DOCSLIB.ORG

Great Reed Warbler), During Reproduction

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Great Reed Warbler), During Reproduction Biharean Biologist (2009) Vol. 3, No.2, Pp.: 105-110 P-ISSN: 1843-5637, E-ISSN: 2065-1155 Article No.: 031115 Aspects concerning the song of Acrocephalus arundinaceus (Great Reed Warbler), during reproduction Constantin ION* and Ştefan Remus ZAMFIRESCU University “Al. I. Cuza” Iasi, Faculty of Biology, University “Al. I. Cuza”, str. Carol 11A, Iasi, 700506, Romania. Corresponding author: C. Ion, E-mail: [email protected] Abstract: The observations concerning the acoustic behaviour and the recordings of the songs of the Great Reed Warbler (Acrocephalus arundinaceus) were made during the reproduction periods, from April to July, in 2003 and 2004. During the reproduction period, while singing, the Great Reed Warbler shows a characteristic posture: he cleans his plumage with the peak; the plumage is slightly ruffled; the tail is spread; the head is orientated towards the lake or reed beds where it intends to establish a territory. Every time when the Great Reed Warbler sings, it chooses a high place for revealing his vocal repertoire. The Great Reed Warbler’s song shows a considerable varied structure. In the studied area, the songs comprise six different types of units. The average song duration is 3.57± 0.10 s. The average number of units per song is 12.29± 0.96, whereas the average number of distinct units per song is 3.75± 0.81. There is a positive correlation between the song duration and the number of units per song. The highest amplitudes of the songs of the Great Reed Warbler from the studied area correspond to frequencies smaller than 3 kHz. Key words: Great Reed Warbler, song duration, song units, spectrogram, relative amplitude spectrum. Introduction of Europe than the West and in the East doesn’t exist such analyses. In our opnion a hiher density of the Great The ornithologists say that warblers, both males and Reed Warblers density could cause a more complex females, are monomorphic, the colour of the plumage songs. being gloomy, without any kind of ornaments (Cramp 1992). The male characteristics that attract the females to reproduce are the song, and especially the posture Material and Methods (Hasselquist 1998). The observations concerning the acoustic behaviour and the The song of the Great Reed Warbler is very complex. recordings of the songs were made during the reproduction It comprises successive units that alternate in various periods of Great Reed Warbler, from April to July, in 2003 and ways, and consequently represents one of the most 2004. The field investigations were carried out in two wet important behavioural characteristics. The male is the zones: Larga Jijia - Vladeni (21 km North from Iasi, 47º26‘N, only one who sings. Great Warblers are able to 27º15‘E) and Botanical Garden (near Iasi, 47º11′N, 27º33′E). modulate the volume, tonality, harmonic structure and For the behavioural observations, we performed 1 km long the succession of the vocal units, which results in a great visual transect surveys and visual fixed point surveys, with the help of binoculars (10x50) and fieldscope (40x60). variety of signals for their potential parteners. However, We recorded the songs (as long as short songs described by the warblers could be easily missidentified if the species Hasselquist & Bensch 1991) using a taperecorder Sony with an identification involves only morphological traits omnidirectional microphone (Sony). Then, 79 selected song (Paspaleva 1977). In our opinion, a detailed analysis of recordings were transformed into digital sound files (.wav), the song would allow the recognition of its role and the which were processed in order to obtain spectograms and species identification. average amplitude spectra (sampling rate=44,100 Hz, sampling Some authors said that are possible to exist some precision= 16 bit or 96 dB, Fast Fourier Transformation- 512 differences between populations (Catchpole & Slater points, spectral line resolution= 86,133 Hz, time line resolution= 11.61ms, smoothing window function- Hanning). 