A multi-method approach to delineate and validate migratory corridors

Context: Managers are faced with numerous methods for delineating wildlife movement corridors, and often must make decisions with limited data. Delineated corridors should be robust to different data and models. Objectives: We present a multi-method approach for delineating and validating wildlife corridors using multiple data sources, which can be used conserve landscape connectivity. We used this approach to delineate and validate migration corridors for wildebeest (Connochaetes taurinus) in the Tarangire Ecosystem of northern Tanzania. Methods: We used two types of locational data (distance sampling detections and GPS collar locations), and three modeling methods (negative binomial regression, logistic regression, and Maxent), to generate resource selection functions (RSFs) and define resistance surfaces. We compared two corridor detection algorithms (cost-distance and circuit theory), to delineate corridors. We validated corridors by comparing random and wildebeest locations that fell within corridors, and cross-validated by data type. Results: Both data types produced similar RSFs. Wildebeest consistently selected migration habitat in flatter terrain farther from human settlements. Validation indicated three of the combinations of data type, modeling, and corridor detection algorithms (detection data with Maxent modeling, GPS collar data with logistic regression modeling, and GPS collar data with Maxent modeling, all using cost-distance) far outperformed the other seven. We merged the predictive corridors from these three data-method combinations to reveal habitat with highest probability of use. Conclusions: The use of multiple methods ensures that planning is able to prioritize conservation of migration corridors based on all available information

Chirurgie der Hyperthyreose

Pathophysiologie, Diagnostik, Operationsindikation und Vorbehandlung, chirurgisches Krankengut, Operationsverfahren und Nachbehandlung mit funktionellen Spätergebnissen wurden gezeigt. Der ätiologisch bedingte Unterschied in Therapie und Prognose der Hyperthyreose vom Typ des M. Basedow gegenüber den anderen Hyperthyreoseformen war dargestellt. Von 1891 schilddrüsenoperierten Patienten in den letzten 10 Jahren waren fast (n = 625) hyperthyreot; 22,7% der Hyperthyreosen waren vom Typ des M. Basedow, 26,5 % multinoduläre Strumen, der Rest autonome AdenomePathophysiology, diagnosis, indication for operation and pretreatment, data of operated patients, surgical treatment, and postoperative care with late results are demonstrated. The differences between Graves' disease and other kinds of hyperthyroidism are pointed out. About (n = 625) of all patients operated upon for goiter (n= 1891) within the last ten years had hyperthyroidism. Exophthalmia was present in 22.7 %, toxic multinodular goiter in 26.5 %; the rest of the patients had autonomous adenoma. The importance of radioimmunoassays to determine preoperative treatment and postoperative hormone levels for long-term results is stressed

Efficient microwave-to-optical conversion using Rydberg atoms

We demonstrate microwave-to-optical conversion using six-wave mixing in $^{87}$Rb atoms where the microwave field couples to two atomic Rydberg states, and propagates collinearly with the converted optical field. We achieve a photon conversion efficiency of ~5% in the linear regime of the converter. In addition, we theoretically investigate all-resonant six-wave mixing and outline a realistic experimental scheme for reaching efficiencies greater than 60%

Driver knowledge and attitudes on animal vehicle collisions in Northern Tanzania

Roads are a major cause of wildlife mortality by animal-vehicle-collisions (AVCs). We monitored the patterns and frequency of AVCs on two sections of a major highway in Northern Tanzania and compared these patterns to the knowledge and perceptions of drivers who frequently use the roads. While actual field survey showed that more birds were killed by AVCs, mammals were perceived by the drivers to be the most common AVC. Drivers were indifferent to whether AVCs were a major problem on the road, and 67% strongly felt that AVCs were mainly accidental, either due to high vehicle speed or poor visibility at night. There was a negative correlation between the likelihood of a species being hit by vehicles and its average body mass. Only 35% of drivers said they had attended an educational program related to the impact of roads on wildlife. This study highlights a need for collaborative efforts between the wildlife conservation and road departments to educate road users on the importance of driving responsibly and exercising due care for wildlife and human safety. This should be coupled with effective mitigation measures to reduce the extent of AVCs

