Preference for Artificial Refugia over Natural Refugia in an Endangered Fish

The availability of appropriate refugia may ameliorate some impacts of habitat degradation and can aid in the conservation of target species. In addition to natural refugia, the provision of artificial refugia may be viable, particularly in degraded habitats. We examined the conservation potential of natural and artificial refugia for the endangered Eastern Cape redfin, Pseudobarbus afer. We show that deeper water is preferred so is likely to constitute a natural refuge. However, this preference is overridden by the provision of artificial refugia (a plastic pipe). We highlight that the most important habitat factor in the conservation of P. afer is availability of suitable natural refugia through avoidance of habitat destruction. However, when redfin habitat is already compromised, appropriate artificial refugia may supplement the protection provided by natural refugia and may provide benefits to the whole aquatic community.

Ice-Associated Amphipods in a Pan-Arctic Scenario of Declining Sea Ice

Sea-ice macrofauna includes ice amphipods and benthic amphipods, as well as mysids. Amphipods are important components of the sympagic food web, which is fuelled by the production of ice algae. Data on the diversity of sea-ice biota have been collected as a part of scientific expeditions over decades, and here we present a pan-Arctic analysis of data on ice-associated amphipods and mysids assimilated over 35 years (1977–2012). The composition of species differed among the 13 locations around the Arctic, with main differences between basins and shelves and also between communities in drift ice and landfast sea ice. The sea ice has been dramatically reduced in extent and thickness during the recorded period, which has resulted in reduced abundance of ice amphipods as well as benthic amphipods in sea ice from the 1980’s to the 2010’s. The decline mainly involved Gammarus wilkitzkii coinciding with the disappearance of much of the multiyear sea ice, which is an important habitat for this long-lived species. Benthic amphipods were most diverse, and also showed a decline over the time-span. They had higher abundance closer to land where they are associated with landfast ice. However, they also occurred in the Central Arctic Ocean, which is likely related to the origin of sea ice over shallow water and subsequent transport in the transpolar ice drift. Recent sampling in the waters east and north of Svalbard has found continued presence of Apherusa glacialis, but almost no G. wilkitzkii. Monitoring by standardized methods is needed to detect further changes in community composition of ice amphipods related to reductions in sea-ice cover and ice type.

Abundance and use pattern of wildcats of ancient human-modified cattle pastures in northern Iberian Peninsula

The wildcat is typically found in low densities. Here, we estimated wildcat abundance in cattle pastures interspersed between forests in northern Iberian Peninsula, and their patterns of intra-annual and daily use. We censused wildcats three times daily (morning, afternoon, and night) from a car during 4 years in summer season. We also carried out four monthly tracks (two in the morning and two in the afternoon) for a complete year. Overall, we recorded 191 wildcats in pastures and 5 on the road in forest zones. Thirteen different individual wildcats were identified during the summer censuses, but only 29.9% of the wildcats observed (n = 196) could be assigned to an individual wildcat. The number of wildcats sighted decreased especially during the last year, when sightings were 52–67% lower than in previous years. Wildcats were seen significantly more during the morning and night censuses than during the afternoon ones. Estimated annual summer densities in pasture areas ranged between 0.11 and 0.46 sightings/km2. Throughout the year, wildcats were observed 5.9 times more during summer-autumn than during winter-spring, and they could be observed in any time of the day, but more often close to dusk. It is noteworthy that the ancient human-transformed landscapes for cattle pastures could be an important habitat for wildcats in northern Iberian Peninsula, and conserving these areas should be important to maintaining wildcat populations.

Invertebrate Assemblages on Biscogniauxia Sporocarps on Oak Dead Wood: An Observation Aided by Squirrels

Dead wood is an important habitat for both fungi and insects, two enormously diverse groups that contribute to forest biodiversity. Unlike the myriad of studies on fungus–insect relationships, insect communities on ascomycete sporocarps are less explored, particularly for those in hidden habitats such as underneath bark. Here, I present my observations of insect community dynamics on Biscogniauxia spp. on oak dead wood from the early anamorphic stage to matured teleomorph stage, aided by the debarking behaviour of squirrels probably targeting on these fungi. In total, 38 insect taxa were observed on Biscogniauxia spp. from March to November. The community composition was significantly correlated with the presence/absence of Biscogniauxia spp. Additionally, Librodor (Glischrochilus) ipsoides, Laemophloeus submonilis, and Neuroctenus castaneus were frequently recorded and closely associated with Biscogniauxia spp. along its change from anamorph to teleomorph. L. submonilis was positively associated with both the anamorph and teleomorph stages. L. ipsoides and N. castaneus were positively associated with only the teleomorph but not with the anamorph stage. N. castaneus reproduced and was found on Biscogniauxia spp. from June to November. These results suggest that sporocarps of Biscogniauxia spp. are important to these insect taxa, depending on their developmental stage.

