bluuebunny/crossref_metadata_2025_split huggingface dataset:
Burrows, surface movement, and swimming of Tachyoryctes splendens (Rodentia: Rhizomyidae) during flood conditions in Kenya
Authors: HICKMAN GRAHAM C. 
Published: August 2009

The effect of flooding on the behaviour of most mammals has not been studied, even though in tropical areas there are well delineated wet and dry seasons which produce flood conditions on a regular basis. Fossorial mammals can be expected to be particularly vulnerable to flooding because of the absolute dependence on a sub‐surface existence and poor climbing ability.Behaviour of the East‐African mole‐rat, Tachyoryctes splendens, was studied under flood conditions and compared with published field work conducted under non‐flood conditions. Four completely excavated burrow systems were obviously abbreviated (2–9 m in length), although the nest area did not appear to be affected. Live‐trapped animals released on the surface travelled as far as 80 m before attempting to dig; surface speed was generally slow (7 m/min). Animals generally (83% of the trials) excavated towards the increase in slope on the study area; total digging time before closure of the tunnel ranged from 7–49 min. In swimming trials, animals were not hesitant to enter water but swimming endurance was short (range 115‐550s).Flooding may be a very disruptive but not an entirely negative aspect of the biology of Tachyoryctes. Dispersal may be instigated and even assisted by providing surface routes over edaphic barriers and moist soils which are readily workable.
Reproductive endocrinology of free living Pied flycatchers (Ficedula hypoleuca): prolactin and FSH secretion in relation to incubation and clutch size
Authors: Silverin Bengt , Goldsmith Arthur R. 
Published: August 2009

Plasma levels of prolactin and FSH in free‐living Pied flycatchers were studied in relation to breeding stage, clutch size and diurnal variations. In the female, the concentration of prolactin started to increase during the egg‐laying and reached maximal values at the end of the incubation period. After hatching prolactin levels decreased. Male Pied flycatchers showed an increase in plasma levels of prolactin at the time when they returned to their home‐territories, i.e. at the end of the incubation period. Males still occupying secondary territories at this time had low levels of prolactin. In the males, as in the females, plasma levels of prolactin decreased after hatching.Male Pied flycatchers showed at all times higher plasma levels of FSH than did females. In both sexes FSH levels were high during the early part of the breeding season and started to decrease after the egg‐laying period. After hatching time plasma levels of FSH were below the sensitivity of the assay. No differences in FSH were found between males occupying secondary territories and males in home‐territories.In incubating females FSH, but not prolactin, showed a distinct unimodal daily cycle.No differences were found in plasma levels of prolactin and FSH between females incubating different sized clutches.
Lead levels in the blood of Mute swans Cygnus olor on the River thames
Authors: Birkhead Mike 
Published: August 2009

In this paper blood lead levels in three categories of Mute swan are examined, (i) flock birds (ii) breeding birds and (iii) cygnets. From these regional, seasonal and sex variation for both 1980 and 1981 was examined. In addition a portable haematofluorometer was assessed to determine its possible use as an alternative to atomic absorption and spectrophotometry for determining a measure of lead exposure.Very few swans on the River Thames had blood lead levels below the maximum acceptable level of 40 mgg/100 ml. In general lead levels increased with proximity to London and the swans on the tributaries consistently had the lowest levels which were always below the maximum acceptable level. Blood lead levels in flock birds were shown to be highest during the coarse fishing season and it was only during the close season that levels dropped to around 40 &#x006d;̀g/1OO ml. Breeding females had significantly higher lead levels than males and females with lead levels in excess of 200 &#x006d;̀g/1OO ml seemed to have a poor chance of producing cygnets or surviving to the next breeding season. Cygnet mortality was significantly higher on the lower Thames where blood lead levels were also known to be at their highest.
Artificial insemination in the Giant panda (Ailuropoda melanoleaca)
Authors: Moore H. D. M. , Bush M. , Celma M. , Garcia A‐L. , Hartman T. D. , Hearn J. P. , Hodges J. K. , Jones D. M. , Knight J. A. , Monsalve L. , Wildt D. E. 
Published: August 2009

