首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
ABSTRACT.   For burrow-nesting seabirds, investigators have examined nestling diet by attaching harnesses to the bills of nestlings to intercept food delivered by the parent. To determine whether this method provides an unbiased estimate of nestling diet, we evaluated its effect on the provisioning behavior of Tufted Puffins ( Fratercula cirrhata ) nesting on Triangle Island, British Columbia. Adults delivering food to nestlings with bill harnesses always hesitated before entering a burrow with food, increasing their susceptibility to kleptoparasitism by gulls, and did not always leave the food intended for the nestling. These responses by adult puffins could lead to underestimates of energy intake rates of nestlings and unreliable comparisons with other species if prey left by adults in nest burrows were the only source of data. We also compared estimates of the species, number, and size of prey delivered by adult puffins as determined by direct observation from blinds to samples of prey collected directly from nest burrows and found that the two sampling techniques produced similar results. However, identifying rare prey species and gathering precise information about prey length, mass, and condition require collection of prey, and we recommend using a combination of techniques to obtain the most reliable estimates of nestling diet.  相似文献   

2.
Renal coccidiosis is reported for the first time in an auk (Alcidae). Infection was detected in seven of 50 nestling Atlantic puffins (Fratercula arctica) and a new species of coccidia, Eimeria fraterculae sp. n., is described. The structure and sporulation of oocysts are characterized. Meronts, gamonts, and developing oocysts were present in collecting duct epithelium of medullary cones. The predominant host response was hypertrophy of infected cells, tubule dilation, and a mild localized peritubular infiltration with mononuclear inflammatory cells.  相似文献   

3.
In 3 different years we glued 29-g satellite transmitters to the back feathers of five Atlantic puffins Fratercula arctica breeding in Røst, southwest of the Lofoten Islands. The birds were tracked for a mean of 26 (range 7–46) days, and four were re-sighted (without transmitters) at their nest sites in the following year. The trajectories documented a unidirectional post-breeding migration towards the Barents Sea, completely opposite of that indicated by all but 1 of the 27 existing ring recoveries of adult puffins from colonies in North Norway outside the breeding season. We discuss the importance of what seems to be a regular visit to the Barents Sea in early autumn for puffins from Røst, which is still one of the largest puffin colonies in the world.  相似文献   

4.
Questing behavior of Ixodes uriae and their associated seasonal, host-feeding patterns are crucial to our understanding of tick life history strategies and the ecology of diseases that they transmit. Consequently, we quantified questing behavior of nymphs and adult female I. uriae ticks at Gull Island, a seabird colony in Newfoundland, Canada, to examine seasonal variation of off-host and on-host tick activity. We sampled a total of 133 adult Atlantic puffins (Fratercula arctica), 152 puffin chicks, and 145 herring gull (Larus argentatus) chicks for ticks during the breeding seasons of 2004 and 2005. Questing ticks were sampled by dragging a white flannel cloth across the grassy breeding areas during the mo of May, June, July, and August. Nymph questing activity reached a peak during mid-July (79 and 110 individuals/hr in 2004 and 2005, respectively). The prevalence of nymphs and adult female ticks on different seabird hosts varied between years and during the seasons. Puffin chicks had the highest prevalence (above 70% in July) of nymphs in both years and this was correlated with questing activity. Female ticks rarely fed on puffin chicks, but were prevalent on adult puffins and gulls, although prevalence and questing of ticks were not correlated in these hosts. These patterns of off-host and on-host tick activity suggests that I. uriae ticks likely use a combination of questing and passive waiting, e.g., in puffin burrows, to detect hosts, depending on the tick stage and the host species.  相似文献   

