Nesting and dust bathing by hens in cages: Matching and mis‐matching between behaviour and environment

1. Medium hybrid hens were housed as groups of 4 at 18 weeks of age in cages of 4 different types: control battery cages allowing 675 cm2/bird; similar cages with a rear‐mounted dust bath, 290×345×240 mm, containing sand (D); cages with a rear‐mounted nest box of the same size, containing wood shavings (N); cages with both (DN). In half the experimental cages access to nests was restricted to the morning and access to baths was restricted to the afternoon, by automatic sliding doors.

2. During the first 24 weeks of lay about 95% of eggs were laid in nest boxes in treatments N and DN. Slightly fewer were laid in boxes where doors were present. Over 90% were laid in dust baths in D cages without doors and 67% with doors, which birds learned to open. Prelaying behaviour was least disturbed in nest boxes, most disturbed on the floor and intermediate in dust baths.

3. Fully developed dust bathing occurred in D and DN as bouts lasting 5 to 10 minutes; its incidence, surprisingly, was greater when doors were present and greater still when nest boxes were present, even though it was not performed in them. It was also performed by some hens in nest boxes in N (without doors). In N with doors and in control cages, dust bathing occurred on the bare floor in truncated form, as serial bouts each lasting only about 10 s. This truncated dust bathing was also occasionally observed in D and DN.

4. Plumage, foot and claw damage were less in hens from modified cages than from controls. Egg production was very good in all treatments but more eggs from control cages were downgraded because they were dirty or cracked.

5. When a choice was available birds generally partitioned their behaviour appropriately between nest box and dust bath. In N and DN virtually all prelaying and nesting behaviour took place in the nest boxes. Matching between dust bathing and the environment was less close; the reasons for its relatively low incidence and occurrence in truncated form outside dust baths remain to be established.     

Nesting,dust bathing and perching by laying hens in cages: Effects of design on behaviour and welfare

1. Laying hens (192 ISA Brown medium hybrids) were housed from 18 to 72 weeks as groups of 4 in conventional or experimental cages. The main area of all cages provided 675 cmVhen. All experimental cages had perches, dust baths and nest boxes, which were of three types: litter (L), artificial turf (A) or plastic rollaway (P). These facilities provided an additional 375 to 480 cm²/hen. The nest boxes and dust baths occupied either high or low positions. Behaviour, physical condition and production of the birds were regularly recorded.

2. Mortality was low (1.6% overall) and egg production very good in all treatments. The proportion of cracked and dirty eggs was slightly (but not significantly) higher in the experimental cages. In the experimental cages 90% of eggs were laid overall in the nest boxes and 3% in the dust baths. The proportion laid in the nest boxes was lower early in the laying cycle and increased with time, reaching 99% in A.

3. The facilities were heavily used. Birds spent about 25% of day time on the perches and 10–15% in or near the nest box and dust bath. At night, the majority of birds (90 to 94%) roosted on perches, but most of the remainder were on the lips of the nest box or dust bath, fouling the interiors.

4. Pre‐laying behaviour was much more settled in the experimental cages (45 min spent in the eventual laying position) than in the conventional ones (20 min) and total duration varied from 68 min in A to 87 min in P. The number of nest entries varied from 3.0 (A and P) to 4.3 (L); disturbance to sitting birds was correspondingly greater in L.

5. Dust bathing in the experimental cages generally took place during the afternoon in a single bout of about 5 min duration, whereas in the conventional cages it was brief and fragmented (3 bouts of 10 s each). The dust bath was also used for foraging behaviour (pecking and scratching). The treatments with small dust baths (A and P) caused problems for the birds.

6. Feather, foot and claw damage all tended to be less in the experimental than in the conventional cages, though only in the last case was the difference significant. Keel bone depressions appeared to be associated with perches; they were present in 43% of hens in the experimental cages but only 4% in conventional cages. There were no significant differences in body weight or in tibial or humerus strength between birds in the various treatments.

7. This study confirms that experimental cages with nest boxes, dust baths and perches offer appreciable benefits for welfare, with few production problems. The most successful treatment (A) could, with relatively minor modifications, form the basis of a practical design for large-scale commercial production.     

Design of nest boxes for laying cages

1. ISA Brown hens were housed in groups of 4 in cages with different designs of nest boxes provided, to determine the effects of nest box design and management on their use and on the pre‐laying behaviour shown by the birds.

2. There were 5 treatments: control (C); a wire‐floored nest box attached to the back of the cage (W); a nest box containing a fibreglass rollaway hollow (N); two rollaway nest boxes (T); a rollaway nest box, protected by a partition from the main part of the cage (P).

