Nesting Activity Research Articles

Understanding sociality and behavior change associated with a nesting event in a captive flock of great white pelicans

Zoo-housed pelicans are commonplace, but their breeding record is poor and little research is published on the activity patterns, as potential predictors of nesting, of captive flocks. Existing literature shows that comparative research can provide useful information for husbandry and conservation planning for pelican populations. The opportunity arose to investigate the time-activity budget and social network of a breeding flock of captive great white pelicans. Three chicks were hatched in June and July 2016 and one in March 2017. Data on state behaviors, space use, and association preferences were collected around these nesting events, from October 2016 to February 2017 and July to October 2017. Results suggest that pre-nesting periods were associated with heightened flock-wide vigilance, suggesting that vigilance may be a precursor for courtship or nesting activity. Social network analysis revealed nonrandom associations between birds and a social structure across the flock, in which subadults seemed to associate more with each other than with adult birds. A limited visitor effect was noted; whilst no overall behavior change was apparent with different numbers of visitors, pelicans did widen their enclosure usage with increased visitor presence. These data are relevant to those attempting to breed this pelican, who wish to know more about the daily behavior patterns of this species across the season and physiological state, and who wish to understand pelican social structure, which is useful to the planning and implementation of bird moves or changes to the social environment of the flock. Further extending such research to include uninterrupted observation over a successful breeding event is recommended.

Using Aerial Photogrammetry to Assess Stock-Wide Marine Turtle Nesting Distribution, Abundance and Cumulative Exposure to Industrial Activity

The lack of accurate distribution maps and reliable abundance estimates for marine species can limit the ability of managers to design scale-appropriate management measures for a stock or population. Here, we tested the utility of aerial photogrammetry for conducting large-scale surveys of nesting marine turtles at remote locations, with a focus on the flatback turtle (Natator depressus) in the Pilbara region of Western Australia. Aerial surveys were conducted between 29 November and 6 December 2016 to overlap with the peak nesting season for flatback turtles and collected imagery was used to examine marine turtle distribution, abundance, and cumulative exposure to industrial activity relative to overlap with protected areas. Two observers independently reviewed aerial georeferenced photographs of 644 beaches and recorded turtle tracks and other evidence of turtle nesting activity. A total of 375 beaches showed signs of nesting activity by either flatback, green (Chelonia mydas) or hawksbill (Eretmochelys imbricata) turtles. Most of these beaches (85.3%) were located on islands, and the rest (14.7%) on the mainland. Half (n = 174) of the active beaches showed evidence of fresh (0–36 h. old) flatback nesting activity, with track abundance varying from 1.0 to 222.0 tracks·night−1. Six rookeries accounted for 62% of the Pilbara flatback stock. Remarkably, 77% of identified flatback rookeries occurred within protected areas. However, one-third (34%) of those were also located within 5 km of a major industrial site, including eight of the highest abundance beaches (50–250 tracks·night−1). Several key rookeries were also identified as being relatively unexposed to industry-related pressures but currently unprotected, highlighting the need for a cumulative impact assessment to be completed for this flatback stock. Finally, our aerial tallies and multiple ground-survey flatback track tallies were highly correlated and together with low intra- and inter-observer errors suggested that reliable data can be collected via aerial photogrammetry for nesting marine turtles. Such large-scale digitized surveys can therefore be used to assess the cumulative exposure of marine turtles to pressures, and to reveal new conservation opportunities.

How changes in beach morphology affect hawksbill turtle (Eretmochelys imbricata) nesting distribution at Celestun, Yucatan, Mexico

