Insights into the feeding ecology of the Seychelles Black Parrot Coracopsis barklyi using two monitoring approaches

Feeding ecology is an important factor for the survival of a species and knowledge of its parameters is a prerequisite for successful conservation work. In this study we describe the feeding ecology of the endemic Seychelles Black Parrot Coracopsis barklyi on Praslin, Seychelles, the only island on which this parrot is resident. We compared two methods to evaluate feeding choices: incidental observations and feeding walks on 25 transects in all habitat types. Black parrots fed on 46 different species, bringing the total number of known food plants to 53 species. They predominantly consumed endemic and native species (58% of observed feeding bouts), mainly their fruit pulp (in 68% of feeding bouts), followed by buds (15%) and seeds (37%) with occasional observations of leaves, bark and scale insects. The incidental method rendered many more observed bouts than the transect approach and the ratios of consumed species differed between methods but the transect results are regarded as more representative. The incidental method is not suitable for quantitative conclusions but complements the transect method, providing information about rarely occurring feeding events.     

Evolutionary distinctiveness and historical decline in genetic diversity in the Seychelles Black Parrot Coracopsis nigra barklyi

Island endemic species are acutely vulnerable to extinction as a result of stochastic and human impacts. Conservation of unique island biodiversity is high priority, and an understanding of the evolutionary history of vulnerable island species is important to inform conservation management. The Seychelles Black Parrot Coracopsis nigra barklyi is an island endemic threatened with extinction. The total population of 520–900 individuals is restricted to the 38‐km² island of Praslin, and it is one of the last few remaining endemic island parrots that survive in the Indian Ocean. We combined mitochondrial and microsatellite DNA markers with morphological data to examine the evolutionary distinctiveness of C. n. barklyi within Coracopsis, and to compare levels of genetic diversity between historical and contemporary specimens. Phylogenetic analyses revealed C. n. barklyi as sister to the remaining three C. nigra subspecies, and discriminant function analysis suggested the Seychelles Black Parrot is the smallest of the four subspecies. Higher levels of genetic diversity were observed in historical specimens, whereas only one mtDNA haplotype was observed in the contemporary specimens, suggesting that C. n. barklyi has lost genetic diversity as a consequence of substantial recent population decline. This study provides a first insight into the evolutionary, genetic and morphological processes that have shaped C. n. barklyi and provides an important perspective on this parrot's current genetic status to guide its future conservation management. Further ecological studies are essential but we suggest that C. n. barklyi should be managed as an evolutionary significant unit to conserve its unique evolutionary pathway.     

杂色山雀的繁殖生态

2004—2006年3—7月在辽宁省白石砬子国家级自然保护区对杂色山雀的繁殖生态进行了观察研究。结果表明:该鸟繁殖期为3—7月,筑巢地除了树洞之外,还见在墙缝、石缝、金腰燕旧巢及电柱孔洞中筑巢,筑巢主要由雌鸟完成,雄鸟从旁协助;产卵期为5～8d,日产1枚,窝卵数为(6.92±0.92)枚(n=13);产满窝卵数后即开始孵化;孵化由雌鸟单独完成,孵化期(14.00±0.00)d(n=10),坐巢时间(570.00±11.02)min.d-1(n=9)(不含夜间),平均坐巢时间(57.00±6.75)min.次-1(n=9),雄鸟担任警卫任务,孵化期较为敏感,受到干扰易弃巢;育雏期(17.50±0.58)d(n=4),由雌雄鸟共同喂雏,雏鸟出飞后先是在亲鸟的带领下在巢周活动,之后活动范围逐渐扩展,2～3d后基本离开巢区。     

红头长尾山雀繁殖生态的研究

在安徽合肥紫蓬山区,对红头长尾山雀的繁殖生态进行了系统的观察,并研究了雏鸟的生长特征。研究表明,红头长尾山雀自3月中旬以后开始发情,3月下旬开始营巢,巢位于杉树枝下,球形侧开口或侧顶开口。4月初产卵,每窝平均产6．25枚卵,孵化期为15—16d,孵化率为88％。育维期15—16d,22维全部成活到离巢,雏成活率达100％。体重、翅、嘴峰、跗跖、第5枚初级飞羽和尾羽等形态学参数适合用Logistic曲线方程拟合,拟合参数中,嘴峰的拐点最小,飞羽、翅和尾羽的增长率较高,表明与取食有关的形态优先发育,与飞行有关的形态则在后期发育较快。     

