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1.
Frog call intensities and sound propagation in the South American temperate forest region 总被引:3,自引:0,他引:3
Sound pressure levels and the spectral structure of the advertisement calls of five species of frogs from the South American
temperate austral forest were analyzed. Males of Eupsophus emiliopugini, Batrachyla antartandica and B. leptopus call from the ground in bogs, while males of Hylorina sylvatica and Pleurodema thaul call from the water surface in marshes. Calling males of the species from bogs and marshes spaced at average distances that
were shorter and longer than 2 m, respectively. The properties of these habitats for sound propagation were evaluated by broadcasting
pure tones, broadband noise and tape-recorded advertisement calls of the three species from bogs and of H. sylvatica. Excess attenuation and spectral degradation were higher for calls broadcast in bogs than in the marsh. The calls of B.␣antartandica and B. leptopus, with dominant frequencies of about 2 kHz, were more affected than those of E.␣emiliopugini and H. sylvatica, with dominant frequencies below 1.5 kHz. These results show the lack of an optimal relationship between properties of habitats
for sound transmission and the spectral structure of these anuran calls. Body size imposes an important constraint on call
spectra and propagation, which frogs counteract by distribution patterns and auditory capabilities.
Received: 18 April 1997 / Accepted after revision: 15 February 1998 相似文献
2.
The distribution and behaviour of cormorants in estuarine environments was examined on the central coast of New South Wales,
Australia, with respect to habitat associations at different spatial scales. No consistent variation in abundance was found
for four species of cormorants (great Phalacrocorax carbo, pied P. varius, little black P. sulcirostris, and little pied P. melanoleucos) with state of tide (high and low) and time of day (early, middle, and late) at five estuarine locations. Differences in
abundance were found among locations that were not confounded by short-term temporal variation (i.e. time of day and tide).
Differences in abundance were detected among habitats (e.g. bays, creeks, and headlands) separated by hundreds of metres to
kilometres in different estuaries. Cormorants of all species were rare on the open coast and near the entrance of estuaries.
Abundances of cormorants varied greatly within and among creeks, bays, and river channels. Presence of seagrass beds explained
much of this variation and most of the cormorants swimming and feeding were found near seagrass. Mapping of seagrass beds
and the positions of cormorants at scales of metres to hundreds of metres showed a close relationship between the presence
of swimming and roosting beds and the presence of seagrass beds for P. melanoleucos and for P. carbo. We argue that cormorants make decisions to visit particular estuarine habitats, especially those with seagrass, where many
types of prey (e.g. fish and crustaceans) are probably most abundant. These choices must be interpreted in the context of
decisions that cormorants make on scales of hundreds to thousands of kilometres during periodic excursions to the interior
of Australia. Further, environmental threats to seagrass beds could impinge on these mobile visitors to the same extent as
on more permanent residents.
Received: 14 February 2000 / Accepted: 17 July 2000 相似文献
3.
A comparison of temperate reef fish assemblages recorded by three underwater stereo-video techniques 总被引:1,自引:0,他引:1
Three underwater stereo-video techniques were used to sample the relative densities and species richness of temperate reef fish assemblages at three reef locations and two habitats (high- and low-relief reef) within Hamelin Bay, south-western Australia. The three techniques compared were diver-operated stereo-video strip transects, baited remote stereo-video and unbaited remote stereo-video. While unbaited remote stereo-video and diver-operated stereo-video transects recorded greater species richness at high compared to low-relief reefs, baited remote stereo-video recorded similar species richness at the two habitat types. The diver-operated stereo-video system was manoeuvred through caves and under overhangs recording small, cryptic, cave-dwelling species that were not recorded by either remote video techniques (Trachinops noarlungae, Trachinops brauni, Chromis klunzingeri, Trachichthys australis). Both remote video techniques recorded greater species richness and relative density of the most common species of Labridae, Ophthalmolepsis lineolatus. Baited remote video recorded the rarer, large predatory fish species (e.g. Seriola hippos, Glaucosoma hebraicum, Heterodontus portusjacksoni). None of the techniques sampled small cryptic fish families such as Gobiidae or Blenniidae. A combination of survey techniques is recommended for comprehensive fishery-independent studies that aim to sample broad components of fish assemblages.An erratum to this article can be found at 相似文献
4.
