Showing papers in "Bird Study in 2017"
TL;DR: More than half of the world's human population lives in cities in which birds constitute the major, or only, contact people have with... as mentioned in this paper. But the authors of this paper do not consider the relationship between birds and humans.
Abstract: As the Editors of this publication note in their introduction, ‘more than half of the world’s human population lives in cities in which birds constitute the major, or only, contact people have with...
41 citations
TL;DR: The first national-scale analysis of the potential drivers of Curlew population change in Britain is presented in this article, which is needed to guide conservation action for this globally near-threatened, declining species.
Abstract: Capsule: Across Britain, breeding Eurasian Curlew Numenius arquata are less numerous and have shown greater population declines in areas with more arable farming, woodland cover and higher generalist predator abundance.Aims: We present the first national-scale analysis of the potential drivers of Curlew population change in Britain, which is needed to guide conservation action for this globally near-threatened, declining species.Methods: Breeding Bird Survey data and environmental predictors were used to model variation in Curlew abundance in 1995–99 and 2007–11, and population change between these periods.Results: Arable farming and woodland cover were negatively associated with Curlew abundance and population declines. Curlew abundance was positively associated with extent of protected area coverage and gamebird numbers. Abundance and population change were positively associated with cooler temperatures and higher summer rainfall, but negatively associated with numbers of generalist predators.Co...
33 citations
TL;DR: In this article, the authors compared nests of six bird species of the families Fringillidae and Motacillidae to investigate the insulative properties in still and moving air treatments.
Abstract: Capsule: Air movement over a nest increases the rate of cooling within the nest cup but the walls
provide good thermal insulation.
Aims: This study compared nests of six bird species of the families Fringillidae and Motacillidae to
investigate the insulative properties in still and moving air treatments. It was hypothesized that
differences in nest size and moving air would differ between species and would have a
significant effect on insulatory values of the nests.
Methods: Nest dimensions were measured for a total of 35 nests from six species. Thermal
properties of the nests were recorded using temperature loggers within nests placed in a wind
tunnel under still and moving air conditions.
Results: Insulatory values and internal nest cooling rates were significantly increased by moving air.
There was no significant difference between species for the thermal properties of nests but nest
mass correlated with greater insulatory values and a lower rate of cooling within the nest cup.
Nest wall thickness had no significant effect on the thermal characteristics of the nests.
Conclusion: The use of a constructed nest mitigated the effects of air movement but the
differences between species reflected difference in nest mass rather than wall thickness.
21 citations
TL;DR: Space use and flight attributes of Lesser Kestrels were revealed by global positioning system tagging at two breeding colonies in Italy.
Abstract: Capsule: Space use and flight attributes of Lesser Kestrels were revealed by global positioning system tagging at two breeding colonies in Italy. Foraging flight distances and home-range sizes were both intermediate in comparison to previous studies in higher and lower quality habitats.
18 citations
TL;DR: Bird populations respond to changes in moorland management, but these changes are not always associated with detectable changes in vegetation, which could help refine agri-environment options and other conservation interventions on moor land.
Abstract: Capsule: Changes in abundance of six bird species showed associations with moorland management.Aims: To assess responses of breeding birds to moorland management over a 14-year period.Methods: Vegetation and birds were surveyed at 2–3-year intervals and changes examined in relation to sheep and cattle grazing, vegetation burning and cutting.Results: Seven correlations between change in management and change in bird abundance were detected, and six between change in vegetation and change in bird abundance. On plots where sheep numbers declined, Golden Plover Pluvialis apricaria and Northern Wheatear Oenanthe oenanthe declined. Where a greater area was burned, Golden Plover increased in the initial post-burning period but Red Grouse Lagopus lagopus scotica declined. Eurasian Curlew Numenius arquata and Sky Lark Alauda arvensis increased where a greater area of moorland vegetation was cut. Whinchat Saxicola rubetra declined with increasing cattle numbers on a plot.Conclusions: Bird populations respon...
17 citations
TL;DR: Differences in breeding biology, migration, moult and vocalizations between the two species are mirrored by a clear genetic separation that dates back to 1.9–2.1 mya at the Plio-Pleistocene transition, when global climate underwent a period of significant cooling and Northern latitudes were probably more favourable to the Common than to the Pallid Swift.
