栖息地选择的理论与模型

栖息地选择理论和模型的发展经历了两个主要阶段：理想自由分布模型和空间直观的栖息地选择模型。随着对理论模型假设的放宽,近年来产生了越来越多的新模型。通过对栖息地选择过程的分析,提出了栖息地选择的几个关键环节：栖息地偏好、信息获取、行为决策及选择行为。在建立栖息地选择模型的各个关键环节上均存在大量有待解决的问题。目前对栖息地偏好的研究主要为相关分析,栖息地信息获取的过程仍然是一黑箱;对动物在栖息地选择过程中的行为决策以及对其生理状态的影响尚不了解,而解决这些问题需要生态学、生态学及认知学等多个领域的研究结果支持,也有待新的理论及方法加以充实,甚至还需要其他学科的介入。     

大沙鼠对栖息地的选择

根据地形特点和植被状况在调查地共划分出５类生境,大沙鼠最适生境为白刺＋盐爪爪＋红柳半固定沙丘。另外,大沙鼠对栖息地的选择有明显的季节差异,在春季大沙鼠多栖息于白刺＋盐爪爪半固定沙丘;秋季,又向盐爪爪＋裸露土岗生境迁移。食物条件、地形特点和植被覆盖度是影响大沙鼠栖息地选择的三个重要因素。     

新疆准噶尔盆地东部波斑鸨秋季栖息地选择

2000年9月,利用粪便示踪和野外直接观察法对准噶尔盆地东部波斑鸨（Chlamydotis undulata)秋季栖息地进行了采样调查。结果表明：波斑鸨秋季栖息地地热平坦,视野开阔,广泛分布旱生和盐生荒膜植物,植被稀疏、低矮,并镶嵌有相对较高的灌丛块;影响波斑鸨秋季栖息地选择的环境因子是植被密度、物种丰富度和物候;秋季栖息地内的植被密度、草木植物种数、叉毛蓬密度、结实植物密度和物种数都极显著高于对照地内的相应成分;生长植物密度显著高于对照地;而假木贼密度和琵琶柴密度显著低于对照地。     

江苏盐城黑嘴鸥的繁殖栖息地选择

对江苏盐城黑嘴鸥繁殖期觅食地和营巢地及其主要特征进行了调查,黑嘴鸥繁殖觅食地有盐田,碱蓬滩,草滩,水产品养殖塘,农田,泥质滩涂及河口港汊7种类型,生境选择的结果表明黑嘴鸥对碱蓬滩涂和泥质滩涂都有正选择性,对农田和河口港汊具有负选择性,繁殖前期对养殖塘具有正选择性,不同繁殖时期黑嘴鸥对碱蓬滩和养殖塘的利用情况变化最明显,两年中,黑嘴鸥对河口港汊的利用情况稳定,黑嘴鸥营巢地有獐毛滩,碱蓬滩和大米草滩3种类型,其中碱蓬滩是其主要营巢栖息地,对巢址选择因子的分析的结果表明：影响黑嘴鸥巢址选择的因子主要有4类,依次为：植被盖度和群集度,人为活动干扰强度,底栖生物量及距水源距离,其贡献率分别为26．23％,20．55％,14．82％,14．02％。     

中国大陆鸟类栖息地选择研究十年

栖息地选择研究一直是鸟类生态学研究的重要内容之一。通过对2001年1月至2010年12月10年期间中国大陆鸟类学家在国内外期刊上发表的鸟类栖息地选择研究的论文进行分析,对我国鸟类栖息地选择研究提出展望。10年间,我国鸟类学家共发表有关鸟类栖息地选择或利用的论文170篇,共涉及到鸟类10目31科73种。在这10年里,中国大陆有关鸟类栖息地选择或利用的文章持续增长。然而,我国鸟类栖息地选择的研究也存在着如下问题:(1)存在栖息地选择和栖息地利用误用的现象,这种现象在10年内并无明显改善;(2)在选择研究方法时,很少考虑个体的可获得性、种群密度及抽样尺度对栖息地选择的影响;(3)大多数的栖息地选择的论文没有对鸟类的栖息地选择行为进行研究,也缺乏对其选择的适合度背景去进行研究。根据这些问题,对我国未来的鸟类栖息地选择研究提出了建议。     

夏秋季羚牛对长青自然保护区境内栖息地的选择初报

1998年夏秋两个季节 ,在分布于保护区境内各种植被类型和不同海拔高度的 1 86个样方中分别调查了秦岭羚牛对栖息地的选择。在夏秋两个季节中 ,羚牛利用过的样方分别为 39和 60个。卡方检验表明秦岭羚牛夏季偏重选择高山草甸、针阔混交林和灌木林 ;秋季喜欢在针叶林、灌木林和竹林中活动。在未受破坏的天然林和经过采伐的森林中 ,羚牛喜欢选择前者 ;在择伐和皆伐迹地中 ,夏季羚牛选择择伐迹地的比例高于皆伐迹地 ;秋季出现在皆伐后人工更新的林地中的比例较高。夏季羚牛选择海拔位于 2 2 0 0m以上的栖息地的比例为 62 % ,而秋季这个比例降低到 4 1 7%。此外 ,羚牛喜欢在小于 30°的缓坡生境中活动。     

