Drinking schedule of four sandgrouse species (<Emphasis Type="Italic">Pterocles</Emphasis> spp.) in relation to sunrise and season

Sandgrouse (Pterocles spp.) are adapted to extreme desert environments. One such adaptation is that males transport water in their abdominal feathers to water the nesting female and hatchlings. Hence, understanding sandgrouse drinking regime and regularly used water holes is of great conservation importance. We studied the arrival of four sandgrouse species at a single water hole in the western Negev Desert, Israel. During our visits, the most numerous species was the Spotted Sandgrouse, and in decreasing abundance, we found Black-bellied Sandgrouse, Crowned Sandgrouse, and Pin-tailed Sandgrouse. Black-bellied Sandgrouse arrived significantly earlier than Spotted Sandgrouse and Crowned Sandgrouse. Spotted Sandgrouse arrival peaked later in the morning than Black-bellied Sandgrouse and Crowned Sandgrouse. The data suggest that this is connected to the absolute number of birds for each of the species which influences their synchronous arrival. Also, we find that the amount of time a species spends at the water hole is influenced by the number of birds present, i.e., the species that stay the longest are also the most numerous. The mean temperature when Spotted Sandgrouse peaked was marginally higher (21.2°C) than recorded for Black-bellied (19.5°C) and Crowned Sandgrouse (19.3°C).     

Assessing the short‐term effects of capture,handling and tagging of sandgrouse

Capturing and marking free‐living birds permits the study of important aspects of their biology but may have undesirable effects. Bird welfare should be a primary concern, so it is necessary to evaluate and minimize any adverse effects of procedures used. We assess short‐term effects associated with the capture, handling and tagging with backpack‐mounted transmitters of Pin‐tailed Pterocles alchata and Black‐bellied Pterocles orientalis Sandgrouse, steppe birds of conservation concern. There was a significantly higher mortality (15%) during the first week after capture than during the following weeks (< 2.5%) in Pin‐tailed Sandgrouse, but no significant temporal mortality pattern in Black‐bellied Sandgrouse. In Pin‐tailed Sandgrouse, mortality rate during the first week increased with increasing relative transmitter and harness weight regardless of season, and with increasing handling time during the breeding season. There were no significant differences in mortality rate between study areas, type of tag, sex or age or an effect of restraint time. These results suggest the use of lighter transmitters (< 3% of the bird's weight) and a reduction of handling time (< 20 min), particularly during the breeding season, as essential improvements in procedure to reduce the mortality risk associated with the capture, handling and tagging of these vulnerable species.     

Disentangling the drivers of Black-bellied Sandgrouse Pterocles orientalis nesting habitat use in a Mediterranean arid environment

ABSTRACT

Capsule: Nest site selection of Black-bellied Sandgrouse Pterocles orientalis in an Algerian arid environment is dictated by a combination of topography, human presence, landscape and space.

Aims: To disentangle the drivers affecting Black-bellied Sandgrouse nest habitat use in an Algerian arid environment.

Methods: We used data on a series of topographic, anthropogenic, landscape and space variables, to identify the predictors of the occurrence probability of Black-bellied Sandgrouse nests. These variables were measured at nests (n?=?33) and random points (n?=?33) within landscape plots of 250?m radius.

Results: The probability of a site being selected for nesting by Black-bellied Sandgrouse was negatively related to distance to the nearest cereal crops, but positively associated with the cover of natural water, cover of rocks, and distance to the nearest road. This probability was also high at elevations between 251 and 289?m.

Conclusion: From a practical perspective, it would be interesting to reproduce the same investigation in other Mediterranean arid environments to find out if this species follows a similar pattern of nesting habitat use. This would provide guidance for future conservation actions and inform appropriate habitat management for this species.     

Species distribution of genus Quadraceps (Mallophaga: Philopteridae) on New Zealand endemic plovers

Abstract

The louse genus Quadraceps Clay & Meinertzhagen is represented on New Zealand endemic Charadriinae by Q. dominella Timmermann, Q. novaeseelandiae Timmermann, and Q. cedemajori Timmermann, which are parasitic on Charadrius obscurus (Gmelin), Thinornis novaeseelandiae (Gmelin), and Anarhynchus frontalis Quoy & Gaimard respectively. Charadrius bicinctus Jardine & Selby is parasitised by both Q. novaeseelandiae and Q. cedemajori. This pattern of distribution is unusual, in that two Quadraceps species are sympatric on the same host individuals, and host species that are not closely related have louse species in common. It seems probable that C. bicinctus has been secondarily colonised by two species of Quadraceps. One species appears to have primarily evolved on 7 novaeseelandiae and the other on A. frontalis.     

