Comparative breeding ecology of Mississippi Kites in urban and exurban areas of West Texas

Birds of prey are becoming increasingly common occupants of urbanized settings, but the comparative benefits or detriments they experience in urban environs compared to exurban areas are poorly understood. We examined the reproductive success and phenology of Mississippi Kites (Ictinia mississippiensis) nesting concurrently in urban and exurban areas in west Texas during the 2010–2012 and 2014 breeding seasons. Our objective was to better understand the reproductive advantages or disadvantages that kites may experience by nesting in urban areas rather than exurban areas. We calculated annual productivity, estimated daily survival rates of nests, and estimated hatch dates. Kites produced 0.52 fledglings per urban nesting attempt and 0.33 fledglings per exurban nesting attempt. We found no difference in the mean number of young that fledged from successful urban (1.06) and exurban (1.07) nests, but kites in urban areas had greater nesting success within years than those in exurban areas. Both heat and drought were associated with low productivity and success in both areas, but the urban landscape appears to have provided some buffer to their effects. These factors may have had direct (e.g., exposure) or indirect (e.g., negative influences on prey availability) influences on reproductive success. Counter to previous studies of urban raptors, we found that exurban kites nested significantly earlier than urban kites. This may be linked to differences in environmental conditions and prey availability between the areas. Our results suggest that urban areas provide a reproductive advantage for Mississippi Kites in terms of facilitating an overall higher nesting success, but this does not translate into increased productivity for successful pairs. Further, our data suggest that, although urban areas may buffer species from drought or heat, that buffer can be breached during severe conditions.     

Using faecal metabarcoding to examine consumption of crop pests and beneficial arthropods in communities of generalist avian insectivores

Generalist insectivorous birds can provide ecosystem services in agricultural landscapes by consuming arthropod pests, or they can provide disservices when they consume beneficial arthropods. To examine bird impacts on arthropod communities, including pest control services, we need to know which arthropods birds commonly consume. Faecal metabarcoding is an emerging technique that can be used to identify prey from faecal samples, often to the species level. We used faecal metabarcoding to study diets of birds inhabiting the ecotone between soybean fields and adjacent grasslands in a largely agricultural landscape in Illinois, USA, during the summer of 2017. Whereas previous studies have used faecal metabarcoding to compare bird diets among species or among capture sites, we analysed samples from multiple species within a community at replicate sites. We collected and sequenced DNA from 132 faecal samples from 25 bird species captured at six sites. We found that birds consumed an extremely large and varied diet that differed among both species and sites, suggesting that birds were consuming prey opportunistically as available at each site. Of the nine most commonly detected prey species, three are known pests of soybeans. Bird diets also contained significantly more species of herbivorous prey than natural enemies. Finally, we discovered that American Goldfinches Spinus tristis, a highly granivorous species, may consume arthropods more frequently than expected and thus may provide ecosystem services in agricultural landscapes. Our study demonstrates that birds within this system consume a large variety of prey, suggesting that they may be able to respond quickly to pest outbreaks and contribute to agricultural resiliency.     

Hedgerow presence does not enhance indicators of nest‐site habitat quality or nesting rates of ground‐nesting bees

A major challenge in habitat restoration is targeting the key aspects of a species' niche for enhancement, particularly for species that use a diverse set of habitat features. However, restoration that focuses on limited aspects of a species' niche may neglect other resources that are critical to population persistence. We evaluated the ability of native plant hedgerows, planted to increase pollen and nectar resources for wild bees in agricultural landscapes, to provide suitable nesting habitat and enhance nesting rates of ground‐nesting bees. We found that, when compared to unmanaged field edges (controls), hedgerows did not augment most indicators of nest habitat quality (bare ground, soil surface irregularity, and soil hardness), although coarser soils were associated with higher incidence and richness of nesting bees. Hedgerows did not augment nesting rates when compared to control edges. Although all the bee species we detected nesting were also found foraging on floral resources, the foraging versus nesting assemblages found within a site were highly dissimilar. These results may reflect sampling error; or, species found foraging but not nesting in hedgerows could be utilizing hedgerows as “partial habitats,” nesting outside hedgerow plantings but foraging on the floral resources they provide. We conclude that although hedgerows are known to provide critical floral resources to wild bees especially in resource‐poor intensive agricultural landscapes, simply increasing vegetative diversity and structure may not be simultaneously enhancing nesting habitat for ground‐nesting bees.     