鸟类栖息地选择研究中的一种数学模型

介绍了近年来在鸟类栖息地选择研究领域中新出现的一种数学建模方法,并对其适用范围和应用前景进行了简要评述。     

黄泥河自然保护区狍冬季栖息地选择

2009年12月—2010年1月,在黄泥河自然保护区采用样线法对狍冬季栖息地选择进行了研究。共设置了47条样线,调查了109个狍利用样方和109个对照样方,测定了海拔、坡度、坡向、坡位、隐蔽级、郁闭度、食物丰富度、灌丛盖度、树胸径、人为干扰距离、林型、裸岩、雪深、倒木和针叶树15类栖息地因子。Baileys法和Mann-WhiteyU检验表明:在黄泥河自然保护区冬季,狍喜欢在坡度平缓、平均海拔602m,位于阳坡或半阴半阳坡的中坡位上雪被较浅,食物丰富度、灌丛盖度和隐蔽级都较高的针阔混交林生境中活动,对倒木因子表现出明显的选择性,避开选择阴坡、裸岩和针叶林生境。在主成分分析中,前5个主成分中的累积贡献率达到88.6%,第一主成分贡献率为30.8%,主要反映利用样方的林型、海拔和隐蔽级的影响,第二主成分贡献率为26.5%,主要反映利用样方的食物丰富度和灌丛盖度影响。     

拉萨藏雪鸡春季栖息地选择

2005年3—4月,在拉萨曲水县雄色寺周围山上的灌丛地,对藏雪鸡栖息地选择,通过调查和测量与其有关的14个参数,发现雪鸡喜欢在灌丛盖度较低、距离民居近的地方觅食,并喜欢在灌丛盖度较低、草本种类较少、草本盖度较低、岩石较多、距民房距离较近的地方休息。另外还发现,人类保护和投食对雪鸡栖息地选择也有很大的影响。调查结果显示,研究地区的雪鸡活动在很大程度上依赖人类活动。     

白头叶猴栖息环境与栖息地选择的研究

通过样方法和焦点动物法分别对白头叶猴栖息环境进行了观察,并对栖息环境的植物多样性进行了统计分析。结果表明,白头叶猴栖息地可分为山脚、山腰、山顶和山弄平地4部分,各部分优势种植物不同,白头叶猴栖息地的Shannon Venner多样性指数为6.152,均匀度为0.8439,白头叶猴对石山山脚、山腰、山顶和山弄平地的利用率分布为66.45 5.65%,21.15±5.49%,12.78±6.8%。在山脚主要是休息和觅食,在山腰主要是移动,在山顶主要是冬季晒太阳。因此,保护白头叶猴的栖息地对保护白头叶猴有特别重要的意义。     

The use of movement data as an assay of habitat quality

Based on our observations and those of others from the literature, we construct a graphical model of habitat use in territorial species at high densities relative to optimal habitat availability. This model ignores differences in abundance among habitats, and, together with other models of habitat use, predicts that there should be greater stability (lower turnover rates) among individuals occupying optimal habitat than among those in suboptimal habitat(s). Future studies assessing quality among habitats might take advantage of this by comparing individual turnover rates among habitat types using standard mark-recapture methodology. As an illustrative example, we present a case in wintering wood thrushes (Catharus mustelinus; Muscicapidae: Turdinae) in which relative abundance and habitat quality were inversely related. Many individuals of this nearctic-neotropic migrant species hold nonbreeding territories in the seemingly crowded rainforest of southern Veracruz, Mexico.     

Habitat suitability models for the conservation of thermophilic grasshoppers and bush crickets—simple or complex?

One goal of conservation biology is the assessment of effects of land use change on species distribution. One approach for identifying the factors, which determine habitat suitability for a species are statistical habitat distribution models. These models are quantitative and can be used for predictions in management scenarios. However, they often have one major shortcoming, which is their complexity. This means that they need several, often costly-to-determine parameters for predictions of species occurrence. We first used habitat suitability models to investigate and determine habitat preferences of three different Orthoptera species. Second, we compared the predictive powers of simple habitat suitability models considering only the ‘habitat type’ as predictor with more complex models taking different habitat factors into account. We found that the habitat type is the most reliable and robust factor, which determines the occurrence of the species studied. Thus, analyses of habitat suitability can easily be carried out on the basis of existing vegetation maps for the conservation of the three species under study. Our results can serve as a basis for the estimation of spatio-temporal distribution and survival probabilities of the species studied and might also be valuable for other species living in dry grasslands.     

