Andrew N. Hoodless

Effects of spring feeding on body condition of captive-reared ring-necked pheasants in Great Britain.

In Great Britain, the captive rearing and release of ring-necked pheasants (Phasianus colchicus) during summer to supplement wild stocks for shooting is widespread, but breeding success of surviving females the following spring is poor. We hypothesized that reduced body condition as caused by low availability of natural food during spring and cessation of supplemental feeding in late winter may affect subsequent breeding success. On an estate in southern England, we provided wheat grain on 3 l-km 2 plots from March to June, while pheasants on 3 other l-km 2 plots foraged solely on natural foods. We switched treatments during the second year. We collected hen pheasants from each plot during February and April. Fat reserves of hen pheasants collected in April from food-supplemented plots were maintained at their February levels (76.9 ± 8.0 g; x ± SE), but fat reserves of birds collected from unsupplemented plots were reduced by >50% of their Febmary levels (34.7 ± 6.9 g; P = 0.01). Body mass, muscle sizes, ceca, and small intestine length were more affected by date than supplemental feeding. We suggest that low food availability and poor spring diet as a result of modern agriculture may affect hen body condition and productivity of pheasants in Great Britain.

Effects of weather and timing on counts of breeding Snipe Gallinago gallinago

Capsule Snipe numbers are assessed most accurately at dusk and at low wind speeds. Aims To identify factors affecting the variability and efficiency of breeding Snipe surveys and to assess the validity of current survey methods for estimating breeding densities or monitoring population change. Methods The effects of cloud cover, rain, wind, diurnal and seasonal timing on estimated densities of breeding Snipe were assessed using data from early morning and evening surveys on moorland during mid-April to early June. The effects of diurnal and seasonal timing of surveys were examined using data from counts of Snipe made at three-hour intervals throughout the day on four dates. Results Estimated total Snipe densities and densities of drumming Snipe declined as wind speed increased (25% and 39% lower, respectively, at force 2–3 on the Beaufort scale and 46% and 83% lower at force 4–5 compared to force 0–1). Drumming Snipe density estimates were 266% higher in light rain than dry conditions. Numbers of drumming Snipe were highest at dusk and low numbers of Snipe were encountered during the middle of the day. There was seasonal variation in drumming activity, with little drumming during late April and early May. Conclusions Surveys of breeding Snipe should not be undertaken when wind exceeds force 3 on the Beaufort scale (or 19 km/h). In situations where only small areas need to be surveyed but absolute numbers are desirable, point counts at dusk will be the most effective method.

MALDI-TOF mass spectrometry as a simple tool to determine the phospholipid/glycolipid composition of sperm: Pheasant spermatozoa as one selected example

Cellular membranes are composed of highly variable lipid molecules, mainly cholesterol and phospholipids (PLs). The cholesterol moiety and the saturation degree of the fatty acyl residues of PL determine the fluidity of the membrane, which is particularly important for sperm because they have to undergo characteristic membrane-dependent processes (acrosomal exocytosis and fusion with the oocyte). Glycolipids are an essential part of the membrane surface acting as key mediators in the interactions of sperm with components of the female genital tract. Although the lipid composition of many mammalian spermatozoa has already been determined, the lipid composition of avian spermatozoa has scarcely been investigated. Using spermatozoa extracts of the ring-necked pheasant (Phasianus colchicus) as a selected example, this work demonstrates that matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a simple and fast method to determine spermatozoal lipid compositions. The lipid compositions of pheasant spermatozoa have not yet been investigated. In addition to common membrane (primarily diacyl) PL (sphingomyelin, phosphatidylcholine, phosphatidylinositol and phosphatidylethanolamine), remarkable variation of different sulfoglycolipids (sulfogalactocerebrosides) was identified. This is in strong contrast to all other animal species investigated so far which nearly exclusively contain the sulfoglycolipid seminolipid (sulfogalactoalkylacylglycerol). We emphasize that the MALDI MS approach allows the characterization of sulfoglycolipids of sperm within a few minutes without the necessity for previous chromatographic separation.

