Arctic Terns Sterna paradisaea have an exceptionally long-distance migration, annually travelling back and forth between the Arctic and the Antarctic. Birds from Greenland, Iceland and the USA were recently found to spend most of the non-breeding period in the Weddell Sea, a small part of the large Antarctic range of Arctic Terns. Based on ring recoveries and sightings of West European Arctic Terns in the Indian Ocean and Australian waters, we expected that terns from The Netherlands (the southern limit of the breeding range) inhabit different Antarctic regions during the non-breeding season to their conspecifics from Greenland. To find out, geolocators were deployed on seven Arctic Terns captured on the nest in 2011 in The Netherlands. All birds were recaptured in 2012 and five devices yielded information on migration routes. The tracked terns spent on average 273 ± 7 days away from The Netherlands, and visited known staging areas in the North Atlantic and the Benguela Current, on both the outward and return journey. Similar tracks were observed in the terns from Greenland. However, hereafter the terns from The Netherlands moved to a previously unknown staging area in the central Indian Ocean, between 20–40°N and 65–100°E, and spent most of the non-breeding season in the Southern Ocean between 35–150°E. One bird migrated as far as New Zealand. Eventually, all five birds spent the austral summer in Wilkes Land, Antarctica, before flying back to the breeding colonies with a small detour to the same North Atlantic staging area they visited on their southward migration. The total travel distance in the course of the non-breeding period was ∼90,000 ± 2000 km, which substantially exceeds previous estimates for this species. Our study revealed new offshore staging areas and a yet unknown route through three different oceans, the longest bird migration described thus far.

We investigated the adaptations of primary moult to conditions on the nonbreeding areas in the Curlew Sandpiper Calidris ferruginea, an Arctic breeding, long-distance migratory wader (shorebird). Parameters of moult (start date, duration, and standard deviation) and how they are affected by rainfall patterns were estimated using and extension of the Underhill—Zucchini (1988) moult models which allows the inclusion of covariates. The estimated start date and duration of moult in Kenya was 2 October and 128 days, respectively; start date was negatively correlated with the rainfall in June. In India, the estimated start date of moult was 15 August, duration 107 days and start of moult was positively correlated to the rainfall in August. Circumstantial evidence also suggests that the rate of growth of the primaries was affected by food supply at the nonbreeding areas. The timing of moult to coincide with rainfall periods is, perhaps, an adaptation to carry out this energy demanding activity during periods of food abundance. This study shows that in these populations of the Curlew Sandpiper, the timing of moult is a direct response to environmental variation and might be used to measuring the impacts of climate change on life-history traits of migratory birds.

Almost all accounts of the reproductive biology of House Martins Delichon urbicum are based on studies of birds breeding in artificial nests that are monitored every few days. Here, I provide a study on House Martins using self-built mud nests at a single colony in Gaast, The Netherlands (225 nest attempts in 2004–2011); the stages of breeding were inferred from ‘remote’ observations of parental and chick behaviour. Small chicks were noticed from 30 May onwards, with a first peak of nestling appearance in 5–9 June. A second, and larger, peak in small chicks occurred in late June. Large chicks from first broods were noticed from mid June to mid August, and the first large chicks from second broods from late July onward. The last fledglings left nests in late September. Among the 205 successful nest attempts, 62% had one brood, and 38% had two broods (three in one case). The first nest sites to be occupied in mid-April were always old nests that had survived the winter. Surprisingly, the use of old nests did not result in earlier incubation and chick-rearing activities. Nevertheless, re-used near-intact old nests hosted multiple broods in 72% of cases, a much higher percentage than in newly built nests (20%). The earlier occupation of old nests and the greater incidence of second broods was further associated with a relatively high percentage of older House Martins. Whereas only 8% of 126 nests hosting one brood were occupied by at least one known >2nd calendar year bird, no fewer than 30% of the 79 nests with two broods were. Despite a steady offering of clean wood-concrete nests at the colony, such artificial alternatives were occupied in only 23 out of 307 possible cases, rather than the near-100% occupancy of old mud nests and nest remains. Also, the start date of occupation was later than that of intact or partial old mud nests. This strong preference by older birds for (the remains of) existing mud nests and the rejection of clean, strong artificial nests, implies that any costs of being exposed to greater numbers of ectoparasites such as louse flies Crataerina hirundinis overwintering in old nests are outweighed by the signal of quality inherent in the occupation of parasite-infested old mud nests.

In Britain the Common Crossbill Loxia curvirostra population has increased markedly in abundance and range with the maturing of the post-war forestry plantations. However, little published information exists on the breeding ecology of the species in these plantations. Crossbills were more abundant in years of high Sitka Spruce Picea sitchensis cone production in the upland forestry plantations of South Wales. The breeding season began early in the year with a median laying date of 13 February and declined after this peak with few nests initiated after April, when the availability of Sitka Spruce seeds declined. The modal clutch size was 3 eggs and an estimated 35% of nests produced fledged young. Most nest failures were associated with adverse weather. Our observations indicate ephemeral occupancy of Sitka Spruce forests as a consequence of variable seed availability, a peak in breeding activity determined by photoperiod and food supply and a low level of breeding productivity.

