The impact of ticks on pheasant territoriality

Pheasants are competent reservoir hosts for the Lyme disease spirochaete, Borrelia burgdorferi s.l., and carry large, but highly over-dispersed, infestations of the vector ticks, Ixodes ricinus . The effects of experimental reduction of tick infestation levels on the survival and territorial behaviour of male pheasants were studied. Over three years in two woodlands in southern England, birds were marked individually and half were fitted with a slow-release acaricide, which substantially reduced their tick burdens from March to August. Acaricide treatment affected reproductive success but had no discernible impact on the survival rates of male pheasants. The degree of wattle inflation by males, an indicator of territorial status and a correlate of harem acquisition, was significantly greater among treated males. In each year, a significantly higher proportion of treated (overall 44%) than control (22%) males acquired harems. Males that acquired females ranged over small areas on field edges. By contrast, those with no females ranged more widely in woods and the adjoining fields, increasing their exposure to questing ticks. The relative contribution of such roving males to tick-borne pathogen transmission may thus increase.     

Oxygen transfer properties and dimensions of red blood cells in high-altitude camelids,dromedary camel and goat

Summary To estimate the advantage of the small red blood cells (RBC) of high-altitude camelids for O₂ transfer, the kinetics of O₂ uptake into and release from the RBC obtained from llama, vicuña and alpaca were investigated at 37°C with a stopped-flow technique. O₂ transfer conductance of RBC (G) was estimated from the rate of O₂ saturation change and the corresponding O₂ pressure difference between medium and hemoglobin. For comparison, O₂ kinetics for the RBC of a lowaltitude camelid (dromedary camel) and the pygmy goat were determined and previously measured values for human RBC were used. O₂ transfer of RBC was found to be strongly influenced by extracellular diffusion, except with O₂ release into dithionite solutions of sufficiently high concentration (>30 mM). TheG values measured in these standard conditions,G _st (in mmol · min^–1 · Torr^–1 · (ml RBC)^–1) were: high-altitude camelids, 0.58 (averaged for llama, alpaca and vicuña since there were no significant interspecific differences); camel 0.42; goat, 0.42; man, 0.39. The differences can in part be attributed to expected effects of the size and shape of the RBC (volume, surface area, mean thickness), as well as to the intracellular O₂ diffusivity which depends on the concentration of cellular hemoglobin. The highG _st of RBC of highaltitude camelids may be considered to enhance O₂ transfer in lungs and tissues. But the O₂ transfer conductance of blood, , equal toG _st multiplied by hematocrit (in mmol · min^–1 · Torr^–1 · (ml blood)^–1), was only slightly higher as compared to other species: 0.20 (llama, alpaca, vicuña), 0.14 (camel), 0.18 (goat), 0.17 (man).Abbreviations DPG 2,3-diphosphoglycerate - G conductance - Hb hemoglobin - RBC red blood cells - percent saturation of hemoglobin     

Light-induced changes in the amounts of the 36000-Mr polypeptide of NADPH-protochlorophyllide oxidoreductase and its mRNA in barley plants grown under a diurnal light/dark cycle

Seedlings of barley were grown either in continuous darkness or under a diurnal 12 h light/12 h dark cycle and the effects on NADPH-protochlorophyllide oxidoreductase were followed at two different levels. Firstly, the relative content of the mRNA encoding the NADPH-protochlorophyllide oxidoreductase was measured by dot-blot hybridization. Secondly, changes in the enzyme polypeptide were monitored either by the method of immunoblotting or by immunogold labelling of ultrathin sections of Lowicryl-embedded leaf tissue. Our results demonstrate that drastic diurnal changes in the level of mRNA sequences and the enzyme protein are unlikely to occur in plants which have been grown under natural light/dark conditions. In the dark, protein and mRNA accumulation occurs at an early developmental stage. These results are difficult to reconcile with the suggestion that the massive accumulation of mRNA and enzyme protein in dark-grown seedlings is primarily the consequence of an artificially extended darkperiod. In addition to the plastid-specific NADPH-protochlorophyllide oxidoreductase a closely related polypeptide has been detected outside the plastid in the surrounding cytoplasm (Dehseh et al. 1986b, Planta 169, 172–183). During the diurnal light/dark treatment of seedlings the concentrations of the two protein populations did not show any variation indicative of an exchange between the two protein populations across the plastid envelope.Abbreviation poly(A)⁺RNA polyadenylated RNA     

The relationship between turgor pressure and titratable acidity in mesophyll cells of intact leaves of a Crassulacean-acid-metabolism plant,Kalanchoe daigremontiana Hamet et Perr

Day/night changes in turgor pressure (P) and titratable acidity content were investigated in the (Crassulacean-acid-metabolism (CAM) plant Kalanchoe daigremontiana. Measurements of P were made on individual mesophyll cells of intact attached leaves using the pressure-probe technique. Under conditions of high relative humidity, when transpiration rates were minimal, changes in P correlated well with changes in the level of titratable acidity. During the standard 12 h light/12 h dark cycle, maximum turgor pressure (0.15 MPa) occurred at the end of the dark period when the level of titratable acidity was highest (about 300 eq H⁺·g^-1 fresh weight). A close relationship between P and titratable acidity was also seen in leaves exposed to perturbations of the standard light/dark cycle. (The dark period was either prolonged, or else only CO₂-free air was supplied in this period). In plants deprived of irrigation for five weeks, diurnal changes in titratable acidity of the leaves were reduced (H=160 eq H⁺·g^-1 fresh weight) and P increased from essentially zero at the end of the light period to 0.02 MPa at the end of the dark period. Following more severe water stress (experiments were made on leaves which had been detached for five weeks), P was zero throughout day and night, yet small diurnal changes in titratable acidity were still measured. These findings are discussed in relation to a hypothesis by Lüttge et al. 1975 (Plant Physiol. 56,613-616) for the role of P in the regulation of acidification/de-acidification cycles of plants exhibiting CAM.Abbreviations CAM crassulacean acid metabolism - FW fresh weight - P turgor pressure     

