Embryonic exposure of chicken chicks (Gallus gallus domesticus) leads to heightened sensitivities towards the exposed scent

In chickens, food consumption can be altered by exposing the chicks to scents as embryos. We exposed eggs to an orange-scented food additive in the final days of incubation. Following hatching, we tested these exposed chicks’ ability to detect this scent at a variety of concentrations. We found that orange-exposed chicks responded to an orange-scented solution at lower concentrations than control chicks. This sensitization may allow chicks to be more effective at locating acceptable food items but requires further testing to determine its significance. Orange-exposed and control chicks were also tested with the scent of raspberry. Orange-exposed chicks responded to the raspberry presentation significantly more than the control chicks did, suggesting that the embryonic exposure to orange may have influenced how the chicks responded towards another fruity smell. This result suggests that chicks may be learning general characteristics of exposed scents while in the egg, though this needs further research

Influences of maternal care on chicken welfare

This review was funded by a BBSRC Future Leader Fellowship to Joanne Edgar.In domestic chickens, the provision of maternal care strongly influences the behavioural development of chicks. Mother hens play an important role in directing their chicks' behaviour and are able to buffer their chicks' response to stressors. Chicks imprint upon their mother, who is key in directing the chicks' behaviour and in allowing them to develop food preferences. Chicks reared by a mother hen are less fearful and show higher levels of behavioural synchronisation than chicks reared artificially. In a commercial setting, more fearful chicks with unsynchronised behaviour are more likely to develop behavioural problems, such as feather pecking. As well as being an inherent welfare problem, fear can also lead to panic responses, smothering, and fractured bones. Despite the beneficial effects of brooding, it is not commercially viable to allow natural brooding on farms and so chicks are hatched in large incubators and reared artificially, without a mother hen. In this review we cover the literature demonstrating the important features of maternal care in domestic chickens, the behavioural consequences of deprivation and the welfare implications on commercial farms. We finish by suggesting ways to use research in natural maternal care to improve commercial chick rearing practice.Publisher PDFPeer reviewe

Using self-organizing maps to investigate environmental factors regulating colony size and breeding success of the White Stork (Ciconia ciconia)

We studied variations in the size of breeding colonies and in breeding performance of White Storks Ciconia ciconia in 2006–2008 in north-east Algeria. Each colony site was characterized using 12 environmental variables describing the physical environment, land-cover categories, and human activities, and by three demographic parameters: the number of breeding pairs, the number of pairs with chicks, and the number of fledged chicks per pair. Generalized linear mixed models and the self-organizing map algorithm (SOM, neural network) were used to investigate effects of biotic, abiotic, and anthropogenic factors on demographic parameters and on their relationships. Numbers of breeding pairs and of pairs with chicks were affected by the same environmental factors, mainly anthropogenic, which differed from those affecting the number of fledged chicks per pair. Numbers of fledged chicks per pair was not affected by colony size or by the number of nests with chicks. The categorization of the environmental variables into natural and anthropogenic, in connection with demographic parameters, was relevant to detect factors explaining variation in colony size and breeding parameters. The SOM proved a relevant tool to help determine actual dynamics in White Stork colonies, and thus to support effective conservation decisions at a regional scale

Does the Source of Chicks have an Impact on Performance of Birds within Organic Table Bird Production Systems ?

Sheepdrove Organic Farm wanted to know whether the source of day old chicks and brooding and production period would have an impact on their enterprise. Sheepdrove Organic Farm wanted to know whether the source of day old chicks and brooding and production period would have an impact on their enterprise. An experiment was undertaken using two different sources of day old chicks and on two sites. 1000 day old chicks from Maurice Millard were exchanged with 1000 organic chicks from Devon Foods. These chicks were then put through the Sheepdrove (SOF) and Devon Foods Bradbury Barton (BB) organic production systems and weighed every week until depletion. The two systems were not identical and there were slight variations between the SOF and BB systems. BB had 500 bird flocks compared to SOFs 1000, BB had a brooding period of four weeks to SOFs three and BB total production period was 11 weeks to SOFs 10 weeks. There is no significant difference between the performances of the birds from the two different sources, although the experiment has highlighted the importance of high stockmanship at all times. There is no overall benefit in brooding the chicks for four weeks but there does appear to be short-term benefits in not brooding for four weeks as the three week brooded birds performed better over the weeks they were introduced to the field (there is a caveat to this that the experiment was undertaken under warm summer conditions). Increasing the production period from 10 to 11 weeks could be beneficial as the final weights of the birds at 11 weeks on the BB site were at or above SOFs optimum weight