Densities and population estimates of breeding Eurasian Woodcock Scolopax rusticola in Britain in 2003

Capsule The breeding Eurasian Woodcock population in Britain was estimated at 78 346 males (95% CL 61 717–96 493), with substantial differences in densities between regions and woodland type. Aim To estimate the breeding population size of Woodcock in Britain using a dedicated survey method, to enable assessment of current status and the creation of a baseline for future monitoring. Methods Passes of roding male Woodcock were recorded on three evening visits to 807 randomly selected sites, stratified by region and woodland size, by volunteer observers during May–June 2003. Results Roding Woodcock were present in 35% of 1‐km squares containing at least 10 ha of woodland and the mean density of males in occupied squares was 2.76 ± 0.29 birds/km2 (± se). There was significant regional variation in the occurrence and density of roding Woodcock. Woodcock presence differed between woodland types at the 1‐km2 level and the stand level, but densities within occupied woods were similar across woodland types. Conclusion Previous estimates of the size of the British breeding Woodcock population are far too low and the species shows much spatial variation in breeding density.

Current status and recent trend of the Eurasian Woodcock Scolopax rusticola as a breeding bird in Britain

Capsule The breeding Woodcock population in Britain in 2013 was estimated at 55 241 males (95% CL: 41 806–69 004), suggesting a large-scale decline that is supported by 2 additional sources of data. Aims To provide an updated estimate of the size of Britains breeding Woodcock population, measure recent trends and identify spatial patterns of change. Methods Displaying male Woodcock were surveyed at a stratified sample of 834 randomly selected sites. Population estimates were compared with a baseline survey conducted in 2003 and the trend with data from annual Woodcock counts (2003–13) and Bird Atlas 2007–11. Results Woodcock were estimated to be present at 22% of 1 × 1 km squares containing ≥10 ha of woodland, compared to 35% in 2003. The British population estimate fell by 29% between 2003 and 2013. The Atlas suggests that presence at the 10 × 10 km scale has declined by 56% between 1970 and 2010. Both data sources suggest regional variation in the rate of decline, with losses greatest in the West and South. Conclusion The Woodcocks population size and breeding range appear to be declining severely across Britain. Regional variation in the rate of decline might be explained by the distribution of large continuous woodlands.

Assessing breeding success in common woodland birds using a novel method

Capsule Repeated counts of fledged broods can provide a useful estimate of breeding success for most common woodland birds. Aims To assess the efficacy of comparing fledged-brood survey data with territory mapping using simple mark–recapture analysis techniques to provide an estimate of breeding success for common woodland birds that does not involve finding nests. Methods Three observers undertook territory mapping surveys of adults, followed by counts of fledged broods four times a week during May–July 2007 in two 15 ha woods each, both in southern England. Using known fledging to maturity periods, these counts were used to calculate daily detection probabilities for broods of ubiquitous species. These enabled fledged brood territory occupancy probabilities (i.e. brood to territory ratios) to be estimated that take account of the possibility that broods were present but missed by surveys. Results Of the 19 species found in all six woods, mean daily detection probability estimates for fledged broods of 17 species ranged from 0.17 to 0.50 with significant variation between woods for 12 species, but within region/observer for four species. The mean probability of detecting a brood at least once was over 75% using four visits per week and over 50% using two visits. Only for Great Spotted Woodpeckers Dendrocopos major and Garden Warblers Sylvia borin was the fledging period too short and the daily detection probability too low to provide a reasonable estimate of the territory occupancy probability. Conclusion Daily detection probabilities for fledged broods of most common woodland birds were sufficiently high to enable useable estimates of fledged-brood territory occupancy probabilities to be made based on a survey programme involving two or three visits per week between late May and the end June. The method used may have application as a means of providing a relatively easily derived productivity index for woodland bird monitoring programmes or for research studies.

Impacts of predator abundance on red grouse Lagopus lagopus scotica during a period of experimental predator control

During a nine-year study manipulating predator abundances, post-breeding numbers of red grouse Lagopus lagopus scotica increased initially in response to experimentally reduced levels of key predator species (i.e. red fox Vulpes vulpes, carrion crow Corvus corone, stoat Mustela erminea and least weasel M. nivalis), but subsequently declined whilst predator control continued. Raptors, which were not controlled, were also present and may have influenced grouse demography. Our study examines the relative importance of controlled predators and raptors on grouse breeding success and survival. Raptor abundance did not differ between periods of predator control and periods of no predator control. However, during the breeding season, the survival of adult grouse was negatively correlated with the abundance of both raptors and controlled predators. Within the group of controlled predators, the strongest effects on red grouse adult survival were attributed to small mustelid abundance. Grouse breeding success was negatively correlated with the abundance of controlled predators, particularly carrion crows; however, no significant effect of raptor abundance was detected.

