Comparison of historical bottleneck effects and genetic consequences of re‐introduction in a critically endangered island passerine

Re‐introduction is an important tool for recovering endangered species; however, the magnitude of genetic consequences for re‐introduced populations remains largely unknown, in particular the relative impacts of historical population bottlenecks compared to those induced by conservation management. We characterize 14 microsatellite loci developed for the Seychelles paradise flycatcher and use them to quantify temporal and spatial measures of genetic variation across a 134‐year time frame encompassing a historical bottleneck that reduced the species to ~28 individuals in the 1960s, through the initial stages of recovery and across a second contemporary conservation‐introduction‐induced bottleneck. We then evaluate the relative impacts of the two bottlenecks, and finally apply our findings to inform broader re‐introduction strategy. We find a temporal trend of significant decrease in standard measures of genetic diversity across the historical bottleneck, but only a nonsignificant downward trend in number of alleles across the contemporary bottleneck. However, accounting for the different timescales of the two bottlenecks (~40 historical generations versus <1 contemporary generation), the loss of genetic diversity per generation is greater across the contemporary bottleneck. Historically, the flycatcher population was genetically structured; however, extinction on four of five islands has resulted in a homogeneous contemporary population. We conclude that severe historical bottlenecks can leave a large footprint in terms of sheer quantity of genetic diversity lost. However, severely depleted genetic diversity does not render a species immune to further genetic erosion upon re‐introduction. In some cases, the loss of genetic diversity per generation can, initially at least, be greater across re‐introduction‐induced bottlenecks.     

Parental care behavior in the monogamous,sexually dimorphic Madagascar paradise flycatcher: sex differences and the effect of brood size

I studied the parental care behavior of the Madagascar paradise flycatcher Terpsiphone mutata in northwestern Madagascar. I especially focused on feeding, brooding and vigilance behaviors. Feeding rate did not differ between males and females, but females spent more time at the nest than males. Females dedicated their time to brooding, while males perched on the nest and were vigilant. Both parents changed the feeding rate in relation to brood size, so the feeding rate per nestling was not different among nests of different brood size. Duration of brooding by females increased with decreasing brood size, suggesting that the Royama effect, the pattern of lower feeding rate per nestling in larger broods, did not apply in this study. Males spent more time on vigilance than females. Anti-predator vigilance by males should be important for nestling survival given the high predation pressure typical of this population. In conclusion, males provide considerable parental care probably to minimize nestling starvation and to avoid nest predation. My results are not consistent with the general pattern of less parental effort by males in monogamous, sexually dimorphic species.     

湖北巴东寿带鸟繁殖行为观察

20 0 2年 5月～ 2 0 0 4年 8月 ,在湖北省巴东县沿渡河镇的东圩口、小溪、锯锯湾、两河口等 4个村 ,对寿带鸟 (Terpsiphoneparadisiincei)的繁殖生态进行了初步研究。研究结果显示 ,寿带鸟在湖北巴东的繁殖时间为 5月下旬～ 7月上旬 ,主要在农田居民区附近的阔叶树上营巢 ,巢材主要有青苔、草叶、草茎、细草根、棕丝、树耳、蜘蛛网等。筑巢工作主要由雌鸟承担 ,一般需要 5～ 7d即可完成。巢距离地面高度1 72～ 6 45m ,巢外径 6 0～ 8 8cm ,巢内径 4 9～ 6 4cm ,巢深 2 9～ 4 1cm ,巢高 6 3～ 9 5cm。雌鸟每天产 1枚卵 ,产卵时间均在清晨。窝卵数 4枚 (n =1 1 ) ,卵产齐后即开始孵化 ,雌雄鸟轮流孵卵 ,孵化期 1 3d。雏鸟晚成性 ,雌雄共同育雏 ,育雏期 9d。寿带鸟对不同的外界干扰反应明显不同 ,当有对其卵和雏鸟构成威胁的动物接近时 ,护巢行为表现十分强烈 ;而对其没有威胁的物种接近其巢时则无动于衷。面对同样的干扰 ,雌雄亲鸟的反应存在显著差异。     

Polymorphic microsatellite loci for paternity analysis in the Madagascar paradise flycatcher (Terpsiphone mutata: Aves)

Nine polymorphic microsatellite loci from the Madagascar paradise flycatcher Terpsiphone mutata were isolated using nonradioactive polymerase chain reaction (PCR)‐based techniques to screen an enriched genomic library. Seven polymorphic loci showed no evidence of null alleles and exhibited high levels of variation in 18 unrelated individuals (mean diversity = 0.80, mean number of alleles = 13.6). These loci are therefore suitable for analysis of population structure and paternity (exclusion probability for six unlinked loci = 0.9998).     

