Report for Idea Wild

TARABORELLI, P.

2011-03-24/2034-12-31

1-56

Biológica

Medio terrestre-Conservacion

THE GENERAL OBJECTIVE OF THIS PROJECT IS: To analyze and determine the influence of environmental, biological and anthropic factors on the sociality of L. guanicoe. SPECIFIC OBJECTIVES AND WORK HYPOTHESIS The work plan will address different specific objectives related to establishing the different factors that would be determining sociality in L. guanicoe: Regarding environmental and biological factors 1. To analyze the influence of climate conditions (frost, snowfall) and of the productivity and availability of forage resources on the social organization of guanacos for a migratory population in the south of Mendoza. Hypotheses and Predictions: H1: Social organization is influenced by environmental conditions (frost, snowfall, drought). P: Therefore, the social organization of migratory populations will disappear in winter because all individuals in large mixed groups congregate to migrate, whereas the basic social structures will be present in summer (family group, groups of males, groups of females, solitary males). H2: Throughout the summer, the distribution and quality of pastures determines the type of social group, group size and group location. P1: Family groups will occupy areas with the best pastures, compared to groups of bachelor males. P2: It is expected that family groups are composed of a greater number of individuals at sites with better food quality. 2. To determine the repertoire of social behaviours (e.g. agonistic behaviour, cooperative behaviour, contact patterns, vocalizations, etc.) and make comparisons between types of social groups. Hypotheses and Predictions: H1: The behavioural repertoire varies among the different social groups due to the different interactions taking place in each of them. P1: Then, behavioural richness (more variety of behaviours) will be greater, and index of association higher, in family groups than in groups of bachelor males due to more numerous mother-offspring interactions. P2: Contact patterns, rate of cooperative behaviour (for example extraparental care) and vocalizations will be superior in family groups and females with young. H2: The agonistic behaviour varies across the year. P: Agonistic behaviours and index of aggressiveness in territorial males toward bachelor and one-year-old males will increase in the reproductive season. 3. To study the antipredator behaviour (vigilance, vocalizations and escape) and relate it to predation risk and group size. Hypotheses and Predictions: H1: Efficiency of the antipredator response is associated with group size. P1: Therefore, in groups with more members, antipredator response will be faster (less latency time until the first antipredator response) and more efficient (with alert calls and larger escape distance). P2: And time spent on vigilance by each individual will diminish on account of a larger number of members in the social group. H2: The antipredator behaviour is related to the predation risk to which social groups are exposed. P: The proportion of antipredator behaviour is expected to increase at sites with taller and denser vegetation. 4. To determine the type of polygyny (mating system) and the influence on it of environmental quality (productivity). Hypothesis and Predictions: H1: Biological variables such as pasture availability and quality have influence on polygyny. P1: Then, at sites with low plant productivity and pronounced drought seasons, like in Payunia, the mating system will be female-defence polygyny. P2: Males will start establishing their territories in summer and the number of females will be positively related to quality of the territory?s pastures. 5. To relate territory defence behaviour to cortisol levels in faeces, during the summer. Hypothesis and Predictions: H1: There is a relationship between territory defence behaviour and cortisol levels in faeces. P: Cortisol levels in faeces are expected to increase with increased agonistic behaviours associated with territorial defence. Regarding anthropic factors 1. To identify and quantify behavioural indicators of stress during management, such as escape attempts, vocalizations, kicking or struggling, and relate them to serum cortisol levels (stress indicator). Hypothesis and Predictions: H1: During management, there are behaviours that vary in response to stress, as does the serum cortisol level. P1: It is expected to find that agonistic behaviour, index of aggressiveness and vocalizations will increase during management. P2: These behavioural indicators of stress are related to higher serum cortisol levels. 2. To determine the effect of management (capture and shearing) on group restructuring. Hypothesis and Predictions: H1: Management temporally modifies social organization. P: Therefore, some percentage of the groups will be composed of new members after shearing. 