Nesting biology of Black-shouldered Kite (Elanus caeruleus) in oil palm landscape in Carey Island,Peninsular Malaysia

Black-shouldered Kite (Elanus caeruleus) is a well-known raptor that inhabits open areas such as oil palm plantation or paddy field. To determine preferable habitat and nesting site of Black-shouldered Kite in oil palm landscape, we conducted a study on Black-shouldered Kite’s nesting biology in Carey Island, Selangor, Malaysia. We divided the island into six types of habitat and conducted road-side count of Black-shouldered Kite from April 2009 to February 2011. Whenever the Black-shouldered Kite was detected, we thoroughly searched the surrounding area for their nest. In total, we have recorded forty nests. The nests were built on 15 species of trees but most of the trees shared common physical characteristics. Some novice breeders also used oil palm tree as their nesting site. Structure and building materials of nests constructed on oil palm trees were different from nests built on other trees. Of all breeding attempts, only four nests which were located in residential area adjacent to young oil palm habitat were successful. Among important characteristics of successful nesting site include taller trees with strong branches and good leaf coverage. These trees not only protect nests from predator detection (except from other predatory birds) and physical environment but also facilitate Black-shouldered Kite’s foraging activities by providing good vantage point.     

Landscape simplification increases vineyard pest outbreaks and insecticide use

Diversifying agricultural landscapes may mitigate biodiversity declines and improve pest management. Yet landscapes are rarely managed to suppress pests, in part because researchers seldom measure key variables related to pest outbreaks and insecticides that drive management decisions. We used a 13‐year government database to analyse landscape effects on European grapevine moth (Lobesia botrana) outbreaks and insecticides across c. 400 Spanish vineyards. At harvest, we found pest outbreaks increased four‐fold in simplified, vineyard‐dominated landscapes compared to complex landscapes in which vineyards are surrounded by semi‐natural habitats. Similarly, insecticide applications doubled in vineyard‐dominated landscapes but declined in vineyards surrounded by shrubland. Importantly, pest population stochasticity would have masked these large effects if numbers of study sites and years were reduced to typical levels in landscape pest‐control studies. Our results suggest increasing landscape complexity may mitigate pest populations and insecticide applications. Habitat conservation represents an economically and environmentally sound approach for achieving sustainable grape production.     

Movement and phenology of bees in a subtropical Australian agricultural landscape

Bees are mobile organisms that seek food and nesting opportunities from a range of habitats. It is important to understand the way they move in agricultural landscapes if we are to conserve them and benefit from their activity as pollinators. We surveyed bees using directional flight interception (Malaise) traps over a 1‐year period in two agricultural landscapes in south‐east Queensland, Australia. We placed traps at the ecotone between crops and remnant vegetation to establish the pattern of movement between these habitats. Species richness in these landscapes (70) was high relative to that in comparable studies. Some bees were active year round, but most were caught in the period September to March. Across the whole assemblage there was a significant pattern where more species were detected leaving rather than entering remnant vegetation. The same bias was true for the number of individuals of the two most abundant species (Homalictus urbanus and Apis mellifera). Species exclusively found in crops were smaller on average (and therefore have smaller foraging range) than their non‐crop counterparts. Together, these patterns indicate that while bees are abundant in crop habitat, the remnant vegetation is important as the point of origin for bee movements, and the riparian remnant in particular is richer than the dry native remnant. Compositional similarity among samples was significantly explained by landscape but also movement direction (i.e. to or from the riparian remnant) because different species showed different patterns of response. The landscape with greater native vegetation cover supported more species in and around crops than the landscape with less native vegetation.     