Extreme offspring ornamentation in American coots is favored by selection within families, not benefits to conspecific brood parasites

Offspring ornamentation typically occurs in taxa with parental care, suggesting that selection arising from social interactions between parents and offspring may underlie signal evolution. American coot babies are among the most ornamented offspring found in nature, sporting vividly orange-red natal plumage, a bright red beak, and other red parts around the face and pate. Previous plumage manipulation experiments showed that ornamented plumage is favored by strong parental choice for chicks with more extreme ornamentation but left unresolved the question as to why parents show the preference. Here we explore natural patterns of variation in coot chick plumage color, both within and between families, to understand the context of parental preference and to determine whose fitness interests are served by the ornamentation. Conspecific brood parasitism is common in coots and brood parasitic chicks could manipulate hosts by tapping into parental choice for ornamented chicks. However, counter to expectation, parasitic chicks were duller (less red) than nonparasitic chicks. This pattern is explained by color variation within families: Chick coloration increases with position in the egg-laying order, but parasitic eggs are usually the first eggs a female lays. Maternal effects influence chick coloration, but coot females do not use this mechanism to benefit the chicks they lay as parasites. However, within families, chick coloration predicts whether chicks become “favorites” when parents begin control over food distribution, implicating a role for the chick ornamentation in the parental life-history strategy, perhaps as a reliable signal of a chick’s size or age. (Includes Supporting information.

Mechanisms promoting higher growth rate in arctic than in temperate shorebirds

We compared prefledging growth, energy expenditure, and time budgets in the arctic-breeding red knot (Calidris canutus) to those in temperate shorebirds, to investigate how arctic chicks achieve a high growth rate despite energetic difficulties associated with precocial development in a cold climate. Growth rate of knot chicks was very high compared to other, mainly temperate, shorebirds of their size, but strongly correlated with weather-induced and seasonal variation in availability of invertebrate prey. Red knot chicks sought less parental brooding and foraged more at the same mass and temperature than chicks of three temperate shorebird species studied in The Netherlands. Fast growth and high muscular activity in the cold tundra environment led to high energy expenditure, as measured using doubly labelled water: total metabolised energy over the 18-day prefledging period was 89% above an allometric prediction, and among the highest values reported for birds. A comparative simulation model based on our observations and data for temperate shorebird chicks showed that several factors combine to enable red knots to meet these high energy requirements: (1) the greater cold-hardiness of red knot chicks increases time available for foraging; (2) their fast growth further shortens the period in which chicks depend on brooding; and (3) the 24-h daylight increases potential foraging time, though knots apparently did not make full use of this. These mechanisms buffer the loss of foraging time due to increased need for brooding at arctic temperatures, but not enough to satisfy the high energy requirements without invoking (4) a higher foraging intake rate as an explanation. Since surface-active arthropods were not more abundant in our arctic study site than in a temperate grassland, this may be due to easier detection or capture of prey in the tundra. The model also suggested that the cold-hardiness of red knot chicks is critical in allowing them sufficient feeding time during the first week of life. Chicks hatched just after the peak of prey abundance in mid-July, but their food requirements were maximal at older ages, when arthropods were already declining. Snow cover early in the season prevented a better temporal match between chick energy requirements and food availability, and this may enforce selection for rapid growth.

Extreme offspring ornamentation in American coots is favored by selection within families, not benefits to conspecific brood parasites

