河北唐海湿地四种鹭的种群动态和繁殖空间生态位

2004年8月—2005年7月对河北唐海湿地夜鹭(Nycticorax nycticorax)、白鹭(Egtetta garzetta)、池鹭(Ardeola bacchus)、大白鹭(Casmerodius albus)的种群动态和繁殖行为进行了观察，并对巢群关系进行了研究。统计了4种鹭垂直和水平巢位的巢密度，计算了不同种鹭巢的生态位重叠、生态位宽度值。结果：4种鹭在唐海数量最多月份为4—9月，最大量达到了近5 800只。共有Ⅰ、Ⅱ两个巢区，迁来Ⅱ区时间较Ⅰ区晚半个月左右。除池鹭外，3种鹭之间均有争巢现象，后期趋于稳定。迫于密度压力和竞争，部分白鹭和池鹭取食范围较广。除大白鹭外，其他3种鹭同种间均有混交现象。 在混巢区，夜鹭迁来最早，数量最大，为优势种，多数占据中心区的顶巢；大白鹭数量最少，亦占据中心区的顶巢；白鹭迁来较晚，占据中位巢；池鹭迁来最晚，数量较白鹭少，多数在边缘区单独筑巢，少数在中心区占下位巢。白鹭巢的垂直生态位最宽；夜鹭巢的水平生态位最宽；池鹭巢的综合空间生态位最宽。池鹭和夜鹭巢位的空间格局最为相似，池鹭和白鹭的生态位重叠较大。夜鹭的数量最多、大白鹭的个体最大，导致其处于优势；白鹭和池鹭数量少、个体小，导致其处于劣势。唐海湿地内丰富的食物和适宜的林带是鹭鸟密度较大的主要原因。此外，鹭类只筑巢在散布的、双行杨树林带均高为22 m以上区域，是该地鹭类巢区的主要特点。     

四川南充太和鹭科鸟类群落空间生态位和种间关系

本文应用空间生态位理论,分析了四川南充太和白鹭自然保护区慈竹林内鹭类繁殖季节的群落结构,对影响鹭类混群繁殖时空分布的因素及各种群间的相互关系进行了探讨.结果 表明:南充太和白鹭自然保护区栖息有白鹭Egetta garzetta、夜鹭Nycticoraxny cticorax、牛背鹭Bubulcus ibis和池鹭Araeola bacchus 4种鹭类种群.4种鹭类具有明显的水平和垂直分布现象,白鹭、夜鹭的水平生态位宽度较大,在垂直生态位宽度上白鹭、夜鹭、牛背鹭都较大,池鹭的最小;生态位重叠值以白鹭-夜鹭间的最高,夜鹭-池鹭间的最小;4种鹭间的聚类分析结果普遍较高.     

云南大理古城3种繁殖鹭类的巢空间隔离

集群繁殖的鹭类通过时间或空间上的筑巢活动隔离来减少物种间的竞争压力。2012年2—5月对云南大理古城市区同质林内的3种鹭巢进行了直接计数和空间定位,研究了混群鹭巢的空间隔离分化。结果表明:大理古城的繁殖鹭类有夜鹭Nycticorax nycticorax、牛背鹭Bubulcus ibis和白鹭Egretta garzetta 3种,巢数分别为195个、132个和112个。与自然繁殖地中的鹭巢水平分化不同,3种鹭类的巢在东西和南北水平方向上均没有显著分化;在垂直方向和巢距主干距离上的分化差异均有统计学意义(P<0.01)。夜鹭巢的分布最为集中,表现为夜鹭在东西水平方向、垂直方向和巢距主干距离上均为生态位宽度值最小的物种。因为较大的体型和较早的迁入日期,夜鹭集中占据了高位和主干上的有利巢位。通过物种间生态位宽度重叠值的比较,发现没有任何2种鹭类的巢在所研究的4个空间方向上发生明显重叠,说明3个物种间巢位的空间分化较为精细。     

