Reindeer (Rangifer tarandus) response to feces and urine from sheep (Ovis aries) and reindeer

In many Norwegian alpine and tundra areas sheep and reindeer graze sympatrically. Areas covered with dung or urine may have consequences for reindeer pasture utilization. Experiments were conducted on 5 stall fed male reindeer calves where animals were individually presenred with two troughs (experimental and control) containing 200 g of concentrate. Fresh and dry sheep and reindeer pellets (50 g wet weight) were mixed with the concentrate in the experimental trough and the aversive response was tested against the control. Both fresh sheep (P < 0.0001) and reindeer (P < 0.0001) pellets were associated with aversive response by reindeer. A similar response was found for dry sheep (P = 0.006) and dry reindeer (P = 0.0009) pellets. Similar trials were conducted using sheep and reindeer urine (20 g sprayed evenly on the food) and the aversive response by reindeer was tested against the control (sprayed with 20 g of water). Both sheep and reindeer urine stimulated an aversive response by reindeer {P = 0.03 for both tests). The differences in the aversive response of reindeer ro fresh sheep and reindeer pellets, dry sheep and reindeer pellets and sheep and reindeer urine were also tested. No differences by reindeer were found between sheep and reindeer pellets, either for fresh (P = 0.28) or dry (P = 0.07), or between food treated with sheep and reindeer urine (P = 0.28). Possible habituation to sheep and reindeer pellets was tested using 8 consecutive trials with dry pellets, followed by 2 additional trials when dry pellets were soaked in water. This was done to simulate natural dry periods followed by rain showers. Habituation effects were found in trials with dry sheep and reindeer pellets. Subsequent trials with fecal pellets soaked in water significantly reduced food intake when compared with the last habituation trial with dry pellets (P < 0.05)

Termitaria as browsing hotspots for African megaherbivores in miombo woodland

Abstract: Thirteen termite mounds and 13 similar-sized control plots were surveyed in central Zimbabwe in order to study large mammalian browsing and vegetation characteristics. The mounds supported almost twice as many tree species as the control plots and the woody vegetation was denser on mounds compared with the woodland plots. Species of woody plants were recorded along with the percentage of branches browsed (cumulative browsing score) by black rhino, Diceros bicornis, elephant, Loxodonta africana and other browsers combined. In addition we measured how the cumulative browsing score on three woody plant species, Acacia nilotica, Colophospermum mopane and Dichrostachys cinerea, which were common both on and off mounds, was related to the distance from mound centre. Both black rhino and elephant cumulative browsing scores were significantly higher on the mound plants compared with the woodland plots. Cumulative browsing score was negatively related to distance from the mound centre for Dichrostachys cinerea, Colophospermum mopane and Acacia nilotica. We propose that termite mound construction in miombo woodland contributes to sustaining populations of megaherbivores and perhaps some woody species in these areas

Reindeer avoidance of pasture contaminated with sheep and reindeer faeces

Contamination by excrements will increase in areas with high animal densities, such as snow free patches with accessible forage in winter and holding paddocks. Avoidance of faeces dropped by other grazers may result in interference competition by reducing optimal forage intake, or offer protection from the transfer of parasites or disease. We conducted two enclosure experiments investigating reindeer (Rangifer tarandus) reactions towards faeces. The first experiment tested whether reindeer avoid pasture contaminated with faeces from reindeer or sheep (Ovis aries). Both high (0.5 kg/m2) and low (0.05 kg/m2) concentrations of faeces reduced reindeer grazing compared to no faeces. Reindeer grazed significantly less in areas with high concentration of faeces compared to areas with low concentrations, with equally strong avoidance regardless of faeces source. The second experiment analysed the defecation pattern (random or not) of reindeer in a 50 m x 40 m enclosure to investigate how this pattern might change following the introduction of female sheep or additional female reindeer. Both reindeer and sheep defecated in a non-random pattern that was related to their preferred bedding sites. When sheep visited reindeer, the species' faeces distributions were positively correlated, indicating that reindeer and sheep had an overlap in area utilization, at least while bedding. When additional reindeer were introduced and then removed, the combined resident and visiting reindeers' faeces distributions were negatively correlated with the resident reindeers' faeces distribution following the removal of the visiting reindeer. This suggested that resident reindeer avoided the visiting reindeers' faeces. Resident reindeer also produced fewer total droppings when visited by new reindeer, while the number of droppings did not change when visited by sheep. Thus, resident reindeer were more adversely affected by the introduction of new reindeer even after their removal than by the introduction of sheep. In conclusion, the amount and distribution of excrements will play an important role in reindeer grazing and area use in pastures maintaining high densities of reindeer or reindeer and sheep