Reptiles and frogs use most land cover types as habitat in a fine‐grained agricultural landscape

Agricultural landscapes comprise much of the earth's terrestrial surface. However, knowledge about how animals use and move through these landscapes is limited, especially for small and cryptic taxa, such as reptiles and amphibians. We aimed to understand the influence of land use on reptile and frog movement in a fine‐grained grazing landscape. We surveyed reptiles and frogs using pitfall and funnel traps in transects located in five land use types: 1) woodland remnants, 2) grazed pastures, 3) coarse woody debris added to grazed pastures, 4) fences in grazed pastures and 5) linear plantings within grazed pastures. We found that the different land cover types influenced the types and distances moved by different species and groups of species. Reptiles moved both within, and out of, grazed paddocks more than they did in woodland remnants. In contrast, frogs exhibited varying movement behaviours. The smooth toadlet (Uperoleia laevigata) moved more often and longer distances within remnants than within paddocks. The spotted marsh frog (Limnodynastes tasmaniensis) moved out of grazed pastures more than out of pastures with coarse woody debris added or fences and were never recaptured in plantings. We found that most recaptured reptiles and frogs (76.3%) did not move between trapping arrays, which added to evidence that they perceived most of the land cover types as habitat. We suggest that even simple fences may provide conduits for movement in the agricultural landscape for frogs. Otherwise, most reptile and frog species used all land cover types as habitat, though of varying quality. Reptiles appeared to perceive the woodland remnants as the highest quality habitat. This landscape is fine‐grained which may facilitate movement and persistence due to high heterogeneity in vegetation cover over short distances. Therefore, intensification and increasing the size of human land use may have negative impacts on these taxa.     

Permeability of Neotropical agricultural lands to a key native ungulate—Are well‐connected forests important?

Much of what remains of the Earth's tropical forests is embedded within agricultural landscapes, where forest is reduced and fragmented. As native forest ungulates are critical to maintaining forest function, it is imperative to understand how this functional group responds to declines in forest cover and connectivity resulting from agricultural expansion. We addressed this issue by evaluating selection of forest cover and forest connectivity by a key native ungulate of Neotropical forests, the white‐lipped peccary (Tayassu pecari Link 1795, Tayassuidae, Cetartiodactyla), in agricultural landscapes of Brazil. We evaluated selection using compositional analysis at two hierarchical levels, landscape, and home range. From 2013 to 2019, we GPS‐tracked eight white‐lipped peccary herds in Southwest Brazil, resulting in a total of 14,460 GPS locations. We found that herds can live in landscapes with a wide range of forest cover (35%–81% of home ranges covered by native forest), with significant, but not strong, selection at the landscape level (p = .045). Nevertheless, herds strongly select for forest cover within their home ranges (81%–97% of locations within native forest; highly significant selection at the home‐range level: p = .008). As for connectivity, herds significantly select the largest, most connected forest fragments at the landscape level (p = .04), but not at the home‐range level (p = .07). Our results support that Neotropical forests within agricultural landscapes need to be well connected in order to preserve this key native ungulate and maintain long‐term forest function. Abstract in Portuguese is available with online material.     

Assembly rules are rare in SE Australian bird communities,but sometimes apply in fragmented agricultural landscapes

Assembly rules have been difficult to observe partly because species interactions vary with resource availability, the amount of disturbance, and species richness. Using bird survey data from two years in five regions of SE Australia (463 sites), we tested six predictions from assembly rules theory. We developed generalised linear models for all pair‐wise species comparisons within a region, after first taking vegetation differences among sites into account. We found: 1) that disturbed and fragmented agricultural landscapes had more negative relationships because aggressive honeyeaters monopolised patches; 2) differences between wet and dry years (high and low resources) were attributed to emigration, immigration, and reduced intensity of negative interactions in the dry year, and not to more intense competition; 3) although negative correlations were expected among ecologically‐similar species, we observed the opposite pattern with significant positive associations in fragmented landscapes; 4) relationships involving aggressive honeyeaters led to more negative relationships as predicted; however, this was only observed in fragmented landscapes and was not significant in every year; 5) in two agricultural landscapes, there were fewer negative relationships in low species‐richness sites, probably because one species from each pair had low abundance. This enabled us to suggest dominance relationships among species pairs; 6) there was evidence of more negative relationships in low‐disturbance sites in agricultural landscapes as predicted. However, instead of the mechanism predicted by theory (reduced disruption allowing assembly processes to approach equilibrium), we suggest that sites with low disturbance represent resources worthy of defence by dominant species. We conclude that bird communities in SE Australia are rarely limited by negative species interactions, although aggressive honeyeaters are a feature of fragmented landscapes. However, diverse mechanisms underlie the temporal and spatial variation in species interactions when they do occur, meaning that simple statements of assembly rules may not be useful in these systems.     