云南大理古城牛背鹭与其竞争种的巢空间生态位分化动态研究

牛背鹭（Bubulcus ibis）作为入侵物种由非洲向美洲的扩散得到了广泛关注,然而牛背鹭与其竞争物种之间的巢空间生态位分化动态尚不明确。为了解牛背鹭与其他混群繁殖鹭类的巢空间生态位分化动态,2012、2016和2021年春夏季,对中国云南大理古城繁殖鹭类的群落结构和巢空间分布进行了调查。结果表明,2012和2016年中国云南大理古城繁殖鹭类群落的组成物种均为牛背鹭、夜鹭（Nycticorax nycticorax）和白鹭（Egretta garzetta）,其中夜鹭为优势鸟种;2021年繁殖群落增加了中白鹭（Ardea intermedia）,且牛背鹭变为优势鸟种。从2016年到2021年群落巢密度增加,其中牛背鹭的巢密度明显增加,夜鹭和白鹭巢密度均减少。对比2016和2021年牛背鹭、夜鹭和白鹭3种鹭的巢空间生态位宽度数值的变化,发现牛背鹭利用的巢空间生态位更泛化,而夜鹭和白鹭更特化;巢空间生态位重叠值变化表明,2021年牛背鹭对夜鹭、白鹭的巢址竞争比2016年的更激烈,而且2021年牛背鹭与夜鹭之间的巢址竞争比牛背鹭与白鹭之间的更激烈。研究表明,在2012、2016和2021年,在大理古城鹭类繁殖地中,牛背鹭在与比自身个体大的夜鹭的竞争中胜出,群落优势鸟种由夜鹭变为牛背鹭,繁殖鹭类的群落结构和生态位分化均发生了明显变化。     

紫蓬山区三种鹭种群繁殖成效的研究

：作者１９９６年４～７月在紫蓬山区国家级森林公园,对白鹭、池鹭和夜鹭繁殖种群的数量和繁殖成效进行了研究。结果表明：三块样地中,夜鹭的种群平均密度最大,白鹭的种群平均密度最小;白鹭、池鹭和夜鹭的种群繁殖生产力分别为２３７４ｉｎｄ／ｈｍ２、１４４１ｉｎｄ／ｈｍ２和２０１２ｉｎｄ／ｈｍ２;繁殖成效分别为５２０％、５５１％和４５１％。繁殖成效与巢位高度有关,低位巢卵损失率高,高位巢雏丢失率高。     

芜湖市及附近地区三种鹭鸟巢址特征

2005年,对芜湖市及附近地区4个营巢地的3种主要营巢鹭鸟--白鹭(Egretta garzetta)、夜鹭(Nycticorax nycticorax)和池鹭(Ardeola bacchus)的巢址特征进行了抽样调查,选取了11个巢址变量,即营巢树种、巢高、巢树高、巢上方郁闭度、巢周围1m半径内植被郁闭度、巢树胸径、巢离树干距离、巢下最大支撑枝直径、巢离巢区边缘的距离、坡位、巢位海拔,运用单因素方差分析和主成分分析方法研究3种鹭乌的巢址特征.结果表明,巢位因子、巢树因子、保护因子、坡位因子等4个主成分描述了3种鹭鸟的巢址特征,其贡献率分别为25.51%、24.42%、13.19%和12.32%.影响鹭鸟巢址选择的最主要因素是微栖息地适合度和巢捕食压力.     