河南董寨寿带鸟繁殖生态及雌雄个体形态类型

寿带(Terpsiphoneincei)是雀形目王鹟科的鸟类,在我国大部分地区均有分布。以往研究曾对我国部分地区寿带的繁殖习性进行了报道,但对其雌雄个体的形态类型缺少描述。为进一步了解寿带的繁殖习性及其雌雄个体的形态类型,本研究于2014至2017年每年的5至7月在河南董寨国家级自然保护区对其进行了观察。观察发现,寿带在董寨国家级自然保护区一般于5月下旬开始筑巢繁殖,雌雄亲鸟均参与筑巢、孵卵和育雏。寿带巢多位于刺槐(Robiniapseudoacacia)、麻栎(Quercus acutissima)、枫杨(Pterocarya stenoptera)等几种植物上,平均窝卵数(±SD)为(3.8±0.6)枚(n=25巢),孵卵期12～13 d(n=4巢),各巢卵的平均孵化率(±SD)为91.7%±17.7%(n=9巢),窝雏数(±SD)为(3.6±0.8)只(n=19巢),巢内育雏期约10 d,巢成功率为34.5%(n=29巢),弃巢和天敌捕食是巢失败的主要原因。寿带雌鸟具有栗色短尾型和栗色长尾型2种形态,而雄鸟具有栗色长尾型、白色长尾型和栗色短尾型3种常见形态,且雄鸟以栗色长尾型所占...     

寿带鸟繁殖期鸣声行为的初步研究

2006年4～7月在四川南充市对寿带鸟繁殖期的鸣声行为进行了初步研究,得到6种不同类型的鸣声,分别为歌声、领域鸣声、警戒鸣声、喂食鸣声、雏鸟乞食鸣声和幼鸟呼唤鸣声。同时还探讨了各类鸣声行为的生物学意义。     

Genetic relationships of Plagioscion squamosissimus (Perciformes,Sciaenidae) from five Neotropical river basins evaluated using mitochondrial atpase6/8 gene sequences

The genetic relationships of native or introduced Plagioscion squamosissimus in five Brazilian Neotropical basins were evaluated using the mitochondrial atpase6/8 genes. Results revealed that the population of the Tocantins River basin is more basal than the native populations of the Amazon and Parnaíba River basins. Moreover, the populations of P. squamosissimus that were introduced in the São Francisco and upper Paraná River basins originated from the population of the Parnaíba River.     

Genetic divergence among invasive and native populations of Plagioscion squamosissimus (Perciformes, Sciaenidae) in Neotropical regions

The genetic divergence among invasive and native populations of Plagioscion squamosissimus from four Neotropical hydrographic basins was assessed using the hypervariable domain of the mitochondrial DNA (mtDNA) control region. Plagioscion squamosissimus is native to the neighbouring hydrographic basins of the Parnaíba and Amazon Rivers, and the latter includes the Araguaia-Tocantins drainage, but it is invasive in other basins due to introductions. The mtDNA nucleotide polymorphism supported the hypothesis that the Amazon and Parnaíba populations constitute the same species and are separated into two independent evolutionary lineages. Absence of nucleotide polymorphism was observed within and among P. squamosissimus populations invasive to the uppper and middle Paraná River basins. Nucleotide divergence was null or low comparing the Paraná invasive populations with the populations native to the Parnaíba River basin, whereas it was significantly high compared to Tocantins populations. These results ascertain that P. squamosissimus populations invasive to the upper Paraná River basin and to the middle Paraná River basin downstream of the Itaipu dam are derived from the Parnaíba River basin. The genetic data presented are potentially useful to assist further studies on P. squamosissimus taxonomic and geographic distribution, development of ecological guidelines for managing populations invasive to the upper Paraná River basin and for preservation of native fish diversity.