Experimental Test of Preferences for an Invasive Prey by an Endangered Predator: Implications for Conservation

Identifying impacts of exotic species on native populations is central to ecology and conservation. Although the effects of exotic predators on native prey have received much attention, the role of exotic prey on native predators is poorly understood. Determining if native predators actively prefer invasive prey over native prey has implications for interpreting invasion impacts, identifying the presence of evolutionary traps, and predator persistence. One of the world’s most invasive species, Pomacea maculata, has recently established in portions of the endangered Everglade snail kite’s (Rostrhamus sociabilis plumbeus) geographic range. Although these exotic snails could provide additional prey resources, they are typically much larger than the native snail, which can lead to lower foraging success and the potential for diminished energetic benefits in comparison to native snails. Nonetheless, snail kites frequently forage on exotic snails. We used choice experiments to evaluate snail kite foraging preference in relation to exotic species and snail size. We found that snail kites do not show a preference for native or exotic snails. Rather, snail kites generally showed a preference for medium-sized snails, the sizes reflective of large native snails. These results suggest that while snail kites frequently forage on exotic snails in the wild, this behavior is likely driven simply by the abundance of exotic snails rather than snail kites preferring exotics. This lack of preference offers insights to hypotheses regarding effects of exotic species, guidance regarding habitat and invasive species management, and illustrates how native-exotic relationships can be misleading in the absence of experimental tests of such interactions.     

Bird community responses to habitat fragmentation: how consistent are they across landscapes?

Aim The woodland ecosystems of south‐eastern Australia have been extensively disturbed by agriculture and urbanization. Herein, the occurrence of birds in woodland remnants in three distinct landscapes was analysed to examine the effects of different types of landscape matrices on species richness vs. area and species richness vs. isolation relationships and individual species responses to woodland fragmentation. Location The study system comprised three distinct woodland landscapes of the northern Australian Capital Territory and bordering areas of New South Wales. These landscapes (termed agricultural, peri‐urban and urban) are located within 50 km of each other, have remnant fragments of similar age, size, isolation, woodland cover, elevation and climates. The major distinguishing feature of the three landscapes was the properties of the habitats surrounding the numerous woodland remnants. Methods Bird surveys, using an area‐search methodology, were conducted in 1999 and 2000 in 127 remnants in the three landscapes to determine bird species presence/absence. Each remnant was characterized by measures of remnant area, isolation and habitat complexity. To characterize differences between each landscape, we conducted an analysis of the amount of tree cover and human disturbance in each landscape using SPOT imagery and aerial photographs. Linear regressions of woodland‐dependent species richness vs. remnant area and remnant isolation for the three different landscapes were calculated to see if there were any apparent differences. Binomial logistic regressions were used to determine the relationships between the occurrence of each species and the size and isolation of woodland habitat, in each landscape. Results All the landscapes displayed a significant (P < 0.01) species vs. area relationship, but the slope of the urban relationship was significantly greater than those of the other landscapes. In contrast, only the agricultural landscape displayed a significant (P < 0.01) species richness vs. isolation relationship. When individual species were investigated, we found species that were: (1) apparently insensitive to reduction in remnant area and increase in isolation across all landscapes, (2) absent in small remnants in all landscapes, (3) absent in small remnants in all landscapes and also absent in isolated remnants in the agricultural landscape, (4) absent in isolated remnants in the agricultural landscape, and (5) absent in small remnants in the urban landscape. Threshold values (50% probability of occurrence) for area and isolation for individual species were highly variable across the three landscapes. Main conclusions These results indicate that woodland bird communities have a varying response to habitat fragmentation in different landscapes. Whilst we cannot be sure how representative our chosen landscapes are of other similarly composed landscapes, these results suggest that the type of landscape matrix may have a considerable influence on how bird species are affected by woodland fragmentation in the region. For instance, the properties of a matrix may influence both the resources available in the landscape as a whole for different bird species, and the connectivity (dispersal of birds), between woodland remnants. We encourage further research that examines these hypotheses and argue that the management of the matrix should be included in conservation strategies for fragmented landscapes.     