Richardson’s ground squirrels (Urocitellus richardsonii) are associated primarily with intermediate levels of grassland, clay loam soils, and human development in Canadian mixed-grass prairies

Richardson’s ground squirrel (Urocitellus richardsonii, Sabine 1822) is a widespread burrowing mammal on the Northern Great Plains. This species is a prominent prey item for a variety of predators, and its burrows provide important habitat for other wildlife; however, Richardson’s ground squirrel is also considered an economically damaging agricultural pest. Despite the ecological importance of Richardson’s ground squirrels and their status as pests, there are gaps in our knowledge about large-scale habitat associations for this species. In 2011 and 2012, we conducted 1840 road-side surveys in a 130,000-km2 area of southern Saskatchewan, Canada to understand which habitat features are associated with Richardson’s ground squirrel occurrence. Ground squirrels were observed on 8% of the surveys. Probability of ground squirrel occurrence was highest in areas with moderate amounts of grassland (approximately 30%), areas that were developed by humans (>30%), and had a high proportion of clay loam soils, presumably for burrowing. Our study highlights the importance of heterogeneous landscapes and that areas disturbed by humans may provide suitable vegetation structure for ground squirrels. This information can help to identify important habitat for species that rely on Richardson’s ground squirrels and identify areas where Richardson’s ground squirrels could come into conflict with agriculture.

Acoustic Monitoring of a Bottlenose Dolphin (Tursiops truncatus) Population: Trends in Presence and Foraging beyond the Limits of the Lower River Shannon SAC

The Shannon dolphins are a population of bottlenose dolphins resident year round within the Lower River Shannon SAC, Ireland, which has been designated to protect this relatively small, genetically discrete population. Although trends in habitat use and foraging have been studied within the estuary, little is known about the movements of the Shannon dolphins outside the boundaries of the SAC, and whether any other foraging hotspots exist for this population outside of the estuary. The purpose of this study was to explore the presence and foraging behavior of these dolphins in adjacent waters located 20–30 km to the southwest of the Lower River Shannon SAC. Static acoustic monitoring was carried out with C-PODs deployed in Ballyheigue Bay, Brandon Bay, and around the Maharees between May and November 2013. A GEE-GLM modelling approach was then used to analyze potential significant environmental predictors of presence and foraging by bottlenose dolphins at these sites. Brandon Bay was found to be a site of particular importance for the Shannon population, where dolphins were present on 92% of days monitored and foraging occurring on 20% of all monitored hours. The results of this study indicate that Brandon Bay is a potentially important habitat for the Shannon dolphins and further support designation of this site as a candidate SAC. However, long-term acoustic monitoring should be conducted at all sites to identify relative use of the areas at year-round and inter-annual scales.