1995) concerning songs structure. The principal aim of These representations allowed the investigation of song units our study was to verify if there are some differences (unit is similar with the syllable described by Cramp 1992), between western and eastern populations of the Great duration, frequencies and relative amplitudes. Consequently, Reed Warbler knowing that the populations of these the resulted data were statistically processed and interpreted birds within the habitats are more numerous in the East (Fowler et al. 2000, Gerhardt 1998, Varvara & Zamfirescu 2001). ©Biharean Biologist, Oradea, Romania, 2009 Biharean Biol. 3, 2009 http://biologie-oradea.xhost.ro/BihBiol/index.html Oradea, Romania 106 Ion, C. & Zamfirescu, S.R. Results while the shortest was 0.8s. The average number of units per song in Acrocephalus arundinaceus was Through the analysis of song repetitive structure we 12.29±0.96 (p=0.95). The maximum value of this cha- identified six types of units, noted A, B, B’, C, D and D’ racteristic was 40, while the minimum one was 3. (Table (Fig. 1). The units types were analyzed separately. We 1). The average number of types of units per song was also observed the postures and the behavioural 3.75±0.81 (p=0.95). The maximum value of this variable movements of the warblers while they were singing, was 5, whereas the minimum one was 2. which are described at the discussion. The song duration and the number of units per song The unit A type is a strong sound with an appro- are correlated (R2= 0.748). The determination coefficient ximate duration of 200ms (Fig. 2). This is the longest (R2) shows that approximately 74% of the values of type. The relative amplitude peak corresponds to a these two variables are correlated (Fig. 14). The reper- frequency of 2 kHz (Fig. 3). The unit B type (Fig. 4) is the toire siye can be correlated with some measures of shortest (40-60ms). The energy of this unit is distributed habitat quality, such as the amount of high quality reed to four distinct frequencies (1.8 kHz, 3 kHz, 4.7 kHz and within the territory as is shown in: Catchpole & Slater 6.3 kHz); therefore the graphic shows 4 peaks (Fig. 5). 1995. The unit B’ type is rather similar to the B type (Fig. 6) The correlation between unit types and song dura- except it is longer (100ms). The spectrum reveals four tion is faible (36). It means that if the songs are longer is better-outlined amplitude peaks (Fig. 7) that correspond not necesarely to be more distinct units. to slightly higher frequencies. The unit type C (Fig. 8) is In order to outline the characteristics of the 79 ana- relatively similar to the A type, except it is shorter lysed songs, we produced average amplitude relative (100ms) and the maximum relative amplitude has a spectra (Fig. 15). This analyse could represent a base for corresponding frequency of 3 kHz (Fig. 9), which is future researches concerning intraspecific differences in higher compared to the A type. The unit type D is songs structure. Each song gave 252 frequencies and the structurally similar to the type B. The approximate corresponding amplitude values. For each frequency we duration is 130ms (Fig. 10). The maximum relative computed the average of the 79 corresponding ampli- amplitude is distributed to several corresponding tudes and the 95 confidence interval (Fig. 15). frequencies. The highest relative ampli-tude peak The amplitude peak corresponds to the 3 kHz corresponds to 4 kHz (Fig. 11). The unit D’ type is not frequency, and decreases at frequencies higher than 4 very different from the D type. Its approximate duration kHz. is 130 ms (Fig. 12). There are several amplitude peaks, among which the highest corresponds to 3 kHz (Fig. 13). We also made a statistic description of 79 analysed Discussion Reed Warbler songs (Table 1). During the reproduction period, the average duration of the song was 3.57± 0.10s Immediately after the spring migration, the singing (Table 1). The longest song duration of all was 13.04s, warblers are sporadic. After the warblers recover their Figure 1. Spectrogram of a song of Acrocephalus arundinaceus- unit types Biharean Biol. 3, 2009 Aspects concerning the song of Acrocephalus arundinaceus during reproduction 107 Figure 2. Spectrogram of four units type A Figure 6. Spectrogram of unit type B (left) and B’ (right) Figure 3. Relative amplitude spectrum of unit type A Figure 7. Relative amplitude spectrum of unit type B’ Figure 4. Spectrogram of unit type B at Figure 8. Spectrogram of two units type C Figure 5. Relative amplitude spectrum of unit type B Figure 9. Relative amplitude spectrum of unit type C Biharean Biol. 3, 2009 108 Ion, C. & Zamfirescu, S.R. Figure 10. Spectrogram of two units type D Figure 12. Spectrogram of two units type D’ Figure 11. Relative amplitude spectrum of unit type D Figure 13. Relative amplitude spectrum of unit type D’ Table 1. Statistic description of song duration, number of units per song and number of types of units per song at Acrocephalus arundinaceus No. of type Time No. of units of units Count 79 79 79 Mean 3.572658228 12.29114 3.759494 Standard Error 0.228991177 0.695689 0.108418 Median 3.18 12 4 Mode 3.41 12 4 Standard Deviation 2.0353181 6.183418 0.963636 Range 12.24 37 4 Minimum 0.8 3 2 Maximum 13.04 40 6 Standrad error x t (0,05, 78) 0.455886517 1.385011 0.215843 Inferior Limit (Mean- 3.116771711 11.3276 2.948034 Standrad error x t (0,05, 78) ) Superior Limit (Mean+ 4.028544745 13.67615 4.570953 Standrad error x t (0,05, 78) ) Biharean Biol.