The breeding biology of the Namaqua Sandgrouse,Pterocles namaqua

The breeding biology of the Namaqua Sandgrouse, Pterocles namaqua, was studied and its nesting success determined through the observation of 278 nests over four consecutive breeding seasons at Droëgrond, Northern Cape Province, South Africa. The normal clutch of three eggs is laid over five days (±48-hour laying interval). The incomplete clutch is left unattended overnight, but is attended during the heat of the day by the female on days when an egg is laid and by the male on alternate days. After clutch completion, the pair share incubation, with the female relieving the male 151 min (±21 S.D.) after sunrise and the male relieving the female 105 min (±21 S.D.) before sunset. The incubation period is 21 days from clutch completion, and the three chicks normally hatch within 18 hours of one another. Nesting success ranged from 5.7% to 13.5% between seasons and averaged 8.2%. Predation, primarily by small mammals, was responsible for 96% of nest losses. Estimates of annual recruitment at Droëgrond ranged from minima of 3–10% to maxima of 6–20%, and are believed to be representative of a core area of the distribution of the Namaqua Sandgrouse in South Africa. These low estimates suggest that annual juvenile recruitment may be too low to maintain Namaqua Sandgrouse populations locally. Possible reasons for the sustained low level of breeding success are discussed.     

Length‐weight relationships of four fish species from Visakhapatnam coast,India

Length‐weight relationships (LWRs) were determined for 4 deep water fish species from Visakhapatnam coast, India. Specimens were collected fortnightly between December 2013 and November 2015 from commercial trawls at Visakhapatnam fish landing centre (16.98°N–20.2°N, Long.82.19°–86.53°E). Individuals were captured between 100 and 300 m depth with shrimp trawl net (head rope length: 37–46 m and cod end mesh size: 30–40 mm). Total length (TL) (nearest to 0.1 cm) and body weights (nearest to 0.1 g) were taken each individual. All LWRs were significant with r² values ranged from 0.958 for Uranoscopus bicinctus Temminkc & Schlegel, 1843 to 0.983 for Uranoscopus chinensis Guichenot, 1882 and “b” values ranged from 2.832 for U. bicinctus to 3. 402 Synodus indicus (Day, 1873).This study provides a new maximum length data for three species (Uranoscopus bicinctus Temminkc & Schlegel, 1843; Uranoscopus chinensis Guichenot, 1882 and Uranoscopus marmoratus Cuvier, 1829).     

Phytoplankton biomass and distribution in a shallow eutrophic lake (Lake George,Uganda)

Summary Lake George, a shallow lake in western Uganda, supports a permanent and dense crop of phytoplankton, and may be regarded as eutrophic although the ambient concentrations of inorganic nitrogen and phosphorus are low. The figures for the annual nutrient loadings (Viner and Smith, 1973) would suggest, however, a eutrophic lake when analysed on the scheme of eutrophication proposed by Vollenweider (1968).The horizontal distribution of chlorophyll a shows a concentric pattern, with the maximum values occurring towards the center. This horizontal variation is thought to reflect water movements, and a general pattern of water flow is proposed.The majority of the species show no seasonal variation but populations of both Anabaena and Melosira show annual variations. These two species also have a horizontal distribution pattern which is the reverse of other species. This pattern is used to support the proposed movements of water.Phytoplankton generation times are discussed in relation to the diurnal cycle occurring in Lake George.     

The biology of the Yellowthroated Sandgrouse Pterocles gutturalis in a South African agricultural landscape

Tarboton, W.R., Blane, S. & Lloyd, P. 1999. The biology of the Yellowthroated Sandgrouse Pterocles gutturalis in a South African agricultural landscape. Ostrich 70 (3&4): 214–219.

A local population of Yellowthroated Sandgrouse was monitored from 1988–1992 at Northam, Northern Province, South Africa, a region in which this species was previously an irruptive, non-breeding visitor. Yellowthroated Sandgrouse were found to be year-round residents, foraging and nesting exclusively in areas cleared for agriculture, particularly one-year fallow lands. They ate the dry seeds of a variety of weedy plants, especially Amaranthus and Crotalaria spp. Males outnumbered females 1.35:1. Egg-laying occurred from April-October, with a peak in June. Clutch size (2–3) averaged 2.85 (n=26), and the incubation period for one nest was 26 days after clutch completion. Nesting success was estimated at 24.8% (n=19 nests, 176 nest days), and the daily nest predation rate at 2.55%; predation and ploughing accounted for most nest losses. Average annual productivity was estimated to be within the range 0.42–0.85 young/pair/year. We suggest that the Yellowthroated Sandgrouse depends on the seeds of early successional plants for food and that the recent agricultural development of the region maintains sufficient areas of fallow land to allow this otherwise nomadic species to become a breeding resident.     