The Yucatan Peninsula harbors important nesting beaches for the largest hawksbill turtle (Eretmochelys imbricata) populations in the Western Atlantic. Over the last decade, erosion has substantially modified segments of the nesting beach along the coastal zone of Celestun town, Mexico. The recent rise in sea level makes this area among the most vulnerable of the Yucatan coastal zone, potentially jeopardizing its suitability as a nesting site for hawksbill turtles. The objectives of this study were to: (1) identify spatiotemporal patterns of the hawksbill nesting season over 11 years (1997–2007); (2) characterize spatiotemporal dynamics in the morphology of the nesting beach; and (3) assess the relationship between beach morphology changes and hawksbill nesting activity. We observed a well-defined spatial pattern of hawksbill nesting activity along the beach, occupying steep and narrow beach zones where human presence and activity was low. The beach was under a strong erosional process, causing a retreat displacement that varied in magnitude along the littoral zone. Principal component analysis showed a strong correlation between beach morphology variables, separating segments of beach according to the effect of morphology. Variation in hawksbill nest densities was inversely correlated to the distance to town and to artificial light intensity. It is suggested that the influence of human activities and infrastructure on nesting females forces the use of beach segments where flooding and nest erosion from high tides and storm surges jeopardize their reproductive success and makes more relevant the identification of spatial priority zones for targeted management strategies that aim to preserve hawksbill nesting.

Irruptive White Ibis breeding is associated with use of freshwater crayfish in the coastal Everglades

AbstractAs avian reproductive success is generally prey limited, identifying important prey types or sizes and understanding mechanisms governing prey availability are important objectives for avian conservation ecology. Irruptive White Ibis (Eudocimus albus) nesting at coastal colonies in the southern Everglades numbered over 100,000 nests in the 1930s. A century of drainage and altered hydrologic patterns reduced aquatic prey availability and eliminated large nesting events; nesting activity in recent decades has been typically less than 5% of historical peaks. Hydrologic restoration is expected to increase ibis nesting activity, but which prey types will support high nesting effort is less clear. In 2017 and 2018, we collected food boluses from White Ibis chicks at coastal colonies in Everglades National Park. We also monitored regional nesting activity from 1999 to 2018. In 2017, the region had 1,075 nests, typical of the past several decades; but in 2018, there were 30,420 nests, representing the highest recorded nesting activity in 87 yr. Prey composition varied between years; estuarine crabs dominated nestling boluses in 2017, while crayfish and fish were dominant prey in 2018. Crayfish, especially Procambarus alleni, were heavily exploited by ibis early in the 2018 breeding season, while fish were used more at the end. Crayfish abundances in wetlands near the colonies were higher prior to 2018, and more crayfish-producing short-hydroperiod wetlands remained available for ibis foraging in 2018. Our results support previous studies indicating that crayfish are important prey for breeding ibises and suggest that unprecedented, extensive flooding of seasonal wetlands promoted crayfish production and initiated the irruptive breeding in 2018. Our observations indicate that rehydration of the southern Everglades could restore ibis nesting activity at coastal colonies, but further investigations of hydrologic variation, crayfish production, and ibis foraging and nesting activity will be helpful to understand these dynamics and the importance of short-hydroperiod wetlands.

Copying nesting attempts in a new site may be the wrong choice. A case in the European Bee-eater (<em>Merops apiaster</em>)

Insistent nesting attempts by a group of European Beeeaters in a new site, a pebbly bank of the middle course of Trebbia River, northern Italy, mostly failed because of the unmovable pebbles encountered during tunnel excavation. The birds later nested in an artificial sand heap, with full success that time. Various considerations suggest that birds insisted in the unsuitable site because they copied the nesting activity of model conspecifics. Finding social attraction and “public information” from conspecifics in a place where no breeding attempt was previously made would allow disentangling social philopatry from spatial philopatry.

Modeling Onset of Hourly Nesting Activity in a Freshwater Turtle Using Abiotic Variables and Physiological Capacity

Nesting is an essential, yet variable, reproductive behavior in most oviparous organisms. Although many factors conceivably influence nesting behaviors, it is unclear which factors strongly influence terrestrial nest timing in aquatic nonavian reptiles. As climate is changing rapidly, understanding the relative influences of biotic and abiotic factors on nesting behaviors may yield important information on future changes in daily and seasonal nesting activity. We collected hourly data to examine the significance of local weather conditions to the timing of within-season nesting activity in a large population of Painted Turtles (Chrysemys picta). We quantified nesting activity as the ratio of females who nested to all females who could nest in each hour, adjusting the size of the denominator to include the time required to shell a subsequent egg clutch. We then used zero-inflated models to identify potential weather predictors of presence/absence of nesting activity and strength of nesting responses (i.e., the fraction of turtles nesting that could nest). Higher temperatures and rainfall predicted stronger nesting responses, whereas lower temperatures and no rainfall predicted the absence of nesting activity, indicating that both temperature and rainfall are important cues in within-season nesting phenology. Our study enhances our understanding of abiotic influences on the terrestrial nesting behavior of aquatic organisms.