5.
Summary Transmission and reception of high-frequency sound in the natural environment of bushcrickets (Tettigonia viridissima L.) was studied using the activity of an identified neuron in the insect's auditory pathway as a biological microphone. Different positions of the receiver within the habitat were simulated by systematic variation of the distance from a loudspeaker and the height above the ground. Attenuation and filtering properties of the habitat were investigated with pure-tone frequencies between 5 and 40 kHz. Sound attenuation in excess of the attenuation due to geometrical spreading alone increased with increasing frequency, distance between sender and receiver, and decreasing height within the vegetation (Figs. 2–4). The data also confirm the existence of two kinds of excess attenuation. The amount of amplitude fluctuations in the sound signals was investigated by analysing the variability of the neuronal responses at a given receiver position. Variability increased with decreasing bandwidth of a noise signal at some distance from the loadspeaker. The variability in the responses to pure tones increased with both increasing frequency and distance from the source (Fig. 7). In the selected habitat, the temporal pattern of the natural calling song of male T. viridissima was very reliably reflected in the activity of the recorded neuron up to a distance of 30 m at the top of the vegetation, and 15–20 m near ground level (Figs. 5, 8). The maximum hearing distance in response to the calling song was about 40 m. Environmental constraints on long-range acoustic communication in the habitat are discussed in relation to possible adaptations of both the signal structure and the behavior of the insects.Abbreviations excessive attenuation
EA
- sound pressure level
SPL
Offprint requests to: H. Romer 相似文献
6.
以内蒙古太仆寺旗地区典型克氏针茅-羊草草原为研究对象,通过调查围封6年后围栏内外典型草原群落特征,分析围封、放牧处理下典型草原植物群落结构及地上生物量的动态变化,揭示围封放牧对植被群落结构、物种丰富度和地上生物量的影响。结果发现,在围封6年后,各功能群物种丰富度与盖度围栏内外的空间变化趋势基本一致。群落物种丰富度和地上生物量均随坡位下降而显著增加,初步显示了物种多样性与生态系统功能的空间变化的一致性。围栏内物种丰富度显著低于围栏外,而地上生物量却显著大于围栏外。围栏内多年生禾草、一年生植物物种丰富度显著低于围栏外,而半灌木盖度、生物量显著高于围栏外。围栏内外在禁牧和放牧不同处理下,表现出不同的草原退化方式:在禁牧条件下,尽管生物量有所恢复,但灌木和半灌木的增加却代表了草原的退化;放牧、刈割等人类活动增加了耐牧物种和不适口植物生长的可能,表现为草原退化指示物种增加,同样是草原退化的表现。围栏外一年生植物盖度和生物量显著高于围栏内,而一年生植物的频数也远远大于围栏内(围栏内外频数比13:71),且独行菜、猪毛菜等仅出现于围栏外。同时,地上生物量随着物种丰富度的增加而增加,但只有围栏外的关系达到统计显著程度,说明围封调制了生物多样性与生态系统功能的关系。本研究表明,对于干旱半干旱典型草原的恢复,不能简单地采用长期完全禁牧措施,应当根据区域环境、植被以及社会经济情况,制定季节性放牧或者间歇性禁牧的恢复措施,从而保证草场的可持续性恢复利用。 相似文献
7.
