The effect of livestock on the physiological condition of roe deer (Capreolus capreolus) is modulated by habitat quality

Helminth-host-environment interactions: Looking down from the tip of the iceberg

In 1978, the theory behind helminth parasites having the potential to regulate the abundance of their host populations was formalized based on the understanding that those helminth macroparasites that reduce survival or fecundity of the infected host population would be among the forces limiting unregulated host population growth. Now, 45 years later, a phenomenal breadth of factors that directly or indirectly affect the host-helminth interaction has emerged. Based largely on publications from the past 5 years, this review explores the host-helminth interaction from three lenses: the perspective of the helminth, the host, and the environment. What biotic and abiotic as well as social and intrinsic host factors affect helminths? What are the negative, and positive, implications for host populations and communities? What are the larger-scale implications of the host-helminth dynamic on the environment, and what evidence do we have that human-induced environmental change will modify this dynamic? The overwhelming message is that context is everything. Our understanding of second-, third-, and fourth-level interactions is extremely limited, and we are far from drawing generalizations about the myriad of microbe-helminth-host interactions.Yet the intricate, co-evolved balance and complexity of these interactions may provide a level of resilience in the face of global environmental change. Hopefully, this albeit limited compilation of recent research will spark new interdisciplinary studies, and application of the One Health approach to all helminth systems will generate new and testable conceptual frameworks that encompass our understanding of the host-helminth-environment triad.

Season-dependent impact of forage quality on stress in alpine chamois

Chronically heightened stress levels in wildlife species may have detrimental effects on individual life history traits, for example, through the increased likelihood of disease, parasitic infections, and overall reduced fitness. Understanding the drivers of stress may thus have great potential for informing wildlife conservation. Although the role of climate and individual status is well studied in stress ecology, the impact of related stressors such as dietary quality is of increasing interest to wildlife research and conservation. In this study, fecal cortisol metabolites (FCMs) in Alpine chamois Rupicapra r. rupicapra used as bioindicators of stress, and their relationship with forage quality-measured as the percentage of fecal crude protein (CP)-were investigated. Data collection took place in 2011 and 2012 in the Gran Paradiso National Park (Western Italian Alps), on 22 individually marked adult males. The relationship between FCMs and CPs was analyzed through linear models and separated between winter and summer months, accounting for the effect of potentially confounding exogenous and endogenous variables. After AICc-based model selection, we found that forage quality was negatively related to FCM levels in Alpine chamois during the summer months, meaning that higher quality forage was associated with the decreased expression of stress hormones. However, during the winter months, we did not find a significant relationship, potentially as a result of forage quality being ubiquitously poor. Although the mechanisms through which dietary variations impact FCM concentrations in wildlife populations are largely unknown, the occurrence of significant relationships between forage quality and stress levels supports potentially important implications for the long-term effect of climatic changes on the fitness of wildlife populations.

Spatiotemporal Analysis of the Coupling Relationship between Habitat Quality and Urbanization in the Lower Yellow River

Natural habitats are damaged by human interference to varying degrees during the urbanization process, which can impede a region's high-quality development. In this study, we examined the spatial-temporal evolution characteristics of habitat quality and urbanization in the Lower Yellow River from 2000 to 2020 using the integrated valuation of ecosystem services and tradeoffs (InVEST) model and the comprehensive indicator method. We also evaluated the coupling relationship between the habitat quality and urbanization using the coupling coordination degree model. The findings indicate the following aspects: (1) Between 2000 and 2020, the Lower Yellow River's habitat quality was typically mediocre, with a steady declining trend. The majority of cities displayed a trend toward declining habitat quality. (2) Both the urbanization subsystem and the urbanization level in 34 cities have demonstrated a consistent growth tendency. The urbanization level is most affected by economic urbanization among the subsystems. (3) The coupling coordination degree have revealed an ongoing trend of growth. In most cities, the relationship between habitat quality and urbanization has been evolving toward coordination. The results of this study have some reference value for ameliorating the habitat quality of the Lower Yellow River and solving the coupling coordination relationship between habitat quality and urbanization.

Free-ranging livestock altered the spatiotemporal behavior of the endangered North Chinese leopard (Panthera pardus japonensis) and its prey and intensified human-leopard conflicts

Widespread distribution of livestock in the natural habitats of large carnivores may negatively impact carnivore populations by reducing wild prey availability and increasing human-carnivore conflicts. In this study, we used camera-trapping data collected in the temperate forests of the Taihang Mountains in North China during 2016-2019 to examine whether and how free-ranging cattle affected habitat use and Diel activity patterns of the endangered North Chinese leopard (Panthera pardus japonensis) and its 2 wild prey species, Siberian roe deer (Capreolus pygargus), and wild boar (Sus scrofa). Residents were also interviewed to record livestock depredation events by leopards during 2015-2019. We found that roe deer spatially avoided sites frequented by cattle, but wild boar did not. In the growing seasons, leopards shared habitats with cattle and tended to increase their diurnal activities where cattle were present. All 3 study species exhibited fine-scale spatial-temporal segregation to cattle. Leopards selectively preyed on calves over adult cattle and livestock depredation frequency was positively correlated with the detection rates of cattle and wild prey, but not that of leopard. These findings not only show that through behavioral adaption large carnivores and their ungulate prey may persist under livestock disturbance, but also highlight how important proper livestock management is for conserving North Chinese leopards in this region. To enhance livestock management and mitigate human-leopard conflicts, we recommend specific actions, such as better guarding of free-ranging cattle or adoption of a captive farming system.