Load more

Recommended publications
  • Host Alarm Calls Attract the Unwanted Attention of the Brood Parasitic
    www.nature.com/scientificreports OPEN Host alarm calls attract the unwanted attention of the brood parasitic common cuckoo Attila Marton 1,2*, Attila Fülöp 2,3, Katalin Ozogány1, Csaba Moskát 4,5 & Miklós Bán 1,3,5 It is well known that avian brood parasites lay their eggs in the nests of other bird species, called hosts. It remains less clear, however, just how parasites are able to recognize their hosts and identify the exact location of the appropriate nests to lay their eggs in. While previous studies attributed high importance to visual signals in fnding the hosts’ nests (e.g. nest building activity or the distance and direct sight of the nest from vantage points used by the brood parasites), the role of host acoustic signals during the nest searching stage has been largely neglected. We present experimental evidence that both female and male common cuckoos Cuculus canorus pay attention to their host’s, the great reed warbler’s Acrocephalus arundinaceus alarm calls, relative to the calls of an unparasitized species used as controls. Parallel to this, we found no diference between the visibility of parasitized and unparasitized nests during drone fights, but great reed warblers that alarmed more frequently experienced higher rates of parasitism. We conclude that alarm calls might be advantageous for the hosts when used against enemies or for alerting conspecifcs, but can act in a detrimental manner by providing important nest location cues for eavesdropping brood parasites. Our results suggest that host alarm calls may constitute a suitable trait on which cuckoo nestlings can imprint on to recognize their primary host species later in life.
    [Show full text]
  • British Birds |
    VOL. XLIX MARCH No. 3 1956 BRITISH BIRDS THICK-BILLED WARBLER AT FAIR ISLE: A NEW BRITISH BIRD By KENNETH WILLIAMSON, VALERIE M. THOM (Fair Isle Bird Observatory), I. J. FERGUSON-LEES and H. E. AXELL AN example of the Thick-billed Warbler (Phragmaticola aedon), a bird from south-east Asia and apparently the first of its species to be recorded in Europe, was captured at Fair Isle on 6th October !955- In the fleeting glimpses we obtained of this bird in the field its large size and long, rounded tail at once attracted attention. The rufous rump, contrasting with the uniform olive-brown of the mantle and wings was a conspicuous feature, much more striking in the field than in the hand. In all these characteristics the bird strongly resembled a Great Reed Warbler (Acrocephalus arundinaceus). When flushed from the turnip rig in which it was found the bird immediately dived again into cover, and on next being disturbed flew to a dense growth of reedy grass and Heracleum sphondylium on the banks of a near-by burn. Its skulking behaviour as it crept between the stems suggested that an attempt to trap it at this site might prove successful, so the Yeoman net with a portable catching-box was assembled, giving a trap with an entrance less than 3 feet wide. With great caution the bird was moved from the turnips to the ditch, where it threaded its way through the vegetation until finally it was flutter­ ing against the glass of the box. The bird was taken to the laboratory for examination: there it was seen that the resemblance to a Great Reed Warbler was purely- superficial, and confined to size and plumage.