Nesting habitat characteristics of green sea turtle (Chelonia mydas) in the Tambelan archipelago, Indonesia

Six species of sea turtles are recognized living in the Indonesia Archipelago and four of them are known for their nesting habitats. The study of sea turtles nesting habitats has been conducted at several locations in Indonesia. Almost all islands in Indonesia are suitable for sea turtles nesting sites, including Tambelan Archipelago in the Karimata Strait and habitat conditions are known to play a vital role in sea turtle nesting activity. Unfortunately, the study of sea turtle ecology, particularly nesting habitats, in this region are still scarce. This study aimed to describe nesting habitat characteristics of green sea turtles (Chelonia mydas) in Tambelan Archipelago. In-situ observation were conducted from March – May, 2019. A total of eleven nesting sites of green sea turtles were found during the period of study. The Tambelan Archipelago have ecological characteristics with natural, functional, and suitable area for a green sea turtle nesting activity. Coastal communities around nesting sites were found to be ideal for sea turtle nesting habitats. This condition will be able to survive if location can be conserved and sustainably managed.

Sampling nesting sea turtles: optimizing survey design to minimize error

Many sea turtle studies globally use counts of nesting activities as a proxy for population abundance estimates and as an indicator of trends within the population. Often these populations are sampled temporally and spatially, but few previous studies have examined the impact of different sampling techniques on the accuracy of these estimates. We investigated temporal sampling errors using a multi-species approach, examining 10 populations comprising green, loggerhead and leatherback sea turtles. Sampling errors were investigated from random, regular and continuous sampling regimes spanning 5-80% coverage. A count approach was used rather than an individual-based capture-mark-recapture approach to broaden the scope and application of the research. Modelling showed that even low survey coverage of 5% gave reasonably accurate estimates of annual nesting activity, with estimated errors of ca. 20% (mean + 1 SD equalling 84.1% of surveys). Survey error is low relative to changes in abundance from the inter-annual variations in nesting activity that occur in sea turtle populations. Thus, annual studies are important to estimate sea turtle abundance, even if these studies have low survey coverage. An increase in survey effort may be more cost effective if spent combining estimates of total nesting activity with sampling turtles as part of a capture-mark-recapture study. This approach will provide a second estimate of annual abundance as well as an estimate of demographic parameters including clutch frequencies, remigration intervals, survivorship, immigration and emigration. This estimation of sampling errors may be useful in the design of monitoring programmes and can be used to guide management and policy decisions.

Nesting features and breeding chronology of the crested coot (Fulica cristata) in two North African high altitude wetlands

The current study aimed to investigate the nesting behavior and breeding chronology of the crested coot (Fulica cristata) in Morocco’s high altitude wetlands. We monitored nesting activities and breeding phenology in two wetlands, Zerrouka and Hachlaf lakes, to achieve our goals. Besides, nesting materials and nest dimensions were analyzed to characterize the crested coot nests. As a result, 52 nests were found in two sites, 18 in Zerouka and 34 in Hachlaf. Nests were built by available twigs on each site, and nest dimensions varied between analyzed wetlands. Nests were larger in Zerrouka compared to Hachlaf Lake. To protect their nests, coots select open waters and submerged vegetation as nesting sites. On the other hand, breeding chronology, including nesting, laying, and hatching dates, was earlier in Zerrouka Lake than Hachlaf. The nesting activities started at Zerrouka during January and February, while at Hachlaf, breeding attempts started during April.