Non-native Nematode Ashworthius sidemi Currently Dominates the Abomasal Parasite Community of Cervid Hosts in the Czech Republic

Ashworthius sidemi is an abomasal nematode typical for Asiatic cervids such as sambar (Rusa unicolor) or sika deer (Cervus nippon). This non-native parasite was introduced into Europe via sika deer in the late 19th and early 20th centuries. The current dynamic spread of this parasite amongst autochthonous wild cervids occurs independently of human activities, and A. sidemi has a negative impact on the health of wild ruminants and may pose a threat to the conservation of endangered wild ungulates and to livestock. This invasive parasite has been previously detected in the Czech Republic, but more accurate information on A. sidemi is required. Only limited information is generally available on the factors influencing the spread of abomasal nematodes in wild ruminants, so more information is necessary for planning effective strategies of parasite control. We therefore conducted a survey on the abomasal nematodes in cervids in both game reserves and hunting grounds across the Czech Republic, taking into account the hosts (species, age, sex) and environmental factors (monthly average temperature). The abomasa of 104 animals belonging to five cervid species originating from various locations of the country were collected. Data on host (species, sex, and age group) and the monthly average temperature in the region were obtained for each animal. The parasitological analyses indicated that 92% of the abomasa were infected by nematodes. Ashworthius sidemi was the most prevalent (72%) and abundant (80% of the total recovered individuals) nematode species and was detected in all cervid species except white-tailed deer. The intensity of A. sidemi was highest in roe deer (Capreolus capreolus) and fallow deer (Dama dama), but A. sidemi abundance did not depend substantially on the host or environmental factors. In contrast, the abundance of nematodes from the subfamily Ostertagiinae was influenced by the host species and temperature. Parasitic load was significantly higher in roe deer and during the warmer periods of the survey. We also detected another non-native nematode species, Spiculopteragia houdemeri. The results of our study suggest that the non-native nematode A. sidemi is now widespread amongst cervid hosts in the Czech Republic, probably due to the high sensitivity of autochthonous cervids to A. sidemi infections as well as adaptation of this parasite to the current climatic conditions of this country.

Spatiotemporal Variation and Influence Factors of Habitat Quality in Loess Hilly and Gully Area of Yellow River Basin: A Case Study of Liulin County, China

China has set up ecological protection and high-quality development of the Yellow River Basin as its national strategy. However, the fragile natural ecosystem and intensive human disturbances pose challenges to it. This study evaluates habitat quality change and analyzes its drivers in a representative county of this region, aiming to provide scientific basis for ecological protection and sustainable development. We took Liulin, a representative county of middle Yellow River Basin as the study area and evaluated the spatiotemporal variation of habitat quality from 2000 to 2020 with the InVEST model. Further, the influencing factors of habitat quality pattern were explored using GeoDetector, and their gradient ranges dominating the habitat quality change were determined by gradient analysis. The results showed that: (1) Areas of low and medium-low habitat quality grades were distributed interactively in the whole county; medium grade areas were scattered in the northeast and southwest parts of the county; and medium-high and high grades area were distributed sporadically along the Yellow River and its branches. (2) Habitat quality of the county almost unchanged from 2000 to 2010. However, from 2010 to 2020, with the rapid expansion of construction land (increased by 9.62 times), the area proportion of medium, medium-high, and high habitat quality grades decreased from 7.01% to 5.31%, while that of low and medium-low habitat quality grades increased from 92.99% to 94.69%. (3) The habitat quality was influenced by multiple natural-human factors. The main influencing factor was land use, followed by elevation. (4) Most changes of habitat quality occurred in areas with lower elevation, gentler slope, and higher vegetation coverage, which were affected by intensive human activities. These results suggest that in future land use policy making and the construction land expansion in Liulin County should be restricted, and differentiated ecological protection and restoration strategies should be implemented in areas with different habitat quality.

Effect of intensity and duration of anthropic noises on European mink locomotor activity and fecal cortisol metabolite levels

Human activities involving noise emission can affect wild animals. European mink was exposed to road noise and human voice playbacks to analyze how sound intensity level and duration of both noises altered the time that individuals were active and if their fecal cortisol metabolite (FCM) levels varied. A Hierarchical Analysis Cluster was performed to establish 2 mink groups with respect to both noise source type: short duration/low intensity (SL) and long duration/high intensity (LH). We performed general linear mixed models to evaluate the variation in locomotor activity duration (s) and FCM (nanogram per gram) levels, respectively. The results showed both road noise and human voices decreased locomotor activity duration in SL more sharply compared with LH, and human voices were the triggers that induced the most pronounced response to both exposure conditions. FCM (ng/g) levels increased in SL compared with LH during road noise while the opposite happened during human voices. Differences based on sex and age of individuals were observed. In conclusion, noise characteristics given by the sound type determined the variations in locomotor activity duration while noise exposure level determined the variations in FCM (ng/g) levels. Attention should be paid to noisy activities (e.g., recreational activities for visitors in protected natural areas) and loud groups of people to conserve wildlife, especially noise sensitive species.