Thermal flight budget of a woodland butterfly in woodland versus agricultural landscapes: An experimental assessment

We assessed the impact of vegetation structure and type of landscape on microclimatic conditions for flight activity, using the heliothermic butterfly Pararge aegeria as a model. Dummies (i.e., dead specimens with spread wings, on a hypodermic needle with a thermocouple) that initially were warmed up to similar thorax temperatures were able to cover larger distances, and they heated up faster, with higher ambient temperature and with lower wind speed. Convective cooling decreased with increasing degree of shelter, and with lower flight height. Simulated flight bouts bridged 140±23 m under unsheltered, 81±13 m under partly sheltered and 29±6 m under sheltered conditions. Ambient temperature and wind force were higher in highly fragmented, agricultural landscapes than in continuous woodland landscapes. Males, and not females, were furrier in agricultural landscapes. This sexual difference is interpreted in terms of differences in life history among the sexes.     

Experimental analysis of diet specialization in the snail kite: the role of behavioral conservatism

We examined factors maintaining extreme diet specialization in the snail kite (Rostrhamus sociabilis), a medium-sized hawk which feed almost exclusively on Pomacea snails, by determining why during some months kites eat crabs (Dilocarcinus dentatus) in the Ilanos of Venezuela. We offered snails and crabs of different sizes to wild free-flying birds to develop estimates for a prey choice model. Handling times of Pomacea doliodes snails averaged 90±39 s and were positively correlated with snail size. Handling times for crabs (x=353±130 s) were significantly longer and exhibited greater variation than for snails, and were not correlated with crab size. Edible crab tissues had greater dry weights and contained more energy (25.37 kJ/g) than tissues of snails (16.91 kJ/g). Total energy of crabs was much greater than that of snails, and total energy of both foods was highly related to body length. We constructed an allometric equation for profitability of snails and crabs. Snails were more profitable than all but the largest crabs, but estimates of variance in profitability were greater for crabs. Predictions from the model were tested by offering crabs that represented equal, greater and much greater profitability than snails, to determine whether kites chose prey according to profitability. Only 15.6% of 289 food items chosen were crabs. Half of the 18 kites tested did not eat crabs and only 3 birds switched from snails to more profitable crabs. Four fledglings showed no preference for snails. The role of neophobia in food choice was investigated by offering unfamiliar snails (Pomacea urceus) to kites. Kites exhibited neophobic behaviors, and 5 of 12 birds chose not to capture P. urceus. Two-thirds of the 12 snails chosen were rejected immediately, but the others were handled efficiently (x=133±89 s). Although morphological adaptations allow kites to specialize on snails, the costs of specialization were overcome for kites when the profitability of alternative food increased sufficiently. Our results suggest a role for behavioral conservatism, in the form of risk-averse foraging and neophobia, in maintaining severe diet specialization in the snail kite.     

不同农业景观结构对麦蚜种群动态的影响

研究表明农业景观结构的复杂性与害虫种群发生强度关系密切,然而在不同农业景观结构下研究麦蚜的发生、种群及寄生蜂的变化还不多。设计了不同的麦田景观结构,调查研究了不同麦田景观结构对麦蚜种群的影响。在简单与复杂两种农业景观结构下,分析了不同种类麦蚜的入田时间、入田量、种群增长率、种群密度及寄生性天敌的多样性与寄生率。结果表明:景观结构对不同种类麦蚜影响不同,但复杂农业景观下麦蚜迁飞入田时间都要晚于简单农业景观(连片种植)下的入田时间,复杂农业景观下有翅蚜的迁入量显著低于简单景观下有翅蚜的迁入量,并且复杂农业景观下麦蚜种群增长速率高于简单农业景观下的增长速率。不同种类麦蚜对景观结构的不同反应可能与形态学与生活史特征有关,两种不同农业景观结构下寄生性天敌的多样性与寄生率无显著差异。复杂景观结构下的麦蚜有翅蚜低的迁入量、高的增长速率可能与生境高度破碎化有关,其中与温室大棚塑料白色反光有的很大的影响。生境破碎化影响了麦蚜对寄主植物寻找以及天敌对猎物的寻找效应。     

Prioritizing species conservation: does the Cape Verde kite exist?