Abstract: Capsule: Common Swift Apus apus and Pallid Swift Apus Pallidus are morphologically very similar but are genetically distinct and diverged 1.9–2.1 million years ago (mya).Aims: To examine genetic differentiation and to estimate separation time between Common and Pallid Swifts.Methods: Estimation of differences in three different mitochondrial DNA markers (COI, ND2 and control region), and a fourth marker, the cytb, that did not differ between taxa. Fossils were used to calibrate the estimate of separation date between the two taxa.Results: The genetic between-species distances were 0.010, 0.006 and 0.033 for the three markers, respectively. These values were from three to ten times higher than within-species distances. Results show that the separation dates back to 1.9–2.1 mya, at the Plio-Pleistocene transition, when global climate underwent a period of significant cooling and Northern latitudes were probably more favourable to the Common than to the Pallid Swift.Conclusion: Differences in breedin...
17 citations
TL;DR: A complete survey of Golden Eagles Aquila chrysaetos in Britain in 2015 found that the population had increased by 15% since 2003 to 508 territorial pairs as discussed by the authors.
Abstract: Capsule: A complete survey of Golden Eagles Aquila chrysaetos in Britain in 2015 found that the population had increased by 15% since 2003 to 508 territorial pairsAims: The survey aimed to investigate the population size, distribution and breeding success of Golden Eagles in Britain, and to compare results with similar surveys since the early 1980sMethods: Every home range was visited on a minimum of three occasions between January and August 2015 First, to look for eagles or signs of their presence (January–March), then to look for evidence of breeding or further checks for occupation (April–June) and finally to record productivity of nesting pairs (July–August)Results: The figure of 508 territorial pairs represents a 15% increase in the population from 442 pairs in 2003 The proportion of home ranges occupied was 70% The largest increases in the proportion of occupied home ranges were in south-central Highlands (71%), northern moors and flows (38%) and northwest Highlands (29%), with modest
17 citations
TL;DR: Kleptoparasitism may well aid invasion and increase the range of environments a gull can tolerate by helping them meet their energy needs in novel environments where normal foraging behaviours are difficult to implement.
Abstract: Capsule: Kleptoparasitism in gulls occurred at a greater rate at an urban compared with a coastal site. Population density and prey size predicted the rate of kleptoparasitism at the urban site.Aims: To investigate and assess the ecological variables associated with kleptoparasitism among gulls at urban and rural sites.Methods: Field observations were conducted at Brancaster (coastal rural) and Billingsgate Market (urban) to examine differences in the rate of kleptoparasitism in mixed-species flocks of gulls. Four key variables (prey size, population density, season and species) were assessed as predictors of kleptoparasitism.Results: Generalized linear models revealed significant effects on kleptoparasitism rate of site, population density and prey size, and two-way interactions between these main terms. Population density and prey size differed significantly between sites, but population density appeared to predict the rate of kleptoparasitism.Conclusion: Kleptoparasitism may well aid invasion a...
17 citations
TL;DR: In this paper, the authors argue that wind farms are a well-developed and cost-effective source of renewable energy for combating human-induced climate change, and that renewable energy developments are increasingly forming an essential part of our efforts to combat human induced climate change.
Abstract: Renewable energy developments such as wind farms are increasingly forming an essential part of our efforts to combat human-induced climate change. Wind farms are a well-developed and cost-effective...
17 citations
TL;DR: Differences in nestling diet between habitat types contribute to explain variance in breeding performance and therefore demonstrate diverse foraging behaviour strategies among populations.
Abstract: Capsule: The nestling diet of Blue Tits Cyanistes caeruleus is influenced by parental effort and habitat type, and consequently has an impact on breeding success.Aims: In a three-year study, we compared the nestling diet of Blue Tits in two Mediterranean forests (pinewood and oakwood) and tested its implications for breeding success.Methods: Adults were captured at the nest to obtain morphological measurements, and provisioning behaviour was recorded when chicks were 11 days old. Nestling tarsus length and body mass were measured on day 13 after hatching.Results: Caterpillars constituted the largest proportion of nestling diet in both habitats, however, higher numbers and biomass of noctuid, as well as higher numbers of tortricid larvae, were provided to nestlings in the pinewood. Furthermore, females provided tortricids more often than males, whereas males supplied more geometrid larvae and spiders. We found a more generalist diet for nestlings raised in the pinewood. Also, a greater number of yo...
