Road proximity and traffic flow perceived as potential predation risks: evidence from the Tibetan antelope

Abstract Context. The risk-disturbance hypothesis predicts that animals exhibit risk-avoidance behaviours when exposed to human disturbance because they perceive the disturbance as a predatory threat. Aims. This study aimed to examine whether Tibetan antelopes (Pantholops hodgsoni) exhibit risk-avoidance behaviour with proximity to a major highway and with increasing traffic flow consistent with the risk-disturbance hypothesis. Methods. Focal-animal sampling was used to observe the behaviour of Tibetan antelopes. The behaviours were categorised as foraging, vigilance, resting, moving, or other. The time, frequency, and duration of foraging and vigilance were calculated. Key results. As distance from the road increased, time spent foraging and foraging duration increased while foraging frequency, time spent being vigilant and vigilance frequency decreased, indicating that there is a risk perception associated with roads. Tibetan antelopes presented more risk-avoidance behaviours during high-traffic periods compared with lowtraffic periods. Conclusions. Tibetan antelopes exhibited risk-avoidance behaviour towards roads that varied with proximity and traffic levels, which is consistent with the risk-disturbance hypothesis. Implications. The consequences of risk-avoidance behaviour should be reflected in wildlife management by considering human disturbance and road design

The functional response of a generalist predator

Peer reviewedPublisher PD

Variation in social systems of fallow deer

The thesis investigates intraspecific variation in grouping patterns and mating systems in free-ranging populations of fallow deer Dama dama inhabiting two distinct environments. The New Forest in southern England consists of large continuous woodlands adjacent to large areas of heathland and grassland. The southern English agricultural landscape is typified by small, discontinuous woodlands interspersed with pasture and arable crops. Fallow populations occur at a range of densities in both environmental types. Despite occurring in environments markedly different in habitat composition and structure, habitat use patterns showed great similarity between sites in terms of utilization of woodland and open habitats. In all study sites, deer predominantly utilized woodlands. Differences between the two main environmental types were more pronounced in respect of population characteristics. Densities were much higher in the New Forest populations, and there was considerable variation in sex ratio within and between environmental categories. These two characteristics appeared to influence the extent of winter and spring sexual segregation exhibited by the populations. Males joined female groups when male numbers were low. In the New Forest, mixed-sex groups were the result of temporary aggregations of females and young males. In contrast, mixed-sex groups in the agricultural sites contained males of all ages. The size of social groups was strongly influenced by season, habitat openness, habitat structure and population density. A common seasonal pattern existed across all sites, with female groups largest in winter and spring, decreasing during parturition in early summer, and increasing again during the autumn rut. Male group size was smallest during the rut and varied little throughout the year. In common with most ungulates, fallow group size was largest in open habitats. Between different populations, variation in the extent of group size between woodland and open habitats may have been influenced by habitat structure and population density. High density populations inhabiting large continuous woodlands were characterised by small groups in woodland and large groups in open habitats. In contrast, in low density populations inhabiting small discontinuous woodlands group size was less variable. The flexibility in fallow grouping patterns was matched by the variation in mating systems. Males adopted a range of mating strategies which could be broadly classified according to the degree and type of territoriality during the autumn rut. In the low density agricultural populations, male territoriality was reduced and males followed groups of females throughout their range. In the higher density New Forest populations a variety of male mating strategies existed including leks, multiple stands, single territories, temporary territories, and non-territorial following. Increased territoriality and the development of multiple territory mating systems was associated with an increase in male and female density. Lekking may be initiated by locally high densites of females aggregating near favoured feeding resources. In one population in the New Forest, lekking occurred as an alternative strategy to single territory defence and non-territorial following. In this population, copulatory success was highest on the lek, but unsuccessful lek males achieved less copulations than some single territory males away from the lek.</p

Can parasites drive population cycles in mountain hares?