Parathyroid localization

Twenty-nine consecutive patients with suspected primary hyperparathyroidism were examined preoperatively using ultrasound, sonographically guided fine needle aspiration, and aspirate immunostaining for PTH. In 25 patients, localization of enlarged parathyroid glands was successful. In 2 patients, the tumors were located retrosternally and, thus, could not be detected by ultrasound. One patient had a multinodular goiter which impeded localization. In 1 patient with renal osteodystrophy, 2 enlarged parathyroid glands in the neck were not visualized preoperatively. Cytology was not diagnostic, although some cytological features were suggestive of parathyroid cells. Immunostaining of the aspirated smears for PTH, however, correctly diagnosed all preoperatively localized lesions. Ultrasound should be the routine procedure of choice for preoperative localization of abnormal parathyroid glands in primary hyperparathyroidism. Fine needle aspiration and immunocytochemistry can supply confirmation, if necessary

Cattle Egret Bubulcus ibis interactions with large mammals in the Tarangire-Manyara Ecosystem, Northern Tanzania

While Cattle Egrets Bubulcus ibis are globally widespread, their ecology is not fully understood. Surveys of the species were undertaken in November 2012, and April 2013, in Lake Manyara National Park, Manyara Ranch, and outside the two protected areas. We investigated the effects of host identity, habitat type and host animal behaviour on Cattle Egret numbers and distribution. Cattle Egrets associated more with grazers than with mixed-feeders or browsers, and chose large-bodied animals over small-bodied ones. They preferred wetland and grassland, over bushland. These findings underscore the importance of wetland management and the maintenance of healthy grasslands for the future of Cattle Egrets. Declines in large-bodied mammal species are likely to negatively affect them

Population dynamics of the Manyara monkey (Cercopithecus mitis manyaraensis) and vervet monkey (Chlorocebus pygerythrus) in Lake Manyara National Park, Tanzania

Estimating population densities and their trends over time is essential for understanding primate ecology and for guiding conservation efforts. From 2011 through to 2019, we counted two guenon species during seasonal road transect surveys in Lake Manyara National Park: the Tanzania-endemic Manyara monkey Cercopithecus mitis manyaraensis (International Union for Conservation of Nature and Natural Resources, IUCN, Red List category of “endangered”) and the vervet monkey Chlorocebus pygerythrus (Red List category of “least concern”). To account for imperfect detectability, we analysed the data in a line distance sampling framework, fitted species-specific detection functions, and subsequently estimated seasonal densities. To test for seasonal differences and yearly trends in the species-specific density estimates, we fitted generalized additive models. Seasonal point density estimates fluctuated considerably during the 9 years (2011–2019) of our study, ranging from 3 to 29 individuals km−2 for Manyara monkeys and from 19 to 83 individuals km−2 for vervet monkeys. Densities of both taxa did not differ seasonally, and we did not detect marked directional population trends. Our study illustrates the utility and limitations of line distance sampling for long-term primate monitoring. Beyond informing primate ecology and management, our results highlight the conservation importance of Lake Manyara National Park for primate conservation.</p

Patterns of livestock loss associated with a recolonizing wolf population in Germany

Predation on livestock presents a daunting challenge for human–carnivore coexistence in agricultural landscapes. In Germany, the recolonization of wolves is ongoing and its consequences are insufficiently understood. Knowledge about which livestock species are susceptible to wolf predation, which farm types are predisposed to attacks by wolves, and when predation on livestock occurs is valuable for mitigating stakeholder conflicts. To this end, we analyzed 14 years of monitoring data and assessed the livestock prey spectrum, identified correlates between predation on livestock, farm type and livestock category, and described temporal patterns of livestock loss caused by a recolonizing wolf population in the state of Brandenburg (Germany). Among a total of 1387 recorded cases, 42% were unequivocally attributed to wolves (SCALP criteria C1 and C2) and 12% of cases were not caused by wolves. The number of head of livestock killed during a single wolf attack was mediated by farm type and livestock species; losses per event were greater in full-time farms vs. other farm types and greater in sheep, farmed deer and other livestock species, compared to cattle. While sheep were the most commonly killed livestock species, the increase in wolf territories over the investigation period was associated with a widening of the domestic prey species spectrum. Count regression models provided evidence for the increasing frequency of predation events over the 14-year period, along with an exponential increase in wolf territories. Predation on livestock occurred throughout the year, yet seasonality of events was evident and differed across livestock categories. Predation on sheep peaked in the fall, coinciding with the post-weaning period of wolf offspring. Predation on cattle peaked in the spring, coinciding with the cattle calving period. These results call for renewed investment in the implementation of prevention methods for all susceptible domestic species, particularly during times of elevated predation risk.Peer Reviewe