挂榜山小鲵的繁殖生态

2004-2006年对挂榜山小鲵(Hynobius guabangshanensis)的繁殖生态进行了观察研究.结果表明:挂榜山小鲵繁殖期为每年的11月中旬至翌年1月;非繁殖期营陆生生活,繁殖期进入水中繁殖;繁殖期活动高峰为20:00到翌日6:00;繁殖种群数量为198条,现存分布区不足10 km2;繁殖期雌雄性比为1.6,存在明显的两性异型,性成熟雌体的体长和体质量显著大于雄体;挂榜山小鲵的抱对行为与东北小鲵、黑小鲵、极北鲵相似;雄体具有求偶炫耀行为和精子竞争行为;繁殖场多为临时水凼和小而浅的池塘,大部分卵袋被固定在浅水的枯枝和水草上;挂榜山小鲵的卵袋较同科物种粗大,幼体刚出膜时卵袋长(18.40±4.21) cm(n=31),直径(4.23±0.52) cm(n=31);卵径(2.10±0.25) mm(n=45);卵粒数(88.90±20.30)个(n=98)(单个卵袋),受精率为(93.3±21.4)%(n=98).     

Breeding ecology and oviposition site selection of black-spotted pond frogs (Rana nigromaculata) in Ningbo, China

The black-spotted pond frog (Rana nigromacu-lata) is one of the most widely distributed species in China. However, there have been only a few qualitative descrip-tions of their breeding ecology and oviposition site selec-tion. From 2004 to 2006, we investigated the breeding ecology and oviposition site selection of K nigromaculata in Ningbo, China, quantitatively. Analyses of breeding ecology show that: (1) mean frog density in the breeding season was 0.0903 ± 0.0029 individuals per meter (n = 11) (mean ± SE); (2) R. nigromaculata was a sexually dimorphic species, with females significantly larger than males in both body weight and snout-vent length; (3) the clutch size averaged 4643.04± 235.96 eggs (range 1546-7897, n = 50); and (4) the egg size ranged from 1.50 to 1.74 mm in diameter, with an average egg size of 1.6050 ± 0.0046 mm (n = 226). Oviposition sites differed significantly from random sites in percentages of water, bare ground and vegetation cover, water depth (cm), water temperature (°C) and water turbidity. Rana nigro-maculata preferred microhabitats with higher percentages of water and vegetation cover, while it avoided microha-bitats with deeper water. The results suggest that micro-habitats with higher percentages of water and vegetation cover, but not deeper water, should be priorities for pro-tection and conservation of the breeding habitats of R. nigromaculata.     

Aspects of the breeding ecology of the Purple Swamphen Porphyrio porphyrio in the wetland complex of Guerbes-Sanhadja,north-east Algeria

The Purple Swamphen Porphyrio porphyrio is a common rail that previously was little investigated in North Africa. From 2011 to 2013, its breeding ecology was studied at two natural wetlands in north-east Algeria, namely Garaet Hadj Tahar and Garaet Messaoussa. Numbers of Purple Swamphens at both localities peaked in late April and early May. Egg-laying started in early March, whereas hatching started in late March. Peak egg-laying took place in late March and early April, and peak hatching from mid-April to early May. There were significant differences in the size and weight of eggs between years and localities. The mean clutch size was 2.75 ± 0.70 eggs and it was not signifi- cantly different between localities and years. Mean hatching success was 51% and it was positively correlated to nest depth only at Garaet Hadj Tahar. Most nests were built in dense tufts of Typha angustifolia and Phragmites australis. The main nesting materials were Phragmites australis and Scirpus maritimus.     

Testing the function of the domed nests of Saltmarsh Sharp-tailed Sparrows

ABSTRACT.   Saltmarsh Sharp-tailed Sparrows ( Ammodramus caudacutus ) build ground nests, often with a closely-woven dome, in marshes that frequently flood during high tides. To test the hypothesis that domed nests help reduce the loss of eggs and chicks due to flooding or predation, we examined the characteristics and fate of 102 nests at sites along the coast of Connecticut. To test whether nest structure was tailored to suit microhabitat conditions, we also measured vegetation characteristics around nests. Finally, we conducted artificial nest-flooding experiments to determine whether removal of domes reduced egg retention during flooding. We found no significant effects of nest structure on breeding success or failure, and few significant correlations between nest structure and microhabitat. The height of nests above the ground, however, increased with vegetation height, supporting the hypothesis that nest construction is influenced by flooding, but not supporting the hypothesis that predation risk is important. Dome removal experiments showed that domes have a highly significant effect on the retention of eggs during flooding, suggesting that domes help eggs survive the regular tidal flooding of marshes.     