5.
ABSTRACT.   Although radiotelemetry is useful for monitoring nest attendance and the foraging ranges and distribution of breeding birds, attachment of transmitters may affect reproductive behavior. In 2003, we captured 25 adult Tufted Puffins ( Fratercula cirrhata ) at two colonies in Chiniak Bay, Kodiak Island, Alaska, and fitted them with subcutaneously anchored radiotransmitters (<1.2% of body mass). We determined the presence of radio-marked birds at each study site using automated, remote radiotelemetry systems, and compared rates of nestling growth, fledging mass, and fledging success for chicks with and without (control group) a radio-marked parent. Although most radio-marked adults continued to attend nests after capture and attachment of transmitters, nestlings with a radio-marked parent had lower mean growth rates (6.9 g/d vs. 14.4 g/d) and fledging success (33% vs. 84%) than control chicks. These results suggest that colony attendance by adult puffins fitted with transmitters declined sharply or completely and this led to high nestling mortality. Given the negative effects of transmitters on Tufted Puffins in our study and in other studies of alcids, we suggest delaying the attachment of transmitters until well after the brooding period. In addition, we recommend pilot studies be undertaken to distinguish the possible effects of capture and handling from those of actually carrying the device.  相似文献   

6.
Western equine encephalitis in avian populations in North Dakota, 1975   总被引:2,自引:0,他引:2  
The involvement of wild birds in western equine encephalitis (WEE) and St. Louis encephalitis (SLE) virus activity in the Red River valley area of North Dakota (USA) during a WEE epidemic was investigated in August 1975. Free-ranging birds were captured with mist nets and nestlings by hand. Virologic and serologic results indicated that a similar rate of WEE virus activity occurred throughout Richland County and between permanent and summer resident birds. The rate of SLE virus activity in the birds of Richland County was lower than for WEE virus, but the SLE antibody prevalence was greater in rural areas than within urban locations. Seven of the nine WEE virus isolations were from nestling birds of four different species; the remaining two from adults of two different species. Overall prevalence of neutralizing (N) antibody against WEE virus was 5% in nestling and 14% in adult birds but was the opposite for N antibody against SLE virus, 17% in nestling and 5% in adult birds. Differences between the two viruses in the presence and persistence of maternal N antibody or differential mortality in nestling birds may have caused the disparity in antibody prevalences.  相似文献   

7.
One adult male, eight pups (including two full term foetuses) and nine adult female harbour seals (Phoca vitulina) were analysed for indices of mixed function oxidase (MFO) activity. MFO activity was present in liver samples, but was at or below detection limits in samples of kidney, lung and pancreas. Hepatic ethoxyresorufin O-de-ethylase and benzo[a]pyrene hydroxylase activities were similar to those reported in other seals and in other mammals. Cytochromes P-450 and b5 concentrations were slightly lower than those observed in other mammals. MFO activities in newborn pups and foetuses were significantly lower than those in adult females. No qualitative differences in cytochrome P-450 isozyme distribution between foetal and adult samples could be discerned by electrophoresis.  相似文献   

8.
本文对几种抗药性和敏感性家蝇品系的乙酰胆碱酯酶(AChE)、羧酸酯酶及多功能氧化酶(MFO)进行了测定.结果表明:①抗药性品系和敏感性品系的AChE活力差异不大, 有机磷抗性品系的AChE对对氧磷的不敏感性比敏感性家蝇明显增大.②某些抗药性家蝇的羧酸酯酶活力比敏感性家蝇大.③抗药性家蝇的MFO活力(O-脱甲基和环氧化)比敏感性家蝇均有不同程度的增高.④二氯苯醚菊酯抗性家蝇对有机磷有负交互抗性.  相似文献   

