Reproductive ecology of blackbirds ( Turdus merula maximus) in a high-altitude location, Tibet

Reproductive data of high-altitude blackbirds (Turdus merula maximus) were collected at an alpine environment covered with scrub vegetation in Lhasa mountains, Tibet. The blackbird nests were found from 3,800 to 4,500 m at a breeding density of 0.07 pairs/ha. Egg-laying occurred from early May to late July, with a peak (73.0% of all nesting attempts) between mid-May and mid-June. Most (79.5%) of the nests were sited in six different plant species with Cotoneaster microphyllus being most preferred. A few (20.5%) nests were against rocky walls. Bushes used for nest sites were significantly higher. Compared with lowland blackbirds, montane blackbirds experienced a shorter breeding season (2.5 months), laid smaller clutches (2–4 eggs, averaging 2.86), but larger eggs (mean volume index 16,348), produced only one brood per year, had a slightly shorter incubation period (12–13 days), but a longer nestling period (16–18 days), and enjoyed a higher breeding success (59.0%). In the alpine environment where climate is harsh and food supply poor, the strategy of increased egg size with decreased clutch size suggests that the high-altitude blackbirds improve their breeding success by investing more reproductive energy in fewer offspring in response to the constraints of time and resources. However, the environmental constraints on reproduction result in a low annual reproductive output.This revised version was published online in December 2004. The german abstract has been included.     

四川南充白颊噪鹛的繁殖行为观察

2009年2～6月,在四川省南充市市郊观察了白颊噪鹛(Garrulax sannio)的繁殖行为。结果显示,白颊噪鹛的营巢成功率为73.3%,影响其巢址选择的主要因素依次为巢位及巢的稳固因素、隐蔽因素、食物因素;孵化期亲鸟的离巢时间随着孵化天数的增加而减少,离巢次数随着孵化天数的增加而增加;育雏期亲鸟喂食频次随着雏鸟日龄增加而增加,且在日间各时段的喂雏次数不同,在7:01～10:00时和17:01～19:00时喂食频次最高,在6:30～7:00时和10:01～14:00时最低;育雏期雏鸟的外部形态变化明显,体长及外部器官的形态学参数可以用Logistic曲线方程很好地拟合,雏鸟体重和各器官的生长曲线在10.5日龄前呈S型;白颊噪鹛的繁殖成功率为23.1%。     

四川南充市区红头长尾山雀的巢址选择、繁殖习性与帮手行为

2003年3月~2004年5月在四川省南充市区的校园和公园内对红头长尾山雀(Aegithalosconcinnus)的繁殖生态进行了研究。结果表明,红头长尾山雀在2月上旬开始求偶、配对。2月中旬开始营巢,巢多筑于圆柏、凤尾竹等上,营巢期10~11 d,影响巢址选择主要因素6种。3月初产卵,窝卵数(5.17±0.41)枚;轮流昼夜孵卵,孵卵期为14~15 d;育雏高峰期每日9:00~10:00、16:00~17:00时,育雏期为14 d。从孵卵开始到育雏结束,其中3个巢均有一个帮手,与生殖鸟轮流孵卵和育雏。     

Human urine is an excellent liquid waste for the culture of fish food organism, Moina micrura

With a view to converting human urine into bio-wealth in the form of zooplankton, the nutrient potentials of liquid wastes (0.11 mL L⁻¹)—(i) human urine (♂), (ii) cow urine, (iii) human–cow mixed urine or some solid wastes (0.11 g L⁻¹): (iv) vermi-compost, (v) cow dung, (vi) poultry droppings and (vii) mixed wastes (vermi-cow-poultry)—were evaluated for the mass culture of zooplankton Moina micrura in 24 outdoor tanks (4500 L) in triplicate treatments using life table as indicator during the period of October–December, 2005. Neonates of Moina micrura held in the treatment with human urine started reproduction at least 4 days earlier than other solid wastes tested. Total number of Moina micrura enumerated in the culture tank, related with offspring production per life span, was maximum in case of human urine treatment, followed by human–cow mixed urine, cow urine, vermin-compost, poultry droppings, mixed wastes (vermin–cow–poultry), cow dung and control treatments. The relationship between the total offspring production per female per life span and the nitrogen content of water in different treatments implied that human urine was an excellent liquid waste that can be used for the mass production of zooplankton Moina micrura required for larval and post larval rearing of commercial fishes.     