16 citations
TL;DR: The higher daily growth rate observed in males during the LGP may determine the extent of sexual size dimorphism at the pre-fledging stage, which contrasts with findings from previous studies, which found sex-biased environmental sensitivity of Blue Tit nestlings.
Abstract: Capsule: Growth trajectories of Blue Tit Cyanistes caeruleus nestlings differed between sexes and were negatively affected by rain but not by temperature during the linear growth phase (LGP).Aims: To model the growth trajectories of Blue Tit nestlings and to identify the main ecological factors affecting them.Methods: Sixty-five nestling Blue Tits from a population in northern Italy were weighed at regular intervals and sexed using molecular genetic techniques. The LGP period was identified and analysed to test for the influence of age, sex, hatching date, brood size, temperature and rainfall on individual daily growth rates during the LGP.Results: Growth curves showed no pre-fledging mass loss. Body mass differed between the sexes, with males being 5% heavier than females at the pre-fledging stage. Daily growth rates during the LGP were higher for males and on non-rainy days, while they were not affected by other factors.Conclusion: The higher daily growth rate observed in males during the LGP ma...
TL;DR: In this paper, the authors examined the home range size and ranging behavior of bearded vulture fledglings during the post-fledging dependence period and determined the onset of natal dispersal.
Abstract: Capsule: Fledglings progressively increase their home range size and ranging behaviour as they age.Aims: To examine the home range size and ranging behaviour of Bearded Vulture fledglings during the post-fledging dependence period and determine the onset of natal dispersal.Methods: Post-fledging movements of three individuals were investigated in southern Africa using global positioning system (GPS) satellite telemetry which enabled home range sizes and distances travelled from the nest to be calculated.Results: Fledglings increased their home range size from an average of 0.4–10 999 km2 (100% Minimum Convex Polygons) and 9.13–11 466 km2 (fixed 95% kernels) within the first six months post fledging. They also increased home range use as they aged with maximum daily distances travelled from the nest occurring between 98 and 136 days post fledging (when fledglings were aged between 222 and 262 days), after which time they dispersed from their natal area. Distances between fixes were highest during t...
TL;DR: In this paper, a nocturnal survey was performed at 36 survey points over three nights in winter in Thetford Forest, England, where the use of call-broadcast significantly increases the number of Tawny owls Strix aluco detected in winter point counts, but requires careful survey design to avoid introducing potential sources of bias into population estimates.
Abstract: Capsule: The use of call-broadcasting significantly increases the number of Tawny Owls Strix aluco detected in winter point counts, but requires careful survey design to avoid introducing potential sources of bias into population estimates.Aims: To examine Tawny Owl response to call-broadcasting to aid survey design in national monitoring efforts.Methods: A nocturnal survey was undertaken at 36 survey points over three nights in winter in Thetford Forest, England. Each survey consisted of four consecutive five-minute segments: a passive count, followed by three counts with the use of call-broadcasting.Results: Few (4%) Tawny Owls were recorded during passive surveys, whereas the greatest response was during the first and second call-broadcast segments (49% and 36%, respectively). New detections declined to 11% in the final segment. Response was fastest at dusk, although time of night did not significantly affect the number of individuals detected. Male owls accounted for 79% of detections.Conclusi...
TL;DR: In this paper, the authors examined whether lek location, size and change in size were associated with habitat and topography surrounding leks and found that lek occurrence was positively associated with the amount of NNW edge habitat.
Abstract: Capsule: Black Grouse population increases were greatest where new native woodland (NNW) within 1500 m of leks comprised approximately 30% of land area and averaged 5 years old.Aims: To examine whether change in a population of Black Grouse Lyrurus tetrix in Scotland was associated with the creation of native woodland.Methods: We examined whether lek location, size and change in size were associated with habitat and topography surrounding leks. We also examined vegetation differences in NNW and adjacent unplanted moorland.Results: From 2002 to 2012 the number of lekking male Black Grouse increased by 90%. Lek occurrence was positively associated with the amount of NNW edge habitat. Leks were larger where there was more adjacent NNW. Lek increases were greatest where NNW plots comprised approximately 30% land area, and were 5 years old, within a 1500 m radius. Plots aged more than approximately 20 years old were associated with Black Grouse population declines. NNW supported taller and denser impor...
TL;DR: It is shown that peanuts, rather than household scraps like bread and cheese, attract the highest number of species and individuals to bird tables, and that some birds still chose the carbohydrate-rich bread.
