Frontiers in Ecology and the Environment最新文献

Climate change is a well-documented driver and threat multiplier of infectious disease in wildlife populations. However, wildlife disease management and climate-change adaptation have largely operated in isolation. To improve conservation outcomes, we consider the role of climate adaptation in initiating or exacerbating the transmission and spread of wildlife disease and the deleterious effects thereof, as illustrated through several case studies. We offer insights into best practices for disease-smart adaptation, including a checklist of key factors for assessing disease risks early in the climate adaptation process. By assessing risk, incorporating uncertainty, planning for change, and monitoring outcomes, natural resource managers and conservation practitioners can better prepare for and respond to wildlife disease threats in a changing climate.

Wildflower plantings are an effective tool for mitigating floral resource scarcity, a major factor contributing to global declines in pollinator populations. However, the configuration of seed mixes for such plantings can encompass two different conservation goals: namely, the enhancement of a regulating ecosystem service (pollination) or the promotion of diverse pollinator communities, including rare or threatened species. According to which goal is prioritized, seed mixes consequently require different designs and implementation approaches. Here, we review common elements of wildflower seed mixes for native bees and highlight differences in application between the two conservation goals. Our focus on bees stems from agreement among different world regions to their functional value as pollinators and concern about recent global declines in their populations. We link the ecology of seed mixes with current challenges in US and EU policies supporting seed mix implementation. Finally, we advocate not only for clarity in goal setting, which will promote tailored seed mix design and application, but also for a reimagination of seed mix policies to increase their effectiveness for pollinator conservation.

When an animal is observed visiting a flower, we tend to think of it as a mutualistic interaction, in which both participants benefit to some degree. However, not all such interactions are mutualisms, as in instances where one partner (the animal) benefits at the expense of the other partner (the plant). In pollination ecology, the lopsided beneficiaries of interactions like these are called nectar “robbers” or “thieves”. This seems to be the case for the bananaquit (Coereba flaveola), a member of the tanager family, seen here in a backyard in the city of Campinas, São Paulo, Brazil, consuming nectar from immature non-native Ixora flowers. Although bananaquits occasionally pierce mature flowers from the side to rob nectar (Sci Rep 2022; doi.org/10.1038/s41598-022-16237-9), the bird pictured here is mechanically opening a closed immature flower with its beak to access the nectar. Does the premature opening of a flower affect its development and the plant's reproductive success? Here, the bananaquit could be considered a nectar thief because of the temporal mismatch, given that the flower's pollen is unavailable or nonviable. Has this behavior spread through the local population of bananaquits, and how did it emerge? Is it a learned behavior by the bananaquit having observed a conspecific or else a different species? Is it a spontaneous behavior that arose independently in certain individuals? Physically opening an immature flower might represent a previously undocumented form of thieving. Further investigations are necessary to determine the relative gains and losses associated with this type of animal–plant interaction.

Natal dens can be a limiting resource for canids on the Arctic tundra, as frozen ground inhibits easy burrow excavation during the spring. Near Churchill, Canada, tundra dens created by Arctic foxes (Vulpes lagopus) have transformed into ecological hotspots (Sci Rep 2016; doi.org/10.1038/srep24020). However, while monitoring these dens for many years, we have observed that both red foxes (Vulpes vulpes) and gray wolves (Canis lupus) are also competing for these sites.

In spring 2021, one den became the site of a fierce canid competition. The den figuratively switched “paws” between both fox species, first being occupied by a pair of red foxes from March through mid-April, then by a pair of Arctic foxes in May. But the return of a red fox in early June led to antagonism between the two fox species, pictured here. Simultaneously, during the volatile period of occupation by one or the other fox species, wolves regularly visited this den, with at least seven visits documented from mid-May to mid-June. On the day that the wolf photograph was captured, all three canid species were observed on camera at the same den within 6 hours of each other. Eventually, the red fox was the last observed canid using the den, despite aggressive defenses from the Arctic fox pair.

