Several North African wetlands are classified as wetlands of international importance (Ramsar sites and Important Bird Area) because thousands of Shelducks (Tadorna tadorna) winter in these habitats. However, Shelduck’s patterns of habitat use in these protected wetlands during the wintering season are still hindered by lack of information in arid and semi-arid regions regarding population dynamics and the effects of climate variables. This ornithological survey aims to study population dynamics and temporal patterns of diurnal activities of the Shelduck at two Ramsar and Important Bird Area sites (Chott Tinsilt and Sebkhet Ezzemoul) with respect to the effect of climatic parameters of the habitat in order to deepen our understanding of wintering strategies and habitat use. Populations were weekly censused from 06:00 to 19:00 during the entire wintering season (September 2015–May 2016). Diurnal behavioural activities were monitored at the same rate, and then the variation of time budget was tested using generalized linear model to determine the effects of climate variables and conspecific density dependence. The Shelduck was observed at both sites from the end of November and remained there until the total desiccation of both lakes in early May. Trends of Shelduck’s population dynamics differed between the two sites. Generalized linear models revealed the significant effects of temperature, wind speed and number of snowy days on population dynamics. Feeding was the main diurnal activity of the Shelduck at both sites with 80.2% of time budget at Chott Tinsilt (mainly feeding at lake shores) and 82% at Sebkhet Ezzemoul (mainly feeding in water). The generalized linear models showed that the variation of time budget allocated to different diurnal activities was not density-dependent, but rather it was negatively affected by the increase of air temperature. Significant effects of the interaction between population size and some climatic variables were found and discussed. During the whole wintering season, Chott Tinsilt and Sebkhet Ezzemoul play an important ecological role since they offer a wide-ranging diurnal forging habitat and a shelter for thousands of this waterfowl.

中文翻译：

---

模拟气候对阿尔及利亚拉姆萨尔湿地 Shelduck (Tadorna tadorna) 越冬种群动态和昼夜时间预算的影响

几个北非湿地被归类为具有国际重要性的湿地（拉姆萨尔湿地和重要鸟类区），因为这些栖息地中有数千只 Shelducks (Tadorna tadorna) 在冬季。然而，由于缺乏干旱和半干旱地区有关种群动态和气候变量影响的信息，Shelduck 在越冬季节在这些受保护湿地中的栖息地利用模式仍然受到阻碍。这项鸟类学调查旨在研究两个拉姆萨尔和重要鸟类区（Chott Tinsilt 和 Sebkhet Ezzemoul）的 Shelduck 的种群动态和昼夜活动的时间模式，以及栖息地气候参数的影响，以加深我们对越冬策略和栖息地利用。每周从 06:00 到 19 进行人口普查：00 在整个越冬季节（2015 年 9 月至 2016 年 5 月）。以相同的速率监测昼夜行为活动，然后使用广义线性模型测试时间预算的变化，以确定气候变量和同种密度依赖性的影响。从 11 月底开始，在两个地点都观察到了 Shelduck，并一直留在那里，直到 5 月初两个湖泊完全干涸。Shelduck 种群动态的趋势在两个站点之间有所不同。广义线性模型揭示了温度、风速和下雪天数对种群动态的显着影响。觅食是两个地点 Shelduck 的主要昼夜活动，在 Chott Tinsilt（主要在湖岸觅食）占 80.2% 的时间预算，在 Sebkhet Ezzemoul 占 82%（主要在水中觅食）。广义线性模型表明，分配给不同昼夜活动的时间预算的变化与密度无关，而是受到气温升高的负面影响。发现并讨论了人口规模和一些气候变量之间相互作用的显着影响。在整个越冬季节，Chott Tinsilt 和 Sebkhet Ezzemoul 都发挥着重要的生态作用，因为它们为数以千计的这种水禽提供了广泛的昼夜锻造栖息地和庇护所。