Artificial insemination was carried out on three adult captive Giant pandas (Ailuropoda melanoleuca). Oestrus in these animals was detected by behavioural observations and by the rise in urinary oestrogen metabolites. Semen was collected from a mature male by electroejaculation. Changes in the quality of semen and the size of the testes indicated a seasonal fluctuation in sperm production. Spermatozoa were capable of penetrating zona‐free hamster oocytes and remained viable for up to five days at 15–20°C in a modified Tyrode's medium. After freezing and thawing in a cryopreserving diluent, approximately 50% of spermatozoa recovered progressive motility and displayed a similar velocity to spermatozoa prior to freezing. Unusual protrusions of the acrosome of the panda spermatozoon were noted.Following insemination, one female conceived and gave birth, after a gestation of 159 days, to two cubs, one of which subsequently died. Another female exhibited a rise in circulating progesterone but pregnancy was not confirmed.
The relationships of cartilaginous fishes: an immunological study of serum transferrins of holocephalans and elasmobranchs
Authors: Burch S. J. , Lawson R. , Davies D. H. 
Published: August 2009

Serum transferrins from two holocephalan, five elasmobranch and three teleost species have been compared using quantitative microcomplement fixation. Calculated immunological distances emphasize the close relationship between the holocephalans and elasmobranchs and strongly support the view that they should be considered as part of a natural assemblage which is widely separated from the teleosts.If the Holocephali and elasmobranchs have been separate since the beginning of the Carboniferous, this implies that transferrin has evolved at a rate approximating to 0‐15‐0‐26 immunological units per million years involving some 9–15% substitution of amino acids. These values are extremely low and indicate that holocephalan and elasmobranch transferrins have evolved some 2–3–7 times more slowly than those known from any other group of vertebrates.
The phosphate‐rich cover on the eggshells of grebes (Aves: Podicipitiformes)
Authors: Board R. G. , Perrott H. R. , Love G. , Scott V. D. 
Published: August 2009

Spheres of a nut‐like morphology–a “kernel” formed from spherules contained in a “shell” of globular sub‐units–were a unique feature of the cover on the eggshells of six species of the order Podicipitiformes: Red‐necked grebe (Podiceps grisegend), Great crested grebe (Podiceps cristatus), Little grebe (Tachybaptus ruficollis), Black‐necked grebe (Podiceps nigrkollis), Slavonian grebe (Podiceps auritus) and Pied‐billed grebe (Podilymbus podiceps). The spheres did not give a pattern with X‐ray diffraction; the innermost ones were embedded in the dense crystalline layer on the outer surface of the calcitic portion of the shell. Electron‐probe microanalysis revealed that the cover of spheres contained principally oxygen, calcium, phosphorus and sulphur and infra‐red analysis demonstrated the presence of phosphate. The outer surface of the stratum of spheres was bounded by a thin, fissured layer of amorphous material.These observations raise questions about the ionic environment obtaining in the shell gland towards the end of shell formation and the adaptive significance of the cover on the eggshells of members of the Podicipitiformes.
Body component growth and composition of the magpie Pica pica
Authors: Tatner Paul 
Published: August 2009

Magpie nestling growth is documented as increments in body mass, tarsus length, and tenth primary length. A sample of 41 nestlings and eight adults was used to provide comparative data on changes in water content, lean dry mass, and fat content for 14 body components.Changes in the composition of various components implicate water index (water content/ lean dry mass) as an indicator of tissue and nestling maturity. Lipid index (fat content/lean dry mass) for the whole body exhibited a sustained linear increase during the first two‐thirds of the nestling period. About 80% of nestling body fat was located in the skin, body shell, and alimentary canal.The state of development of particular components appeared to be related to the current functional requirements of the nestling. Thus the food processing components assumed an early significance, while the development of insulative and locomotory components was somewhat curtailed by comparison.
Aspiratory respiration in Arapaima gigas (Teleostei, Osteoglossomorpha): A reappraisal
Authors: Greenwood P. H. , Liem Karel F. 
Published: August 2009

