. Facultad de Ciencias Exactas yNaturales. Universidad de Buenos Aires. PabellónII. Ciudad Universitaria (C1428EHA), CiudadAutónoma de Buenos Aires. Argentina.
2 Laboratorio de Herpetología, Departamento deVertebrados. Facultad de Ciencias Naturales yMuseo. Universidad Nacional de La Plata. Paseodel Bosque s/n. (B1900FWA), La Plata. BuenosAires. Argentina.
NATRIX MAURA (Viperine snake): DEFENCEBEHAVIOUR. The ways in which animals respondto a perceived threat are varied and depend on manyfactors, for example the size of the predator, its bodytemperature, its size or sex or the nature of the terrainwhere the encounter takes place. Snakes employ avariety of defence behaviours in response to predators.Included in this array is `balling`, a behaviour that isperhaps most commonly seen in the small boid Pythonregius, but this has also been observed in the viperinesnake Natrix maura in Spain (Hailey & Davies, 1986).The present note describes the behaviour in N. maurain the Vendee region of France and gives aphotographic example. On June 23rd, 2007 at thesouthern end of the village of Chasnais in the Vendeeregion of western France, a male N. maura (s.v. length37cm) was captured whilst basking next to a drainageditch. The snake was in the process of ecdysis (Figure1) and this probably enabled the close approach andrelatively easy capture as usually the snakes rapidlyflee into water when approached. The weather wassunny at the time with an air temperature 23°C. Aftera few minutes handling, to enable the taking ofphotographs, the snake adopted the behaviour shownin Figure 2. As can be seen, the head is hidden and inthe centre of the ̀ ball` with the tail raised above, whichcould represent a tail lure where a less valuable part ofthe body is offered as a diversionary tactic. Accordingto Arnold & Ovenden (2002), N. maura may attaintotal lengths of 100cm and hence this individual was at
the smaller end of the size range. Hailey & Davies(1986) found that the behaviour was more frequentlyemployed by smaller V. maura due perhaps to theirlower endurance and suggested that static defence mayreduce the feeding stimulus of a predator and adoptedwhen fasting or where performance capacity wasreduced, for example low body temperature. It may bethat in the present instance ecdysis was also acontributing factor. However, it should be noted thathere the behaviour was apparently used as a last resortand adopted after flight and then musk release hadfailed. Biting has also been cited as a defence responsein N. maura (Arnold & Ovenden, 2002) but was notobserved in this snake nor in any of the N. mauracaptured in this area – perhaps there are regionaldifferences. Roth & Johnson (2004) attribute anabsence of biting in certain snakes to the potentialdanger of reducing the distance between predator andsnake and hence the vulnerability of the head and neckregion to injury.
42 Herpetological Bulletin [2008] - Number 104
Natural History Notes
Figure 1. Natrix maura, just after capture. As can be
seen the snake was in the process of ecdysis, as
indicated by the cloudy eye condition. © R. Meek.
Figure 2. Natrix maura employing ‘balling’ behaviour.
Herp. Bulletin 104.qxd 21/08/2008 09:05 Page 42
REFERENCES
Arnold, E. N. & Ovenden, D. W. (2002). A Field Guideto the Reptiles and Amphibians of Britain and Europe.HarperCollins, London.
Hailey, A. & Davies, P. M. C. (1986). Effects of size, sex,temperature and condition on activity metabolism anddefence behaviour of the viperine snake, Natrixmaura. J. Zool., Lond. 208, 541–558.
Roth, D. R. & Johnson, J. A. (2004). Size based variationin antipredator behaviour within a snake (Agkistrodonpiscivorous) population. Behav. Ecol. 15, 365–370.
ROGER MEEK. 7 Rue Georges Clemenceau,
Chasnais 85400, France. [email protected]
COMMON TOAD (Bufo bufo): BREEDINGPHENOLOGY. The Common toad (Bufo bufo) isa cosmopolitan species occupying a variety ofterrestrial habitats all over Europe (Gasc et al.,1997). As the species has a wide distribution itseems logical that there will be differentreproductive patterns across its distribution.