四种鹭类繁殖生态生物学研究

本文对夜鹭,白鹭,黄鹭白鹭,池鹭混群在同一巢区的繁殖,种间协高及雏鸟生长进行进行了观察研究,其中黄嘴白路豫南大别山类新纪录,在此繁殖亦为首次发现。几种路在巢位,食性,取食活动和习性方面都表现出其混居同一巢地繁殖的种间协调性,符合高期假说。比较４种鹭鸟雏鸟生长过程中各生长参数。其中池鹭虽个体最小,但体重和各部位生长却对较快。     

三种鹭异步孵化与雏鸟生长的比较研究

根据1996～1999年的野外工作和实验饲养,研究了池鹭、白鹭、夜鹭3种鹭的繁殖、雏鸟生长和异步孵化对雏鸟生长的影响.3种鹭于4月上、中旬迁到常山、余杭鹭保护区,9月下旬陆续迁离.孵卵期池鹭为23.0 d(n=26),白鹭23.9 d(n=32),夜鹭25.3 d(n=34);孵化率池鹭为76.32%,自鹭86.96%,夜鹭95.45%,池鹭繁殖力为3.21只,白鹭3.38只,夜鹭3.50只.雏鸟体重增长与成体体形大小呈负相关.幼雏体重增长与孵化顺序相关.在生长早期(≤8 d)全部雏鸟正常发育,之后差异显著.第1和第2孵化雏鸟生长曲线相似,但明显高于第4雏鸟,表明较早孵化者获得食物能力较强,而迟孵出雏鸟有食物不足现象.该3种鹭孵育幼雏能力的最适度估计为3只左右.     

鹭与蚊之间的关系

1960年在宜昌市桃花岭发现一个由池鹭(Ardeola bacchus)、小白鹭(Egretta garzetta garzetta)、夜鹭(Nycticorax nycticorax nycticorax)组成的大鹭群,前者占优势,小白鹭次之,夜鹭较少。 在我们观察前二者繁殖习性时发现在池鹭和白鹭育雏期间,恰是蚊类活跃盛期,当雏鸟留巢时,观察到吸血蚊类经常飞至雏鸟巢中或绕巢飞行,为了探明蚊类与鹭之间的关系,特决定以留巢雏鸟进行诱蚊试验,从6月28日至8月7日,分别以小白鹭、池鹭孵出之不满20日龄的雏鸟为诱饵,置诱饵雏鸟一只于方     

广西防城7种鹭类混群繁殖的空间生态位研究

2002年3~8月对广西防城万鹤山营巢的鹭类繁殖种群进行了调查研究,结果表明:万鹤山栖息有大白鹭(Egretta alba)、中白鹭(Egretta intermedia)、白鹭(Egretta garzetta)、黄嘴白鹭(Egretta eulophotes)、牛背鹭(Bubulcus ibis)、池鹭(Ardeda bacchus)、夜鹭(Nycticorax nycticorax)7种鹭类种群。除黄嘴白鹭为均匀分布之外,其他6种均为成群分布。鹭类在万鹤山上营巢繁殖具有明显的水平分布和垂直分布现象。对影响鹭类混群繁殖时空间分布的因素及各种群间的相互关系进行了探讨。     

BIOLOGY OF THE IMMIGRANT CATTLE EGRET ARDEOLA IBIS IN GUYANA, SOUTH AMERICA

The success of the immigrant Cattle Egret Ardeola ibis in Guyana appears to be due mainly to its breeding biology, combined with man's activities in clearing and draining land for stock and by his selective shioting.
Long.-established heronries are beine taken over bv the Cattle Egret. In Aurmst 1959 during the principal nesting season in the main rains 90% of the 1786 heron nests in the Botanic Gardens Georgetown, belonged to Cattle Egrets, the others to Little Blue Herons Hydranassa caerutea , Black-crowned Night Herons Nycticorac nycticorux , Snowy Egrets Egretta thula , Tricolour Herons Hydranassu tricolor , and Streaked Herons Butorides striatus . In the December rains the same year another 1700 Cattle Egret nests were in use here, but no indigenous herons were nesting. These were, however, joined in January by Black-crowned Night Herons, Snowy Egrets, Little Blue and Tricolour Herons.
In addition to having two peak nesting periods a year, instead of one as the indigenous herons generally have, the Cattle Egrets react faster to the onset of the rains and obtain the best nest-sites, and they are helped by the tendency of the indigenous herons to display more aggressively against their own species than against the intruder; also now that Cattle Egret numbers are high they can find mates very rapidly. Both indigenous herons and Cattle Egrets have one to three young per brood in Guyana, and the nesting period lasts about two months.
The peak nesting time varies from year to year with the advent of the rains. Nesting appears to be stimulated by, and its success related to, rainfall. A cycle of wet years in Guyana preceded the arrival of the Cattle Egrets in North America in 1952. In Guyana their dispersal inland was restricted, probably by the forest, until 1961.     