Abstract: Capsule: Providing peanuts on bird feeders was shown to attract more individuals and more species than providing cheese or bread.Aims: To investigate how the provision of different human-derived foods affected visit rates of urban birds at bird feeders.Methods: A fully replicated study design was set up in parkland, offering a binary choice from three food types (peanuts, bread and cheese) on bird tables. Birds were observed by using a scan-sample method.Results: Peanuts attracted more visits, and a greater diversity of bird species, than cheese or bread. This preference was strongest for Blue Tits Cyanistes caeruleus and Great Tits Parus major, whereas European Robins Erithacus rubecula visited all food types equally, and Blackbirds Turdus merula preferred cheese. Bread was the most consumed food type when measured by mass, but this could be linked to varying bite sizes.Conclusion: Our results indicate that birds preferred to visit feeding stations with the most protein- and energy-rich foods, bu...
TL;DR: This paper quantified the fat loads of 2125 Yellow-browed Warblers Phylloscopus inornatus trapped at a stop-over site in Far East Russia during autumn migration.
Abstract: Fat loads were quantified for 2125 Yellow-browed Warblers Phylloscopus inornatus trapped at a stop-over site in Far East Russia during autumn migration. Flight ranges of 660–820 km were estimated for the fattest individuals, suggesting that they would need to stop for refuelling at least six times to reach their wintering areas in South East Asia.
TL;DR: In this paper, the extent of the overlap between wind farms and breeding Hen Harriers and investigate their potential impact on Hen Harrier population trends was assessed, but evidence for a negative impact of wind farms on their population is weak.
Abstract: Capsule: The data presented here demonstrate a considerable spatial overlap between wind farms and the breeding distribution of Hen Harriers in Ireland, but evidence for a negative impact of wind farms on their population is weak.Aims: To assess the extent of the overlap between wind farms and breeding Hen Harriers and to investigate their potential impact on Hen Harrier population trends.Methods: Data on Hen Harrier breeding distribution in 10 km × 10 km survey squares from national surveys were used in conjunction with information on the location of wind farms to examine whether, and to what extent, changes in Hen Harrier distribution and abundance between 2000 and 2010 were related to wind energy development.Results: Of the 69 survey squares holding Hen Harriers during the 2010 breeding season, 28% also overlapped with one or more wind farms. Data from 36 of the squares with breeding Hen Harriers during the 2000 survey revealed a marginally non-significant negative relationship between wind far...
TL;DR: Correlation between detrended Herring Gull breeding numbers and detrending demersal fish landings provided strong evidence for a causal link between fishery discarding and gull breeding numbers.
Abstract: Capsule: Long-term population trends of gulls on the Isle of Canna, Scotland, showed a correlation to fish tonnage landed in a nearby port.Aims: To assess whether gull numbers and breeding success at Canna have been influenced by the amount of fish discarded in the area.Methods: We examined data on gull breeding numbers, breeding success and diet studied at Canna from 1969 to 2014, and data on fish landings at the nearby port of Mallaig for 1985 to 2014. We examined correlations between gull and fishery data, and performed a detrended analysis of Herring Gull Larus argentatus numbers in relation to demersal fish catch (the latter as a proxy for discard volumes).Results: Gulls fed extensively on discards. Gull breeding numbers declined at Canna, especially between 2000 and 2006, the decline being more pronounced than seen in national totals. Gull breeding numbers correlated with demersal landings, even after detrending for long-term decreases in both.Conclusions: Correlation between detrended Herri...
TL;DR: High levels of nest and chick predation in wet grassland landscapes limit the capacity for breeding wader populations to be self-sustaining, and identifying manageable landscape features that influence predation rates is an important focus of conservation research.
Abstract: Capsule: Northern Lapwing Vanellus vanellus avoid nesting close to small woodland patches but nest predation rates do not vary with distance to woodland patches, either because risky areas are avoided or perceived nest predation risk does not reflect actual risk.Aims: To explore the effects of woodland patches in wet grassland landscapes on nest distribution and success of Lapwings.Methods: We quantified the effect of woodland patches on the distribution and outcome of Lapwing nests across four wet grassland sites by mapping nest distribution and monitoring nest outcomes.Results: Lapwing nested significantly further from woods than expected by chance. Neither nest predation rates nor the probability of predation occurring at night (thus primarily mammalian predators) or day (primarily avian predators) varied in relation to distance from woodland patches.Conclusions: High levels of nest and chick predation in wet grassland landscapes limit the capacity for breeding wader populations to be self-sust...