3. The holes in the rollaway nests in treatment N, T and P were shut initially, but the proportion of eggs laid in these nests only reached 50%. This proportion rose to over 80% when wood shavings were added daily, but fell to below 30% when rollaway holes were opened. These rollaway hollows are apparently not suitable for use in laying cages.

4. Use of nest boxes in treatment W varied between 60 and 80%. However, when pre‐laying behaviour was recorded (in 19 hens) two birds which laid in the nest boxes nevertheless showed abnormal behaviour.

5. Individual hens had on average 29 to 60% of their pre‐laying behaviour overlapped by that of others in the cage. Nesting space for at least two birds is probably necessary in a cage for 4 birds. However, in treatment T pre‐laying behaviour was disturbed by hens moving between the two boxes. This would be avoided by provision of one box big enough for two hens.

6. Soiling of hollows resulted in dirty eggs and suggested that nest boxes for laying cages may have to be provided with doors to prevent hens from roosting in them.     

Effect of substrate provision on performance and behaviour of laying hens in the pecking and scratching area of furnished cages

1. An experiment was set up to study the effects of substrate provision on performance and behaviour in the pecking and scratching area (PSA) of non-beak-trimmed hens housed in large furnished cages (60 hens/cage).

2. Three layer hybrids (two brown and one white, ISA-Hendrix Genetics, France) and two substrate conditions (with or without wheat bran automatically distributed on the PSA) were compared in a 3 × 2 experimental design with 12 cages per treatment.

3. Substrate distribution improved laying rate with no impact on the frequency of dirty or cracked eggs.

4. Substrate distribution improved the viability and body integrity of hens, which were not beak-trimmed.

5. Distribution of substrate tended to increase the number of hens in the PSA and enhanced their pecking and scratching behaviours but had a negative impact on the number of dust bath bouts per cage and encouraged dust bathing on the wire floor close to the feeder.

6. The white hens laid more eggs in the nest than the brown birds and used the PSA more for pecking, scratching and dust bathing at the end of the day than the brown hens, underlining the necessity to adapt cage furnishing and rearing management to specific behaviours of each layer genotype.     

Individual variation in prelaying behaviour and the incidence of floor eggs

1. Floor eggs are a problem in non‐cage systems for laying hens, as they require secondary egg collecting. Failure to lay in a well‐defined nest site may also be a welfare problem for the hens, but only if their nesting motivation has been thwarted.

2. We investigated the relationships between a hen's prelaying behaviour and its tendency to lay on the floor by recording the behaviour of 20 hens housed individually in wire cages with single littered nest boxes.

3. Most floor eggs (80%) were laid by the same 6 hens. These 6 “floor‐layers” performed more nest seeking behaviour, less nest‐building behaviour and less sitting prior to oviposition than the 14 hens that consistently laid in nest boxes.

4. The incidence of floor eggs declined with age. Both nest and floor laying hens performed less nest seeking behaviour with age. Floor layers, however, increased their performance of nesting behaviour, whilst nest layers performed less nesting behaviour with age.

5. Floor laying hens behaved as if they found the nest box less attractive than nest‐laying hens; perhaps because they had lower nesting motivation, or perhaps because their nesting motivation was as high, but they less readily perceived the nest box as an appropriate nest site.     

Perch length in cages for medium hybrid laying hens

1. ISA Brown hens were housed as groups of 4 from 18 to 72 weeks in 24 cages 450 mm deep, each with a softwood perch of rectangular cross‐section fitted across the rear. There were 4 treatments, each with 6 cages: cage widths and perch lengths were 480, 520, 560 or 600 mm.

2. Daytime perching did not differ significantly between the treatments. At night, over the whole year, 81% of birds in the 480 mm cages and 86% in the 520 mm cages roosted on the perch. This figure reached about 95% in the 560 and 600 mm cages, significantly more at most ages than in the 480 mm cages.

3. Feather damage was slightly less, but claw problems slightly more, in the 2 wider treatments than in the 2 narrower treatments. Birds in the wider cages were calmer when approached or handled by humans than those in the narrower cages. This may have been associated with variation in space allowance between the treatments.

4. There was a trend for lower production in the 480 mm cages than in the other treatments which may have been associated with the reduced feeding space in this treatment. There were few other treatment differences in production traits.

5. The balance of the evidence from this study is that when perches are provided in laying cages for medium weight hybrids, 140 mm of perch space per hen is adequate. For the amelioration of a number of the welfare problems of conventional cages, provision of perches should be combined with other modifications.     