Pasture shade and farm management effects on cow productivity in the tropics

This is the postprint version of the article. The published article can be located at the publisher's webpageShade, provided by trees within pastures, can affect cattle productivity through mitigating heat stress and by altering understorey pasture growth and cattle behaviour. Models for daily milk yield and body condition were used to evaluate the effect of pasture shade on dual purpose cow productivity within a silvopastoral system in a dry tropical province of Nicaragua. Daily milk yield and body condition were both negatively affected by pasture shade. Stocking density and age also had negative effects on daily milk yield, whilst night grazing had a positive effect. In addition, body condition was negatively affected by average daily milk yield and was positively affected by feed supplementation. There was a correlation between pasture shade and stocking density in both production models suggesting farmers compensated for decreased cow productivity, associated with increased pasture shade, by reducing stocking density. It is proposed that the positive effect of shade mitigating heat stress was likely present but its effect did not compensate for the decreased nutrient intake by the cows caused by either negative behavioural effects or reduced pasture productivity, or both

Reindeer 24-hr within and between group synchronicity in summer versus environmental variables

Abstract: The impact of abiotic stimuli on the circadian activity rhythm of Rangifer has long been debated. Their highly gregarious and mobile behaviour presupposes synchronized behaviour within a group, while a predominant abiotic influence would be expected to synchronize separate, independent groups subjected to the same environment. We tested within and between group synchronization of semi-domestic reindeer during summer observing 6 independent groups located in close proximity to each other. We also tested how some external environmental factors affected the animals’ behaviour. Activity of all individuals (3 females in 6 groups, n = 18 reindeer) was recorded every 10 minutes 24-hrs a day, along with weather variables and biotic factors such as insect harassment. Data were divided into two periods of 8 and 6 days, respectively, separated by a period of 6 days. Animals within a group showed highly synchronized behaviour, reflected in overlapping periods of grazing and ruminating. There was little or no synchronization between groups, reflected by little or infrequent overlapping of activities amongst some of the groups. Rarely were all 6 groups active or inactive simultaneously. There was no consistent or significant influence on the reindeers’ behaviour by any of the environmental variables recorded. Thus, and as expected, in the absence of external environmental stimuli, the activity of individuals within a group was synchronized. However, there was no synchronization amongst independent groups. This supports the claim that during summer, in the absence of disturbance from stimuli such as insect harassment or anthropogenic activities, reindeer have a 24-hr polycyclic activity rhythm independent of climatic variables. Instead of abiotic factors, such as light, reindeers’ activity rhythms were defined by internal physiological processes and intra-specific group interactions reflected in almost complete within group synchronization and lack of between group synchronization. Abstract in Norwegian / Sammendrag: Betydningen av abiotiske variabler på reinens døgnrytme har lenge vært diskutert. Med sin gruppeadferd og mobilitet forventer man samhandling innenfor ei gruppe, mens abiotiske variabler faktorer forventes å synkronisere adferden mellom adskilte grupper i samme miljø. Vi testet adferdssynkroniseringen innenfor og mellom grupper av tamrein ved å observere aktiviteteter i seks uavhengige grupper hver med tre simler. Vi testet også hvordan noen miljøvariabler påvirker dyrenes adferd. Aktiviteten til alle individene ble observert hvert tiende minutt hele døgnet sammen med klimatiske forhold og biotiske variabler som insektplage. Dyrene innenfor ei gruppe viste klart felles adferd med samme beite- og liggeperioder. Det var lite eller ingen synkronisering mellom grupper, idet det var lite eller tilfeldig sammenfall av aktiviteter. Sjelden var alle seks gruppene aktive eller inaktive samtidig. Aktiviteten til individer innenfor en gruppe var synkronisert som forventet, uten eksterne miljøvariabler. Derimot var det ingen synkronisering mellom uavhengige grupper. Dette støtter teorien at reinsdyr har en 24-t polysyklisk aktivitetsrytme uavhengig av klimatiske variabler på sommeren og uten sterke påvirkninger utenfra som parasittiske insekter eller menneskelige aktiviteter. Vårt forsøk viste at reinens aktivitetsrytme tydeligvis var definert av interne fysiologiske prosesser og interaksjoner innen gruppen