Notes on the postembryonic development and ecology of Grosphus hirtus Kraepelin, 1901 (Scorpiones, Buthidae) from the Parc National d’Ankarafantsika, northwest Madagascar

Among several specimens of Grosphus hirtus Kraepelin (Scorpiones, Buthidae), obtained in Madagascar, Mahajanga Province, Parc National d’Ankarafantsika, Station Forestière d’Ampijoroa, and then held in captivity, the courtship and mating behaviour of two females was observed. These two animals gave birth in captivity to 26 and 37 offspring of which two and three reached maturity, respectively. The duration of the five instars needed to reach the adult stage in both males and females averaged 14, 112, 117, 274, and 334 days. These developmental periods are much longer than those of Grosphus flavopiceus Kraepelin, the only other species in this genus studied, and longer than those of most examined species of Buthidae. Morphometric values for the different instars are presented from the individual offspring and from specimens collected in the wild. On the basis of these values, the average growth factor (Dyar's constant) per moult for three different measured structures was calculated from the pooled data. Dyar's constant is expressed for the first time in scorpions of the genus Grosphus. Instars growth factors are also comparable to other species of Buthidae.     

Feeding ecology of common carp (Cyprinus carpio L.) in a rice–fish culture system of the Apatani plateau (Arunachal Pradesh, India)

For two years (2002, 2003) selective feeding ecology of the common carp (Cyprinus carpio L.) has been studied in carp-integrated rice fields in Apatani Plateau of Arunachal Pradesh (India). Sampling strategy was based on the water depths in the fields and on the flood phases: early flood phase (June–July), mid flood phase (July–August), and late flood phase (September–October). In 2003 the water level was higher and therefore periphyton availability was better. This resulted in larger gut contents and better growth of the carp compared with 2002 when the water levels were lower. Gut contents analyses revealed a total of 60 food items of which 22 belonged to the Chlorophycea, 12 to the Cyanobacteria, 10 to the Bacillariophycea and 16 to several zooplankton taxa. With the progress of flood phases, the fish increased its feeding on periphyton food items; simultaneously, feeding on plankton items gradually declined. This was caused by the increasing periphyton availability on the rice-stems. Selective feeding on plankton and periphyton taxa was studied, selectivity changed with the flood phases. Periphytic Chlorophycea and Cyanobacteria, especially, were strongly positively selected. Generally, periphyton was the most important resource for the common carp in the rice fields.     

Candidates for biocontrol of Macfadyena unguis-cati in South Africa: biology, host ranges and potential impact of Carvalhotingis visenda and Carvalhotingis hollandi under quarantine conditions

Macfadyena unguis-cati (L.) Gentry (Bignoniaceae) was introduced as an ornamental in South Africa, but is fast becoming an important invasive plant in many areas. It is difficult to control the plant chemically and mechanically. The first biocontrol agent, the chrysomelid Charidotis auroguttata (Boheman), has been released. It established at some release sites, but numbers have so far remained low. Additional biocontrol agents were sought to augment C. auroguttata. The potential host ranges of two foliage feeding lace bugs, Carvalhotingis visenda (Drake and Hambleton) and C. hollandi (Drake) (Hemiptera: Tingidae) were evaluated on the basis of nymphal no-choice and adult multi-choice tests involving 23 plant species in 11 families. In no-choice tests, nymphs of both species were able to survive and complete development on M. unguis-cati only, and adults of both species only fed and oviposited on M. unguis-cati during the adult multi-choice tests. Host specificity tests thus confirm that the tingids are highly host specific biocontrol agents, and will not pose risk to any non-target plants in South Africa. A study to determine the potential impact of C. hollandi nymphal feeding on M. unguis-cati showed a significant decrease in the chlorophyll contents of leaves when compared to those of control plants. These studies indicate that, once released, the two lace bug species could contribute significantly to the biological control of M. unguis-cati in South Africa.     