Habitat correlates of Eurasian Woodcock Scolopax rusticola abundance in a declining resident population

AbstractIn Europe, woodland bird populations have been declining since at least the 1970s, and in Britain, around one third of woodland bird species have undergone declines over this period. Habitat change has been highlighted as a possible cause, but for some species clear evidence of this is lacking owing to an incomplete knowledge of the species’ habitat requirements. Here, we analyse national data to explain the variation in abundance of a declining woodland bird, the Eurasian Woodcock. A nationwide, species-specific survey of breeding Woodcock was conducted in 2003 and 2013 at 807 and 823 randomly selected 1-km squares respectively. The counts were compared with a range of landscape-scale habitat variables as well as local habitat measures recorded by surveyors, using generalised linear mixed models. Habitat variables were measured at a variety of spatial scales using ring buffers, although our analyses show that strong collinearity between scales hinders interpretation. At large landscape scales, breeding Woodcock abundance was correlated with total woodland area and the way this interacted with woodland type. Woodcock were more abundant in woods containing a more heterogeneous mix of woodland habitat types and in woods further from urban areas. On a smaller spatial scale, Woodcock were less likely to be found at sites dominated by beech Fagus spp. and more likely to occur in woods containing birch Betula spp. The Woodcock’s association with large, heterogeneous woods and the apparent attractiveness of certain woodland types present the most relevant topics for future research into the role of habitat change in long-term declines.ZusammenfassungHabitatkorrelate der Abundanz der WaldschnepfeScolopax rusticolain einer zurückgehenden Standvogelpopulation In Europa haben Waldvogelpopulationen spätestens seit den 1970er Jahren abgenommen, und in Großbritannien hat etwa ein Drittel der Waldvogelarten in diesen Zeitraum Bestandsrückgänge erfahren. Als eine mögliche Ursache wurde Habitatveränderung hervorgehoben, aber für einige Arten fehlen hierfür klare Beweise, da das Wissen über ihre Habitatansprüche lückenhaft ist. Hier analysieren wir landesweite Daten, um die Variation in der Abundanz eines im Bestand abnehmenden Waldvogels, der Waldschnepfe, zu erklären. Eine landesweite artspezifische Zählung brütender Waldschnepfen wurde in den Jahren 2003 und 2013 in 807 bzw. 823 zufällig ausgewählten 1-km-Quadraten durchgeführt. Mit Hilfe generalisierter linearer gemischter Modelle wurden die gewonnenen Zahlen mit einer Reihe von Landschafts-Habitatvariablen sowie lokalen Habitatparametern, die von den Gutachtern vor Ort aufgenommen worden waren, verglichen. Habitatvariablen wurden auf mehreren räumlichen Skalen mit Hilfe von Ringpuffern gemessen, wobei unsere Analysen zeigen, dass eine starke Kollinearität zwischen den Skalen die Interpretation erschwert. Auf großräumigen Landschaftsskalen hing die Abundanz brütender Waldschnepfen mit der Gesamtwaldfläche sowie deren Interaktion mit dem Waldtyp zusammen. Waldschnepfen kamen häufiger in Wäldern vor, die eine heterogenere Mischung von Waldhabitattypen aufwiesen, sowie in Wäldern, die weiter von Stadtgebieten entfernt waren. Auf einer kleinräumigeren Skala waren Waldschnepfen an von Buchen Fagus spp dominierten Standorten seltener anzutreffen und häufiger in Wäldern mit Birken Betula spp. Die Assoziation von Waldschnepfen mit großen, heterogenen Wäldern und die offensichtliche Attraktivität gewisser Waldtypen stellen die relevantesten Themen für zukünftige Forschung zur Rolle von Habitatveränderungen bei langfristigen Bestandsrückgängen dar.

A method for mist-netting breeding Eurasian Woodcock: use of visual and audio lures increases capture rate

ABSTRACT We describe a method for mist-netting Eurasian Woodcock Scolopax rusticola in the breeding season using a remote-control playback lure and a decoy. Nineteen roding woodcock were caught in 39 sessions in 2016. A GLM, in which length of mist-net was specified as an offset, was used to compare our capture rate to that of a previous study in which no lure was used, suggesting our ‘number of captures per session’ was approximately nine times higher. Ringing individuals that are known to belong to Britain’s resident breeding population could provide more comprehensive data, which are of particular value given this population’s ongoing decline.