Influence of age on reproductive performance in the Seychelles warbler

I studied age-related breeding performance of the cooperativelybreeding Seychelles warbler (Acrocephalus sechellensis) on CousinIsland, Seychelles, during 14 years. The annual number of youngthat fledged is significantly related to territory quality andnumber of helpers in the breeding group. Accounting for thesefactors and for the partner's breeding experience, annual productionof fledglings by breeding birds increases from 2 to 5 yearsand decreases beyond 5 years of age. Age-related changes inreproductive success within breeding individuals, paired withthe same experienced partner and occupying the same breedingterritory with similar amount of food from 2 to 8 years of age,show that Seychelles warblers have higher hatching success andproduce more hatchlings and fledglings as they become older.This is probably not a response to decreasing residual reproductivevalue caused by decreasing life expectancy as they become older.Primiparous warblers produce the same number of fledglings asmultiparous warblers of the same age, have a similar life expectancyas multiparous warblers, and occupy territories with similaramounts of resources available for reproduction. As all warblershave similar access to food before reproduction and similarforaging efficiency, the low reproductive success in youngerwarblers cannot be ascribed to differences in environment butto the bird's ability to breed successfully (e.g., a resultof previous helping and/or breeding experience). Effects ofsenescence on reproduction begin to occur from age 6 for bothsexes. From that age, eggs have lower hatching success, butfledging success remains the same. Birds that start breedingat a young age on a given quality territory produce more fledglingsin their lifetime than birds that delay breeding. Many old birdsnever fledge young of their own. They have not been able tobreed because of a shortage of breeding territory vacancies.[BehavEcol 7: 417–425 (1996)]     

杭州城市环境中白头鹎的繁殖生态

白头鹎(Pycnonotus sinensis)是一种中国南方城市分布广泛、种群数量丰富的鸟类。其对环境变化和人类活动的适应能力已引起关注。2012年3—7月,在杭州城市环境下,对白头鹎的繁殖生态进行了系统调查,共记录到白头鹎繁殖鸟巢117巢。结果显示,在杭州市区,白头鹎主要在居民小区、行道树和绿化带的树冠层筑巢,主要营巢植物为桂树(Osmanthus fragrans),占总数的84.6%(n=117)。所有繁殖巢距地面均高(3.16±0.91)m(n=117)。3月底开始筑巢产卵,产卵高峰集中在4月11—25日。窝卵数为(3.37±0.48)枚(n=103),孵化期为(11.34±1.12)d(n=32),育雏期为(11.85±1.12)d(n=47)。孵化率为68.3%(n=111),离巢率为52.1%(n=117),总繁殖成功率为34.7%(n=111)。繁殖失败原因主要包括卵及雏鸟被捕食、人为干扰等。     

Secondhand homes: The multilayered influence of woodpeckers as ecosystem engineers

Ecosystem engineers alter, and can be influenced in turn by, the ecosystems they live in. Woodpeckers choose foraging and nesting sites based, in part, on food availability. Once abandoned, these cavities, particularly within areas of high forage, may be crucial to secondary cavity‐nesting birds otherwise limited by cavities formed through decay. Our study examined factors that influence the nesting success of primary cavity nesters and the subsequent impact on secondary cavity‐nesting birds. Using 5 years of point count data, we monitored the outcomes of cavity‐nesting birds in South Texas. We used logistic‐exposure models to predict daily survival rates based on cavity metrics and used woodpecker foraging trends and insect surveys to determine if nesting where woodpeckers actively forage benefits secondary cavity‐nesting birds. Both woodpeckers and secondary cavity nesters shared predictors of daily survival; nests were more successful in cavities with small openings in minimally decayed trees. All secondary cavity nesters had higher probabilities of success when nesting in an abandoned woodpecker cavity, opposed to ones formed by decay. Woodpeckers tended to forage in areas with higher‐than‐average levels of the insect orders Coleoptera, Hymenoptera, and Orthoptera, and secondary cavity nesters had higher rates of success when nesting in these areas. Our results suggest abandoned woodpecker cavities may be constructed in a way that directly benefit secondary cavity nesters. Additionally, we suggest an interplay between these ecosystem engineers, food availability, and secondary cavity nesters: Woodpeckers engineer superior nesting cavities in areas where food is more abundant, and the resultant cavities in areas of high forage may benefit local secondary cavity nesters. Our findings indicate that there is still much to be explored in the role of ecosystem engineers, and how they influence local communities on multiple trophic levels.     