9.
Packed cell volumes (PCVs) and plasma chemistry parameters were measured in 15 adult and 18 nestling African fish eagles (Haliaeetus vocifer) sampled from June 2002 through January 2003 in Uganda. Morphologic measurements were obtained from 15 adult eagles. All eagles were examined for blood parasites and sexed by examination of DNA from red blood cells. Ten adults and eight nestlings were sampled from Lake Mburo and five adults and 10 nestlings were sampled from Lake Victoria near Entebbe, Uganda. Analysis of variance was conducted to assess the association between site, age, sex, and plasma chemistry parameters and the association between sex and morphologic characteristics. Plasma chemistry values for nestling and adult African fish eagles were similar to those reported for other captive and free-ranging eagle species. Packed cell volumes for nestling African fish eagles were markedly lower than values reported for nestlings of other eagle species, although the mean estimated age of nestlings sampled also was lower. A significant association (P < or =0.05) was found between PCV of nestling eagles and study site (lower at Lake Mburo) but no association was found between PCV and nestling body weight (P> or =0.05). An unidentified Plasmodium sp. was present in erythrocytes of three nestlings from Lake Mburo. No other blood parasites were seen. There was significant variation (P< or =0.05) in PCV, calcium, phosphorous, potassium, cholesterol concentrations, and creatine kinase activity between adults and nestlings; all were lower in adults. Aspartate transaminase activity was higher in adults. Like other Haliaeetus sp., body weight, bill depth, culmen length, footpad length, and hallux length as well as bill depth measurements were significantly (P < or = 0.05) greater for females than males. The objective of the study was to provide baseline biologic and physiologic information that may prove useful in the management and study of captive and wild populations of African fish eagles.  相似文献   

10.
Eduardo  Mianguez 《Journal of Zoology》1996,239(4):633-643
The pattern of chick feeding of the British storm-petrel Hydrobates pelagicus in a Mediterranean colony was examined by weighing chicks at 24-h intervals on different days during the nestling period. In order to calibrate daily mass increments (NET) against number of feedings, daily mass changes of chicks were regressed upon the sum of positive mass increments recorded overnight (SUM) during four nights. The average meal size delivered to chicks per night by one parent was 3.5 ß 1.3 g or 12% of adult weight. This was insufficient for sustaining constant chick mass during a day. On average 85% of chicks were fed each night, and the mean interval between feeds was 1.2 ß 0.5 nights. Nightly feeding frequencies differed among days, but this night-to-night variation was not related to meteorological conditions. Both food requirements necessary for chick body maintenance (zero-growth) and meal size were relatively constant for ages up to 59 days. However, feeding frequency decreased throughout the fledging period, accounting for agespecific variation in growth rates until fledging. Food requirement and feeding patterns at Benidorm were different from North Atlantic colonies. None the less, growth patterns were almost identical, suggesting adjustment to maintain chick body mass at a determined level, as food delivery to nestling appears to be regulated to chicks'nutritional requirements.  相似文献   

11.
1. Three experiments were conducted to determine the effect of dietary methionine levels on the hepatic microsomal mixed-function oxidase (MFO) system in male broiler chicks. 2. The level of dietary methionine for the highest growth coincided with that for the MFO activity. 3. Dietary methionine deficiency reduced MFO activity, but the reduction effect was not constant. 4. Dietary methionine excess also reduced MFO activity, even though growth rate was held at a maximum.  相似文献   

12.
Previous work has established the marked potentiation of CCl4 hepatoxicity by prior exposure to chlordecone (CD). This study was conducted to determine if prior exposure to CD results in enhancement of CCl4-induced destruction of the hepatic microsomal mixed-function oxygenase (MFO) system. Male Sprague-Dawley rats received a single oral dose of CD (10 mg/kg) or corn oil vehicle alone (1 ml/kg) 24 hr prior to a single ip injection of CCl4 (0-100 microliter/kg). Mirex (M; 10 mg/kg) and phenobarbital (PB; 80 mg/kg/day for two days) were used as negative and positive controls respectively for the potentiation of CCl4 hepatotoxicity. Hepatotoxicity was evaluated 24 hrs after CCl4 administration by elevations of three serum enzymes (GPT, GOT, and ICD). The key hepatic microsomal MFO parameters measured were microsomal protein, cytochrome P-450 content, glucose-6-phosphatase (G-6-Pase), and aminopyrine demethylase (APD). As previously demonstrated using a subchronic dietary pretreatment protocol, CD potentiated CCl4 hepatotoxicity over a range of CCl4 doses to a greater extent than PB or M, as judged by elevations in serum enzymes. PB caused the greatest increase in total P-450 content and the greatest increase in CCl4-mediated destruction of microsomal protein and APD activity. M caused the least destruction of total hepatic cytochrome P-450, despite the same level of cytochrome P-450 as in the PB group. CD treatment caused the greatest decrease in G-6-Pase activity in comparison to PB or M pretreatments and a similar degree of P-450 destruction as observed with the PB group. These findings suggest that in general, CCl4-induced destruction of hepatic MFO parameters measured in this study is disproportional to the known degree of potentiated hepatotoxicity by the pretreatments and does not accurately reflect the potentiation of CCl4 hepatotoxicity by CD.  相似文献   