Die Entwicklung der Laut?u?erungen bei der Graugans (Anser anser)

Zusammenfassung Das Lautrepertoire von sechs handaufgezogenen Graugänsen wurde in individuellen Längsschnitten vom Schlüpfen bis zum Alter von 100 Tagen mit sonagraphischer Methode analysiert. Die Einteilung des Repertoires erfolgte nach drei verschiedenen Kriterien: Klang, Sonagramm und Kontext. Im jugendlichen Repertoire ließen sich 4 Rufklassen voneinander trennen. Im Laufe der Jugendentwicklung veränderten sich vor allem die phonetischen Parameter der Rufe, während die syntaktischen weitgehend konstant blieben. Nach einem Anstieg in der ersten Woche fiel die Tonhöhe der Rufe bei allen untersuchten Individuen und Rufklassen gleichmäßig ab. Der Stimmbruch, meßbar an der Zunahme geräuschhafter Komponenten, war ein kontinuierlicher, langfristiger Prozeß. Die Individualität war nicht in einem einzelnen, wohl aber in der Kombination mehrerer Merkmale faßbar. Die Geschlechter waren schon früh an Unterschieden in der Tonhöhe erkennbar. An sonstigen ontogenetischen Veränderungen innerhalb des Untersuchungszeitraumes konnten die Erweiterung des Repertories durch Aufspaltung und Reifung sowie ein möglicher Verlust von Rufklassen beobachtet werden.

---

Juvenile development of vocalizations in Greylag Geese (Anser anser)

Summary The juvenile vocal development of six Greylag Geese from hatching up to the age of 100 days was analysed by using sonagraphic methods. The calls were classified by means of the acoustic phenomenon, sonagrams, and context criteria. The juvenile repertoire included four main call types. During ontogeny, changes of call parameters mainly referred to phonetic characteristics, whereas syntactic parameters remained more or less constant. The frequency pitch of calls changed to higher levels during the first week of development while in older goslings this parameter decreased constantly. This held true for each individual and call type. Breaking of the voice, defined as an increment of noisy parts in the vocalizations, is described as a continuous long term process. Structural individuality of calls apparently was not based on one single parameter, but on the combination of several ones. Sex differences were found in the pitch of vocalizations, correlating with different body weights of male and female geese. Additional developmental processes of the vocal repertoire included differentiation, maturation of new call types, and apparent suppression of juvenile ones. The functional organization of the juvenile call system in Greylags is discussed.

---

---

Herrn Dr. Hans Löhrl zum 75. Geburtstag gewidmet     

Aufbau, Variabilit?t und m?gliche Funktionen des Rufduetts beim ThermometerhuhnLeipoa ocellata

Zusammenfassung Beim ThermometerhuhnLeipoa ocellata tragen die Partner eine Paares ein Rufduett vor. Der Anteil des besteht aus einer Rufreihe, die sich aus einer Folge von 2–7 identischen, zweisilbigen Rufen zusammensetzt. Das trägt einen einzelnen, obertonreichen und langgezogenen Ruf vor. Sowohl der Ruf des als auch die Rufreihe des wird in Serien vorgetragen. Innerhalb einer solcher Ruf- bzw. Rufreihenserie können mehrere Duette auftreten. Die Rufe sind jedoch nicht ausschließlich an das Duett gebunden. Die Variabilität im Aufbau des Duetts äußert sich im Zeitpunkt des Einsatzes des antwortenden Vogels, in der Anzahl der -Rufe während des Duetts und in der Anzahl der Einheiten, aus denen sich der Duettanteil des zusammensetzt. Das beginnt signifikant häufiger als das eine Serie, in der ein oder mehrere Duette vorkommen. Ebenso ist es häufiger der Initiator des ersten in dieser Serie liegenden Duetts. Das Duett dient wohl hauptsächlich zur Festigung des Zusammenhalts zwischen den Paarpartnern. Es erfüllt jedoch von seinen physikalischen Eigenschaften her auch die Bedingungen, die für ein territorial wirksames Signal gelten.

---

Structure, variability and possible functions of duetting in the Mallee FowlLeipoa ocellata

Summary In the Australian Mallee Fowl,Leipoa ocellata, both and of a pair are involved in a call duet. The part of the consists of a sequence of 2–7 identical two-syllable calls. The contributes a single long-drawn-out call rich in harmonics. The call of the as well as the call sequence of the are presented in series. Within a series of calls () or call sequences () several duets can occur. The respective vocalizations, however, do not exclusively occur during the duet.The variability in the details of the duet expresses itself in the lag period after which the mate responds, in the number of -calls during the duet, and in the number of calls within the call sequence of the . The begins a series during which one or several duets occur significantly more frequently than the . The circumstances under which duetting occurs indicate that duet calling mainly serves to maintain the pair bond. Moreover, due to its physical characteristics the duet also seems to be suited to serve as a territorial signal.