Recently it has been hypothesized that the osteoglossoid fish Arapaima gigas is unique amongst air‐breathing bony fishes in that it ventilates its respiratory swimbladder by aspiration. Aspiration, it was suggested, is effected by a diaphragm‐like septum lying below the swimbladder, and activated through lateral movement of the ribs.By using both high‐speed X‐ray and light cinematography this hypothesis can be refuted. Furthermore, dissection shows that the presumed anatomical basis for aspiration stems from a misinterpretation of the usual retroperitoneal position of the swimbladder, and that the ribs are capable of only a very restricted lateral movement. Arapaima gigas, like other bony fishes with a respiratory swimbladder, ventilates that organ by means of a buccopharyngeal pump.The principal afferent vascular supply to the swimbladder is, however, unusual since it stems from the caudal vein via the renal‐portal system. This and other aspects of swimbladder structure and anatomy may throw further light on the interrelationships of osteoglossoid fishes.
Breeding biology and population dynamics of giant petrels Macronectes at South Georgia (Aves: Procellariiformes)
Authors: Hunter S. 
Published: August 2009

The breeding biology and population dynamics of the two species of giant petrels, Macronectes halli and M. giganteus, were studied at Bird Island, South Georgia during 1978–81. The mean laying date of M. halli was in early October, five to six weeks ahead of M. giganteus. In both species males take the larger share (c. 54%) of incubation. The eggs of the two species are of the same size but in M. halli the egg formed a significantly higher proportion of the female body weight. On hatching M. giganteus chicks are 5% heavier than M. halli chicks but there are no sexual differences in weight. Brooding and guarding in M. halli is 11 days longer than in M giganteus and males undertake 60–68% of the duties during this time. Males of both species take five to six days longer to fledge than females and M. halli chicks have a seven to nine day shorter fledging period. The sex ratio amongst chicks is 1: 1.Chick growth (weight, culmen length and wing length) is summarized. Males reach higher peak and fledging weights than females in both species and have significantly larger bills through most of the fledging period. The increase in wing length was similar in both sexes until near the end of the fledging period. Adult M. halli tend to be shorter‐winged, larger‐billed and lighter in weight than M. giganteus at Bird Island.Chick mortality was on average c. 10% higher in M. giganteus than in M. halli leading to a lower overall breeding success in the former. Whilst the breeding population of M. giganteus seems to have stayed relatively stable M. halli has increased in numbers over the last 20 years. However 26‐9‐57–5% of birds colour‐ringed in 1978 did not breed in the subsequent two breeding seasons. Mean annual survival of breeding adults was c. 0–90. Breeding commenced between age 6 and 9 years with males possibly starting earlier than females. The increased population of M. halli and the better survival of their chicks is attributed to the considerable increase in breeding Antarctic fur seals Arctocephalus gazella which provide an abundance of carrion for M. halli nestlings during the first 30 days after hatching.
Nest construction, fighting, and larval behaviour in a geotrupine dung beetle, Ceratophyus hoffmannseggi (Coleoptera: Scarabaeidae)
Authors: Klemperer* H.G. 
Published: August 2009

The female beetleCeratophyus hoffmanseggiburies dung, with the assistance of a male, to form a series of underground brood masses. An egg is laid in the soil near each mass. Beetles of either sex resist intruders in the entrance to their burrows by a head‐to‐head pushing contest, without injury to either opponent. The larva feeds within the brood mass forming an elongated cavity. This chamber is lined with a tube built from larval excrement. The larva does not immediately repair holes made in this tube, and can neither isolate itself from another larva introduced into the same chamber, nor maintain a closed chamber when it is placed in a free‐standing brood ball.SummaryA pair of beetles worked together to make a series of horizontal brood masses by packing dung into underground chambers. An egg was laid in the soil just beyond the tip of each mass. Resident beetles used their horns to resist intruders of either sex. During head‐to‐head pushing contests in the nest entrance‐tunnel, a stable position was adopted where the horns of each opponent thrust harmlessly against the pronotum of the other. The larva prevented collapse of its chamber by building a rigid tube from accurately positioned faecal pellets. Defects in the larval chamber released no obvious repair behaviour and the larva was, therefore, not able to survive in a free‐standing brood ball or in the presence of another larva in the same chamber.It is a pleasure to thank Sr J. de Ferrer (8 Av. F. Franco, Algeciras) for his help and advice.
Early vertebrate evolution: pharyngeal structure and the origin of gnathostomes
Authors: Mallatt Jon 
Published: August 2009