TL;DR: In the migratory Lesser Spotted Eagle Clanga pomarina, colour rings and Global Positioning System transmitters indicated annual survival rates similar to other large raptors, but the rate suggested by wing-tags was significantly lower due to the higher rate of tag loss.
Abstract: Capsule: In the migratory Lesser Spotted Eagle Clanga pomarina, colour rings and Global Positioning System transmitters indicated annual survival rates similar to other large raptors, but the rate suggested by wing-tags was significantly lower due to the higher rate of tag loss.
TL;DR: In seasonal ecosystems, however, harsh environmental conditions duri... as discussed by the authors showed that many protected forests at high elevations show higher endemic biodiversity than unprotected habitats at low elevations, which is not the case in seasonal ecosystems.
Abstract: Capsule: Many protected forests at high elevations show higher endemic biodiversity than unprotected habitats at low elevations. In seasonal ecosystems, however, harsh environmental conditions duri...
TL;DR: This is the first evidence of carry-over effects between geographical regions for a European passerine, and conservation measures should focus on all aspects of seasonal cycles, not just breeding grounds.
Abstract: Capsule: Breeding success in female Pied Flycatchers Ficedula hypoleuca is related to isotopic signature of feathers grown in Africa, suggesting wintering habitat links to breeding performance 5000km away.
Aims: Better understanding of interseasonal carry-over effects is a research priority, especially for declining migrants. We use stable isotope analysis to relate Pied Flycatcher winter habitat to summer reproductive success.
Methods: Flycatchers were captured in three UK woodlands in 2013-2015. An Africa-grown tertial was trimmed and analysed using Isotope Ratio Mass Spectrometry to quantify Nitrogen-15 (δ15N) and Carbon-13 (δ13C). In total, 135 samples were taken from 80 individuals.
Results: Wintering δ15N and δ13C differed significantly between years. δ13C correlated with lay date, such that birds with lower carbon levels (indicative of more mesic habitat) bred earlier. There was a significant correlation between wintering δ13C and productivity after allowing for year, site, and lay date; birds with low δ13C were more successful. This suggests δ13C links productivity directly as well as indirectly through phenological effects. δ15N did not relate to phenology or productivity.
Conclusion: This is the first evidence of carry-over effects between geographical regions for a European passerine. Conservation measures should focus on all aspects of seasonal cycles, not just breeding grounds.
TL;DR: In this article, trail cameras monitoring clutches of ground-nesting birds in Australia revealed survival rates and new causes of egg loss and showed that nests with artificial eggs versus real eggs do not perform well.
Abstract: Capsule: Trail cameras monitoring clutches of ground-nesting birds in Australia revealed survival rates and new causes of egg loss. We also show that nests with artificial eggs versus real eggs do ...
TL;DR: The Dupont’s Lark Chersophilus duponti in Iberia has relatively high breeding success in both core and fragmented habitats, so population declines are more likely to be the result of low juvenile or adult survival.
Abstract: Capsule: The Dupont’s Lark Chersophilus duponti in Iberia has relatively high breeding success in both core and fragmented habitats, so population declines are more likely to be the result of low juvenile or adult survival.Aims: To measure important aspects of the reproductive biology of one of the most endangered and least known larks: the Dupont’s Lark C. duponti.Methods: We monitored 36 nests in 2 Spanish shrub-steppes, one holding one of the largest European populations (250 pairs) and one composed by fragmented habitat patches holding a smaller population (50 pairs).Results: The breeding season went from late-March to early July. Overall mean (±sd) clutch size was 3.47 ± 0.56, and the number of fledglings per successful nest was 3.0 ± 1.15. Mean nestling period was short (8.2 days). Nests showed similar daily survival rate during the incubation period (0.9750 ± 0.0110) as during the nestling period (0.9545 ± 0.0168), with a mean breeding success of 50%. Predation was the main cause of complet...
TL;DR: It is suggested that major transformations occurring in agroforestry systems are affecting the main preferred prey of important forest predators, which may have consequences for conservation of both the predators and their prey.