Landscape topography and the distribution of Lahontan cutthroat trout (Oncorhynchus clarki henshawi) in a high desert stream

Lahontan cutthroat trout, Oncorhynchus clarki henshawi, are currently limited in their distribution to a patchwork of small isolated populations, the result of habitat degradation and natural variation in landscape and in-stream conditions. The objectives of this study were to determine if landscape topography influences trout distribution, and if water temperatures control this response. The work was carried out in a sub-basin of the Quinn River system, McDermitt Creek, which drains the sagebrush desert of southeastern Oregon and northern Nevada. Headwater tributaries of this creek consist of alternating canyon-confined and valley bounded reaches. Trout within these systems are challenged by low discharge and high temperatures during the summer, and anchor ice during the winter. Contiguous whole stream surveys were used to look at trout distribution during the summer of 2003 and spring and fall of 2004. Our results suggested that topography can affect trout distribution. Trout numbers were highest in areas with greater numbers of nick-points (the transition zones between less confined and more confined valley segments) and greater valley confinement. Additionally, in the downstream portion of our headwater reaches, more trout were found in nick-points than expected based on the availability of this habitat type. Our data suggest that hyporheic inputs may be high in such areas, thus providing trout with shelter from warm water in the summer, anchor ice in the winter, and shallow stream depths during all seasons. Spatial occurrence of these areas of refugia can be taken into consideration when planning land use activities and restoration efforts. Further research is required to confirm that topography can affect the distribution of Lahontan cutthroat trout in other systems, and to better understand the mechanisms behind these patterns.     

The morphology and ultrastructure of the peripheral olfactory organ in newly metamorphosed coral-dwelling gobies, Paragobiodon xanthosomus Bleeker (Gobiidae, Teleostei)

We examined the peripheral olfactory organ in newly metamorphosed coral-dwelling gobies, Paragobiodon xanthosomus (SL=5.8mm+/-0.8mm, N=15), by the aid of electron microscopy (scanning and transmission) and light microscopy. Two bilateral olfactory placodes were present in each fish. They were oval-shaped and located medio-ventrally, one in each of the olfactory chambers. Each placode had a continuous cover of cilia. The placode epithelium contained three different types of olfactory receptor neurons: ciliated, microvillous and crypt cells. The latter type was rare. Following a pelagic larval phase, P. xanthosomus settle to the reef and form an obligate association with one species of coral, Seriatopora hystrix. Their well-developed olfactory organs likely enable larvae of P. xanthosomus to detect chemical cues that assist in navigating towards and selecting appropriate coral habitat at settlement. Our findings support past studies showing that the peripheral olfactory organ develops early in coral reef fishes.     

Local specialization and maladaptation in the Mediterranean blue tit (Parus caeruleus)

Although the evolutionary interplay between gene flow and local adaptation of organisms in heterogeneous environments has been widely discussed from a theoretical point of view, few empirical studies have been designed to test predictions on the consequences of habitat patchiness on the evolution of life history traits. Using blue tits in Mediterranean habitat mosaics as a model, we defined two nested levels of habitat heterogeneity: an inter-regional level which compares two isolated landscapes (mainland, southern France vs the island of Corsica), and an intra-regional level which compares two habitat types within each landscape (deciduous vs evergreen trees). Deciduous habitats are more common than evergreen habitats on the mainland whereas the opposite is true on the island. Results suggest that: (1) on a regional scale, each population is specialized to the more common habitat, i.e. life history traits have evolved in such a way that breeding success is high; (2) in the less common habitats within each landscape, birds are clearly mistimed because they mismatch the best period of food availability, and hence their breeding success is lower; and (3) the density of the populations and the morphometry of the birds support the model of ideal despotic distribution. These results, which are supported by preliminary data on the genetic variation and gene flow of populations in the mainland landscape, are consistent with a source-sink model of population structure within each landscape. They are discussed in the framework of metapopulation theory and habitat selection models.     

钦州湾越冬鸻鹬类对不同生境利用分析

2008年12月至2009年1月及2011年12月至2012年1月先后两次对钦州湾的越冬鸻鹬类进行了调查,对越冬鸻鹬类退潮后在各类型生境的分布情况和原因进行了分析,以期为制定有效保护越冬鸟类及其生境的措施提供科学依据。结果表明,在不同的天气情况下退潮后各生境内记录到的鸻鹬类物种数和种群数量均不同,钦州湾不同生境鸻鹬类结构特征随天气变化改变。相似性比较显示,晴天各生境中鸻鹬类相似性指数最高的是盐田-养殖塘生境和农田生境,相似性指数为0.96;鸻鹬类相似性指数最低的是红树林滩涂生境和光滩生境,相似性指数为0.49。阴冷天气各生境中鸻鹬类相似性指数最高的是光滩生境和盐田-养殖塘生境,相似性指数为0.79;最低是红树林滩涂生境和光滩生境,相似性指数为0.52。分析表明人类活动的干扰对越冬鸻鹬类生境选择的影响较大。     

四川山鹧鸪的分布及生境选择

研究了四川山鹧鸪(Arborophila rufipectus)的分布区域和栖息地的生境,认为四川山鹧鸪的分布范围比已知的要大,但其实际分布区呈明显的岛屿状,显示出生境的破碎化;指出四川山鹧鸪的适宜生境是原始的常绿阔叶林、针阔混交林和具有较大常绿落叶阔叶乔木树种盖度的多年生次生林,亦可选择部分人工林,而对地表灌丛密度大的次生幼林以及人工幼林生境不喜好。由于天然林的禁伐和生态林的管护,四川山鹧鸪的栖息地趋于稳定并有所扩大。但四川山鹧鸪仍然处于濒危状态。