Spatiotemporal effects of urban sprawl on habitat quality in the Pearl River Delta from 1990 to 2018

Since the implementation of the Chinese economic reforms. The habitat quality of coastal has gradually deteriorated with economic development, but the concept of "ecological construction" has slowed the negative trend. For quantitative analysis of the correlation between the Pearl River Delta urban expansion and changes in habitat quality under the influence of the policy, we first analyzed the habitat quality change based on the InVEST model and then measured the impact of construction land expansion on the habitat quality through habitat quality change index (HQCI) and contribution index (CI) indicators. Finally, the correlation between urbanization level and habitat quality was evaluated using geographically weighted regression (GWR) and the Self-organizing feature mapping neural network (SOFM). The results indicated that: (1) during the study period from 2000 to 2020, habitat quality declined due to urban sprawl, indicating a deterioration of ecological structure and function, and the decrease was most significant from 2000 to 2010. (2) The urbanization index had a negative effect on the habitat quality, but the negative effect have improved after 2000, reflecting the positive effect of policies such as "ecological civilization construction" (3) The implementation degree of ecological civilization varies greatly among cities in the study area: Shenzhen, Dongguan, Foshan, and Zhongshan have the best level of green development. These results reflect the positive role of policies in the prevention of damage to habitat quality caused by economic development and provide a reference for the formulation of sustainable urban development policies with spatial differences.

The spatio-temporal co-occurrence of free-ranging common fallow deer and domestic caprines on the island of Rhodes, Greece

The Dama dama dama population of the island of Rhodes has an important conservation significance because of its unique genetic characters. Currently, many are the factors that threaten its survival. Aim of this paper is to provide the first data on the spatio-temporal co-occurrence between the only free-ranging Greek population of common fallow deer and local domestic caprines. Kilometric abundance index (KAI) was derived from spotlight counts. The unattended domestic caprines appear to impact on fallow deer, in particular during fawning season. Livestock monitoring over time can act as a proxy indicator of the status of this deer population.

Social environment modulates investment in sex trait versus lifespan: red deer produce bigger antlers when facing more rivalry

Theory predicts that the plastic expression of sex-traits should be modulated not only by their production costs but also by the benefits derived from the presence of rivals and mates, yet there is a paucity of evidence for an adaptive response of sex-trait expression to social environment. We studied antler size, a costly and plastic sex trait, and tooth wear, a trait related to food intake and longevity, in over 4,000 male Iberian red deer (Cervus elaphus hispanicus) from 56 wild populations characterized by two contrasting management practices that affect male age structure and adult sex-ratio. As a consequence, these populations exhibit high and low levels of male-male competition for mating opportunities. We hypothesized that males under conditions of low intra-sexual competition would develop smaller antlers, after controlling for body size and age, than males under conditions of high intra-sexual competition, thus reducing energy demands (i.e. reducing intake and food comminution), and as a consequence, leading to less tooth wear and a concomitant longer potential lifespan. Our results supported these predictions. To reject possible uncontrolled factors that may have occurred in the wild populations, we carried out an experimental design on red deer in captivity, placing males in separate plots with females or with rival males during the period of antler growth. Males living with rivals grew larger antlers than males living in a female environment, which corroborates the results found in the wild populations. As far as we know, these results show, for the first time, the modulation of a sexual trait and its costs on longevity conditional upon the level of intra-sexual competition.

Testosterone and the dark ventral patch of male red deer: the role of the social environment

The expression of male sexual traits, which is stimulated by testosterone, entails significant costs for individuals. Consequently, natural selection is expected to favour the modulation of sexual trait development according to the balance between its costs and benefits. The proportion of rivals in a population may affect this balance by increasing or decreasing the reproductive benefits associated with the development of sex traits. Here, we explore the relationship between testosterone level and sex trait size under two populational conditions of mate competition: fenced (i.e. high male-male competition; all male age groups are present) and unfenced (i.e. low competition; most males present are juveniles). Our model species is the Iberian red deer (Cervus elaphus hispanicus), and the sex trait is the dark ventral patch that males exhibit during the rutting season. Our results showed that the positive relationship between testosterone levels and the size of the dark ventral patch depends on the environmental level of male-male competition. Only in populations where the operational sex ratio was high (i.e. high proportion of rival males), individuals with high levels of testosterone developed the sex trait. Conversely, when mate competition was low, there was no significant relationship between testosterone level and trait size. This result reinforces the idea that the effect of testosterone in promoting the development of sex traits may be mediated by the intensity of mate competition in the population, as well as the role of sexual selection in the evolution of the dark ventral patch in red deer.