Effectiveness of using nest boxes as a form of bird protection after building modernization

Modernization of urban buildings can decrease the availability of nesting sites in buildings, leading to sudden decreases in the density of avifauna. In this study, we investigated the use of nest boxes as a bird conservation measure after buildings were thermally modernized. In a 10 ha experimental area we mounted five types of nest boxes of different sizes and dimensions (a total of 132). Nest boxes were dedicated to species that lost access to their previous nesting sites. All species associated with the buildings significantly declined or disappeared. In the first year after the modernization, the House Sparrow (Passer domesticus) decreased by 66% compared with the period before the modernization, Eurasian Jackdaw (Corvus monedula) by 68%, Common Starling (Sturnus vulgaris) by 70%, and Common Swift (Apus apus) by 100%. In the first two years after the modernization, the birds nested only in nest boxes. Five years of monitoring showed that using nest boxes as compensation for bird nesting sites lost during the renovation of buildings can cause a population to recover to ca. 50% of its original level. To optimize deployments of nest boxes, wildlife managers should consider target species’ preferences for the dimensions and placement of boxes and limit the time boxes are used if a species prefers nesting outside nest-boxes, but in buildings (e. g. the House Sparrow) and does not require additional support.

Settling in: Reintroduced Persian Fallow Deer Adjust the Borders and Habitats of Their Home-Range During the First 5 Years Post Release

Translocated animals typically find themselves in a novel environment in which they must establish a home range in a manner that will maximize their fitness. We hypothesized that the initial establishment of a home range is followed by adjustments expressed as home range shifting, and occurs as familiarity with the landscape increases, until the home range is stabilized. We studied the process of home range shifting in 42 female Persian fallow deer (Dama mesopotamica) reintroduced into the Galilee, Israel over a period of 2–5 years. We used changes in the degree of home range overlap between consecutive years as an indicator of stabilization. We then compared how the mean percent cover of the key vegetation types (woodland, scrubland and open pastures) differed between the areas abandoned in the first year's home range and the areas added to the last year's home range relative to the first (using a weighted paired t-test). We also compared the distribution (using χ2 test of independence and Levene's test for homogeneity of variance) of %cover of the 3 vegetation types between the first and last year's home range. The average home range overlap increased over the 5 years following the first release. During the first-year post release, deer avoided open pastures and preferred woodland. In later years deer increase in the % open pastures (weighted t-test: p < 0.001) and decreased the % woodland cover (weighted t-test: p = 0.07) by abandoning areas with little open pasture and steeper terrain and moving into areas with more open pasture and moderate terrain. Variance of the cover types across individuals increased with time. We conclude that the home ranges of the reintroduced deer stabilized with time. The changes in vegetation and slope are driven by time-dependent changing needs reflecting a tradeoff between safety (refuge) and foraging. Our findings suggest that using the initially established home range to determine species preferences can create a misleading picture of what the optimal home range of the species really is. Individual variation in term of preferences can take a few years to be expressed due to the initial high-risk perceived by individuals in a novel environment.

TREE SPECIES CULTIVATION ON SUBSISTENCE AGRICULTURAL FIELDS IN NORTHWESTERN ETHIOPIA

The study was intended to identify species preferences, the relationship between livelihood status and tree planting, and the major tree growing patterns of smallholder subsistence farmers in rural Ethiopia. Data was collected through household interviews and the total enumeration of all tree species on respondents’ landholdings. A total of 23 tree species were recorded integrated within the farming landscape as boundary plantings, scattered on crop fields, around the homestead and woodlots. There was a significant difference in the mean number of trees per household across the three wealth classes. Among the three wealth classes, the medium wealth category households have a relatively higher number of tree species than rich and poor households (p<0.05). Considering the ever-increasing population and the resulting demand for construction poles, fuelwood, household utensils, farm implements, and the fast-growing performance of the species, Eucalyptus camaldulensis Dehnh. was the first preferred tree species to households for planting. Tree integration in the farming landscape should be recognized since it will be invaluable in developing plans for agroforestry interventions. However, exotic tree species have dominated the status of indigenous tree species. Then, there should be a continuous and detailed extension system to upgrade the traditional management system and the tree selection to be integrated.

Effect of density and species preferences on collective choices: an experimental study on maggot aggregation behaviours

ABSTRACTCollective decisions have been extensively studied in arthropods, but they remain poorly understood in heterospecific groups. This study was designed to (1) assess the collective behaviours of blow fly larvae (Diptera: Calliphoridae) in groups varying in density and species composition, and (2) relate them to the costs and benefits of aggregating on fresh or decomposed food. First, experiments testing conspecific groups of Lucilia sericata and Calliphora vicina larvae, two species feeding at the same time on fresh carcasses, demonstrated decreases in growth and survival on rotten beef liver compared with fresh liver. However, mixing species together reduced this adverse impact of decomposition by increasing the mass of emerged adults. Second, larval groups were observed in binary choice tests between fresh and rotten liver (i.e. optimal and sub-optimal food sources). The results showed that larvae interacted with each other and that these interactions influenced their food preferences. We observed that (1) larvae were able to collectively choose the optimal food, (2) their choice accuracy increased with larval density and (3) the presence of another species induced a reversal in larval preference towards rotten food. These results highlight the ubiquity of collective decision properties in gregarious insects. They also reveal an unexpected effect of interspecific association, suggesting the colonization of new resources through a developmental niche construction.

Factors Influencing the Fish Consumption Preferences: Understandings from the tribes of Wayanad, Kerala

Fish consumption preferences vary with communities. The study aims to study the socio personal and fish consumption profile of the seven major tribes of Wayanad, Kerala. Species preferences, factors affecting the fish purchase and consumption, health profile and symptoms of tribes in relation with iron deficiency anaemia, association between fish consumption and health of tribes were investigated. Data were gathered through a questionnaire completed by 200 tribal households from different socioeconomic backgrounds. Results indicate that Sardine was the most consumed and preferred fish and percapita fish consumption of tribes was far below the state average. In conclusion, the price of fish ranked as the first and foremost important factor affecting the fish purchase and consumption of the tribes surveyed, and the fish consumption variables were highly associated with health values. Increasing awareness about the health benefits of fish consumption and building capacity of tribes to prepare fish-based products based on their taste and preferences can aid improved fish consumption among Wayanad tribes. Therefore, to establish and adopt fish consumption guidelines for the tribes of Wayanad, the factors mentioned in the study need to be integrated into the projects and policies.

Plasticity in shell selection behaviour by the endemic hermit crab Diogenes alias (Anomura, Diogenidae) from the northeastern Arabian Sea, India

Selection of gastropod shells as shelter by hermit crabs in controlled experiments would provide useful information on the utility of these shells in nature. In this study, shell size and species preferences of Diogenes alias from the northeastern Arabian Sea were quantified by free choice experiments. Males of D. alias, prefer Indothais lacera and Tibia curta, when choice was given; no differences were found for other demographic groups. All hermit crabs occupied larger shells than the shells they occupied in nature. The best correlation was observed between internal volume, weight, and aperture width of the shell with the size of the hermit crab. This pattern has also been reported for other species (i.e., Clibanarius albidigitus, Calcinus tibicen, and C. obscurus). Furthermore, the present study highlights the importance of optimal resources in a scarce environment.