Methodology "Study of wild fauna"
As previously indicated, one of the main purposes of the EER; is the generation of information for the "Design of the Monitoring and Evaluation System of Biological Indicators ", for this reason the methodologies for the capture of information of the main taxa of wild fauna have been designed to correspond to the generation of information that allows the formulation of the design.
The sampling methodologies (information capture) will have as main characteristic the ease of sampling, the speed with which it will be carried out, the participation of local actors and the generation of databases that will allow the monitoring of the investigation.
to. Biological data collection
The methodology used to obtain the basic biological data for the Rapid Ecological Assessment (REA) will be based on:
Indices of abundance
Indices of abundance will be established based on:
- Number of footprints or animals observed or heard per distance of travel; Auditory counts for birds; Bird counting points at established fixed points; Census of raptors from hills or emerging trees.
Relative abundance indices for mammals
The fixed width transect will be used as the sampling unit, whose length will vary according to the different areas, in the same way the width of the transect can be defined according to the characteristics of the gap, path or road used. In each area, specific sampling areas will be defined in the core zone and buffer zone, walking at a pace of 2 kilometers per hour, along the path or established gaps looking for mammals or tracks. Upon finding a footprint, the species, the date and the place where it was found will be recorded in the designed field collection forms (Annex 2).
The tracks will be identified according to Aranda (2000) and Carrillo et al (1999). The tracks that will cross the trail (transect) will be recorded as an observation. When the tracks extend over a large part of the transect, they will also be considered as an observation. In the case of gregarious species (such as fish), the group of animals or tracks will be recorded as a single observation. In the particular case of primates, when a group is located, it will be recorded as an observation. All sampling transects will be geo-referenced and their distance determined with a tape or GPS.
Indices of abundance will be calculated by dividing the number of observations of tracks (footprints, feces, troop of primates, songs, others) of animals by length of trail in kilometers, number of individuals per kilometer. (See Annex No. 2 “Information capture forms”)
Relative abundance indices for birds
To determine the abundance indices of birds, the methods described by Whitacre (1991) will be used, which consists of:
Opportunistic counts: Using between 06:00 and 08:00 hours. These will consist of walking established trails recording the species of birds observed and the number of individuals of each one of them. The start and end time of the route will be noted and an estimate of the length of the path traveled will be made in order to standardize the sampling. However, this information will not be applied for statistical comparisons.
Auditory counts: It will consist of recording all the species and the number of individuals of each one heard during 60 minutes, from a determined sampling point. Method used for the rest of the areas except for those mentioned above.
Sampling by counting points (PC): This technique will consist of staying (the researchers) in several pre-determined points in the forest or outside it and recording the bird species and the number of individuals of said species, which are observed or listened for a period of 10 minutes. Sampling will take place at dawn, during the period of greatest bird activity, which runs from approximately 5:45 a.m. to 9:00 a.m. In each area there will be four to eight counting points, all points will be georeferenced with a GPS. This method applied to the rest of the areas except those mentioned in the opportunistic counts.
Counting of birds of prey: Census of raptors will be carried out from viewpoints located on hills with good visibility or on the crown of emerging trees. Raptor species shall be recorded, the number of individuals of raptor species and the number of individuals of each species in a period of two hours; that is, between 9:30 a.m. and 11:30 a.m.
Use of mist nets: The use of nets and the application of the capture, tagging and recapture method has been widely used to estimate bird populations. Mist nets are made with very fine and resistant “nylon” threads. They can vary from 2 to 12 m in length and be black, gray, dark green, white, etc. They are installed between two supports (wood, metal tubes, and others), which ensure and keep it extended during the study time. They can be installed on paths in the forest, in clearings, tied to tree branches, and even in open fields (Bleitz, 1970).
The indices of relative abundance of birds will be obtained by dividing the number of individuals of each species by the number of count points. In this way, this index is expressed as, Number of individuals divided by the counting points.
b. Wealth and diversity indices
The simplest measure of species diversity and richness is to count the number of species that occur in a unit area; however, this count itself has two main limitations: first, it turns out to be an unweighted measure, since it does not take into account the abundance of the species present. The second limitation refers to the fact that the species count depends on the size of the sample.