The Cape Verde kite (Milvus milvus fasciicauda) is considered to be one of the rarest birds of prey in the world and at significant risk of extinction. For this reason there is great interest in both the taxonomic and the population status of this group. To help resolve its taxonomic status, we provide phylogenetic analyses based on three mitochondrial genes for a sampling of kites in the genus Milvus, including a broad geographical sampling of black kites (Milvus migrans), red kites (Milvus milvus), Cape Verde kite museum specimens collected between 1897 and 1924, and five kites trapped on the Cape Verde Islands during August 2002. We found that the historical Cape Verde kites, including the type specimen, were non-monophyletic and scattered within a larger red kite clade. The recently trapped kites from the Cape Verde Islands were all phylogenetically diagnosed as black kites. Our findings suggest that the traditional Cape Verde kite is not a distinctive evolutionary unit, and the case for species status, as recently suggested by others, is not supported. We do find support for recognition of at least one clade of yellow-billed kites, traditionally considered as a black kite subspecies, as a distinctive phylogenetic species.     

Resource selection by Indiana bats during the maternity season

Little information exists on resource selection by foraging Indiana bats (Myotis sodalis) during the maternity season. Existing studies are based on modest sample sizes because of the rarity of this endangered species and the difficulty of radio-tracking bats. Our objectives were to determine resource selection by foraging Indiana bats during the maternity season and to compare resource use between pregnant and lactating individuals. We used an information theoretic approach with discrete choice modeling based on telemetry data to evaluate our hypotheses that land cover, percent canopy cover, distance to water, and prescribed fire affected the relative probability a point was used by a foraging Indiana bat. We fit models for individual bats and a population-level model based on all individuals with a random factor to account for differences in sample size among individuals. We radio-tracked 29 individuals and found variation in resource selection among individuals. However, among individuals with the same supported covariates, the magnitude and direction of the covariates were similar. Eighteen bats selected areas with greater canopy closure and 5 of 6 bats that had areas burned by low-intensity prescribed fire in their home range selected burned areas. Resource selection was related to land cover for 13 individuals; they selected forest and shrubland over agricultural land, which composed >50% of the landscape within 10 km. We found no support for our hypothesis that resource selection was related to individual reproductive condition or Julian date in our population-level model indicating habitat selection was not determined by reproductive status or date within the maternity season. Land use or forest management that greatly reduces canopy cover may have a negative impact on Indiana bat use. Maintaining forest cover in agricultural landscapes is likely critical to persistence of maternity colonies in these landscapes. Sites managed with low severity prescribed fire may be selected by some individuals because of reduced understory vegetation. © 2013 The Wildlife Society.     

The evolution of movements and behaviour at boundaries in different landscapes: a common arena experiment with butterflies

As landscapes change, mobility patterns of species may alter. Different mechanistic scenarios may, however, lead to particular patterns. Here, we tested conflicting predictions from two hypotheses on butterfly movements in relation to habitat fragmentation. According to the resource distribution hypothesis, butterflies in more fragmented landscapes would have higher levels of mobility as resources are more scattered. However, these butterflies could have lower levels of mobility as they experience 'hard' habitat boundaries more frequently (i.e. higher crossing costs) compared with butterflies in landscapes with continuous habitat; i.e. the behaviour-at-boundaries hypothesis. We studied movements, habitat boundary crossing and habitat preference of laboratory-reared individuals of Pararge aegeria that originated from woodland and agricultural landscapes, by using an experimental landscape as a common environment (outdoor cages) to test the predictions, taking into account sexual differences and weather. Woodland butterflies covered longer distances, were more prone to cross open-shade boundaries, travelled more frequently between woodland parts of the cages and were more at flight than agricultural butterflies. Our results support the behaviour-at-boundaries hypothesis, with 'softer' boundaries for woodland landscapes. Because the butterflies were reared in a common environment, the observed behavioural differences rely on heritable variation between populations from woodland and agricultural landscapes.     