13.
二化螟对杀螟硫磷产生抗性的机理   总被引:6,自引:0,他引:6  
韩启发  庄佩君 《昆虫学报》1995,38(3):266-271
本文就二化螟Ckilo suppressalis Walker对杀螟硫磷抗性发生的机理进行了较为全面的研究。活体增效作用研究表明,脱叶磷(DEF)和氧化胡椒基丁醚(PBO)对抗性种群可分别增效1.3和34.8倍。这表明了多功能氧化酶(MFO)活性增强,而似乎与水解酶的活性无关。对寓体解毒酶的进一步研究表明,抗性和敏感种群的非特异性酯酶活力无明显差异,但羧酸酮酶(CarE,加入10-4mol/L的毒扁豆碱)和MFO的活力在抗性种群中有所增高。R种群幼虫CarE活力分别是s的2.42和2.92倍(以a-和β-乙酸萘酯为底物);R种群幼虫MFO的O-脱甲基作用的活力为s幼虫的1.43倍(以对硝基茴香醚为底物);R幼虫乙酰胆碱酯酶(AChE)对乙酰胆碱的活力是s的1.3倍,两者相差不大。但从米氏常数Km)和最大反应速度(Vmax)看,R幼虫是s幼虫的1.9和1.6倍;以对氧磷为抑制剂的R幼虫150是s幼虫的2倍。这些表明了R和s的AChE是不同的。研究结果还表明,二化螟对杀螟硫磷抗性的机理至少包括:(1)CarE活性的增高;(2)MFO的O-脱甲基活力的增高和(3)AChE敏感性的降低等。  相似文献   

14.
Respiratory motor outputs contain medium-(MFO) and high-frequency oscillations (HFO) that are much faster than the fundamental breathing rhythm. However, the associated changes in power spectral characteristics of the major respiratory outputs in unanesthetized animals during the transition from normal eupneic breathing to hypoxic gasping have not been well characterized. Experiments were performed on nine unanesthetized, chemo- and barodenervated, decerebrate adult rats, in which asphyxia elicited hyperpnea, followed by apnea and gasping. A gated fast Fourier transform (FFT) analysis and a novel time-frequency representation (TFR) analysis were developed and applied to whole phrenic and to medial branch hypoglossal nerve recordings. Our results revealed one MFO and one HFO peak in the phrenic output during eupnea, where HFO was prominent in the first two-thirds of the burst and MFO was prominent in the latter two-thirds of the burst. The hypoglossal activity contained broadband power distribution with several distinct peaks. During gasping, two high-amplitude MFO peaks were present in phrenic activity, and this state was characterized by a conspicuous loss in HFO power. Hypoglossal activity showed a significant reduction in power and a shift in its distribution toward lower frequencies during gasping. TFR analysis of phrenic activity revealed the increasing importance of an initial low-frequency "start-up" burst that grew in relative intensity as hypoxic conditions persisted. Significant changes in MFO and HFO rhythm generation during the transition from eupnea to gasping presumably reflect a reconfiguration of the respiratory network and/or alterations in signal processing by the circuitry associated with the two motor pools.  相似文献   