蚂蚁筑巢对西双版纳热带森林土壤有机氮矿化的影响

蚂蚁作为生态系统工程师能够调节土壤微生物及理化环境，进而对热带森林土壤有机氮矿化速率及其时间动态产生显著影响。以西双版纳白背桐热带森林群落为研究对象，采用室内需氧培养法测定土壤有机氮矿化速率，比较蚁巢和非蚁巢土壤有机氮矿化速率的时间动态，揭示蚂蚁筑巢活动引起土壤无机氮库、微生物生物量碳及化学性质改变对有机氮矿化速率时间动态的影响。结果表明：（1）蚂蚁筑巢显著影响土壤有机氮矿化速率（P<0.01），相较于非蚁巢，蚁巢土壤有机氮矿化速率提高了261%；（2）土壤有机氮矿化速率随月份推移呈明显的单峰型变化趋势，即6月最大（蚁巢1.22 mg kg^-1 d^-1、非蚁巢0.41 mg kg^-1 d^-1），12月最小（蚁巢0.82 mg kg^-1 d^-1、非蚁巢0.18 mg kg^-1 d^-1）；（3）两因素方差分析表明，不同月份及不同处理对土壤有机氮矿化速率、NH₄-N及NO₃-N产生显著影响（P<0.05），但对NO₃-N的交互作用不显著；（4）蚂蚁筑巢显著提高了无机氮库（NH₄-N与NO₃-N）、微生物生物量碳、有机质、水解氮、全氮及易氧化有机碳等土壤养分含量，而降低了土壤pH值；（5）回归分析表明，铵态氮和硝态氮对土壤有机氮矿化速率产生显著影响，分别解释87.89%、61.84%的有机氮矿化速率变化；（6）主成份分析表明NH₄-N、微生物生物量碳及有机质是影响有机氮矿化速率时间动态的主要因素，而全氮、NO₃-N、易氧化有机碳、水解氮及pH对土壤有机氮矿化速率的影响次之，且pH与土壤有机氮矿化速率呈显著负相关。总之，蚂蚁筑巢活动主要通过影响土壤NH₄-N、微生物生物量碳及有机质的状况，进而调控西双版纳热带森林土壤有机氮矿化速率的时间动态。研究结果将有助于进一步提高对土壤氮矿化生物调控机制的认识。;Ants often act as ecosystem engineers in mediating the soil microbial and physicochemical properties. This thus can exert a crucial effect on soil organic nitrogen mineralization and its temporal dynamics in tropical forest. The indoor-aerobic incubation method was used to determine soil organic nitrogen mineralization rates in Mallotus paniculatus community of Xishuangbanna tropical forest. This study aimed to compare temporal dynamics of soil organic nitrogen mineralization rates in ant nests and the reference soils. We also revealed the effects of the changes of soil inorganic nitrogen pool (i.e., NH₄-N and NO₃-N), microbial biomass carbon, and chemical properties on the temporal dynamics of organic nitrogen mineralization rates driven by the ant nesting activities. The results were as follows:(1) Ant colonization had a significant effect on soil nitrogen mineralization rates (P<0.01). The mean organic nitrogen mineralization rates were 261% higher in ant nests than in reference soils. (2) The monthly dynamics in soil organic nitrogen mineralization rates showed an obvious trend of single peak, which was the largest in June (ant nests:1.22 mg kg^-1 d^-1, reference soils:0.41 mg kg^-1 d^-1) and the smallest in December (ant nests:0.82 mg kg^-1 d^-1, reference soils:0.18 mg kg^-1 d^-1). (3) Two-way ANOVAs showed that the factors of month and treatment had significant effects on the concentrations of soil organic nitrogen mineralization rates, NH₄-N, and NO₃-N (P<0.05), but no significant interaction of them was observed on NO₃-N. (4) Ant colonization significantly increased the concentrations of soil inorganic nitrogen pool (NH₄-N and NO₃-N), microbial biomass carbon, organic matter, hydrolyzable nitrogen, total nitrogen, readily oxidizable organic carbon, but reduced the value of soil pH. (5) The regression analysis showed that ammonium and nitrate nitrogen had significant effects on soil organic nitrogen mineralization rates, accounting for 87.89% and 61.84% of the changes in soil organic nitrogen mineralization rates, respectively. 6) Principal component analysis indicated that ammonium nitrogen, microbial biomass carbon, and organic matter were the main factors affecting the temporal dynamics of soil nitrogen mineralization rates, followed by total and nitrate nitrogen, readily oxidizable organic carbon, hydrolyzable nitrogen, and pH. Soil pH was negatively correlated with soil nitrogen mineralization rates. In short, the ant colonization had a crucial role in regulating the temporal dynamics in soil organic nitrogen mineralization rates, through affecting ammonium nitrogen, microbial biomass carbon, and soil organic matter in the Xishuangbanna tropical forest. The results would be helpful to further improve our understanding of the biological regulation mechanism of soil nitrogen mineralization.