Multiple determinants of community structure in shallow marsh habitats,Cape Fear River estuary,North Carolina,USA 总被引:5,自引:0,他引:5
The nekton of tidal creeks was studied at 17 sampling localities from September 1977 through August 1978, in the Cape Fear River estuary, North Carolina, USA. Prior to these dates, collections were made at 9 stations beginning in January 1977; these data were used to supplement conclusions drawn from the larger effort. Species recruited from the ocean utilized marsh habitats only temporarily and dominated the catches with over 70% of the total abundance. Their distribution was influenced by salinity gradients and to a lesser extent by substrate characteristics. In addition, temporal habitat partitioning with associated size differences of related species played an important role in structuring marsh nekton communities. A clearly defined ecotone was associated with the mesohaline-polyhaline transition zone, in slainities between 14 and 21 S. Numerous marine stenohaline forms were restricted to salinities above 16 S, thus increasing species richness in high salinity marshes. Despite differences in freshwater flows in 1977 and 1978, major features of the various marsh communities (species associations and relative abundances) exhibited little change throughout the Cape Fear estuary, indicating that these communities were relatively persistent in time. Standing crops for ocean-spawned species at the end of the growing season indicated that considerable annual export in the form of living biomass of fish and shellfish takes place from the marshes. Since most individuals of these species return to the ocean in the fall, an important energy link between the marshes and nearshore marine environment is demonstrated. 相似文献
8.
Wolfgang Forstmeier Dennis Hasselquist Staffan Bensch Bernd Leisler 《Behavioral ecology and sociobiology》2006,59(5):634-643
Song complexity is often regarded as a sexually selected trait that reflects the overall quality of a male. In many passerine
species, old males possess larger song repertoires than younger males. This may be either because individual males improve
their performance as they get older (longitudinal increase) or because poor singers have reduced viability and, hence, are
underrepresented in old age classes (cross-sectional increase). We studied the age dependence of repertoire size and other
song traits in a German and a Swedish great reed warbler (Acrocephalus arundinaceus) population. We found marked differences between longitudinal and cross-sectional approaches, as well as between the two
study populations. In the German population, we found that syllable switching, a measure of immediate versatility and strophe
length, increased with age in a cross-sectional analysis. This was not because birds improved with age (longitudinally) but
because syllable switching was positively correlated with male longevity. However, in Sweden, syllable switching seemed to
be unrelated to age and longevity. In the Swedish population, individual males increased their repertoire size as they got
older (longitudinal increase), but this did not happen in the German population. Hence, two populations, even when belonging
to the same subspecies, may differ in whether or not they show delayed song maturation. 相似文献
9.
Recognition of individual neighbors by song in the song sparrow,a species with song repertoires 总被引:2,自引:0,他引:2
Philip K. Stoddard Michael D. Beecher Cynthia L. Horning S. Elizabeth Campbell 《Behavioral ecology and sociobiology》1991,29(3):211-215
Summary Previous theory and research have suggested that bird species with song repertoires in general, and song sparrows (Melospiza melodia) in particular, cannot readily discriminate between the songs of neighbors and strangers. In a recent study (Stoddard et al. 1991) we showed that song sparrows can in fact discriminate neighbors from strangers on the basis of song. In this study we sought to demonstrate that song sparrows can make the finer discrimination between individual neighbors and that they can do so on the basis of a single song type. We compared the response of territorial males to song playback of neighbors and strangers at three locations: the neighbor's regular boundary, the opposite boundary, and the center of the territory. The birds showed strong neighbor-stranger discrimination at the regular boundary but not at the opposite boundary, nor in the center of the territory. The differences in song discrimination between different boundary locations indicate that song sparrows associate particular songs with particular territories, effectively discriminating between individual neighbors on the basis of song. Song repertoires themselves do not interfere with neighbor recognition to the extent originally postulated. As speakers are moved inside the territory from the border, however, the degree of discrimination diminishes. We believe that differences in speaker placement may have contributed to the variability in neighbor-stranger discrimination observed in previous studies of the song sparrow and perhaps other repertoire species as well. This interpretation is consistent with data from another song sparrow population showing that half the territory takeovers are by immediate neighbors. 相似文献
10.