Duplication of the Rdl GABA receptor subunit gene in an insecticide-resistant aphid, Myzus persicae

Resistance to cyclodiene insecticides is associated with replacements of a single amino acid (alanine 302) in a γ-aminobutyric acid (GABA) receptor subunit encoded by the single-copy gene Resistance to dieldrin (Rdl). Alanine 302 is predicted to reside within the second membrane-spanning region of the Rdl receptor, a region that is thought to line the integral chloride ion channel pore. In all cyclodiene-resistant insects studied to date, this same alanine residue is replaced either by a serine, or, in some resistant strains of Drosophila simulans, a glycine residue. Therefore, individuals can carry only two different Rdl alleles. In contrast, here we report the presence of up to four different Rdl-like alleles in individual clones of the green peach aphid, Myzus persicae. In addition to the wild-type copy of Rdl gene (encoding A302 or allele A), M. persicae carries three other alleles with the following amino acid replacements: A302 → Glycine (allele G), A302 → Serine^TCG (allele S) and A302 → Serine^AGT (allele S′). Evidence from direct nucleotide sequencing and Single Stranded Conformational Polymorphism (SSCP) analysis shows that at least three of these different Rdl alleles (i.e. A, G and S) are commonly present in individual aphids or aphid clones. Southern analysis using allele-specific probes and analysis of sequences downstream of the exon containing the resistance-associated mutation confirm the presence of two independent Rdl-like loci in M. persicae. One locus carries the susceptible alanine (A) and/or resistant glycine (G) allele while the other carries the two serine alleles (S or S′). Whereas resistance levels are correlated with the glycine replacement, the S allele was present in all aphid clones, regardless of their resistance status. These results suggest that target site insensitivity is associated with replacements at the first (A/G) but not the second (S/S′) locus. Phylogenetic analysis of nucleotide sequences indicates that both putative aphid Rdl loci are monophyletic with respect to other insect Rdl genes and may have arisen through a recent gene duplication event. The implications of this duplication with respect to insecticide resistance and insect GABA receptor subunit diversity are discussed. Received: 10 March 1998 / Accepted: 21 July 1998     

Biology and ecology of Thallomys nigricauda (Rodentia, Muridae) in the Thornveld savannah of South Africa

The black-tailed tree rat, Thallomys nigricauda, is one of the few arboreal rodents inhabiting the southern African savannahs. During three field campaigns in 2001 and 2002 we collected data on the biology and ecology of T. nigricauda in the Thornveld savannah of the Molopo Nature Reserve (NW Province, South Africa). T. nigricauda lives a solitarily lifestyle in the Molopo Nature Reserve. Diet analyses shows that they are folivorous, specializing on leaves of Acacia mellifera and Acacia luederitzii. Male and female animals have a similar body size (≈80 g). Mean age at weaning was 30 days and mean litter size at this age was 1.8. Monthly survival rates varied between 0.25 and 0.86. Density was estimated to be 0.5–1 individual ha⁻¹. Overall, our results show that the basic ecological characteristics of this arboreal rodent are fairly similar to other rodent species.     

Lipid, carbohydrate and nitrogen content of long- and short-winged Gryllus firmus: Implications for the physiological cost of flight capability

Concentrations of total lipid, triglyceride, soluble carbohydrate, total nitrogen and water were measured in the long-winged (LW) and short-winged (SW) morphs of the cricket, Gryllus firmus. In addition, the weights and composition of wings and oviposited eggs were compared between morphs. This was done to obtain information on the energetic cost of flight capability in the LW morph. Whole-cricket content (% dry mass) of triglyceride was significantly higher in LW vs SW individuals of both sexes. Since triglyceride is a likely flight fuel in G. firmus, the biosynthesis of elevated levels of this high energy substance in the LW morph may represent an important energetic cost of flight capability. The existence of such a cost is consistent with the elevated respiratory metabolism previously observed in LW vs SW G. firmus. A highly significant negative correlation was observed between triglycerides and non-triglycerides in LW but not SW crickets. This suggests that lipid biosynthesis may be operating under some constraint in the LW morph. Increased triglyceride biosynthesis may require a concomitant decreased biosynthesis of non-triglycerides. In contrast to the elevated triglyceride level in the LW morph, carbohydrate concentration was higher in the SW morph during early adulthood. Carbohydrate content also decreased with age in the SW but not in the LW adults. No differences were observed between morphs in (1) the total nitrogen or water contents of whole crickets, (2) the nitrogen content of wings or (3) the wet weight, dry weight, lipid content, or total nitrogen content of oviposited eggs.     