郑州地区夜鹭的求偶行为

2003年及2004年3~6月在河南郑州市区对夜鹭(Nycticorax nycticorax)的求偶行为进行了观察。结果表明,3月中旬至5月底雄性夜鹭表现出占区及固定的仪式化求偶行为,主要包括伸展炫耀、扬举炫耀、炫耀羽毛和配偶形成后的相互爱抚4个方面,其中前两种行为是夜鹭主要的求偶行为。在营巢地,求偶行为从早上日出之前夜鹭觅食归来开始,一直持续至日落前后。夜鹭的配偶选择包括雄性之间对巢区的竞争、雄鹭与雌鹭的相互选择等一系列过程。     

Bias in aerial estimates of the number of nests in White Ibis and Great Egret colonies

ABSTRACT Estimating detection error, as well as the magnitude of other potential survey biases, is essential when sampling efforts play a role in the estimation of population size and management of wildlife populations. We quantified visual biases in aerial surveys of nesting wading birds (Ciconiiformes) in colonies in the Florida Everglades using a negative binomial count regression model to compare numbers of nests in quadrats counted on the ground with numbers estimated from aerial photographs of the same quadrats. The model also allowed the determination of degree of difference between monitoring results based upon such factors as nest density, vegetative cover, and nest turnover rates. Aerial surveys of White Ibis (Eudocimus albus) colonies underestimated the true number of nests found during ground counts by 11.1%, and underestimates were significantly greater (P= 0.047) in a colony with high nest turnover. Error rates did not differ for quadrats that varied in the density of White Ibis nests did not differ, and visual bias did not increase with vegetative complexity (P= 0.73). Estimates of nest density in colonies of Great Egrets (Ardea alba) based on aerial surveys were higher than ground counts for 38% of the quadrats sampled, and mean visual bias was 23.1%. Species misidentification likely contributed to visibility bias for Great Egrets in our study, with some Snowy Egrets almost certainly mistaken for Great Egrets in aerial photos. Biases of the magnitude we observed fro Great Egrets and White Ibises can mask true population trends in long‐term monitoring and, therefore, we recommend that detection probability be explicitly evaluated when conducting aerial surveys of nesting birds.     

Nest position,breeding success and diet of the Black-crowned Night Heron,Nycticorax nycticorax in the Anzali Wetland,Northern Iran (Aves: Ardeidae)

Breeding ecology of the Black-crowned Night Heron (Nycticorax nycticorax) was studied in a mono-specific colony in the Anzali wetland, Northern Iran during the breeding season of 2016. The breeding period lasted from mid-May to late July. The average clutch size was 3.1±0.6 eggs and the breeding success 77.6%. No significant differences were found between nests built on trunks and those built on branches of trees. The clutch size and breeding success appeared to be independent of the structural variables of the nesting site (diameter of trees, height from the ground, height of nests from the canopy, nest number per tree, location of nests on trunks and branches). No significant difference was found between the timing of the start of incubation and the height of nests above the ground. The average vertical and horizontal distances between nests was one metre. Fish, particularly Carassius gibelio, dominated the diet of the nestlings.     

Factors affecting the length of the breeding cycle and the frequency of nest attendance by Grey Herons Ardea cinerea

An investigation of the length of the breeding cycle and of the frequency of nest visits by Grey Herons at 3 heronries with different degrees of breeding success showed that the duration of reproduction, particularly the chickrearing period, decreased and the frequency of daily nest visits increased with increasing average breeding success of a colony. Successful pairs also seemed to spend less time displaying and incubating eggs. Herons arrived at their nests most frequently during twilight, especially in the morning. The mean time absent from the nest was greatest during incubation and smallest when feeding small chicks. The total reproductive period tended to be longer for those pairs whose periods of absence from the nest were longer.     