环境因子对笼养朱鹮自然繁殖的影响

2004年3~7月,在陕西省洋县对人工饲养条件下朱鹮(Nipponia nippon)的自然繁殖进行了研究。18对繁殖鸟的窝卵数平均为(3.10±0.54)枚,孵化率26.2%,育雏成功率64.7%。当笼舍面积低于某一阈值时,窝卵数与笼舍面积呈明显正相关(Pearson,r=0.591,P<0.01)。出壳数、出飞数均与巢距遮荫树的距离呈负相关(Pearson,r1=-0.674,P1<0.05;r2=-0.677,P2<0.05)。亲鸟的繁殖经验对繁殖成功率没有显著影响,营巢环境是影响自然繁殖成功率的重要因素。     

The long-term ecology of the lost forests of La Laguna, Tenerife (Canary Islands)

Aim We report the first analysis of the long‐term ecology of Tenerife, in order to establish a pre‐colonization base‐line and to assess the effect of human activity and the role of climatic variation on vegetation during the Late Holocene. Location A former lake bed in the city of La Laguna (Tenerife, Canary Islands, Spain). Methods A sedimentary sequence of over 2 m was obtained from the former lake bed. Fossil pollen and microfossil charcoal concentrations were analysed. Radiocarbon dating of the sequence indicates that it spans approximately the last 4700 years. The pollen diagram was zoned using optimal splitting within psimpoll 4.25. Results Three pollen zones were differentiated: (1) in Zone L1 (c. 4700–2900 cal. yr bp ) a mixed forest was dominated by Quercus, Carpinus, Myrica and Pinus; (2) in Zone L2 (c. 2900–2000 cal. yr bp ) the laurel forest taxa increased, while Pinus, Juniperus and Phoenix declined; and (3) Zone L3 (c. 2000–400 cal. yr bp ) was characterized by the decline of Carpinus and Quercus and the abundance of laurel forest taxa (e.g. Myrica). Neither Carpinus nor Quercus was hitherto considered to be native to the Canary Islands. Their decline started c. 2000 years ago, coinciding with microfossil charcoal evidence of increased burning and with archaeological evidence for the first human settlement on Tenerife. Main conclusions Between c. 4700 and 2000 cal. yr bp , the composition of the forest in the valley of La Laguna was very different from what it is at present. In particular, Quercus and Carpinus appear to have been significant components, alongside components of the present‐day laurel forest, and the native pine (Pinus canariensis) forest and thermophilous woodland were also more prevalent in the region (but probably not within the lake basin itself) until 3000 cal. yr bp . The subsequent decline of Quercus and Carpinus led to the establishment of the present laurel forest in the region and a shift to more open vegetation types. These changes indicate that the aboriginal inhabitants of the islands, the Guanches, had a far more profound impact on the vegetation of Tenerife than hitherto realized.     

Breeding ecology of Red‐faced Cormorants in the Pribilof Islands,Alaska

ABSTRACT Red‐faced Cormorants (Phalacrocorax urile) are North Pacific endemics recognized as a vulnerable species, but little is known about their breeding ecology. We studied Red‐faced Cormorants on St. Paul Island, Alaska, from 1975 to 2009, with more detailed data collected in 2004 and 2005. Mean clutch sizes in 2004 (3.2 ± 0.8 [SD] eggs) and 2005 (3.1 ± 0.8 eggs) were similar to the long‐term average (2.9 ± 0.3 eggs from 1976 to 2009). The mean laying interval in 2004 and 2005 was 2.15 ± 0.80 d (N= 407), and the mean egg period (number of days between laying of an egg and hatching) was 31.1 ± 1.4 d (N= 158). Approximately 64 ± 17% of eggs hatched during the period from 1975 to 2009. The mean number of chicks per nest in 2004 and 2005 was 2.8 ± 0.8 (N= 232), and the mean number of fledglings per initiated nest in all years was 1.22 ± 0.52. Chicks fledged 46 to 66 d posthatching. In 2004 and 2005, the primary causes of egg loss were predation by Arctic foxes (Vulpes lagopus) and destruction of eggs and abandonment of nests due to storms. Starvation was the primary cause of nestling mortality in both years. Because chicks are dependent on parents to provide food for over 45 d, consistent near‐shore foraging opportunities must be available. From 1975 to 2009, Red‐faced Cormorants experienced only 1 yr of complete reproductive failure (1984). The consistent reproductive success of Red‐faced Cormorants suggests that conditions may be relatively stable for this species on St. Paul Island, or that the variability in their breeding ecology (e.g., phenology, clutch sizes, and incubation strategies) provides the flexibility needed to successfully fledge some chicks nearly every year.     