3. To determine the effect of shearing on temperature regulation, using foraging and resting rates and proportions as indicators, comparing shorn and non-shorn guanacos. And to relate these indicators to cortisol levels in faeces. Hypothesis and Predictions: H1: There are behaviours related to temperature regulation that vary temporally between shorn and non-shorn guanacos. P1: Then, the proportions of resting behaviour will be higher in shorn guanacos in the first months after shearing, and foraging behaviour will decline. P2: An increase is expected in cortisol levels in the faeces of shorn guanacos due to thermal stress. MATERIAL AND METHODS For obtaining basic information Samplings: Five to six field trips a year will be made to obtain behavioural and population data: during the management experiences in October, after shearing in November-December (parturition season), in February (reproductive season), May-June (period of lowest forage availability and the start of migratory activity) and September (period when mixed groups disperse and return from migration). Environmental variables: records of temperature, rainfall, winds and snowfall will be obtained from a weather station set up at La Payunia Reserve. Vegetation sampling (food quality and availability): The spatiotemporal variation in the primary productivity of the system will be estimated from vegetation reflectance indices. In this case, the index used will be EVI (Enhanced Vegetation Index, Huete et al. 2002) which is less sensitive than NDVI (Normalized Difference Vegetation Index) to the interference caused by the reflectivity of bare soil and, therefore, very appropriate for arid and semiarid areas where vegetation is poor and sparse. The seasonal EVI for the study area will be obtained from the database generated by the NASA MODIS/MODLAND team/Earth Observation System, from MODIS satellite images with an approximate resolution of 0.25 km (Huete et al. 2002). Given that food availability is also affected by vegetation composition in terms of dominance of plant species palatable to herbivores, and of the distribution of functional groups, the available vegetation maps (León et al. 1988) and maps of ecosystem functional types or biozones (Paruelo et al. 1998, Paruelo et al. 2001) will be included in the GIS. Combining this baseline information with seasonal EVI will allow relating the presence of guanacos to the spatiotemporal variation in primary productivity, composition of the vegetation and its functional heterogeneity. In a parallel manner, these data will be validated in the field with information obtained from visual estimates of relative abundance and plant coverage of functional groups and dominant species, using the ?point quadrat? method (Braun Blanquet 1950, Braun 1973). Indicator of predation risk: on the same transects used for guanaco population surveys (see below) the presence of guanacos dead from predation will be recorded, confirming whether they had been attacked by a puma using as a guide the Manual to identify Andean carnivores (Palacios 2007). Each carcass will be georeferenced and dated, also sex and relative age of the guanaco will be determined and the environment will be characterized (Puig & Monge 1983). Presence of predators will be recorded as well from direct observation and different signs of activity such as footprints and droppings (Cajal & Lopez 1987). Identification of individuals: Animals will be marked during shearing with a blue collar for males and a red one for females. Each collar will have a numbered tag for identification. During the shearing stage, sex, relative age and reproductive status will be determined for each individual. For developing the objectives related to biological (1, 4) and anthropic (2) factors Abundance of guanacos, their social structure and age composition will be estimated throughout the year, from surveys on line transects of variable width and an approximate length of 5 km (Buckland et al. 1993), which will consist in drive along the trails available in the Reserve on a pick-up like vehicle, at low speed (between 20 and 30 km/hour). Two observers standing on the back of the vehicle detect the presence of animals, and the vehicle stops each time a group is observed so as to count the animals, discriminating among adults, juveniles and young, sex, and relative age when possible, as well as social category: family groups, groups of males, of females and of solitary individuals (Baldi et al. 2001). Tagged animals will also be identified whenever possible. Distance between each group and the vehicle will be estimated using a laser telemeter, calculating the angle between the north and the group or individual, and the position of the vehicle will be recorded using a portable satellite positioning system (GPS, First National Census of Camelids 2006). The data will be analyzed with the Distance software (Buckland et al. 1993), which will be used to estimate animal density (individuals.km-2), along with other parameters like group size and group density. For developing the objectives related to biological (2, 3, 4, 5) and anthropic (1, 3) factors Social group and behaviour: Daily observations will be carried out during the period of diurnal activity of animals using binoculars and a telescope; each observation will be recorded with a digital voice recorder. Observations will be made from different natural high spots (4-6) within the Reserve. One of the methods used will be 360º scanning with instant record, from fixed observation points (Altman 1974, Martin & Bateson 1993, Lehner 1996). The other method will be continual focal records, recording all behaviours displayed during observation time (Altman 1974, Martin & Bateson 1993, Lehner 1996). Adjustment of focal sampling time will be made during the first trip to each site using ad libitum samplings, from which the sampling unit will be determined with the minimum time-area method (Matteucci & Colma 1982). Number of animals per group (marked and unmarked), number and type of groups, animal activity, distance between guanacos within the group (measured in guanaco units GU), distance between groups and environment characterization will be recorded through scanning. These samplings will be carried out on a yearly basis, for each season