Temporal Overlap Among Feral Horses,Cattle, and Native Ungulates at Water Sources

Feral horse (Equus ferus caballus) populations on public rangelands in the western United States threaten forage production for livestock and wildlife habitat. Interference competition between feral horses and heterospecifics at watering sources can have negative effects on livestock and wildlife. Researchers have documented altered timing and behavior of wild ungulates at water sources when horses were present. The few studies examining these interactions have infrequently occurred within areas specifically managed for feral equids and have not occurred in sites with cattle. We used motion-sensitive cameras at 8 watering sources to document watering activity patterns and construct indices of temporal overlap among feral horses, cattle, elk (Cervus canadensis), mule deer (Odocoileus hemionus), and pronghorn (Antilocapra americana) within the Adobe Town Herd Management Area in southern Wyoming, USA, between June and September 2018 and 2019. Feral horses, cattle, and pronghorn exhibited a high degree of temporal overlap (>79%) in water use, with feral horses and pronghorn exhibiting the highest estimated percent overlap (88.1%, 95% CI = 86.5–89.6%). Mule deer and elk watering activity also overlapped with horses and cattle but to a lesser degree (<55%). Feral horses spent a mean of 16.7 ± 30.5 (SD) minutes during a watering event and were present at a given water source on average 4.5 ± 6.3% and up to 34.9% of the day, which is less than reported in previous studies. Cattle spent on average 23.5 ± 44.9 minutes during a watering event, and were present on average 4.2 ± 7.7% and up to 42.4% of the day at a single water source. Results of generalized linear mixed-effects models indicated that number of conspecifics was the strongest predictor of visit duration for pronghorn and horses; hour of the day and group size of heterospecifics were informative, but less important, variables. There was no difference in peak visitation time for any species between sites of high versus low horse or cattle use. Despite temporal overlap, we did not find evidence of interference competition between feral horses, cattle, and pronghorn. We recommend future examination of interference competition and its biological consequences between introduced and native ungulates at water sources of varying size across sites, equid population levels, and livestock stocking rates. © 2020 The Wildlife Society.     

Distinguishing features of immature stages of Panchaetothripinae (Thysanoptera: Thripidae) known in New Zealand

Diagnostic morphological characters of the juvenile Panchaetothripinae in New Zealand are illustrated. Keys developed enable colonies with only immature stages to be identified without needing to rear adults. Live larvae or larvae in ethanol are distinguished by the presence of expanded tips of body setae (Parthenothrips dracaenae), the absence of setae at the abdomen tip (Hercinothrips bicinctus), setae at abdomen tip not longer than abdominal tip width (Heliothrips haemorrhoidalis) and abdominal tip setae longer than abdominal tip width (Sigmothrips aotearoana, endemic species). The presence or absence of spine-like setae on abdominal segments 9 and 10, and the number and length of setae on the wing buds, enable identification of pupae. Abdominal spine-like setae were on the prepupa and pupa of H. bicinctus and S. aotearoana, species that pupate off the plant, and are probably defensive structures. This is the first record of spine-like setae on segment 10 of terebrantian pupae.     

Two circadian eclosion times in Chironomus thummi (Diptera), alternately selected with different temperatures

Summary Chironomus thummi emerged from cold water (9–12°C) during daylight, from warm water (16–25°C) mainly after dusk. At medium temperatures no intermediate peak occurred, but the pattern became biphasic. The midges switched from one eclosion time to the other without any transition. This happened in constant as well as in falling and rising temperatures. The biphasic pattern is explained by some intraspecific variability of the critical temperature. Midges bred in cold water changed the pattern at the same temperature level as those bred in warm water, indicating that there was no long-term adaptation. Both eclosion times were synchronized with the light-dark cycle (LD), and continued in constant light (LL) as well as in constant darkness (DD) with a free running circadian rhythm. A single step from LL to DD given to arhythmic populations resulted in rhythmic eclosion persisting for up to two weeks. The phase and shape of the peaks depended on the temperature level and resembled the two alternate patterns in LD.The duration of development in this polyvoltine species is scarcely affected by the photoperiod. Since eclosion is not restricted to a short suitable season, the variable pattern may be an adjustment to different seasonal temperature levels.Supported by a grant from the Deutsche Forschungsgemeinschaft     

Electric discharges of two species of stargazers from the South China Sea (Uranoscopidae,Perciformes)