We analysed the vocalisation behaviour of Rockhopper Penguin chicks Eudyptes chrysocome during hatching. Hatching vocalisation rates (in number per minute) were not consistently influenced by ambient air temperature. They did not differ between chicks hatching from first-laid eggs (which are smaller, hatch second, and usually suffer brood reduction) and chicks hatching from second-laid eggs (which usually develop into fledglings). Hatchlings did not show significantly different vocalisation rates in the presence of a sibling during hatching. Hatching vocalisation rates also did not increase between the penultimate day and the last day before hatching. These results suggest that Rockhopper Penguin chicks might gain little benefit (parental care) from increased vocal behaviour at the late incubation stage.

To determine the start of the breeding season of Common Woodpigeon Columba palumbus in Flanders, the gonads of 185 adult Woodpigeons were examined. Analysis of testis size showed that male Woodpigeons became sexually active in March. Follicle size analysis indicated that the first female Woodpigeons became sexually active from the end of February onwards. The observations however indicated an overall start of the breeding season on a population level by late March/early April.

Estimating the number of genome copies in a tissue sample can serve various purposes. For example, such an estimate serves as a scaling variable when measuring telomeres with quantitative PCR. We describe the primer development and evaluation for the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene in the Great Tit Parus major, as a control gene to estimate genome copy number. We demonstrate specific amplification with negligible variation in 48 Great Tits and cross-amplification in 53 Blue Tits Cyanistes caeruleus. We conclude this primer set to be reliable for amplification of GAPDH as a reference gene for quantitative PCR analysis in Great and Blue Tits.

Contrary to expectations, a manyfold increase in human-provided carcasses was paralleled by a near-total failure of breeding success in a small Raven Corvus corax population in the central Netherlands. Shot game and road casualties had been deposited at two to three point sources, where the bonanza was quickly monopolized by flocks of non-breeding Ravens. Breeding success improved substantially as soon as carcasses were dispersed throughout the terrain, enabling territorial pairs to profit from nutritious food without being outcompeted by non-breeding Ravens.

Green Woodhoopoes (Phoeniculidae: Phoeniculus purpureus) are cooperative breeding birds that live throughout the year in groups of 2 to 16 individuals. Individuals roost in groups in cavities at night. The energy savings associated with communal cavity roosting has been implicated as an important determinant of survival in woodhoopoes. We measured field metabolic rate (FMR) and water influx of free-ranging adult woodhoopoes living in different group sizes in South Africa. We tested the hypotheses that woodhoopoes have a low FMR relative to other species of similar body mass, and that woodhoopoes roosting in small groups have a higher FMR than do individuals spending the night with large groups. For a male and females woodhoopoes, FMR differed from allometric predictions by -44.5% and -44.2%, respectively, supporting the idea that woodhoopoes have a markedly reduced FMR. Our data also indicated that females in small groups tended to have an elevated FMR compared with females in larger groups, but no such trends were identified for males.

The Yellow Wagtail Motacilla flava consists of about 18 taxa whose taxonomic relationships are unclear. Some authors elevate 11 taxa to species based on often characteristic nuptial plumages of males, whereas others recognize two species based on molecular data. Hybridization is a regular event but with intriguingly varying intensity between different taxa. In spite of breeding generally in damp fields, their breeding habitat is actually rather diverse, which offers an opportunity for ecological segregation by breeding habitat. Indeed, some authors describe habitat differences between taxa but others do not. Two sympatrically occurring taxa are thunbergi and beema in European Russia and Western Siberia. In this study we describe their breeding habitat and determine whether this differs between taxa. We aimed to determine whether breeding habitat could be an ecological factor for sub-specific segregation in this part of their breeding range. We found strong indications for segregated breeding, despite the rather limited dataset: thunbergi occurred in bogs as a breeding bird and beema was dominantly found breeding in floodplain meadows. On one location bog and floodplain were separated by only 1.5-2 km of forest, yet here too only thunbergi occurred on the bog and beema on floodplain meadows. Following recent molecular taxonomic findings our thunbergi might very well concern plexa, belonging to the eastern species. As beema is assigned to the western species, the observed spatial segregation between plexa and beema may be representative of habitat separation of the western and eastern species in areas where they occur sympatrically. Large scale segregated breeding due to different habitat preferences could have consequences for taxonomic interpretations within the M. flava complex.

Observations on the diet and feeding behaviour of naturalised Yellow-headed Amazona oratrix and Blue-fronted Amazon Parrots Amazona aestiva xanthopteryx and their hybrids were carried out in the city of Stuttgart, southwest Germany, the only European city known to host an established population. Food items taken ranged from bark, young shoots, flower and leaf buds, flowers, and seeds to fruit. Since the introduction of the Amazon Parrots in 1984, a total of 64 food plant taxa from 23 plant families were identified, amongst them 37 native taxa, and 27 non-native trees and shrubs. Food resources seem widely available for this naturalised population and therefore appear not to be a limiting factor for population growth. Some food items containing bitter and poisonous compounds are used exclusively by Amazon Parrots, reducing food competition with native birds.