Latitudinal variation in abundance of herbivorous fishes: a comparison of temperate and tropical reefs 总被引:1,自引:0,他引:1
The aim of the study was to provide comparable estimates of abundance of herbivorous reef fishes at temperate and tropical
localities using a standardized methodology. Faunas of herbivorous fish were sampled on the rocky reefs of temperate northern
New Zealand and on the coral reefs of the northern Great Barrier Reef (GBR), Australia, and the San Blas Archipelago in the
Caribbean. A pilot study established the most appropriate habitat setting and the scale and magnitude of replication for the
sampling program in temperate waters. Herbivorous fishes, including members of families endemic to the southern hemisphere
(Odacidae and Aplodactylidae), were most abundant in turbulent, shallow water (0 to 6 m) and had patchy distributions within
this habitat. A hierarchical sampling program using 10-min transect counts within the 0 to 6 m depth stratum examined abundance
patterns at a range of spatial scales including mainland and island coasts, localities separated by up to 100 km and sites
separated by up to 10 km. This program identified a characteristic fauna of seven species of herbivorous fishes with mean
total abundances ranging from 23 to 30 individuals per 10-min transect. Species composition of the fauna varied between islands
and coasts. A similar methodology was used to sample the major families of herbivorous fish in a number of sites in each of
the tropical regions. These sampling programs revealed a fauna dominated by acanthurids and scarids in both the GBR and Caribbean
localities. Estimates of abundance from these regions were similar, with a mean of 108 individuals recorded on the GBR and
129 per 10-min transect in the Caribbean. Species richness varied between each region, with 44 taxa recorded from the GBR
and 11 from the Caribbean. Abundances of temperate water herbivores in New Zealand were found to be 75 to 80% lower than those
recorded from shallow water habitats sampled on coral reefs. This was not related to species richness, since both New Zealand
and the Caribbean locality had patterns of low richness. We suggest that the differences in abundance found by our study between
temperate and tropical regions are not restricted to herbivorous fishes, but are representative of general latitudinal trends
in reef fish faunas.
Received: 4 November 1996 / Accepted: 15 December 1996 相似文献
11.
K. M. Veerannan 《Marine Biology》1974,26(1):35-43
The gill-surface area and R-T (metabolic rate-temperature) response during aquatic and aerial respiration of three different species of crabs, the subtidal Scylla serrata, the intertidal Sesarma quadratum, and the supratidal Ocypoda platytarsis, were compared. Scylla serrata has the highest, Sesarma quadratum the second highest, and O.platytarsis the lowest gill-surface area. Oxygen-consumption values in water under different ambient partial pressures of oxygen indicate that all three species display equally efficient aquatic respiration despite variation in gill area and number. There is no coherent R-T response either inter- or intra-specifically. However, the ability to extract oxygen from the surrounding medium (respiratory efficiency) conditions the R-T response in the different species. The R-T trends in aquatic respiration of Scylla serrata and aerial respiration of O.platytarsis reveal a normal response to temperature. The proportion of aquaticoxygen uptake to total respiration in all sizes in both Scylla serrata and Sesarma quadratum remains more or less constant (between 88 and 92%), whereas in the supratidal O.platytarsis, this proportion decreases with increasing weight (from 88 to 64 %), indicating a progressive loss of gill respiration to total respiration. All three species are metabolically equally efficient; what one lacks in respiratory surface it compensates by respiratory efficiency. 相似文献
12.
13.
Philip K. Stoddard Michael D. Beecher Mary S. Willis 《Behavioral ecology and sociobiology》1988,22(2):125-130
Summary The song repertoires of male song sparrows (Melospiza melodia) are comprised of distinct song types and many overlapping variations within each type. This study examines the sensitivity of territorial male song sparrows to both multiple song types and variation within types. A playback experiment was conducted using stimulus tapes that had either single songs (but not variations), song variations (but not types) or a single song. Response during playback was similar for all three stimulus groups, but diminished sooner after playback for the single-song tape. Thus our results indicate that male song sparrows are sensitive to song variability both within and among song types. 相似文献
14.