Experimentally, the specialized electrogenerative activity is discovered in two representatives of the family Uranoscopidae (Uranoscopus bicinctus and U. affinis) living in the coastal zone of Nha Trang Bay of the South China Sea (Vietnam). For the first time, the electric discharges of duration up to 100 ms are recorded in U. bicinctus and up to 300 ms in U. affinis. The discharges are monopolar oscillations of the potential with electronegativity in the area of the fish head. Distribution of potentials on the body surface of the stargazer was investigated. It is shown that the electric field during the discharge has dipole characteristics and the zone of the “null” equipotential is situated in the area of the soft dorsal fin. Electrophysiological experiments, using the method of microelectrode stimulation of different regions of the brain, demonstrated that stable electric discharges are caused by stimulation of the medial zone of the bottom of the fourth ventricle in medulla oblongata. The discharges caused in such way are fully analogous to those generated spontaneously and under mechanical stimulation of the skin. Thus, the conclusion could be made on localization of the stargazer’s electromotor center in this zone.     

Effect of maleic hydrazide on peroxidase isoenzymes in relation to rooting hypocotyl cuttings ofPhaseolus mungo

A time course study of changes in the pattern of peroxidase isoenzymes shows that two new isoenzymesa andb appeared in hypocotyl cuttings cultured either in indolyl-3 acetic acid (IAA) + sucrose or in water but not in maleic hydrazide (MH). Roots were also initiated in the former two cases but not in the last case. That these isoenzymes may be associated with root initiation is also evident from the fact that these appeared when hypocotyl cuttings were transferred from MH to IAA + sucrose. The time of appearance of these isoenzymes in different cultures also synchronized with the time of microscopic root initiation. While the isoenzymea disappeared,b persisted in cuttings transferred from IAA + sucrose to MH. The number of roots produced on cuttings transferred to MH was very low, though their development was normal. It is suggested that isoenzymesa andb may be associated with root initiation andc andd with root development.     

Nectar secretion pattern of the dish-shaped flower,Cayratia japonica (Vitaceae), and nectar utilization patterns by insect visitors

We studied the relationship between the diurnal nectar secretion pattern of flowers of Cayratia japonica and insect visiting patterns to these flowers. Flower morphology of C. japonica changed greatly for about 12 hours after flower-opening and the maximum duration of nectar secretion was 2 days. The nectar volume peaked at 11∶00 and 15∶00, and declined at night and at 13∶00 regardless of time elapsed after flower-opening. The nectar volume at the two peaks was, on average, 0.25 μl on bagged inflorescences and 0.1μl on unbagged inflorescences (both, sugar concentration=60%). The flower secreted nectar compensatory when the nectar was removed. This means that insects consume more nectar than the difference of nectar volume between bagged and unbagged flowers. Apis cerana is a primary visitor of this flower, and was the only species for which we confirmed pollen on the body, among many species of flower visiting insects to this flower. Apis cerana visited intensively at the two peaks of nectar secretion. Visits of the other insects were rather constant or intensive only when there was no nectar secretion. Thus flowers of C. japonica with morphologically unprotected nectaries may increase likelihood that their nectar is used by certain pollinators, by controlling the nectar secretion time in day. In this study the pattern of nectar secretion allowed A. cerana maximum harvest of nectar.     

In vivo effects of recombinant human lymphotoxin on human medulloblastoma xenograft: Enhancement of antitumor activity of etoposide

The authors investigated the antitumor activities of rHuLT alone and in combination with etoposide on human medulloblastoma xenografts growing subcutaneously in nude mice. Intravenous administration of rHuLT (1.0×10⁵U/kg, 5.0×10⁵U/kg, 2.5×10⁶U/kg, three times a week for three weeks) suppressed medulloblastoma growth depending on the dose. However, the highest dosage caused serious side effects. Combining rHuLT (intravenously, 5.0×10⁵U/kg, three times a week for three weeks) with etoposide (intraperitoneally, 20mg/kg, once a week for three weeks) increased the antitumor activity without causing serious toxicity. Microscopically, tumor specimen showed thrombosed tumor vessels and massive necrosis 3 weeks after rHuLT treatment. Ultrastructural examination revealed that 120 minutes after the administration of rHuLT alone, disruption of interendothelial junctions was evident, and that the endothelial cells were destroyed at 240 minutes.Concentration of etoposide in tumor tissue peaked 30 minutes after intraperitoneal administration, and then decreased with time. When etoposide was administered in combination with rHuLT, the concentration of etoposide in tumor tissue after 60 to 240 minutes was significantly higher than when etoposide was given alone, and the area under the concentrationversus time curve was also greater for the tumors of mice with combination treatment.The findings suggest that the proper combination of rHuLT and etoposide may have synergistic antitumor activities. Histological changes suggest that increased concentrations of etoposide within the tumor after combination therapy may occur due to increased vascular permeability and/or decreased etoposide clearance which is the result of blood stasis in the tumor vasculature.Abbreviations AUC area under the concentration versus time curve - LT lymphotoxin - rHuLT recombinant human lymphotoxin - rHuTNF recombinant human tumor necrosis factor - TNF tumor necrosis factor     