Determinants of tick-borne encephalitis in counties of southern Germany, 2001-2008

<p>Abstract</p> <p>Background</p> <p>Tick-borne encephalitis (TBE) virus can cause severe symptoms in humans. The incidence of this vector-borne pathogen in humans is characterised by spatial and temporal heterogeneity. To explain the variation in reported human TBE cases per county in southern Germany, we designed a time-lagged, spatially-explicit model that incorporates ecological, environmental, and climatic factors.</p> <p>Results</p> <p>We fitted a logistic regression model to the annual counts of reported human TBE cases in each of 140 counties over an eight year period. The model controlled for spatial autocorrelation and unexplained temporal variation. The occurrence of human TBE was found to be positively correlated with the proportions of broad-leafed, mixed and coniferous forest cover. An index of forest fragmentation was negatively correlated with TBE incidence, suggesting that infection risk is higher in fragmented landscapes. The results contradict previous evidence regarding the relevance of a specific spring-time temperature regime for TBE epidemiology. Hunting bag data of roe deer (<it>Capreolus capreolus</it>) in the previous year was positively correlated with human TBE incidence, and hunting bag density of red fox (<it>Vulpes vulpes</it>) and red deer (<it>Cervus elaphus</it>) in the previous year were negatively correlated with human TBE incidence.</p> <p>Conclusions</p> <p>Our approach suggests that a combination of landscape and climatic variables as well as host-species dynamics influence TBE infection risk in humans. The model was unable to explain some of the temporal variation, specifically the high counts in 2005 and 2006. Factors such as the exposure of humans to infected ticks and forest rodent population dynamics, for which we have no data, are likely to be explanatory factors. Such information is required to identify the determinants of TBE more reliably. Having records of TBE infection sites at a finer scale would also be necessary.</p

Multiple anthropogenic pressures challenge the effectiveness of protected areas in western Tanzania

This research article was published by John Wiley & Sons, Inc. in 2022Despite being key conservation instruments, the ecological effectiveness of protected areas (PAs) is contested. To assess the ecological effectiveness of PAs in the Katavi-Rukwa Ecosystem (KRE) in western Tanzania, we investigated temporal changes in land-use and population densities of six large mammal target species (elephant, buffalo, giraffe, zebra, topi, and hartebeest) across areas with different conservation category, ranging from unprotected to strictly protected. During six survey periods between 1991 and 2018, we analyzed data from remote sensing and aerial wildlife surveys to derive (i) spatiotemporal patterns of cropland cover in relation to protection category; (ii) population densities of the six-target species; and (iii) distribution of these species across protection category, land-use and environmental variables. During the surveyed period, cropland increased from 3.4 % to 9.6 % on unprotected land and from ≤0.05 % to <1 % on protected land. Wildlife densities of most, but not all target species declined across the entire landscape, yet the onset of the observed wildlife declines occurred several years before the onset of cropland expansion. Logistic regression models indicated that target species preferred the national park over less strictly PAs and areas distant to cropland. As our data do not support a direct link between land-use change and wildlife densities, additional factors may explain the apparent ecosystem-wide decline in wildlife. To bolster wildlife conservation in the KRE, we recommended proactive strategies to reduce direct threats to wildlife and cropland expansion toward wildlife dispersal areas and migratory corridors