Mate guarding in the Linnet Carduelis cannabina

Capsule?House Sparrow (Passer domesticus) populations in south Swedish farmland are not affected by supplemental winter feeding, irrespective of agricultural landscape type or presence of animal husbandry, although winter populations declined more in mixed farmland and when farms contained animal husbandry.

Aims?To investigate whether food limitation of House Sparrow population size during the winter varied spatially in relation to agricultural landscape intensification and farm management.

Methods?We experimentally increased the winter food supply for populations on farmsteads in replicated landscapes that differed in agricultural intensification (open plains versus mixed farming) and/or farm management (crop farming versus animal husbandry), and estimated possible differences in effects on winter population change.

Results?We found no effect of supplementary winter feeding on changes in House Sparrow population sizes over the winter, irrespective of agricultural landscape type or presence of animal husbandry at the farm. However, we found a significantly larger winter population decline in mixed farmland and when farms contained animal husbandry.

Conclusions?The results suggest that House Sparrow populations in south Swedish farmland are not primarily limited by winter food availability. Alternatively, supplemental winter feeding may augment interspecific competition or attracts predators, offsetting any positive effect on population change. However, the stronger population decline in landscapes in which more breeding resources may be available (animal husbandry farms, mixed farmland), suggests stronger intraspecific competition during the winter in line with the resource separation hypothesis.     

Row crop fields provide mid‐summer forage for honey bees

Honey bees provide invaluable economic and ecological services while simultaneously facing stressors that may compromise their health. For example, agricultural landscapes, such as a row crop system, are necessary for our food production, but they may cause poor nutrition in bees from a lack of available nectar and pollen. Here, we investigated the foraging dynamics of honey bees in a row crop environment. We decoded, mapped, and analyzed 3459 waggle dances, which communicate the location of where bees collected food, for two full foraging seasons (April–October, 2018–2019). We found that bees recruited nestmates mostly locally (<2 km) throughout the season. The shortest communicated median distances (0.474 and 0.310 km), indicating abundant food availability, occurred in July in both years, which was when our row crops were in full bloom. We determined, by plotting and analyzing the communicated locations, that almost half of the mid‐summer recruitment was to row crops, with 37% (2018) and 50% (2019) of honey bee dances indicating these fields. Peanut was the most attractive in July, followed by corn and cotton but not soybean. Overall, row crop fields are indicated by a surprisingly large proportion of recruitment dances, suggesting that similar agricultural landscapes may also provide mid‐summer foraging opportunities for honey bees.     

Landscape structure and phenotypic plasticity in flight morphology in the butterfly Pararge aegeria

In evolutionary time, varying environments may lead to different morphs as a result of genetic adaptation and divergence or phenotypic plasticity. Landscapes that differ in the extent of habitat fragmentation may provide different selection regimes for dispersal, but also for other ecological functions. Several studies on flying insects have shown differences in flight morphology between landscapes, but whether such differences result from plastic responses have rarely been tested. We did a reciprocal transplant experiment with offspring of speckled wood butterfly females (Parargeaegeria) from three types of landscape differing in fragmentation: woodland landscape, landscape with woodland fragments and agricultural landscape with only hedgerows. Young caterpillars were allowed to grow individually on potted host grasses in small enclosures under the three landscape conditions (split‐brood design). Mortality in caterpillars was much higher in agricultural landscape compared to the other landscapes. Additive to the effect of landscape of development, landscape of origin also affected mortality rate in a similar way. Flight morphology of the adults resulting from the experiment differed significantly with landscape. Independent of the landscape of origin, males and females that developed in agricultural landscape were the heaviest and had the greatest wing loadings. Females that developed in agricultural landscape had higher relative thorax mass (i.e. greater flight muscle allocation) in line with adaptive predictions on altered dispersal behaviour with type of landscape. In males, relative thorax mass did not respond significantly relative to landscape of development, but males originating from landscape with woodland fragments allocated more into their thorax compared to males from the other types. We found significant G×E interactions for total dry mass and wing loading. Our results suggest the existence of phenotypic plasticity in butterfly flight morphology associated with landscape structure.