Melissa Hughes Stephen Nowicki William A. Searcy Susan Peters 《Behavioral ecology and sociobiology》1998,42(6):437-446
One hypothesis for the function of song repertoires is that males learn multiple song types so that they may share songs
with neighbors, allowing them to match during territorial interactions. In at least one song sparrow population, in Washington,
territorial males share a high proportion of song types with their neighbors and use these shared songs in matching. We recorded
song sparrows in Pennsylvania and quantified sharing of whole songs and song segments. We found that song sharing is an order
of magnitude less common in the Pennsylvania population. We found sharing of song segments to be significantly more common
than the sharing of whole songs in three of the five fields we examined, while we found no significant differences between
whole and partial song sharing in the remaining two fields. Finally, we found no evidence that sharing is greater between
birds in the same field compared to birds in different fields. Taken with the data from Washington song sparrows, these results
provide evidence for intraspecific geographic variation in the organization of song repertoires, and suggest that song sharing
has not been a strong selective force in the evolution of song repertoires in song sparrows as a species. Furthermore, Washington
and Pennsylvania song sparrows differ in how they learn song, in that Washington birds copy whole songs, while Pennsylvania
birds appear to copy and recombine song segments, as has been found in laboratory studies of song learning. Thus both song
learning and the function of song repertoires differ between populations of song sparrows. Such intraspecific geographic variation
offers a unique opportunity to explore the ecological and historical factors which have influenced the evolution of song.
Received: 30 June 1997 / Accepted after revision: 8 March 1998 相似文献
15.
Local adaptation is an important mechanism generating physiological diversity and can be especially pronounced in species with restricted dispersal and gene flow such as direct developing snails of the genus Littorina. We compared physiological responses to salinity and desiccation stress in two co-occurring species of northeastern Pacific Littorina (L. subrotundata and L. sitkana) with salt marsh and open shore ecotypes. The animals from salt marsh populations were significantly more tolerant to low salinities and significantly less resistant to desiccation stress than their open shore counterparts. The lower resistance to desiccation in salt marsh animals was not associated with a higher rate of water loss during air exposure or with lower body water reserves, but instead reflected a lower tolerance to high salinities. These habitat-related physiological differences occurred in parallel in the two studied species of Littorina and persisted after prolonged laboratory acclimation, suggesting that they may reflect selection for markedly different local optima in the salt marsh habitats than in the open shore habitats. We used a neutral polymorphic nuclear DNA marker (intron of aminopeptidase N) to estimate the level of gene flow between the populations from different habitats and found isolation by distance regardless of the habitat from which the snails were collected. Our molecular data suggest that physiological cohesiveness of ecotypes can arise despite different genetic backgrounds, and could potentially be due to parallel evolution of convergent phenotypes in similar habitats.Communicated by O. Kinne, Oldendorf/Luhe 相似文献
16.
Christopher N. Templeton ?a?lar Ak?ay S. Elizabeth Campbell Michael D. Beecher 《Behavioral ecology and sociobiology》2012,66(11):1503-1509
Animals frequently use signals to modulate aggressive interactions. Establishing that a signal is aggressive or threatening requires demonstrating that it is more commonly used in agonistic contexts, that it predicts subsequent aggressive behaviors by the sender, and that receivers respond differently to this signal. Like many birds, song sparrows (Melospiza melodia) produce a low-amplitude “soft song” vocalization that has been hypothesized to be an aggressive signal. Soft song meets the first two criteria, but previous research has failed to demonstrate that soft song provokes aggression or that receivers even perceive soft song differently from normal loud song. We used a playback experiment with taxidermic mount presentation to test whether territorial male song sparrows respond differently to loud and soft song playbacks. Subjects reacted more strongly to the soft song playback by approaching the mount more closely, increasing wing wave displays, and increasing the proportion of their own songs that were soft songs, with further trends toward increasing the number of flights and attacks. These results confirm that soft song is a conventional signal of aggression in song sparrows and that increased receiver retaliation maintains its reliability. 相似文献
17.
A comparison of two models with Landsat data for estimating above ground grassland biomass in Inner Mongolia,China 总被引:2,自引:0,他引:2
Two models, artificial neural network (ANN) and multiple linear regression (MLR), were developed to estimate typical grassland aboveground dry biomass in Xilingol River Basin, Inner Mongolia, China. The normalized difference vegetation index (NDVI) and topographic variables (elevation, aspect, and slope) were combined with atmospherically corrected reflectance from the Landsat ETM+ reflective bands as the candidate input variables for building both models. Seven variables (NDVI, aspect, and bands 1, 3, 4, 5 and 7) were selected by the ANN model (implemented in Statistica 6.0 neural network module), while six (elevation, NDVI, and bands 1, 3, 5 and 7) were picked to fit the MLR function after a stepwise analysis was executed between the candidate input variables and the above ground dry biomass. Both models achieved reasonable results with RMSEs ranging from 39.88% to 50.08%. The ANN model provided a more accurate estimation (RMSEr = 39.88% for the training set, and RMSEr = 42.36% for the testing set) than MLR (RMSEr = 49.51% for the training, and RMSEr = 53.20% for the testing). The final above ground dry biomass maps of the research area were produced based on the ANN and MLR models, generating the estimated mean values of 121 and 147 g/m2, respectively. 相似文献
18.