Understanding the drivers of population fluctuations is a central goal of ecology. Although well-established theory suggests that parasites can drive cyclic population fluctuations in their hosts, field evidence is lacking. Theory predicts that a parasite that loosely aggregates in the host population and has stronger impact on host fecundity than survival should induce cycling. The helminth Trichostrongylus retortaeformis in the UK's only native lagomorph, the mountain hare, has exactly these properties, and the hares exhibit strong population fluctuations. Here we use a host–parasite model parametrized using the available empirical data to test this superficial concordance between theory and observation. In fact, through an innovative combination of sensitivity and stability analyses, we show that hare population cycles do not seem to be driven by the parasite. Potential limitations in our parametrization and model formulation, together with the possible secondary roles for parasites in determining hare demography, are discussed. Improving our knowledge of leveret biology and the quantification of harvesting emerge as future research priorities. With the growing concern over the present management of mountain hares for disease control in Scotland, understanding their population drivers is an important prerequisite for the effective management of this species

Appendix A. Measures of goodness-of-fit for wildebeest pathways from eight objective functions averaged for multiple-resolution comparisons from 5 to 50 km square blocks.

Measures of goodness-of-fit for wildebeest pathways from eight objective functions averaged for multiple-resolution comparisons from 5 to 50 km square blocks

Parental differences in brood provisioning by Hen Harriers Circus cyaneus

Aims To quantify how parents balance the needs of their offspring for food and protection. Methods We studied 13 nests from hides and spent on average 101 hours per nest monitoring prey types, provisioning rate and the time spent at the nest by both sexes in relation to brood size and brood age. Results Males always provided more food than females. Males brought similar amounts of prey items irrespective of brood size and nestling age, whereas females brought more prey and bigger items to larger and older broods. Females spent less time brooding larger broods, particularly early on. Conclusions Hen Harrier parents share the provisioning burden, with each parent delivering prey as a function of brood care requirements, hunting capability and the behaviour of the other parent

Using PIT-tag technology to target supplementary feeding studies

Szakdolgozatunkban a Sprego – Spreadsheet Lego – informatika tantervbe történő beillesztésének lehetőségét emeltük ki, mivel úgy gondoljuk, hogy ez egy remek alternatívát nyújt a tanulók gondolkodásának, algoritmizálási képességének fejlesztésére. A szakdolgozatunk több részből tevődik össze, melyben elsőként bemutatjuk a Sprego módszert, a táblázatkezelő általános célú függvényeire épülő programozási megközelítést. A tanulók e módszer segítségével tizenkét darab függvény ismerete és alkalmazása által táblázatkezelői keretek között bármilyen felmerülő problémát könnyedén megoldhatnak. Egyik legfőbb jellemzője, hogy nem verziófüggő, így ennek köszönhetően bármilyen táblázatkezelő szoftver használata során működik, legyen az Microsoft Excel, OpenOffice, vagy akár LibreOffice. Emellett részletezzük az informatika oktatását szabályozó tanterveket is és egy általunk készített táblázatkezelési tanmenetet mutatunk be. Végül pedig megállapításunkat igazolva készítettünk néhány, a tanulók számára motiváló, valós adatot tartalmazó feladatot, amelyek segítségével prezentáljuk a módszer működését.MSc/MAInformatika és könyvtárpedagógia taná

Compensating for the costs of polygyny in hen harriers (Circus cyaneus)

In polygynous species, the adults are faced with a dilemma during chick rearing. Males must decide how to distribute food between their females and food allocation patterns are often highly unequal. In turn, the females that receive less food from males have to decide how much time to invest in additional hunting. If they spend more time hunting, then they leave their young exposed to weather and predators. However, if they stay at the nest, they increase the risk of their chicks starving. One way that birds may compensate for reduced provisioning is by increasing the size of prey caught. We tested this hypothesis by comparing prey deliveries to nests of hen harriers, Circus cyaneus, with females of different breeding status. As expected, male harriers delivered less food items to the nests of polygynous females, and especially their secondary, or β females. However, both sexes were able to compensate by delivering larger items and there was no difference in the overall mass of food delivered to nests. Moreover, females spent a similar amount of time at the nest, irrespective of status, and there were no overall differences in breeding success. Our results show that polygynous female harriers can compensate for the costs of polygyny, but we suggest that their ability to do so will vary according to the abundance of both large prey and predator

Appendix B. Locations on the 15th of each month of wildebeest simulated in the evolutionary stage for models influenced by rainfall and new vegetation growth, as reflected in NDVI.

Locations on the 15th of each month of wildebeest simulated in the evolutionary stage for models influenced by rainfall and new vegetation growth, as reflected in NDVI