15.
1. MFO enzyme activities were measured in microsomes from whole mussels (Mytilus galloprovincialis) comber livers (Serranus cabrilla), or Posidonia oceanica etiolated tissues, and PAH contents were determined in sediments collected in coastal locations of the French Riviera and Corsica during 3 oceanographic cruises in 1987-1988. 2. BaP activities in mussel and EROD activities measured in fish were strongly correlated to the log of PAH content in sediments. The first results for CA4H in Posidonia showed significant differences related to PAH pollution levels. The increase in MFO activities measured in Corsica in summer 1988 indicated a recent petroleum contamination.  相似文献   

16.
烟粉虱体内几种抗性酶对寄主转换的响应   总被引:1,自引:0,他引:1  
将烟粉虱分别从嗜性较强的番茄植株上转移到嗜性相对较弱的国抗22(GK22)棉花、泗棉3号(S3)棉花和辣椒植株上,以及从嗜性较弱的辣椒植株上转移到嗜性相对较强的番茄、GK22棉花和S3棉花植株上,观察寄主转移后F1代、F2代和F3代烟粉虱体内α-NA羧酸酯酶、谷胱甘肽-s-转移酶和多功能氧化酶活性的变化,再将F4代烟粉虱转移到原寄主,同样观察这3种抗性酶的变化。结果表明,不同嗜性的寄主上烟粉虱体内3种酶活性的强弱与烟粉虱对这种寄主的嗜性相关,在嗜性较强的寄主上,3种酶的活性相对较低。烟粉虱从嗜性较强的寄主转移到嗜性相对较弱的寄主后,成虫体内α-NA羧酸酯酶、谷胱甘肽-s-转移酶和多功能氧化酶的活性显著上升,从嗜性较弱的寄主转移到嗜性较强的寄主后,羧酸酯酶和谷胱甘肽-s-转移酶的活性下降。在寄主转移过程中,烟粉虱体内的α-NA羧酸酯酶和谷胱甘肽-s-转移酶活性一般在F2代基本稳定,而多功能氧化酶在F1代就能迅速稳定。烟粉虱从过渡寄主再转移到原寄主的过程中,其3种酶的变化规律与上述寄主基本一致。结果提示,在烟粉虱寄主转换过程中,多功能氧化酶具有快速响应特性和较强的稳定性,而α-NA羧酸酯酶和谷胱甘肽-s-转移酶活性的变化与烟粉虱对寄主的适应度变化基本一致。  相似文献   

17.
二化螟对杀螟硫磷产生抗性的机理   总被引:9,自引:1,他引:9  
本文就二化螟Ckilo suppressalis Walker对杀螟硫磷抗性发生的机理进行了较为全面的研究。活体增效作用研究表明,脱叶磷(DEF)和氧化胡椒基丁醚(PBO)对抗性种群可分别增效1.3和34.8倍。这表明了多功能氧化酶(MFO)活性增强,而似乎与水解酶的活性无关。对寓体解毒酶的进一步研究表明,抗性和敏感种群的非特异性酯酶活力无明显差异,但羧酸酮酶(CarE,加入10-4mol/L的毒扁豆碱)和MFO的活力在抗性种群中有所增高。R种群幼虫CarE活力分别是s的2.42和2.92倍(以a-和β-乙酸萘酯为底物);R种群幼虫MFO的O-脱甲基作用的活力为s幼虫的1.43倍(以对硝基茴香醚为底物);R幼虫乙酰胆碱酯酶(AChE)对乙酰胆碱的活力是s的1.3倍,两者相差不大。但从米氏常数Km)和最大反应速度(Vmax)看,R幼虫是s幼虫的1.9和1.6倍;以对氧磷为抑制剂的R幼虫150是s幼虫的2倍。这些表明了R和s的AChE是不同的。研究结果还表明,二化螟对杀螟硫磷抗性的机理至少包括:(1)CarE活性的增高;(2)MFO的O-脱甲基活力的增高和(3)AChE敏感性的降低等。  相似文献   