    [Show full text]
  • Tour Report 30 April – 6 May 2014
    Spring Birding in Sicily Naturetrek Tour Report 30 April – 6 May 2014 Little Terns Penduline Tit Purple Swamphen Sardinian Warbler Report compiled by Dave Nevitt & Marcus John Images supplied by Peter Spillett Naturetrek Cheriton Mill Cheriton Alresford Hampshire SO24 0NG England T: +44 (0)1962 733051 F: +44 (0)1962 736426 E: [email protected] W: www.naturetrek.co.uk Tour Report The Somerset Levels Tour Leaders: Dave Nevitt Ornithologist/Naturalist Marcus John Ornithologist/Naturalist Participants Sue Beddows Roy Beddows Ian Fletcher Laura Clare Brian Morris Bev Minett-Smith Fran Smith Peter Spillett Eve Ellis Margaret Gorely Hugh Griffiths Jenny Griffiths Norma Parrack Ann Pardy Peter Somerville Isabelle Somerville Day 1 Wednesday 30th April The trip started with a flight from Gatwick, arriving at Catania an hour late at 19:30. On the flight the group were fortunate in having good views of Vesuvius and then the snow-capped Mount Etna as the flight descended. The group met up with Dave who was already in Sicily from leading the group the previous week. After loading up in our minibuses, we left Catania and made the hour’s journey to the Case del Feudo, where we were welcomed by Jassin who was to look after our day to day needs. Having settled in to our wonderful rooms, we assembled for our “light dinner”. We sampled for the first time the superb wines which are made on the premises. What a welcome! We retired, tired but replete. Day 2 Thursday 1st May As we had put the moth trap on last night, we had a look at our catch.
    [Show full text]
  • Egg-Spot Matching in Common Cuckoo Parasitism of the Oriental Reed
    Li et al. Avian Res (2016) 7:21 DOI 10.1186/s40657-016-0057-y Avian Research RESEARCH Open Access Egg‑spot matching in common cuckoo parasitism of the oriental reed warbler: effects of host nest availability and egg rejection Donglai Li1†, Yanan Ruan1†, Ying Wang1, Alan K. Chang1, Dongmei Wan1* and Zhengwang Zhang2 Abstract Background: The success of cuckoo parasitism is thought to depend largely on the extent of egg matching between cuckoo and host eggs, since poor-matching cuckoo egg would lead to more frequent egg rejection by the host. In this study, we investigated how egg-spot matching between the Common Cuckoo (Cuculus canorus) and its host, the Oriental Reed Warbler (Acrocephalus orientalis) is affected by the local parasitism rate, nest availability in breeding synchronization and egg rejection. Methods: We used the paired design of parasitized and their nearest non-parasitized nests where breeding occurred simultaneously to compare egg-spot matching. The image analysis was used to compare four eggshell pattern vari- ables, namely spot size, density, coverage on the different areas of egg surface, and the distribution on the whole egg surface. Egg recognition experiments were conducted to test the effect of egg spots on egg rejection by the host. Results: Our results show that much better matching in almost all spot parameters tested on the side of the egg and the spot distribution on the whole egg occurred in parasitized nests than in non-parasitized nests. Matching of spot density between cuckoo and host eggs in parasitized nests increased with the synchronization between temporal availability of nests and the egg-laying period of female cuckoos.