The breeding season of this species is highlyvariable, influenced by altitudinal and climategradients. In Spain, B.bufo is supposed to have ahighly synchronized reproductive period (Richter-Boix et al., 2006) but with regional differences due tolatitude. In Doñana National Park (SW Spain), thebreeding season begins in January-February (Diaz-Paniagua et al., 2005); in mountanous populationsfrom Madrid, reproduction occurs in June (Martinez-Solano et al., 2006). In Cataluña, in the east of Spain,breeding onset ranges between January and March(Salvador & Garcia-Paris, 2001).
During the monitoring of Gandaras de Budiño eRibeiras do Louro wetland, Porriño, NW Spain(29TNG36), some strings of B.bufo eggs weredetected on 6th December 2006. This is the earliestrecord of toad egg-laying recorded during the last 10years of monitoring there. This fact was alsocoincident with the early metamorphosis of toadlets atthat site, these being found during the first week ofMarch 2007.The breeding season in Galicia starts inMarch according to published data about B.bufo inour region (Galan & Fernandez Arias, 1993; Galan,pers. comm.) but it seems that there is a trend towardsearlier breeding (Ayres & Garcia, 2007; Ayres, 2008).
The temporal spacing of the toad breeding seasonis not well known, it would be interesting to obtainmore information about reproductive differences dueto altitudinal and hydroperiod gradients (Hartel et al.,
2007). Also, climate change could modify thebreeding phenology of temperate amphibians and isknown to affect reproduction and survival(Tryjanowski et al., 2003; Reading, 2007; Sparks etal., 2007). This could be the reason for these earlyspawn strings, as Galicia sometimes suffers in thisdecade severe drought during summer-autumm, withthe driest period in the last 60 years recorded in 2006-2007. Daily maximum temperature was also high,reaching 20ºC on some days. It seems that acombination of rainfall and high temperature could bethe driving factor that led B.bufo to start the breedingseason earlier than in previous years.
REFERENCES
Ayres, C. (2008). Post-mortem amplexus in maraudedBufo bufo (Linnaeus, 1758). Podarcis 9 (In press).
Ayres, C. & Garcia, P. (2007). Depredación de nutriaLutra lutra (Linnaeus, 1758) sobre sapo común Bufobufo (Linnaeus, 1758) en el lic Gándaras de Budiño(Galicia). Galemys 19, 45–50.
Díaz-Paniagua, C., Rodríguez, C., Portheault, A. & deVries, W. (2005). Los anfibios de Doñana. OrganismoAutónomo de Parques Nacionales, Madrid.
Galán, P. & Fernández-Arias, G. (1993). Anfibios yréptiles de Galicia. Edicions Xerais de Galicia, Vigo.
Martínez-Solano, I., García-París, M. & Bosch, J. (2006).Anfibios de Peñalara, Identificación y Conservacion.Direccion General de Promocion y DisciplinaAmbiental. Comunidad de Madrid.
Hartel, T., Sas, I.; Pernetta, A.P. & Geltsch, I.C. (2007).The reproductive dynamics of temperate amphibians:Areview. North-Western J. Zool. 3, 127–145.
Richter-Boix, A., Llorente, G. A.& Montori, A. (2006).Breeding phenology of an amphibian community in aMediterranean area. Amphibia-Reptilia 27, 549–559.
Reading, C. J. (2007). Linking global warming toamphibian declines through its effects on female bodycondition and survivorship. Oecologia 151, 125–131.
Salvador, A. & García-París, M. (2001). AnfibiosEspañoles. Identificación, historia natural ydistribución. Canseco Editores, Talavera de la Reina.
Sparks, T., Tryjanowski, P., Cooke, A., Crick, H. &Kuzniak, S. (2007). Vertebrate phenology at similarlatitudes: temperature responses differ between Polandand the United Kingdom. Climate Research 34, 93–98.
Tryjanowski, P., Mariusz, R. & Sparks, T. (2003).Changes in spawning dates of common frogs andcommon toads in western Poland in 1978–2002.Annales Zoologica Fennici 40, 459–464.
CESAR AYRES. ROAGA. Centro de Investigación eInformación Ambiental -Estrada PO-546 Pontevedra-Marín, km. 4 Apdo. 127- C.P. 36080. Lourizán -Pontevedra-Spain. [email protected]
Number 104 - Herpetological Bulletin [2008] 43
Natural History Notes
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