18.
Twenty-three species within the avian family Alcidae are capable of wing-propelled flight in the air and underwater. Alcids have been viewed as Northern Hemisphere parallels to penguins, and have often been studied to see if their underwater flight comes at a cost, compromising their aerial flying ability. We examined the anatomy and histochemistry of select wing muscles (Mm. pectoralis, supracoracoideus, latissimus dorsi caudalis, coracobrachialis caudalis, triceps scapularis, and scapulohumeralis caudalis) from Atlantic puffins (Fratercula arctica) to assess if the muscle fiber types reveal the existence of a compromise associated with "dual-medium" flight. Pectoralis was found to be proportional in size with that of nondiving species, although the supracoracoideus was proportionally larger in puffins. Muscle fiber types were largely aerobic in both muscles, with two distinct fast-twitch types demonstrable: a smaller, aerobic, moderately glycolytic population (FOg), and a larger, moderately aerobic, glycolytic population (FoG). The presence of these two fiber types in the primary flight muscles of puffins suggests that aerial and underwater flight necessitate a largely aerobic fiber complement. We suggest that alcids do not represent an adaptive compromise, but a stable adaptation for wing-propelled locomotion both in the air and underwater.  相似文献   

19.
The Alcidae is a unique assemblage of Northern Hemisphere seabirds that forage by "flying" underwater. Despite obvious affinities among the species, their evolutionary relationships are unclear. We analyzed nucleotide sequences of 1,045 base pairs of the mitochondrial cytochrome b gene and allelic profiles for 37 allozyme loci in all 22 extant species. Trees were constructed on independent and combined data sets using maximum parsimony and distance methods that correct for superimposed changes. Alternative methods of analysis produced only minor differences in relationships that were supported strongly by bootstrapping or standard error tests. Combining sequence and allozyme data into a single analysis provided the greatest number of relationships receiving strong support. Addition of published morphological and ecological data did not improve support for any additional relationship. All analyses grouped species into six distinct lineages: (1) the dovekie (Alle alle) and auks, (2) guillemots, (3) brachyramphine murrelets, (4) synthliboramphine murrelets, (5) true auklets, and (6) the rhinoceros auklet (Cerorhinca monocerata) and puffins. The two murres (genus Uria) were sister taxa, and the black guillemot (Cepphus grylle) was basal to the other guillemots. The Asian subspecies of the marbled murrelet (Brachyramphus marmoratus perdix) was the most divergent brachyramphine murrelet, and two distinct lineages occurred within the synthliboramphine murrelets. Cassin's auklet (Ptychoramphus aleuticus) and the rhinoceros auklet were basal to the other auklets and puffins, respectively, and the Atlantic (Fratercula arctica) and horned (Fratercula corniculata) puffins were sister taxa. Several relationships among tribes, among the dovekie and auks, and among the auklets could not be resolved but resembled "star" phylogenies indicative of adaptive radiations at different depths within the trees.   相似文献   

20.
1. Ringed seals were exposed experimentally to oil contamination, by feeding of a [14C]naphthalene marked crude oil in fish for up to 4 days at a rate of 5 ml/day. 2. Mixed function oxygenase (MFO) activity, measured as aryl hydrocarbon hydroxylase in liver and kidney, was found to be induced, in particular in kidney tissue where the activity increased 3-fold. 3. MFO induction correlated with a high degree of conversion of crude oil hydrocarbons to water-soluble metabolites. Most of the radioactivity was found in the polar fraction of plasma and urine. 4. Plasma cortisol levels were somewhat elevated by captive holding, and increased markedly after oil-exposure. Cortisol half-life decreased after oil exposure from 1 3/4 to 1 hr.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号