Ecology, phenology and wintering behavior of Anatidae in the wetlands of Souk-Ahras (north-eastern Algeria)

Study Extent

The wilaya of Souk-Ahras (4,365.59 km2) is located in north-eastern Algeria, at the limit of the Tunisian border on a strip of 88 km. It is bound to the northeast by the wilaya of El-Taref, Guelma in the northwest, Oum El-Bouaghi in the southwest, Tébessa in the south, and Tunisia in the east. The region has a Mediterranean climate; it is subhumid in the north and semi-arid in the south with cold winters and scorching summers in the south. Most wetlands in the region depend on the climatic conditions for their water supply, mainly rainfall. Our work covered three natural wetlands: Tiffech and El-Kaf hill reservoirs and the marsh of Madjen Djedj.

Sampling

The phenology and structure of the Anatidae population was monitored bi-monthly over 12 months, from September 2019 to August 2020. Our counts allowed an individual count when the flock of waterbirds was close to the point. When the number of individuals was less than 200, we counted them individually. When the number of individuals was greater than 200 or at a greater distance, we made a visual estimate (Lamotte and Bourlière, 1969; Blondel, 1975; Houhamdi, 2002). The counts were carried out by direct observation using a KONUSPOT 20-60x80 telescope. The estimated total number represents the sum of all flock snumbers (Houhamdi and Samraoui, 2001, 2003, 2008; Aissaoui et al., 2011). This method often has an estimated margin of error among professionals of 05-10%. It also depends on the observers' experience and the quality of the optical equipment used (Legendre and Legendre, 1979; Tamisier and Dehorter, 1999). To characterize the waterbird community, a few ecological indices were calculated, namely the total abundance, species richness, the Shannon and Weaver diversity index (H') and the index of fairness (E) (Chessel et al., 2004). The second part of our study consisted of monitoring the rhythm of the daily activities of Anatidae. We used the the SCAN method, carried out every hour, from 9 a.m. to 4 p.m. (Baldassare et al., 1988; Losito et al., 1989; Tamisier and Dehorter, 1999; Boulekhssaim et al., 2006). The activities monitored were feeding, sleeping, swimming, grooming, flight, courtship, and antagonism (Houhamdi and Samraoui, 2001, 2003, 2008; Metallaoui et al., 2009).

Method steps

1. We used R 3.5.2 (R Development Core Team 2019) ) provided with the FactoMineR package. Data were expressed as mean ± SD for analysis. The Shannon and Weaver diversity index (H ') and equitability index (E) were calculated using ADE software (Chessel et al., 2004). Species are presented in the systematic order of Sibley and Monroe (1990). To conduct comparisons of diversity indices across the three sites, we applied the Kruskal-Wallis test (nonparametric alternative to ANOVA), first because our data did not meet the normality and homoscedasticity assumptions, and second to assess the difference in abundance across sites.

1. Anseriformes
   rank: order
2. Anatidae
   rank: family
3. Anas clypeata
   rank: species
4. Anas penelope
   rank: species
5. Anas platyrhynchos
   rank: species
6. Anas acuta
   rank: species
7. Anas strepera
   rank: species
8. Oxyura leucocephala
   rank: species
9. Aythya nyroca
   rank: species
10. Aythya ferina
    rank: species
11. Marmaronetta angustirostris
    rank: species
12. Anas crecca crecca
    rank: species
13. Anas querquedula
    rank: species
14. Tadorna tadorna
    rank: species
15. Aythya fuligula
    rank: species

The wilaya of Souk-Ahras (4,365.59 km2) is located in north-eastern Algeria, at the limit of the Tunisian border on a strip of 88 km. It is bound to the northeast by the wilaya of El-Taref, Guelma in the northwest, Oum El-Bouaghi in the southwest, Tébessa in the south, and Tunisia in the east