The basic problem of measuring these parameters is that it is not possible to count all the individual species of a community, and therefore, there is no index that was extracted in their measurement. There are better rates than others, depending on the type of collection that is carried out.
In the case of Protected Natural Areas, two indices will be used to determine the richness and diversity of species. The Margalef index (Equation No. 1) will be used to measure the richness of species of birds and mammals, its main virtue is that it eliminates the effect of sample size, but it does not allow comparing the richness between two communities. The values fluctuate from 0 onwards, as it is larger, that value the greater the wealth.
The diversity of species of birds and mammals will also be determined using the Shannon-Weaver index (H ', Equation No. 2), which is one of the simplest and widely used indices, it has the advantage of being independent of the size of the sample (Brower et al.; 1989), this means that it works well with few counting data (birds, mammals, plants, and others.), but in small scattered samples it produces a lot of bias. It also allows statistical comparisons between communities, areas, complexes, and others. The index takes values from 0 to a maximum close to 6 (very rare); therefore, the higher the index value, the greater the diversity of an area.
c. Analysis of capture data by neblinear networks
When birds are caught in nets, they can be marked with numbered aluminum or plastic rings; birds are released and are later recaptured. Placing a mark on the bird provides information on the movement of species, many of which are emigrants from different parts of the planet. With these data it is possible to understand the dynamics of the population. According to Seber (1972), cited by Almeida (1981) it is also important to report on longevity, growth, age and sex of birds. Robbins (1978) presented the following advantages in tagging and recapturing birds:
- Determine the species present. Distinguish resident species from non-resident ones. Help in determining the size of territories. Help in determining the size of populations; yAllows the census of females and juveniles in the same way as adult males.
Stam et al. (1960) calculated the populations of some species in Maryland using Petersen's principle, which is based on the reasoning that “if a number of birds is tagged and released, the proportion of birds tagged in a next sample in relation to the that were marked earlier, gives an estimate of the original population. Such relationship is expressed by the formula:
Bailey (1951), cited by Stam et al. (1960), gave a formula to calculate the standard deviation of the variable N:
Where:
N = Total number of birds present during the tagging period.
M = Number of birds tagged and released during the tagging period.
C = Total number of birds caught (with or without tags) during the sampling period.
R = Number of birds recaptured (caught with tag) in the sampling period.
The same authors confirmed that the population estimates made from this method are based on the following assumptions:
- Markings do not occur or are lost randomly. There is no difference in mortality between marked and unmarked individuals. The distribution of marked and unmarked individuals is random. The number of individuals remains unchanged in the population, there is no entry or Output of tagged and unmarked birds Animal behavior and capture efficiency are the same for tagged and unmarked individuals.
These assumptions required in the method of estimating bird populations through capture, tagging and recapture, have been the subject of many studies and observations by many authors. Cormack (1968), cited by Almeida (1981), stated that the difficulty of capture and recapture studies is in the random distribution, equal vulnerability and other factors linked to behavior.
Eberhardt (1969) analyzed different estimates of wild animal populations, based on the frequency of capture. Studying 40 data sets for 10 species of animals, he concluded that much of the data from the capture-recapture studies suggests that the fundamental assumptions are violated, that is, the probability of capture does not appear to be the same for all animals.
The aforementioned author mentions that the simple fact of a territorial behavior promotes an argument contrary to the assumption of "random distribution". It also suggests that there is evidence that sex and age influence capture intensity and that mortality and emigration must also be considered.
Roff (1973) cited by Almeida (1981), examined some statistical tests used in the analysis of markings and recaptures. It showed that the tests are not adequate under certain conditions. The most important of this is that the population stratified with respect to the probability of capture, cannot be distinguished from a homogeneous population. The tests that were applied are:
- Chi-square test for recapture frequency models Poisson test and Leslie test to analyze equal probability of capture Regression analysis to see equal probability of capture for multiple samples of a closed population.
The author concluded that there is considerable evidence that animal populations in general are not homogeneous with respect to the probability of capture.
In net work, initially the capture rate is high, decreasing over time, so a greater number of birds resident in the vicinity are captured and later learn to avoid the nets. Eventually, the high asymptotic catch rate depends on the number of nonresident individuals (Mac Arthur and Mac Arthur, 1974).