Nesting Biology, Sexual Dimorphism, and Populational Morphometric Variation in Podium denticulatum F. Smith, 1856 (Hymenoptera: Sphecidae)

Podium denticulatum occurs from Mexico to southern Brazil, including northeastern Argentina. Females use pre-existing cavities to build nests, consisting of cells separated by walls of mud and resin and massively provisioned with paralyzed cockroaches. Trap nests were disposed in three localities in the state of São Paulo, Brazil (Araras, São Carlos, Rifaina), resulting in the collection of 201 nests from December/2003 to June/2007. The founding nests were brought to the laboratory, opened and the pupae transferred to identified vials until the emergence of the adults, when they were then weighed, sexed and stored at -20ºC. The nesting activity was seasonal, with a higher number of nests in the warm and rainy season of the year. The number of constructed cells ranged from one to nine per nest. The emergence rate of adults in the 716 brood cells was 74%, with homogeneous distribution of mortality by egg, larva and pupa stages. This mortality was partly due to parasitism observed in 39% of nests, predominantly by Melittobia sp. and rarely by Diptera (Tachinidae). A 1:1 sex ratio was observed among the newly emerged adults of each locality analyzed. Strong sexual dimorphism was characterized by linear measurements of wings and body mass, with females and males showing a mass between 27-116 mg and 14-70 mg, respectively. The geometric morphometry confirmed this dimorphism and revealed significant variation of wing size and shape among individuals of the analyzed populations, a result that deserves subsequent studies to point out the factors that account for this differentiation.

Insights into the Nesting Ecology and Annual Hatchling Production of the Komodo Dragon

We studied annual trends and characteristics of nesting activities and hatchling production by female Komodo Dragons (Varanus komodoensis) in Komodo National Park, Indonesia between 2002 and 2006. During this period, we recorded 12, 16, 15, 13, and 6 females nesting annually at 42 potential nesting sites. An average female nesting periodicity was estimated at 1.2±0.4 years. This result arose because most females bred annually and some biennially. Some females reused nest sites in successive years while others did not. Nesting females had significantly lower body mass compared to when they were recaptured again in a non-nesting state. All-female nesting activities were conducted within their resident valleys and suggested a strong tendency for spatial fidelity. Komodo Dragons were generally considered solitary nesters as only on one occasion were two nesting females observed to use the same nesting site. On average, 21.0±3.6 Komodo Dragon hatchlings emerged from each nest. We estimated that within the study area, nesting female Komodo Dragons produced between 129.0±21.8 and 344.0±58.16 hatchlings per annum. We discuss the ecological and evolutionary significance of these attributes. However, the main conservation management implications drawn from this study are that there are a low annual number of nesting females and associated hatchling production in Komodo National Park. Hence, a continuation of more extensive nesting surveys could provide a cost-effective and accurate way to gather important long-term demographic information for this species.