Some authors have claimed that pharyngeal morphology supports the classical division of vertebrates into Gnathostomata and Agnatha. Assuming the branchial arches of jawed and jawless fish to be homologous, and noting that the arches lie on opposite sides of the gills (internal vs. external), these authors necessarily concluded that the gills evolved independently in the two groups (ectobranchiates, endobranchiates). A gill‐less common vertebrate ancestor must have been very simple and ancient (early Cambrian or older). The present paper challenges this scheme by arguing that the gills of lampreys and gnathostome fish are too structurally similar to have been independently derived. Rather, the branchial arches in the two groups are non‐homologous, for they differ in location, not only with respect to the gills, but also with respect to other major organs (ventral aorta, thyroid, visceral musculature). It is concluded that the common ancestors of gnathostomes and lampreys were not simple animals, but fish with fully developed gills that could have existed well after the Cambrian period. Constructing a gnathostome‐like pharynx requires only the addition of internal branchial arches to an agnathan pharynx (larval lamprey). It is widely held that vertebrates initially fed on microscopic particles; if so, the mere addition of larger, zooplankton‐sized items to the pre‐gnathostome diet would have provided selection for protectively re‐enforcing the medial margins of the gills with internal arches.SummaryContrary to one widely held view, pharyngeal morphology does not separate jawless vertebrates (lampreys) from gnathostome fish. Despite differences in branchial arch location, gills of lampreys and gnathostomes are fundamentally alike. Phylogenetic considerations might take a fruitful new direction by asking how the branchial arches came to differ in the two groups.Thanks are extended to Quentin Bone, Philippe Janvier, R. P. S. Jefferies, Malcolm Jollie, Ken Kardong, Colin Patterson, Barbara Stahl, Keith Thomson and Richard Wassersug for discussion of the ideas in this paper, and to Barbara Comstock and Sue Rose for typing the manuscript.
Development of the head and pectoral skeleton of Polypterus with a note on scales (Pisces: Actinopterygii)
Authors: Jollie M. 
Published: August 2009

Comparative study of the bony head and pectoral girdle skeletons of fishes requires the establishment of sound and acceptable homologies. In this paper, the bony elements seen in a number of species of Polypterus (and Erpeloichlhys) are described in terms of several developmental stages and the mature condition. Variations in these bones are considered in a developmental sense. As a part of the problem of bone development, a summary account of lateral‐line development is included.A number of particular problems of homology are discussed in some detail. The most radical differences of view involve the endocranial bones. The ideas of Patterson (1975) are examined and an alternative interpretation offered. The main bone in the posterolateral angle of the endo‐cranium is viewed as the pterotic‐epiotic. The epiotic of the teleost is seen not as the homologue of the epioccipital of the pholidophorid but a part of the so‐called “pterotic” of those fishes. Other endocranial problems appear to be of a similar (interpretative) nature. The suspensorium of Polypterus is peculiar in lacking a symplectic and an interhyal. The branchial skeleton is quite like that of a “palaeoniscoid”. The pectoral girdle presents a number of problems such as the form of the posttemporal, the lack of a sensory canal on the supracleithrum and the lack of an interclavicle.The subject matter of this paper, and other papers by this author on the development of bones in fishes, lead to several developmental concepts. These are summarized in 18 statements. A table (Table II) summarizes some of the anatomical information useful in taxonomy in terms of being derived, primitive or unique.
The effect of animal design on jumping performance
Authors: Gabriel Julie M. 
Published: August 2009