Offspring ornamentation typically occurs in taxa with parental care, suggesting that selection arising from social interactions between parents and offspring may underlie signal evolution. American coot babies are among the most ornamented offspring found in nature, sporting vividly orange-red natal plumage, a bright red beak, and other red parts around the face and pate. Previous plumage manipulation experiments showed that ornamented plumage is favored by strong parental choice for chicks with more extreme ornamentation but left unresolved the question as to why parents show the preference. Here we explore natural patterns of variation in coot chick plumage color, both within and between families, to understand the context of parental preference and to determine whose fitness interests are served by the ornamentation. Conspecific brood parasitism is common in coots and brood parasitic chicks could manipulate hosts by tapping into parental choice for ornamented chicks. However, counter to expectation, parasitic chicks were duller (less red) than nonparasitic chicks. This pattern is explained by color variation within families: Chick coloration increases with position in the egg-laying order, but parasitic eggs are usually the first eggs a female lays. Maternal effects influence chick coloration, but coot females do not use this mechanism to benefit the chicks they lay as parasites. However, within families, chick coloration predicts whether chicks become “favorites” when parents begin control over food distribution, implicating a role for the chick ornamentation in the parental life-history strategy, perhaps as a reliable signal of a chick’s size or age. (Includes Supporting information.

Investigation of parental care in avocets from the perspectives of behavioural ecology and conservation biology

This research encompasses both basic (behavioural ecology) and applied (conservation biology) aspects of the biology of Avocets (Recurvirostra avosetta L.). My central question is whether adoption of alien young can be adaptive for adults and the adopted chicks. I evaluate proximate-level hypotheses by quantifying costs and/or bene�ts of both adopters and adoptees. I observed adoption of alien chicks in 19% of the families in 1998 and 1999. My �rst results suggest that adoption may be adaptive for both the adoptive adult and the adopted chick. This is because adopted chicks were more likely to �edge than their siblings remaining in their own family and the �edging success of the adopter adults' own chicks was higher than that of nonadoptive adults' chicks. In my applied research I collect data on avocet breeding biology to �nd out whether the current population increase in Hungary results from the reproductive output of the Hungarian population or is maintained by an in�ux of birds from coastal populations. I also use these data to design and implement e�ective conservation measures by which to further enhance the Hungarian population of the endangered Avocet. I successfully increased the hatching success of mainland nests by erecting a fence to keep ground predators away. The �edging success of chicks also increased after a predator control in the most a�ected areas. By providing information about the timing of nesting to nature conservation authorities I assured the successful breeding of one �fth of Hungary's avocet population on a �shpond in 1999

To establish whether there are differences in performance between 757 (Lloyd Maunders) birds and the Maurice Millard 257 those currently used within the Sheepdrove system

Sheepdrove Organic Farm wanted to know whether the performance of the Lloyd Maunders (757) birds would differ from that of their current breed the Maurice Millard (257) and whether chicks sourced from an organic parent flock would perform differently to those from a conventional parent flock. An experiment was undertaken using two different sources of day old chicks, 1000 day old Maurice Millard (257) and 1000 day old Lloyd Maunders (757). These chicks were then put through the Sheepdrove (SOF) organic production system and 30 random birds were weighed every week until depletion, at 11 weeks

Food provisioning and growth in the Atlantic puffin fratercular Arctica: an experimental approach

This study provided Puffin chicks with an additional 25g of food per day during the period of maximum growth rate to determine whether: 1) adult puffins can evaluate and respond to the nutritional requirements of their chicks, and 2) whether growth parameters (rate and elevation) of structural body components are flexible in response to variable levels of nutrition. Adult provisioning rates were significantly reduced in response to supplementary feeding, with experimental chicks receiving a mean of 2.1 feeds/d(^-1) compared to control chicks which received 4.7 feeds/d(^-1). There was no difference in the mean weight or energy content of the loads delivered to both groups, suggesting that the adult response to supplementary feeding took the form of a decrease in feeding frequency rather than a decrease m the size or nutritional quality of the load. No significant differences were found between the experimental and control groups in both the growth rate of overall body size and body weight. Neither was there a difference between groups in body mass elevation (mass corrected for age). However, chicks provided with supplementary food grew significantly larger for their age than control chicks. The fact that control birds were smaller but body masses were identical between the two groups suggests that control birds were not energy limited but nutrient limited; supplementary food may have provided the additional nutrients allowing structural tissues of experimental birds to grow larger. Differences in body tissue composition, and thus differences in metabolic energy requirements, may have been indirectly responsible for the similarities in body mass between the two groups. Identical growth rates between the two groups may have been a result of constraints acting at the physiological level, which prevented any further increase in rate once maximum size was reached for a given nutrient intake. In conclusion, variation in the quality or quantity of Puffin nestling diets does effect growth patterns of structural body components. Environmental sources of morphological variation should not be neglected in studies of phenotypic variation in birds