Abstract: Capsule: Northern Goshawk Accipiter gentilis diet has changed significantly since the 1980s, probably due to changes in populations of preferred prey species.Aims and methods: To assess changes to the breeding season diet of the Northern Goshawk in southwest Europe over three decades. We examined prey remains at and around nests and assessed avian prey availability using point count and line transect surveys.Results: During 2008–11, Goshawks mainly ate birds, with Feral Pigeons Columba livia f. domestica being the most important prey species. Goshawks preferred prey of 100−400 g and forest prey species to non-forest species. Goshawk diet has changed significantly over recent decades: 22% of current prey items belong to species that were not part of the diet in the 1980s. We suggest that these dietary changes reflect changes in the abundance of prey species of the preferred size caused by changes in land use leading to an increase in forest cover, new prey species colonization and changes in the ab...
TL;DR: The abundance of Tree sparrow Passer montanus, House Sparrow Passer domesticus and Yellowhammer Emberiza citrinella, three priority farmland birds, increased over a 5-year period in this paper.
Abstract: Capsule: The abundance of Tree sparrow Passer montanus, House Sparrow Passer domesticus and Yellowhammer Emberiza citrinella, three priority farmland birds, increased over a 5-year period in respon...
TL;DR: In this paper, the effects of Sky Lark plots and additional tramlines on Alauda arvensis territory densities in winter cereals and oilseed rape were analyzed.
Abstract: Capsule: Sky Lark plots and additional tramlines increase Sky Lark Alauda arvensis territory densities in winter crops.Aims: To analyse the effects on Sky Lark territory density of Sky Lark plots and additional tramlines in winter cereals and oilseed rape.Methods: We mapped Sky Lark territories on fields with Sky Lark plots or additional tramlines as well as on adjacent control sites, from 2010 to 2013 in Saxony, Germany, where agricultural land use is intensive, dominated by winter-sown crops and takes place in large fields.Results: In test sites with Sky Lark plots, 5.6 and 3.1 territories per 10 ha were found in the early (April/May) and late periods (June/July) respectively, compared to 3.3 and 1.4 territories per 10 ha in control sites. Sky Lark territory densities in fields with additional tramlines were 1.6 times higher in the early period (4.2 versus 2.6 territories per 10 ha) and 2.2 times higher in the late period (3.6 versus 1.6 territories per 10 ha).Conclusion: Sky Lark plots and addi...
TL;DR: It is suggested that reedbed management should ensure adequate areas of old, dry and unmanaged reed are available when aiming to encourage breeding Bearded Reedlings, as the apparently flexible structure of the nest may assist this species when coping with changeable climatic conditions.
Abstract: Capsule: Bearded Reedlings Panurus biarmicus show consistent nest timing, select old, compacted areas of reed when positioning their nests, and may adjust nest structure in relation to local reed characteristics and temperature.Aims: To investigate the nest timing, nest site selection and nest structure of a rare and elusive passerine, the Bearded Reedling at the northern limit of this species’ range.Methods: A sample of Bearded Reedling nests from the Tay Reedbeds in Scotland were located and monitored with regard to the timing of nesting, fate, fine-scale habitat characteristics and nest structure.Results: First egg dates and brood sizes were consistent between years of the study despite variation in spring temperatures. Bearded Reedlings nested within unmanaged patches of reed, positively selecting deep leaf litters and compacted reed. Attributes of nest structure, namely internal and external diameter, were influenced by nest site characteristics and local temperature.Conclusion: Despite a lim...
TL;DR: A significant positive correlation between parents and the nutritional condition of their offspring is found, measured as urea, uric acid and beta-hydroxybutyrate concentrations in blood, demonstrating that condition of the young seems to be merely a reflection of parental condition.
Abstract: Capsule: In Black-browed Albatrosses Thalassarche melanophris nutritional condition is correlated between parents and their offspring.Aims: To test resource allocation hypotheses analysing the relationship between parental and offspring nutritional condition.Methods: We measured blood chemistry parameters related with nutritional condition in 24 parents and their nestlings in a colony of Black-browed Albatrosses.Results: There were no significant differences in blood parameters between sexes or location of the nest within the colony, neither among adults nor among nestlings. We found a significant positive correlation between parents and the nutritional condition of their offspring, measured as urea, uric acid and beta-hydroxybutyrate concentrations in blood.Discussion: These relationships demonstrate that condition of the young seems to be merely a reflection of parental condition. An interesting relationship between alkaline phosphatase concentration in adults and nutritional condition of their ...