The aforementioned authors stated that this trend increases more in certain species than in others, and it seems that it is accentuated more in the tropics than in temperate zones. Finally they concluded that bird populations are made up of two or more parts, the first is made up of those who own territory, called residents, which are constantly subject to probable capture and are usually almost all captured, marked and released, 'la The second consists of transitory birds (non-resident and migratory individuals) that seem to pass through the site of the net at an almost constant intensity, with some new capture of unmarked individuals occurring every day, no matter how many days the nets are in operation..
Otis et al (1978) analyzed the three basic types of variations in the probability of catches:
- Capture probabilities vary over time, capture probabilities vary with behavior, and capture probabilities vary individually for each animal.
Botkin and Miller (1974) studied the mortality and survival rate of birds and concluded that the assumed constant mortality rate is not true. Chapman (1954) cited by Almeida (1981) analyzed various statistical models to estimate biological populations. He concluded that the study of the processes of birth and death; and the processes associated with random distribution, as well as migratory movements, are necessarily associated with the population estimation problem, and this will only be fully resolved when the associated problems are also.
Due to the drawbacks previously presented, in this work traditional capture and recapture methods cannot be used to estimate populations.
d. Interviews
Semi-structured interviews will be carried out with the inhabitants of communities close to the core areas (hunters, fishermen, farmers, community leaders and resource guards) to determine the presence or absence of the species. This information will be part of the analysis, as part of the discussion of critical areas and uses of fauna species in the Natural Protected Areas.
and. Analysis of data
The relative abundance indices of each of the species of birds and mammals will be plotted, located on the Y axis of the value and the index on the X axis the different locations where the species are present. In the same way, these indices will be used to make comparisons between areas and between conservation units and buffer zones, using the Mann-Withney tests for two samples, to test differences in the abundance of a certain species in each area. In the case of the Shannon-Weaver indices, the comparison will be made with the t-student test, to determine if the difference in diversity is significant between areas or between zones. In the latter case, the analyzes will be made for songbirds and raptors separately.
Information capture forms
In Annex No. 2, you can see the forms that will be used for the work of collecting field information for wild fauna, mammalian and bird taxa.
Form No. 1 "Bird counting points"
Form No. 2 "Visual census of birds of prey"
Form No. 3 "Auditory Bird Count"
Form No. 4 "Capture in mist nets"
Form No. 5 "Mammals in transects"
Form No. 6 "Special Animals"
Form No. 7 "Interview on animal observations"
Phase III "Integration of information" (Final Cabinet)
Based on Phase I and Phase II, the primary and secondary information collected will be integrated to establish the following results:
to. Results
Vegetation:
The main results obtained from the vegetation field study are:
- Map of vegetation cover of conservation units, buffer zone and region of influence of the San Diego-La Barra Natural Protected Area and Montecristo National Park; Map of delimitation of plant communities; Ecological variables on floristic composition of plant communities; Idealized profiles of communities plants in different seral stages (successional); Digitized base of plant communities used for the superposition of plant communities and main ecological variables; List of trees and shrubs, with categories of abundant, rare, threatened and of value for conservation; List of flora at a general level within each sampled area; Characterization of plant and anthropogenic communities;Database of plant communities used to generate a map of distribution and abundance of wild fauna; Document presenting the results.
Wildlife
- Indices of relative abundance of mammals and birds; Index of richness and diversity of mammals and birds; Comparative distribution diagrams of mammals and birds in the macro-management zones of Natural Protected Areas; List (inventories) of mastofauna and determined avifauna; Database and thematic maps of relative distribution of mastofauna and avifauna by macro-management zone, Relationship of ecological variables based on: 1. Structure of communities (flora and fauna); 2. Identification of metapopulations; 3. Identification of the incidence of fragmentation of ecosystems. Comparative variables of frequency and abundance with previous studies carried out in the area.
The integration of results will be presented in a technical document (EER report), which will contain in descriptive and statistical form the results obtained from the office and field stages. In addition, a database will be established together with thematic maps (printed and digitized) on the results of distribution and abundance of plant ecosystems, mammals and birds.