    [Show full text]
  • A New Subspecies of Eurasian Reed Warbler Acrocephalus Scirpaceus in Egypt
    Jens Hering et al. 101 Bull. B.O.C. 2016 136(2) A new subspecies of Eurasian Reed Warbler Acrocephalus scirpaceus in Egypt by Jens Hering, Hans Winkler & Frank D. Steinheimer Received 4 December 2015 Summary.—A new subspecies of European Reed Warbler Acrocephalus scirpaceus is described from the Egypt / Libya border region in the northern Sahara. Intensive studies revealed the new form to be clearly diagnosable within the Eurasian / African Reed Warbler superspecies, especially in biometrics, habitat, breeding biology and behaviour. The range of this sedentary form lies entirely below sea level, in the large depressions of the eastern Libyan Desert, in Qattara, Siwa, Sitra and Al Jaghbub. The most important field characters are the short wings and tarsi, which are significantly different from closely related A. s. scirpaceus, A. s. fuscus and A. s. avicenniae, less so from A. baeticatus cinnamomeus, which is more clearly separated by behaviour / nest sites and toe length. Molecular genetic analyses determined that uncorrected distances to A. s. scirpaceus are 1.0–1.3%, to avicenniae 1.1–1.5% and to fuscus 0.3–1.2%. The song is similar to that of other Eurasian Reed Warbler taxa as well as that of African Reed Warbler A. baeticatus, but the succession of individual elements appears slower than in A. s. scirpaceus and therefore shows more resemblance to A. s. avicenniae. Among the new subspecies’ unique traits are that its preferred breeding habitat in the Siwa Oasis complex, besides stands of reed, is date palms and olive trees. A breeding density of 107 territories per 10 ha was recorded in the cultivated area.
    [Show full text]
  • Acrocephalus and Hippolais Warblers from the Western Palearctic David T
    Species limits in Acrocephalus and Hippolais warblers from the Western Palearctic David T. Parkin, Martin Collinson, Andreas J. Helbig, Alan G. Knox, George Sangster and Lars Svensson Sedge Warbler Acrocephalus schoenobaenus Richard Johnson ABSTRACT The taxonomic affiliations within the genera Acrocephalus and Hippolais have long been a matter for debate. Recent molecular and behavioural studies have provided a wealth of new data which can be used to analyse the evolutionary relationships of the Palearctic taxa in these genera. In this paper, we make a series of recommendations for changes in species limits, highlight some problem areas and discuss situations where more research is needed. 276 © British Birds 97 • June 2004 • 276-299 Species limits in Acrocephalus and Hippolais warblers Introduction dering array of small and difficult birds (for long period of taxonomic stability fol- example Emei Leaf Warbler Phylloscopus lowed the publication of the ‘Voous List’ emeiensis, Alström & Olsson 1995; the chiffchaff Afor Holarctic birds (Voous 1977), but in complex, Helbig et al. 1996; and the Greenish recent years there have been dramatic advances Warbler P. trochiloides, Irwin et al. 2001a,b,c), in our knowledge of the evolutionary relation- which has led to an improved understanding of ships of birds, leading to a period of activity their evolution, and hence their taxonomic rela- that shows no sign of abating. These advances tionships. This paper draws together some stem largely from new and exciting ways to recent studies which together provide a clearer study birds, both in the field and in the labora- picture of an especially complex group, the tory.
    [Show full text]
  • Landscape and Patch Characteristics Affecting the Assemblages of Birds in Reedbeds in Terrestrial Matrix
    Ann. Zool. Fennici 50: 36–51 ISSN 0003-455X (print), ISSN 1797-2450 (online) Helsinki 12 April 2013 © Finnish Zoological and Botanical Publishing Board 2013 Landscape and patch characteristics affecting the assemblages of birds in reedbeds in terrestrial matrix Grzegorz Orłowski1,* & Waldemar Górka2 1) Institute of Agricultural and Forest Environment, Polish Academy of Sciences, Bukowska 19, PL-60-809 Poznań, Poland (*corresponding author’s e-mails: [email protected], orlog72@ gmail.com) 2) Strzegomska 262/7, PL-54-432 Wrocław, Poland Received 19 Mar. 2012, final version received 7 Sep. 2012, accepted 18 Sep. 2012 Orłowski, G. & Górka, W. 2013: Landscape and patch characteristics affecting the assemblages of birds in reedbeds in terrestrial matrix. — Ann. Zool. Fennici 50: 36–51. We conducted an analysis of relationships between results of survey on breeding com- munity of birds, including species richness, abundance of individual species and eco- logical groups of birds, and habitat features of 91 isolated reed patches in southwestern Poland. The approach to the reedbed habitat involves environmental differentiation at the patch level, landscape context and isolation, including the impact of man-made structures as potential constraints to the occurrence of birds. Generalized linear models have shown that 12 out of 14 analyzed environmental predictors had a statistically sig- nificant effect on birds. The results from individual species (sedge warbler, great reed warbler, bluethroat, Savi’s warbler, water rail, moorhen and coot) models revealed that the number of territories was affected from two to four predictors. The number of reedbed specialists was affected positively by reed edge, water area and proportion of reed habitat within a 100-m radius, and negatively by railway.