Artificial nest box use by the North Island saddleback: Effects of nest box design and mite infestations on nest site selection and reproductive success

Abstract

The pests and weeds that can affect conservation values in New Zealand are mostly introduced species, including 31 species of mammals, a small number of birds, a few fish and amphibians, an unknown number of invertebrate species (but particularly two wasps), and at least 75 introduced plants capable of permanently altering native ecosystems.     

Island ecology and contingent theory: the role of spatial scale and taxonomic bias

Scale, the scale dependency of patterns and processes, and the ways that organisms scale their responses to these patterns and processes are central to island and landscape ecology. Here, we take a database of studies in island ecology and investigate how studies have changed over a 40-year period with respect to spatial scale and organisms studied. We demonstrate that there have been changes in the spatial scale of islands studied and that there is taxonomic bias in favour of vertebrates in island ecological studies when compared to scientific publications as a whole. We discuss how such taxonomic bias may have arisen and discuss the implications for ecology and biogeography.     

Availability and selection of arboreal termitaria as nest-sites by Orange-fronted Parakeets Aratinga canicularis in conserved and modified landscapes in Mexico

Few studies have investigated the use of termitaria by nesting parrots, or how this may be affected by habitat transformation. We determined selection of termitaria by nesting Orange-fronted Parakeets Aratinga canicularis , and evaluated the effect of habitat transformation on the availability of termitaria nest-sites for Parakeets in the tropical dry forest of Western Mexico. Availability of termitaria was quantified in 24 survey plots in a factorial design of six 1-ha plots in each of conserved and modified, deciduous and semi-deciduous forest. Characteristics of termitaria were determined in survey plots, as well as 21 nest-termitaria used by Parakeets, and their nearest adjacent termitarium. There was an overall density of 1.6 termitaria/ha suitable for nesting by Parakeets, which did not differ between habitats, although only 8% of apparently suitable termitaria were occupied by nesting Parakeets. However, termitaria in conserved semi-deciduous forest were significantly higher above the ground, and termitaria in conserved deciduous forest were significantly smaller in volume. In the modified landscape, termitaria were significantly lower and their volume significantly larger than in conserved landscapes. Termitaria used by nesting parrots were at a significantly greater height above the ground than the nearest adjacent termitaria. Termitarium volume did not reliably predict the likelihood of nest-site selection, although Parakeets only used termitaria between 15 and 150 l. Parakeets nesting in modified habitats used termitaria at a significantly lower height than Parakeets nesting in conserved habitat. It is unclear whether this represents a decline in nest-site quality in modified habitats, which could affect reproductive success of Parakeet populations in fragmented landscapes.     

Breeding systems in two species of the genus Helleborus (Ranunculaceae)

ABSTRACT

The results of various types of manual and free pollination are reported in Helleborus bocconei and Helleborus foetidus, two sympatric species of the understorey of submediterranean woods that flower in January–March and are pollinated by bumble-bees of the genus Bombus. Both species were found to be partially self-compatible even if at different rates; geitonogamy seems to be more frequent in H. foetidus and spontaneous self-pollination does not usually occur for morphological reasons, and the species are not apomictic. Efficiency in seed production after free pollination was very high indicating that in spite of harsh climatic condition, there were no limitations imposed by pollen or pollinators.     

Artificial covering on trap nests improves the colonization of trap-nesting wasps

To evaluate the role that a trap‐nest cover might have on sampling methodologies, the abundance of each species of trap‐nesting Hymenoptera and the parasitism rate in a Canadian forest were compared between artificially covered and uncovered traps. Of trap tubes exposed at eight forest sites in six trap‐nest boxes, 531 trap tubes were occupied and 1216 individuals of 12 wasp species of four predatory families, Vespidae (Eumeninae), Crabronidae, Sphecidae and Pompilidae emerged over 2 years, and no bee species were found. Results indicated that artificial covering led to a significant increase in the number of nested tubes of Ancistrocerus adiabatus, Ancistrocerus antilope, Ancistrocerus campestris and Auplopus mellipes, and significant effects of covering were not found for the other species. No significant difference in the overall parasitism rate between covered and uncovered traps was noted. These suggested that the covering technique could provide more opportunities for some wasp species to colonize trap nests.