Warmer April Temperatures on Breeding Grounds Promote Earlier Nesting in a Long-Distance Migratory Bird, the Prothonotary Warbler

Global climate change and warming are altering hemispheric and local weather patterns. Altered weather patterns have great potential to affect the phenology of life history events, such as the initiation of breeding in organisms that reproduce seasonally. Long-distance migratory birds may be particularly challenged by changes in local weather on breeding grounds because they arrive from distant locations and must commence breeding when conditions are appropriate. Here we explore the effects of local temperature on first egg dates and annual productivity in a long-distance Neotropical migratory songbird, the prothonotary warblerProtonotaria citrea. We present results from a 20-year (1994 to 2013) study documenting the detailed nesting activities of a color-marked population (average of 155 individual females each year) of warblers in southern Illinois, United States. The warblers typically arrive in April and start breeding in late April and May in our study system. We tested for an effect of local average April daily temperature and female age on first egg dates, total number of offspring produced per female, and the probability of fledging two broods. We found that warmer April temperatures promoted earlier first egg dates and higher average annual productivity in the warblers. On average, older females had earlier first egg dates than 1-year-old females, but both age groups responded similarly to local April temperatures. The reproductive gains associated with earlier first egg dates in warmer years stemmed from an increased probability of successfully fledging two broods, suggesting that earlier first egg dates do not currently create a mismatch with food (insect) resources. Earliest arrival dates of warblers to the region of our study system were not affected by local April temperatures, suggesting that females vary their first egg date based on conditions they experience/assess after their arrival. Whereas these birds currently adjust the timing of their breeding and actually produce more offspring in warmer years, continued global warming may eventually upset the current balance between arrival dates, food resources, and the commencement of nesting.

Inter‐group conflict in a cooperatively breeding bird: New insights into “home field advantage”

AbstractConflicts between groups of animals have individual‐level fitness consequences that can influence the evolution of social behaviour. In the cooperatively breeding greater ani (Crotophaga major), groups occasionally destroy the eggs of their neighbours, causing the attacked group to abandon their nest. Prior research suggested that such conflicts occur when two groups build nests in close proximity, and that established groups tend to evict newcomers. However, inter‐group conflict had never been directly observed. Here, we report the first photographic evidence of egg destruction by greater anis. Twelve artificial nests containing clay eggs were placed in the field with the intent of attracting nest predators. Camera footage revealed that although only two nests were discovered by heterospecific predators (white‐faced capuchins, Cebus capucinus), five nests were visited by resident anis, who in three cases damaged the clay eggs by grasping them with their bills and ejecting them from the nest cup. Nests were discovered between 2 and 96 hr after being placed in the field (mean = 34 hr) and were visited up to 18 times by up to 4 individuals simultaneously. The distance between artificial nests and the nearest known ani territory ranged from 0.13 to 0.28 km (mean = 0.2 km). Resident groups did not subsequently breed at the nest sites that they attacked, consistent with the hypothesis that the main benefit of inter‐group conflict is to reduce competition for local resources rather than to usurp nest sites. This accidental experiment reveals that greater anis closely monitor nesting activity near their territories, which may contribute to the strong “home field advantage” that resident groups hold over intruders.

A long-term decline in the abundance of endangered leatherback turtles, Dermochelys coriacea, at a foraging ground in the California Current Ecosystem

Pacific leatherback turtles (Dermochelys coriacea) are critically endangered, and declines have been documented at multiple nesting sites throughout the Pacific. The western Pacific leatherback forages in temperate and tropical waters of the Indo-Pacific region, and about 38–57% of summer-nesting females from the largest remaining nesting population in Papua Barat (Indonesia) migrate to distant foraging grounds off the U.S. West Coast, including neritic waters off central California. In this study, we examined the trend in leatherback abundance off central California from 28 years of aerial survey data from coast-wide and adaptive fine-scale surveys. We used a Bayesian hierarchical analysis framework, including a process model of leatherback population density and an observation model relating leatherback observations to distance sampling methods. We also used time-depth data from biologgers deployed on 21 foraging leatherback turtles in the study area to account for detection biases associated with diving animals. Our results indicate that leatherback abundance has declined at an annual rate of −5.6% (95% credible interval −9.8% to −1.5%), without any marked changes in ocean conditions or prey availability. These results are similar to the nesting population trends of −5.9% and −6.1% per year estimated at Indonesian index beaches, which comprise 75% of western Pacific nesting activity. Combined, the declining trends underscore the need for coordinated international conservation efforts and long-term population monitoring to avoid extirpation of western Pacific leatherback turtles.