Keanekaragaman Larva Ikan di Sekitar Muara Sungai Musi, Sumatra Selatan

Abstrak Estuari adalah salah satu habitat penting bagi ikan, namun terancam akibat peningkatan aktivitas manusia. Hal tersebut dapat memengaruhi keanekaragaman ikan di sekitarnya. Tujuan penelitian ini untuk menganalisis keanekaragaman dan kelimpahan larva ikan di sekitar muara Sungai Musi Sumatra Selatan. Penelitian ini menggunakan metode survei dengan cruise track design dan lintasan survei continuous parallel pada setiap stasiun secara swept area. Hasil penelitian menunjukkan bahwa indeks keanekaragaman (H’) di muara Sungai Musi pada Maret 2019 sebesar 0,639 sedangkan pada Mei 2019 sebesar 1,253. Kelimpahan relatif pada Maret 2019 lebih tinggi daripada Mei 2019. Kelimpahan Relatif (Kr) pada Maret 2019 antara 0,69–84,61% dan pada Mei 2019 antara 0,21–58,77%. Kelimpahan larva ikan yang ditemukan pada Mei lebih tinggi, yaitu sebanyak 456 individu dari 10 famili. Pada Maret ditemukan lebih rendah, yaitu sebanyak 143 individu dari 6 famili. Ditemukan larva ikan dari famili Engraulidae, Belonidae, Osphronemidae, Nemipteridae, Gerreidae, dan Gobiidae pada Maret. Sedangkan pada Mei 2019, yaitu Nemipteridae, Engraulidae, Scatophagidae, Chandidae, Lobotidae, Terapoinidae, Belonidae, Osphronemidae, Chanidae, Clupeidae. Abstract Estuary is one of important habitat for fish, yet is threatened by an increase in human activities. Thus affecting the diversity of fish around it. This study aim to determine the diversity and abundance of fish larvae around the mouth of Musi River in South Sumatra. This study was conducted using survey method with Cruise Track Design and continuous parallel survey track by swept area at each station. The results showed that the diversity index (H ') at the mouth of the Musi River in March 2019 was 0.639 while in May 2019 was 1.253. Relative Abundance (Kr) in March 2019 between 0.69–84.61% and in May 2019 between 0.21–58.77%. Abundance of fish larvae in May was found higher at 456 individuals from 10 families. Whereas in March it was found to be lower as many as 143 individuals from 6 families. The relative abundance in March 2019 was lower than in May. Fish larvae from the Engraulidae, Belonidae, Osphronemidae, Nemipteridae, Gerreidae and Gobiidae families were found in March. Whereas in May 2019 were Nemipteridae, Engraulidae, Scatophagidae, Chandidae, Lobotidae, Terapoinidae, Belonidae, Osphronemidae, Chanidae, Clupeidae.

Integration of Constructed Floodplain Ponds into Nature-Like Fish Passes Supports Fish Diversity in a Heavily Modified Water Body

Fish passes facilitate fish movement in fragmented river systems, yet they can also provide important habitat functions. This study investigated the fish community composition of different constructed habitat types (fluvial habitats, floodplain ponds) within fish passes in relation to habitat characteristics in order to deduce recommendations for fish-friendly designs of such structures. Fish community structures within passes differed significantly from those in the main river, comprising a high number of rheophilic species in fluvial habitats (Thymallus thymallus, Hucho hucho, Salmo trutta, Cottus gobio, Chondrostoma nasus, and Barbus barbus), and of stagnophilic species in floodplain ponds (Rhodeus amarus, Scardinius erythrophthalmus, Misgurnus bipartitus, and Tinca tinca). During summer, floodplain ponds also provided important juvenile habitats for the target species C. nasus and B. barbus. Differences between the two habitat types in fish abundance were mostly explained by differences in macrophyte coverage, gravel, boulders, temperature, and current speed. The findings of this study stress the important habitat functions of fish passes. They also suggest that integration of diverse habitat structures, especially of currently hardly considered constructed floodplain ponds into fish passes, can greatly enhance their fish communities and contribute to the restoration of several declining target species of conservation.

Plant species occupy different habitats on the fortress walls in Elbasan, Albania

Vegetated walls are an important habitat for urban biodiversity. We conducted an analysis of the plant species that grow on the Elbasan, Albania fortress walls. Walls vary in age from 4th to 21st century, and in composition. On 71 walls we assessed 2787 plants of 35 species and recorded plant size, presence of flowers or fruits, height from the ground, crevice depth, wall aspect, wall age and composition, and distance to nearest opposing wall. Eleven species, two of which were ferns, composed 93.8% of the plants. The vast majority of plants flowered and fruited on the walls. Plant density ranged from 0.1–70 plants/m2. Species distributions varied significantly based on height on the wall, crevice depth, aspect and distance to the opposing wall. These differences may be influenced by dispersal mechanisms, moisture, substrate composition, and other important environmental factors. For example, Antirrhinum majus was generally found high on south facing walls in deep cracks whereas Umbilicus rupestris was found lower on north facing walls in shallower cracks. It is important that older walls colonized by plants be maintained such that a native flora can persist where natural rocky features are lacking.