Neutral processes related to regional bee commonness and dispersal distances are important predictors of plant–pollinator networks along gradients of climate and landscape conditions

Understanding how niche-based and neutral processes contribute to the spatial varia-tion in plant–pollinator interactions is central to designing effective pollination con-servation schemes. Such schemes are needed to reverse declines of wild bees and other pollinating insects, and to promote pollination services to wild and cultivated plants. We used data on wild bee interactions with plants belonging to the four tribes Loteae, Trifolieae, Anthemideae and either spring- or summer-flowering Cichorieae, sampled systematically along a 682 km latitudinal gradient to build models that allowed us to 1) predict occurrences of pairwise bee–flower interactions across 115 sampling locations, and 2) estimate the contribution of variables hypothesized to be related to niche-based assembly structuring processes (viz. annual mean temperature, landscape diversity, bee sociality, bee phenology and flower preferences of bees) and neutral processes (viz. regional commonness and dispersal distance to conspecifics). While neutral processes were important predictors of plant–pollinator distributions, niche-based processes were reflected in the contrasting distributions of solitary bee and bumble bees along the temperature gradient, and in the influence of bee flower preferences on the distri-bution of bee species across plant types. In particular, bee flower preferences separated bees into three main groups, albeit with some overlap: visitors to spring-flowering Cichorieae; visitors to Anthemideae and summer-flowering Cichorieae; and visitors to Trifolieae and Loteae. Our findings suggest that both neutral and niche-based pro-cesses are significant contributors to the spatial distribution of plant–pollinator inter-actions so that conservation actions in our region should be directed towards areas: Page 2 of 11near high concentrations of known occurrences of regionally rare bees; in mild climatic conditions; and that are surrounded by heterogenous landscapes. Given the observed niche-based differences, the proportion of functionally distinct plants in flower-mixes could be chosen to target bee species, or guilds, of conservation concern. Keywords: ecological networks, machine learning, plant–pollinator interactions, spatial, wild beesNeutral processes related to regional bee commonness and dispersal distances are important predictors of plant–pollinator networks along gradients of climate and landscape conditionspublishedVersionpublishedVersio

First LIGO search for gravitational wave bursts from cosmic (super)strings

We report on a matched-filter search for gravitational wave bursts from cosmic string cusps using LIGO data from the fourth science run (S4) which took place in February and March 2005. No gravitational waves were detected in 14.9 days of data from times when all three LIGO detectors were operating. We interpret the result in terms of a frequentist upper limit on the rate of gravitational wave bursts and use the limits on the rate to constrain the parameter space (string tension, reconnection probability, and loop sizes) of cosmic string models.Comment: 11 pages, 3 figures. Replaced with version submitted to PR

Search for Gravitational Wave Bursts from Soft Gamma Repeaters

We present the results of a LIGO search for short-duration gravitational waves (GWs) associated with Soft Gamma Repeater (SGR) bursts. This is the first search sensitive to neutron star f-modes, usually considered the most efficient GW emitting modes. We find no evidence of GWs associated with any SGR burst in a sample consisting of the 27 Dec. 2004 giant flare from SGR 1806-20 and 190 lesser events from SGR 1806-20 and SGR 1900+14 which occurred during the first year of LIGO's fifth science run. GW strain upper limits and model-dependent GW emission energy upper limits are estimated for individual bursts using a variety of simulated waveforms. The unprecedented sensitivity of the detectors allows us to set the most stringent limits on transient GW amplitudes published to date. We find upper limit estimates on the model-dependent isotropic GW emission energies (at a nominal distance of 10 kpc) between 3x10^45 and 9x10^52 erg depending on waveform type, detector antenna factors and noise characteristics at the time of the burst. These upper limits are within the theoretically predicted range of some SGR models.Comment: 6 pages, 1 Postscript figur