TIME-KEEPING SYSTEM OF THE EEL POUT,ZOARCES VIVIPARUS

Observations on the rhythmic activity of 71 juvenile specimens of the inter-tidal blenny Zoarces viviparus reveal an endogenous pattern of swimming at three different periodicities. Circatidal swimming, with activity peaks phased to high water or the ebb of the subjective 12.4-h tides, was found in 50 fish and was the predominant pattern seen immediately after collection, when the rhythm generally persisted for between 3 and 12 cycles. Discrete activity peaks, with a free running period of approximately 24 h were also evident in the swimming pattern of eight fish. A circadian influence was also manifest as a modulation in amplitude, phase shifts and changes in free-running period of the circa-tidal rhythm. Overall, the activity level declined with time but those fish that remained active long enough showed a semi-lunar rhythm, with maximum activity at the time of the spring tides. A comparison of the behavior of animals collected at different times of the year suggests a seasonal variation in the persistence of circatidal swimming. The results are consistent with a control system involving circatidal, circadian, and semi-lunar oscillators. (Chronobiology International, 18(1), 27–46, 2001)     

Phase analysis of circadian-related genes in two tissues

Background  

Recent circadian clock studies using gene expression microarray in two different tissues of mouse have revealed not all circadian-related genes are synchronized in phase or peak expression times across tissues in vivo. Instead, some circadian-related genes may be delayed by 4–8 hrs in peak expression in one tissue relative to the other. These interesting biological observations prompt a statistical question regarding how to distinguish the synchronized genes from genes that are systematically lagged in phase/peak expression time across two tissues.     

Behavioural responses of female Queensland fruit fly, Bactrocera tryoni, to mineral oil deposits

Behavioural responses of Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), females to fruit dipped in water and fruit dipped in 0.5% (vol/vol) aqueous emulsions of a mineral oil were determined and analysed. The mineral oil was an nC20–22 distillation fraction of the base oil used to produce an nC23 horticultural mineral oil. Females caged with oil‐treated fruit had significantly longer prelanding intervals than females caged with water‐dipped fruit. The latter was attacked immediately or shortly after being caged with flies whereas some oil‐dipped fruit was not attacked within 180 min. The percentage of landings that led to oviposition on water‐ and oil‐treated fruit were 58 and 13%, respectively, and the percentages ovipositing after probing were 74 and 25%, respectively. Likewise, average times spent probing were 7 vs. 31 s whereas average times spent ovipositing were 321 vs. 223 s. Females spent less than half as much time on oil‐treated fruit than on water‐treated fruit. Transition probabilities of rejection, when applied to the behaviour sequence indicated that oil‐treated fruits are about nine times less likely to be infested with B. tryoni.     

Mating System,Resource Defence and Sex Change in the Anemonefish Amphiprion akallopisos

Ecology and mating system of A. akallopisos were investigated at Aldabra Atoll and data compared with A. bicinctus from the Red Sea. A. akallopisos inhabits Radianthus ritteri, a colonial species forming aggregations up to 198 anemones. A. bicinctus occupies Gyrostoma helianthus, a solitary-living anemone. Both Amphiprion species are monogamous. A. akallopisos, on its larger host clusters, forms groups of up to 9 adults, consisting of a large breeding ♂, a functional breeding ♂ and a varying number of non-breeding ♂♂. A size-dependent aggressive hierarchy exists; as the breeding ♂ prevents all others from mating with the ♀, monogamy obtains even in larger groups. The ♀ — a breeding ♂♂ having changed sex — defends and monopolizes a territory and so attracts and controls potential mates. The ♀-dominance system, resource defence and distribution, inter- and intrasexual competition are discussed in the light of Emlen and Oring's (1977) theories. The many A. akallopisos non-breeding ♂♂ in the overall population and in groups are suggested to be helpers. In Amphiprion helping would not mean caring for the eggs to increase the breeders' reproductive success. One could speculate that nonbreeding adults improve their own reproductive chances by remaining on the breeders' territory and waiting for a vacant breeding position.