Arctic fox abundance in this area has declined steadily for several decades, largely due to climate-induced changes in prey availability and abundance (Oecologia 2023; doi.org/10.1007/s00442-023-05418-6). As climate change progresses, what will be the long-term fate of these Arctic fox–created hotspots? Antagonistic interactions like those pictured here may foreshadow a slow turnover of Arctic fox dens toward occupation by larger, more dominant competitors typically associated with patches of boreal forest at the low-Arctic tundra border.

Despite the expansive old-growth forests of California's Sierra Nevada, its greatest diversity of butterflies is found in non-forested habitats, such as alpine meadows and fell-fields. These unique “sky island” habitats support a number of endemic butterflies, such as the Ivallda Arctic (Oeneis chryxus ivallda). Unlike other, more colorful butterflies in the region, the dark, cryptic coloration of O c ivallda is hypothesized to aid in both thermoregulation and camouflage in the relatively cool, rocky environments they inhabit. Faced with warming temperatures, some alpine butterfly populations may track their climatic niche and stay ahead of advancing treelines by moving up mountain slopes. However, many O c ivallda populations already occur at or near mountain summits, limiting their potential for elevational shifts. On 2 July 2022, we observed a previously unrecorded O c ivallda population at the summit of Mount Whitney (4421 m). Popular data repositories (eg GBIF and iNaturalist) confirmed that no other butterflies have been observed here. Mount Whitney is the highest mountain in the conterminous US, and all higher summits in Canada and Alaska are—at least for the moment—permanently snow- or glacier-covered, unsuitable for butterfly occupancy. This observation therefore marks what we believe is the highest extant butterfly population in North America. Of the 12 O c ivallda individuals observed during a one-hour survey, three were collected for whole-genome resequencing as part of the California Conservation Genomics Project (CCGP; https://www.ccgproject.org/). Two individuals are pictured, one from the summit of Mount Whitney (above) and the other from the summit of Mount Dana (3981 m; below), approximately 170 km to the northwest of Whitney. In light of this observation, alpine butterflies in the Sierra Nevada are clearly exhausting their potential for elevational shifts in the face of warming temperatures. Preventing extinction may require proactive conservation practices, such as translocation and even assisted migration. Detailed population genomic data, such as those produced by the CCGP, will help inform these efforts.

This Cape buffalo (Syncerus caffer) skull was found in Kruger National Park, South Africa. The distinctive projections on its horns are tubes made of silk and frass (excrement) created by larvae of the horn moth Ceratophaga vastella (family Tineidae).

An adult moth oviposits on the horn, perhaps placing its eggs in small cracks or holes on the horn's outer surface. Upon hatching, a larva begins to consume the horn, incorporating its frass into an enveloping tube. Eventually, the larva will pupate inside the tube, from which it will later emerge as an adult. Tubes with closed ends are occupied by individual larvae or pupae, while tubes with open ends are unoccupied. The exuviae (casts) of previously emerged moths might be seen protruding from a subset of the open-ended tubes.

Keratinophagy, the consumption of keratin as a substantial portion of the diet, is rare (New Zeal J Zool 2002; doi.org/10.1080/03014223.2002.9518285). Ceratophaga are the only tineids that feed exclusively on keratin. The tubes may protect subadults from predators and the physical environment. It would be interesting to learn how the larvae—inside their respective tubes—maintain their water balance, and what role the tubes play in that process. Because keratin is nitrogen-rich, horn consumption and processing by larvae could have important implications for nitrogen cycling and soil microbe communities at local scales.

These tubes have been documented on the horns of other bovids, such as the kob antelope (Kobus kob). Nevertheless, the output from an online image search suggests that there is a strong preference for horns of the Cape buffalo. If there is indeed such a predilection, might it be due to the relative thickness of the buffalo's horn sheath? Both the number of tubes per horn and the length of individual tubes vary, though the reasons for such differences are not understood. Relatedly, we have not found evidence of these larvae feeding on the keratin in hooves. Many questions arise in trying to understand these moths and their curious tubes.