described in Samplings. Focal samplings will be used to record behaviours of all different members of the groups. Focal guanacos will be chosen at random, and there will be no repetition of individuals, at least not daily. Locomotion, resting and foraging behaviour (Rey et al. 2009) will be recorded, as well as contact patterns, agonistic interactions in general and those associated with territoriality, alert to conspecifics, playing, filial behaviour, mating behaviour, defecation, urine excretion, antipredator responses (alert postures, vigilante, escape, vocalizations) and interaction with other social groups. These samplings will also be on a yearly basis, for each season described in Samplings. Rates = frequency of behaviour/observation period in minutes, and proportions = behaviour duration in minutes/observation period in minutes, will be obtained to compare behaviours. Frequency is the total number of occurrences of a given behaviour (Martín & Bateson 1993). Behavioural richness for the different types of social groups will be estimated as the number of behaviours recorded for each of them. The Association Index (Martín & Bateson 1993) will be obtained for the different types of social groups as follows: NAB / (NA + NB + NAB), where NAB= Number of occasions when A and B were seen together, NA= Number of occasions when A was seen without B, and NB= Number of occasions when B was observed without A. Only focal samplings will be carried out during shearing, characterizing each animal by sex and age. Vocalizations, kicking or struggling and sputtering or spitting will be recorded during this period (Vilá 1992, Vilá 1994, Puig 1995, Young & Franklin 2004). Agonistic interactions will be quantified by estimating an Aggressiveness Index for each age and sex category, both during and after shearing: Ag= I - R/I + R. Where I= number of aggressive encounters initiated, and R= number of aggressive encounters received, the index varies between 1 and -1 (Vilá 1992). Territory defence: territorial encounters will be mapped to determine territorial limits between males; location of dung piles used by territorial males (determined by direct observation) will be recorded, as well as daily location of each individual and territory area; all of these sites will be marked with GPS, and the territory will be characterized (vegetation, hill, slope, lowland, etc.) Aggressive interactions will be grouped into indirect (by intimidation through menacing postures, defecation on dung piles, ears low, shorts, spitting, vocalizations) and direct (which involve physical contact, fights with blows with neck and or/knees, biting, runs with attacks; Raedeke 1979, Wilson & Franklin 1985). This sampling will take place in summer (reproductive season). Antipredator behaviour: Visual recognition and response to a predator will be tested by bringing a potential predator (a puma and/or a man) near a social group (a person approaching on foot, on a vehicle, on horse and using a fake puma). Sites with different type of vegetation will be chosen, grassland and closed shrubland. Individual and group antipredator responses will be videotaped, analyzing number of individuals and composition of the social group. Latency time until the first antipredator response will be recorded, as well as escape distance and type of response (escape, vocalization, no reaction; Fortín & Andruskiw 2003, Donadio & Buskirk 2006). These experiments will be performed for family groups with or without offspring, and for groups of bachelors, to test for differences in the effectiveness of the antipredator response. These experiments will be conducted in summer (reproductive season). Behavioural samplings, both focal and scanning, will be transcribed using the Digital Wave Player programme and the data will be captured, edited and analyzed with JWatcher V 1.0. For developing the objectives related to biological (5) and anthropic (1, 3) factors Cortisol levels: Non-invasive techniques have recently been developed to measure cortisol metabolites (Cavigelli 1999, Foley et al. 2001, Millspaugh et al. 2001, Creel et al. 2002, Muller & Wrangham 2004, Touma et al. 2004) in faecal samples. This is an innovative method that affords many advantages, such as easy sample collection, the possibility of year-round collection and an integrated measurement of hormone secretion (Harper & Austad 2000). Fresh faeces will be collected after observing an individual defecate on a dung pile. Samples will be kept in sterile plastic bags and placed in dry ice for hormone determination (Ovejero et al. 2007a and b, Carmanchahi et al. 2005). These samplings will be carried out on a yearly basis, for each season described in Samplings. To relate the frequency of agonistic behaviours and behavioural indicators of stress to cortisol levels during shearing, blood samples will be taken while the animal is shorn. Blood samples will be extracted from the femoral vein using 18G needles and sterile syringes of 20 cm3. In the field, blood will be centrifuged for 20 minutes at 2000 rpm with a portable centrifuge. The obtained serum will be fractionated into Eppendorf tubes, labelled and frozen in liquid nitrogen until transport to the laboratory where samples will be preserved at -20°C. Cortisol concentration, both in the faecal and serum fractions, will be determined using Radioimmunoassay kit (RIA). These analyses will be carried out in laboratorios of the Institute of Medicine and Experimental Biology of Cuyo (IMBECU), CCT-Mendoza, which are furnished with all the necessary infrastructure and equipment to perform this methodology.