    [Show full text]
  • Geolocator Tracking of Great Reed-Warblers (Acrocephalus
    Geolocator tracking of Great Reed-Warblers (Acrocephalus arundinaceus) identifies key regions for migratory wetland specialists in the Middle East and sub- Saharan East Africa Author(s): Joshua J. Horns, Evan Buechley, Mark Chynoweth, Lale Aktay, Emrah Çoban, Mehmet Ali Kırpık, Jordan M. Herman, Yakup Şaşmaz, and Çağan H. Şekercioğlu Source: The Condor, 118(4):835-849. Published By: American Ornithological Society https://doi.org/10.1650/CONDOR-16-63.1 URL: http://www.bioone.org/doi/full/10.1650/CONDOR-16-63.1 BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. Volume 118, 2016, pp. 835–849 DOI: 10.1650/CONDOR-16-63.1 RESEARCH ARTICLE Geolocator tracking of Great Reed-Warblers (Acrocephalus arundinaceus) identifies key regions for migratory wetland specialists in the Middle East and sub-Saharan East Africa Joshua J. Horns,1* Evan Buechley,1 Mark Chynoweth,1 Lale Aktay,2 EmrahCoban, ¸ 3 Mehmet Ali Kırpık,4 Jordan M.
    [Show full text]
  • Bringing Reedbeds to Life: Creating and Managing Reedbeds for Wildlife
    Section heading Bringing Reedbeds to Life: creating and managing reedbeds for wildlife Graham White, Matt Self and Sarah Blyth Bringing Reedbeds to Life: creating and managing reedbeds for wildlife 3 Andy Hay (rspb-images.com) 2 Bringing Reedbeds to Life: creating and managing reedbeds for wildlife The creation of new reedbeds and the re-invigorated management of existing sites has been a real conservation success in recent years. Significant progress has been made towards meeting nature conservation targets. Much of the work has focused on providing suitable habitat for one of the key associated species, the bittern, which had declined to just 11 booming males by 1997. By 2013 at least 1,500 ha of new reedbed had been created, or was in the process of creation, and restoration work had been undertaken on many of our existing reedbeds. Bitterns increased to 120 boomers, a remarkable response to the work undertaken. During this period, much information has been generated on reedbed design, establishment and management, and work on the ground, combined with continuing research into particular aspects of reedbed or species ecology, has continued to add to our knowledge and experience. This booklet aims to present an up-to-date summary of the techniques involved in creating and establishing reedbeds that maximise their value for wildlife. It is a result of discussion amongst RSPB staff involved in reedbed creation and management, as well as the experience of partner organisations and individuals. Bringing Reedbeds to Life: creating and managing
    [Show full text]
  • Antiparasite Behaviour in Response to Experimental Brood Parasitism in the Great Reed Warbler: a Comparison of Single and Multiple Parasitism
    Ann. Zool. Fennici 42: 627–633 ISSN 0003-455X Helsinki 21 December 2005 © Finnish Zoological and Botanical Publishing Board 2005 Antiparasite behaviour in response to experimental brood parasitism in the great reed warbler: a comparison of single and multiple parasitism Marcel Honza1 & Csaba Moskát2 1) Institute of Vertebrate Biology, AS CR, Květná 8, CZ-603 65 Brno, Czech Republic (e-mail: [email protected]) 2) Animal Ecology Research Group of the Hungarian Academy of Sciences, c/o Hungarian Natural History Museum, Ludovika ter 2, H-1083 Budapest, Hungary (e-mail: [email protected]) Received 19 Aug. 2005, revised version received 1 Oct. 2005, accepted 1 Oct. 2005 Honza, M. & Moskát, C. 2005: Antiparasite behaviour in response to experimental brood parasit- ism in the great reed warbler: a comparison of single and multiple parasitism. — Ann. Zool. Fennici 42: 627–633. Rejection of parasitic eggs is one of the most important adaptations of avian hosts against brood parasites. Multiple brood parasitism is relatively rare in hosts of the common cuckoo (Cuculus canorus), but naturally occurs when the rate of parasitism is high. We experimentally parasitised great reed warbler (Acrocephalus arundinaceus) clutches with non-mimetic and moderately mimetic model cuckoo eggs. In the case of single parasitism, each egg type was rejected at the same rate (68%–75%), but in the case of multiple parasitism, the rejection rate significantly increased to 96%. So multiple parasitism is in some way facilitating anti-parasite behaviour in the host. We suggest that when parasitism rate reaches high levels, e.g. at the beginning of the coevolutionary arms race, multiple parasitism may be an important component of the host’s adaptation to brood parasitism in general.