Habitat modelling locates nesting areas of the Endangered Black-capped Petrel Pterodroma hasitata on Hispaniola and identifies habitat loss

SummaryThe Black-capped Petrel or Diablotin Pterodroma hasitata has a fragmented and declining population estimated at c.1,000 breeding pairs. On land, the species nests underground in steep ravines with dense understorey vegetation. The only confirmed breeding sites are located in the mountain ranges of Hispaniola in the Caribbean, where habitat loss and degradation are continuing threats. Other nesting populations may still remain undiscovered but, to locate them, laborious in situ nest searches must be conducted over expansive geographical areas. To focus nest-search efforts more efficiently, we analysed the environmental characteristics of Black-capped Petrel nesting habitat and modeled suitable habitat on Hispaniola using openly available environmental datasets. We used a univariate generalized linear model to compare the habitat characteristics of active Black-capped Petrel nests sites with those of potentially available sites (i.e. random pseudo-absences). Elevation, distance to coast, and the influence of tree cover and density emerged as important environmental variables. We then applied multivariate generalized linear models to these environmental variables that showed a significant relationship with petrel nesting activity. We used the top performing model of habitat suitability model to create maps of predicted suitability for Hispaniola. In addition to areas of known petrel activity, the model identified possible nesting areas for Black-capped Petrels in habitats not previously considered suitable. Based on model results, we estimated the total area of predicted suitable nesting habitat for Black-capped Petrels on Hispaniola and found that forest loss due to hurricanes, forest fires, and encroachment from agriculture had severely decreased availability of predicted suitable habitat between 2000 and 2018.

Acute contact with imidacloprid in soil affects the nesting and survival success of a solitary wild bee, Osmia lignaria (Hymenoptera: Megachilidae)

We assessed impacts of direct acute contact with imidacloprid-treated soil on nesting behavior and mortality of the blue orchard mason bee (Osmia lignaria Say), which is a native solitary cavity-nesting species that collects mud for nest partitions. Laboratory-reared O. lignaria females were exposed to three concentrations of imidacloprid (0, 50, 390 and 780 ppb), in wet (30% moisture) soil for 20 min and released in large flight cages, where impacts on nesting activity and nest cell production were evaluated. Mortality was tested in another experiment using exposure at the same concentrations with two differing soil moisture levels (20% and 40%). Nesting activity was reduced by 42% for females exposed at 390 ppb and by 66% for females exposed at 780 ppb. Females treated at 780 ppb produced 40% fewer nest cells per day. Sex ratios of F1 generation were skewed toward male in the 50 ppb treatment group with 50% fewer females. The number of cells and pre-pupae per nest, as well as the weight of pre-pupal cocoons did not vary among exposure levels. There were no mortality effects at 20% soil moisture for any level of imidacloprid, but at 40%, mortality of females was >50% at all levels of imidacloprid. These results suggest that acute exposure to imidacloprid residue in soil can have negative impacts on soil-interacting bees, and the effects may be relative to the degree of soil moisture.

First data on the bionomics of Leptochilus (Euleptochilus) limbiferus (Morawitz, 1867) (Hymenoptera: Vespidae: Eumeninae), with taxonomic notes and new records.