Advantage of residualizing radiolabels for an internalizing antibody against the B-cell lymphoma antigen, CD22

 LL2 is an anti-CD22 pan-B-cell monoclonal antibody which, when radiolabeled, has a high sensitivity for detecting B-cell, non-Hodgkin’s lymphoma (NHL), as well as an antitumor efficacy in therapeutic applications. The aim of this study was to determine whether intracellularly retained radiolabels have an advantage in the diagnosis and therapy of lymphoma with LL2. In vitro studies showed that iodinated LL2 is intracellularly catabolized, with a rapid release of the radioiodine from the cell. In contrast, residualizing radiolabels, such as radioactive metals, are retained intracellularly for substantially longer. In vivo studies were performed using LL2-labeled with radioiodine by a non-residualizing (chloramine-T) or a residualizing method (dilactitol-tyramine, DLT), or with a radioactive metal (¹¹¹In). The biodistribution of a mixture of ¹²⁵I (non-residualizing chloramine-T compared to residualizing DLT), ¹¹¹In-labeled LL2 murine IgG2a or its fragments [F(ab′)₂, Fab′], as well as its humanized, CDR-grafted form, was studied in nude mice bearing the RL human B-cell NHL cell line. Radiation doses were calculated from the biodistribution data according to the Medical International Radiation Dose scheme to assess the potential advantage for therapeutic applications. At all assay times, tumor uptake was higher with the residualizing labels (i.e., ¹¹¹In and DLT-¹²⁵I) than with the non-residualizing iodine label. For example, tumor/blood ratios of ¹¹¹In-labeled IgG were 3.2-, 3.5- and 2.8-fold higher than for non-residualizing iodinated IgG on days 3, 7 and 14, respectively. Similar results were obtained for DLT-labeled IgG and fragments with residualized radiolabels. Tumor/organ ratios also were higher with residualizing labels. No significant differences in tumor, blood and organ uptake were observed between murine and humanized LL2. The conventionally iodinated anti-CD20 antibody, 1F5, had tumor uptake values comparable to those of iodinated LL2, the uptake of both antibodies being strongly dependent on tumor size. These data suggest that, with internalizing antibodies such as LL2, labeling with intracellularly retained isotopes has an advantage over released ones, which justifies further clinical trials with residualizing ¹¹¹In-labeled LL2 for diagnosis, and residualizing ¹³¹I and ⁹⁰Y labels for therapy. Received: 23 August 1996 / Accepted: 7 February 1997     

Effects of spatial heterogeneity on butterfly species richness in Rocky Mountain National Park, CO, USA

We investigated butterfly responses to plot-level characteristics (plant species richness, vegetation height, and range in NDVI [normalized difference vegetation index]) and spatial heterogeneity in topography and landscape patterns (composition and configuration) at multiple spatial scales. Stratified random sampling was used to collect data on butterfly species richness from seventy-six 20 × 50 m plots. The plant species richness and average vegetation height data were collected from 76 modified-Whittaker plots overlaid on 76 butterfly plots. Spatial heterogeneity around sample plots was quantified by measuring topographic variables and landscape metrics at eight spatial extents (radii of 300, 600 to 2,400 m). The number of butterfly species recorded was strongly positively correlated with plant species richness, proportion of shrubland and mean patch size of shrubland. Patterns in butterfly species richness were negatively correlated with other variables including mean patch size, average vegetation height, elevation, and range in NDVI. The best predictive model selected using Akaike’s Information Criterion corrected for small sample size (AIC_c), explained 62% of the variation in butterfly species richness at the 2,100 m spatial extent. Average vegetation height and mean patch size were among the best predictors of butterfly species richness. The models that included plot-level information and topographic variables explained relatively less variation in butterfly species richness, and were improved significantly after including landscape metrics. Our results suggest that spatial heterogeneity greatly influences patterns in butterfly species richness, and that it should be explicitly considered in conservation and management actions.