    [Show full text]
  • Acrocephalus Arundinaceus
    Acrocephalus arundinaceus -- (Temminck & Schlegel, 1847) ANIMALIA -- CHORDATA -- AVES -- PASSERIFORMES -- SYLVIIDAE Common names: Great Reed-warbler; Great Reed Warbler; Rousserolle turdoïde European Red List Assessment European Red List Status LC -- Least Concern, (IUCN version 3.1) Assessment Information Year published: 2015 Date assessed: 2015-03-31 Assessor(s): BirdLife International Reviewer(s): Symes, A. Compiler(s): Ashpole, J., Burfield, I., Ieronymidou, C., Pople, R., Wheatley, H. & Wright, L. Assessment Rationale European regional assessment: Least Concern (LC) EU 27 regional assessment: Least Concern (LC) In Europe this species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence 10% in ten years or three generations, or with a specified population structure). The population trend is not known, but the population is not believed to be decreasing sufficiently rapidly to approach the thresholds under the population trend criterion (30% decline over ten years or three generations). For these reasons the species is evaluated as Least Concern in Europe. Within the EU27 this species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence 10% in ten years or three generations, or with a specified population structure). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion
    [Show full text]
  • Long-Term Effects of Rotational Wetland Mowing on Breeding Birds: Evidence from a 30-Year Experiment
    Biodivers Conserv DOI 10.1007/s10531-017-1462-1 ORIGINAL PAPER Long-term effects of rotational wetland mowing on breeding birds: evidence from a 30-year experiment 1 1 1 Michel Antoniazza • Christian Clerc • Christophe Le Ne´dic • 1,2,3 1,4 Thomas Sattler • Guillaume Lavanchy Received: 4 January 2017 / Revised: 5 October 2017 / Accepted: 4 November 2017 Ó The Author(s) 2017. This article is an open access publication Abstract Wetlands are amongst the richest, yet most threatened types of habitats on Earth. One major threat is the modification of water regime for human activities, which disrupts normal ecosystem equilibrium. In lacustrine wetlands, reduced flooding allows shrubs to take over, ultimately leading to a shift towards woody communities. To counter this, wetland managers have initiated a variety of measures, including mowing, burning, and pasturing. Because of the short time frames of previous studies on the subject, little is known on their potential negative side effects on the ecosystem. Here, we evaluate the long-term effect of mowing on breeding populations of the five most abundant species in our central European study area (the reed warbler Acrocephalus scirpaceus, the common reed bunting Emberiza schoeniclus, Savi’s warbler Locustella luscinioides, the water rail Rallus aquaticus, and the bearded reedling Panurus biarmicus). This study, of an unprecedented time scale (30 years), shows that rotational mowing has no long-term detrimental effects on birds. However, optimal mowing regime for the birds might often be less frequent than what is usually applied. We recommend that mowing be spaced every 3 years at least, and ideally every 6 years or more.
    [Show full text]