Rindy C. Anderson Stephen Nowicki William A. Searcy 《Behavioral ecology and sociobiology》2007,61(8):1267-1274
Low-amplitude “soft song” is used by a variety of songbirds; in some species during aggressive encounters, in others during
courtship, and yet others in both these contexts. In song sparrows (Melospiza melodia), soft song has thus far been observed only in aggressive encounters, where its production is a more reliable predictor of
attack than any other signaling behavior. We used song playback to test the response of both male and female song sparrows
to soft song. The design of the playback experiments took into account the existence of two classes of soft song: crystallized
soft song, which consists of song types also found in the broadcast repertoire, and warbled soft song, which consists of less-structured
song types not found in the broadcast repertoire. Female song sparrows responded with significantly less courtship display
to the playback of crystallized soft song than to that of normal broadcast song, and response to warbled soft song was if
anything lower than to that of crystallized soft song. Male song sparrows responded equally aggressively to normal broadcast
song as to crystallized soft song, and equally aggressively to warbled soft song as to crystallized soft song. The female
results support the conclusion that neither form of soft song functions in courtship. The male results suggest that the reliability
of soft song as a signal of aggressive intent is not maintained by a receiver retaliation rule. 相似文献
19.
Henrik Brumm Sue Anne Zollinger Peter J. B. Slater 《Behavioral ecology and sociobiology》2009,63(9):1387-1395
Several recent studies have tested the hypothesis that song quality in adult birds may reflect early developmental conditions,
specifically nutritional stress during the nestling period. Whilst all of these earlier studies found apparent links between
early nutritional stress and song quality, their results disagree as to which aspects of song learning or production were
affected. In this study, we attempted to reconcile these apparently inconsistent results. Our study also provides the first
assessment of song amplitude in relation to early developmental stress and as a potential cue to male quality. We used an
experimental manipulation in which the seeds on which the birds were reared were mixed with husks, making them more difficult
for the parents to obtain. Compared with controls, such chicks were lighter at fledging; they were thereafter placed on a
normal diet and had caught up by 100 days. We show that nutritional stress during the first 30 days of life reduced the birds’
accuracy of song syntax learning, resulting in poorer copies of tutor songs. Our experimental manipulations did not lead to
significant changes in song amplitude, song duration or repertoire size. Thus, individual differences observed in song performance
features probably reflect differences in current condition or motivation rather than past condition. 相似文献
20.
J. R. Krebs 《Behavioral ecology and sociobiology》1976,1(2):215-227
Summary This paper is concerned with the idea that the song repertoires of passerine birds are an evolutionary adaptation to reduce habituation in listeners. In an experiment involving 16 territorial males I played either a single song or a repertoire of songs for 15 two-min trials through a single loudspeaker near the edge of the territory. In a second experiment with 10 birds I played the songs through one of two loudspeakers in different parts of the territory, alternating between loudspeakers on successive trials. The birds tended to habituate more rapidly to single song playback than to repertoires. In the second experiment the overall level of habituation was lower and the difference between the two treatments was less marked.Two features of song repertoire organisation are consistent with the habituation hypothesis (1) the avoidance of low recurrence intervals in switches between song types, and (2) the fact that within repertoire variability is as great or greater than between repertoire varability.The main problem with the habituation hypothesis is that habituation by listeners does not seem to be adaptive, so it is not clear why they should habituate. I suggest a hypothesis. Intruders may assess the density of birds in an area by listening to songs, so that habituation may be a mechanism by which this density assessment is achieved. Repertoires could be a mechanism by which resident birds cheat, through increasing the apparent density of singing birds. 相似文献