Effects of waterbirds on water quality

The effect of cormorants, egrets, herons and a species of duck were studied on the eutrophication of Bhanderaj and Pandloli reservoirs in Matar tahsil of Kheda district, Gujarat, India. The quantity of consumed food and of excrement were estimated. The Little Cormorants (1000 pairs and their fledglings) inhabiting the area of reservoir complex took up 11.8 tonnes of N and 3.9 tonnes of P, while the Cattle Egrets and Pond Herons together took up 13.47 tonnes of N and 3.98 tonnes of P in 1999. The effect of fish-eating cormorants, egrets and herons can be quantified better than those of coots which feed only on plant materials.     

Formation and growth of a heronry in a managed wetland in Doñana,southwest Spain

Capsule A newly created wetland has been beneficial for the breeding of five heron species and for the settlement and expansion of Glossy Ibises in the region.

Aim To determine whether created wetland would lead to the establishment of a heron and ibis breeding colony, and if so, to determine its effects on the distribution of these species in the wider region.

Methods Number of pairs breeding at the new wetland and in the region were estimated annually from 1996 to 2008. We investigated whether the growth of the new colony was explained by redistribution of breeding pairs within the region.

Results Purple Herons, Squacco Herons and Glossy Ibises colonised the new wetland in 1996. Black‐crowned Night Herons settled in 1998, while Cattle and Little Egrets were the last species to establish in the mixed colony in 2001. The population increase was particularly marked for Glossy Ibises (which had bred in Doñana only sporadically through the 20th century). Our findings suggest that simple redistribution of pairs does not explain the formation and growth of the new colony. Since the first year of establishment numbers of Glossy Ibises and Purple Herons have shown a significant growth trend at both the new colony and in Doñana.

Conclusion The creation and management of a new wetland has been successful for the conservation of heron and egret species and promoted the expansion of the Glossy Ibis population across the western Mediterranean region.     

Breeding success of a colony of Boat-billed Herons Cochlearius cochlearius (Ciconiiformes: Ardeidae) in pasturelands of Costa Rica

The breeding success of a double-brooding colony of Boat-billed Herons Cochlearius cochlearius was studied in pasturelands of Costa Rica. Mean clutch size in the first clutches (2.9 eggs/nest) was higher than in second and repeat clutches (2.3 eggs/nest). Breeding success was similar in the first attempt and second attempts (20.7% and 21.7%, respectively). In both attempts earlier nests enjoyed a higher breeding success. Starvation of the youngest chicks within the nest and destruction of nests by bad weather conditions were the main factors related to nestling death. No effects of human activity on the reproduction of the breeding colony were observed.     

Co-breeding involving herons and a potential egg predator,the Indian House Crow (Corvus splendens), in Peninsular India

Association between species may strengthen the fitness of the species involved It is not rare that avian species associate on the breeding and feeding grounds. However, a species associated with a potential egg predator is less common. In this study, a synchronized breeding of Indian House Crow (Corvus splendens) and breeding Indian Pond Herons (Ardeola grayii) in urban conditions is reported. Both the crow abundance and the crow nest abundance increased with the number of heronry nests on sites. Crows were mostly observed when flying over or when resting nearby, but they also attempted egg predation from heronry nests. Crows also used the heronry sites for collecting nesting resources, such as twigs, scavenging dead chicks and for stealing the food brought to feed the heronry chicks. A dearth of suitable nesting places and provisions in an urban environment may be the reason why these birds share nesting trees. Vigilant breeding crows, despite their ability to depredate heron nests, may be more beneficial to herons as they are known to mob and distract heron predators, but a full cost-benefit analysis needs to be undertaken.