Nesting of Leptochilus limbiferus (Morawitz, 1867) was observed in the Krasnodar Territory, Russia. Twelve nests were studied; all of them were located in empty shells of a terrestrial snail species, Xeropicta derbentina (Krynicki). The building material used by the wasps was pellets of dry soil and gravel particles, as well as shell bits, and sometimes also tiny shells. Females hunted for caterpillars of a gelechiid moth Syncopacma coronillella (Treitschke) and two unidentified species. Imagoes of L. limbiferus were observed feeding on nectar at flowers of five plant species in five families. Males were also observed patrolling the nesting site and sleeping inside a shell of X. derbentina. Nests were invaded by ants and an anthracine fly. Nesting activity and structure of the nests and cocoons are described in detail. The species is univoltine; hibernation occurs at the prepupa stage. The present contribution is the first detailed report on the bionomics of the subgenus Euleptochilus Blüthgen, 1943. Nesting of Old World species of Leptochilus de Saussure, 1853 is discussed with special reference to use of gravel as building material in two phylogenetic lineages: Leptochilus and unrelated genus Alastor Lepeletier de Saint-Fargeau, 1841. The distribution of L. limbiferus is summarized; particularly, the species is reported from Montenegro and Azerbaijan for the first time. At the same time, its previous records from Armenia were found to be based on a misidentification of Leptochilus (Euleptochilus) duplicatus (Klug, 1835) (new for Armenia and the Caucasus as a whole). Leptochilus limbiferus anatolicus Blüthgen, 1955 and L. limbiferus achaeus Gusenleitner, 1970 are treated as synonyms of L. limbiferus s. str. (new synonymies). The lectotype of Odynerus limbiferus Morawitz, 1867 is designated. A key to subgenera of Leptochilus is provided.

Findings of overground nests of rodents in the Ukrainian Beskids (upper course of the Dnister)

Materials are collected and generalised on the overground nesting activity of 4 rodent species under conditions of the north Carpathian taiga: the red squirrel (Sciurus vulgaris), the edible dormouse (Glis glis), the hazel dormouse (Muscardinus avellanarius), and the harvest mouse (Micromys minutus). The locality is characterised by a combination various habitats. Common and unique variants of nests of these species are described, particularly the arrangement by the hazel dormouse of its own nests in nests of the Eurasian wren and song thrush, an unusual nest of the red squirrel, and the nesting of the edible dormouse in an abandoned dress.

Caspian Tern Response to Managed Reductions in Nesting Habitat

ABSTRACTPredation on smolts by Caspian terns (Hydroprogne caspia) has been identified as a factor limiting the restoration of some populations of anadromous salmonids (Oncorhynchus spp.) from the Columbia River basin that are listed under the U.S. Endangered Species Act. Implementation of a management plan to reduce numbers of Caspian terns nesting at the 2 largest colonies in the Columbia Plateau region of Oregon and Washington, USA, began in 2014 and is ongoing. We investigated the response of Caspian terns during 2014–2016 to reductions in nesting habitat at these 2 colonies. Management prevented terns from nesting at both colonies, and the estimated numbers of nesting pairs in the region declined significantly from a mean of 877 pairs during premanagement to 769 and 675 pairs in 2015 and 2016, respectively. The management objective of reducing numbers of nesting terns in the Columbia Plateau region to ≤200 breeding pairs was not achieved during the first 2 years of full implementation of the plan. Regional nesting success did not decline significantly following the initiation of management, and remained at levels considered sufficient to sustain the regional subpopulation. Despite the species’ capacity for long‐distance breeding dispersal, the majority of displaced terns exhibited stronger than expected philopatry to the Columbia Plateau region. Analysis of resightings of banded terns indicated that most (&gt;80%) terns that nested in the Columbia Plateau region premanagement returned to the region in 2015 and 2016, but the proportion that returned as breeders decreased while the proportion that returned as nonbreeding floaters increased compared with premanagement. The proportion of banded terns that were unobserved also increased during management years, suggesting that more terns became floaters in the Pacific Flyway and went unobserved because they were prospecting and foraging in locations or regions where there was little or no monitoring. The unexpectedly high regional philopatry exhibited by terns during management was likely a reflection of the low availability of suitable alternative nesting habitat outside the region. Most terns that remained in the region displayed considerable flexibility in nest site selection by nesting either at a previously smaller, intermittently successful breeding colony or at a small new colony where nesting activity had not previously been recorded. As long‐lived seabirds, Caspian terns may integrate information regarding nesting success over several years before choosing to change nesting locations, longer than the 2 years of this study, especially if alternate locations are distant or intermittently available, or a history of nesting at multiple locations exists within the region. © 2020 The Wildlife Society.