Previous workers have shown that the jumping performance of small animals is limited by power requirements, while that of large animals is limited by energy requirements. This is confirmed here, and the theory is extended to include animals that store energy, prior to a jump. Factors affecting jump range for animals of different sizes are discussed. For animals that store energy, a power amplification factor may be calculated, if the animal's range, mass and leg length are known. Alternatively, range may be predicted for an animal of known design. Animals that show a marked increase in jump range with an increase in body size are probably energy storers.SummaryThe range of large jumping animals will be limited by their ability to produce energy. In order to jump further, a large animal would need to give over a greater proportion of its body mass to jumping muscle. Small animals will be limited by their ability to produce power, but this problem can be overcome by increasing the relative length of the jumping legs or by introducing an energy storage system. Animals showing increased range with increased body size probably use energy storage systems.My thanks are due to Dr H. C. Bennet‐Clark and Dr J. F. lles for supervision of this work, to Professor T. R. E. Southwood for accommodation in the Dept of Zoology, Oxford, and to the SERC for financial support.
The feeding ecology of a selective browser, the giraffe (Giraffa camelopardalis tippelskirchi)
Authors: Pellew Robin A. 
Published: August 2009

A herbivore can manipulate certain factors of its feeding behaviour in order to achieve the metabolic requirements for reproduction. These factors include the choice of habitat in which to feed, the selection criteria for choosing food items, and the time allocated to feeding or devoted to other energy‐consuming activities. The manipulation of these behavioural factors by giraffe in the Serengeti National Park, Tanzania is analysed in relation to the seasonal changes in the quantity and quality of the food resource.The pattern of habitat choice demonstrates seasonal movements by giraffe across the drainage catena in response to differences in the rates of browse production between woodland types.Giraffe show a positive inter‐specific selection for the minor food items with a low available biomass, and utilize the dominant species in approximate proportion to their availability. Plant part selection is shown for the flushing shoots with very high protein contents.Selection criteria include a significant selection for phosphorus, and in the dry season a selection for high energy material by breeding females. With the high nutritional qualities of the diets, negative criteria such as secondary chemical compounds are important. Patterns of browse selection are correlated with inter‐specific seasonal changes in plant phenology.Giraffe devote more time to foraging as the biomass and quality of the food declines in the dry season. Energy is conserved by minimizing energy‐consuming activities at the most demanding times of day.
Breeding biology and population dynamics of Ringed ploversCharadrius hiaticulain Britain and Greenland: nest‐predation as a possible factor limiting distribution and timing of breeding
Authors: Pienkowski Michael W. 
Published: August 2009

The nesting of Ringed plovers was investigated in 1974 at Mestersvig, north‐east Greenland, and in 1974–76 at Lindisfarne, north‐east England. Difficulties in the use of Nest Record Cards for this species (to obtain information from more sites) are discussed. Territory sizes tended to be smaller, and more feeding took place within territories, at Lindisfarne than at Mestersvig. Clutch sizes were similar in different areas. Incubation (mean period about 25 days) was shared fairly equally by the two sexes. Longer incubation shifts at Mestersvig and some areas at Lindisfarne than at other Lindisfarne sites were associated with greater distances between nests and feeding areas. Most egg losses were probably due to predation, and were fewer in the Arctic than in Britain, where nesting success varied greatly in different areas and years, and in relation to timing within a season. Up to five nestings per pair per year were made at Lindisfarne, but only one at Mestersvig.The timing of breeding is discussed, and it is concluded that the date of start of egg‐laying in north‐east Greenland is determined by the timing of snow clearance, while that at Lindisfarne is related to the decreasing probability of egg‐predation later in the season. Because of the high nest losses, the production of young at many temperate sites, including parts of Lindisfarne, was probably inadequate for the population to be self‐supporting. The reasons for the large seasonal, annual and geographical differences are discussed. It is concluded that increasing predation probably determines the southern nesting limits of Ringed plovers, but that this limit may be modified by varying degrees of different types of natural and artificial protection, and extent of habitat suitable for egg camouflage. Increased human usage of nesting beaches probably has an adverse effect on nesting success, but because of the complexity of the number of inter‐related factors affecting the latter, without field experiments it is difficult to predict how this could best be offset by protection measures.