Comparative analysis of pre‐laying behaviour in battery cages and in three alternative systems

1. Pre‐laying behaviour was compared in battery cages (C) and in three alternative husbandry systems: perchery (P), deep‐litter (DL) and covered strawyard (S).

2. Twenty ISA Brown hens were observed in each system for 60 min before oviposition and 5 min afterwards.

3. There were significant between‐system differences in a number of behavioural elements associated with the nest. Most varied along the sequence: C, P, DL, S, but the differences between the three alternative systems were generally less than between them and C.

4. The main factor governing the expression of pre‐laying behaviour appeared to be the availability, the number and the arrangement of littered nests.

5. Behaviour elements preceding nest entry and which were associated with area per bird again varied along the sequence C, P, DL and S with the major discontinuity between P and DL.

6. In P and C the searching phase was extended, in C at the expense of sitting. In P much time was spent inspecting the nests and many nest entries were made.

7. The Gakel call appeared to be related to finding a suitable nest site. In P the number of calls and the mean duration per nest inspection declined in a parallel fashion towards oviposition. In C, where no suitable nest could be found, Gakel calling remained high during the whole observation period.

8. These behavioural differences suggested that pre‐laying behaviour was poorly expressed in C and most fully in S, but that expression was in general relatively complete in all three alternative systems.

9. The ability of hens to express pre‐laying behaviour fully and coherently may be relevant to their welfare.     

Battery cage shape: Its effect on diurnal feeding pattern,egg shell cracking and feather pecking

1. Battery cages 460 mm in depth (deep) were compared with 305 mm cages (shallow); the two shapes provided equal areas per bird.

2. More eggs were produced per hen housed from 30 to 70 weeks in the shallow cages; the difference approached significance.

3. The pattern of feeding activity over the day was significantly more U‐shaped in the shallow cages; this pattern accords more closely with physiological requirements.

4. Feather damage caused by pecking was slightly but significantly more severe in the deep cages at 70 weeks.

5. The proportion of cracked eggs (collected from 60 to 70 weeks) was significantly lower in the shallow cages.

6. The arrangement of the hens was such that within the shallow cages a higher proportion of birds was present in the front half.

7. It is suggested that some of the advantages conferred by the shallow cage may be related to the greater accessibility of the food trough.     

Diurnal patterns of feeding and activity in laying hens in relation to dietary restriction and cage shape

1. The diurnal feeding pattern and motor activity of medium‐weight hybrid hens housed in groups of four were observed. Cages of two shapes were compared: conventional deep cages (406 × 457 mm) and shallow cages (610 × 305 mm).

2. Birds in conventional deep cages were more active than those in shallow cages in each of four different periods of day. Activity reached a peak between 11.00 and 13.00 h irrespective of cage shape.

3. Mean feeding activity was greater in the shallow (45.6%) than in the conventional deep cages (39.9%).

4. Mean feeding activity was greater in birds fed ad libitum (43.3%) than in those fed on a restricted diet (40.4%).

5. Although restricted birds in shallow cages showed more feeding activity than those in conventional deep cages they consumed less food (56% against 67%) in the 7 h between supply of their daily ration and the onset of the dark period.

6. Feather damage was greater in the conventional deep cages than in the shallow cages.

7. The more efficient utilisation of food by hens in shallow cages is probably due largely to three factors: reduced levels of motor activity and general disturbance, a more leisurely eating pattern and better feather cover.     

Behaviour,health and integument of four hybrids of laying hens in modified and conventional cages

1. In 2 trials the health and behaviour of a total of 3552 caged laying hens of 4 hybrids, Dekalb XL, Lohmann Selected Leghorn (LSL) and Shaver 288 in trial 1 and ISA Brown and LSL in trial 2, were studied. The cage designs were Get‐away cages (GA) with 15 hens per cage, a special version of the ‘Edinburgh modified cage’ called ‘Modified and enriched cage’ (ME) with 4 ISA or 5 Leghorn hens per cage, conventional metal cages with 4 hens per cage without (CO) and with a perch (PC) and conventional plastic cages (PL) with three hens per cage. GA and ME included nests, perches and sandbaths.

2. In the first trial two nest models were used, artificial turf and welded wire floor. In the second trial both nest models were used in GA, while all nests in ME were equipped with artificial turf. In the second trial there were 4 sandbath treatments in ME; no sandbath, sandbath (25×50 cm) first opened at 16 weeks of age, sandbath first opened at 26 weeks and double size sandbath (50 × 50 cm) first opened at 16 weeks. Hens in GA were allowed access to the sandbaths from 26 weeks.

3. At 35 and 55 weeks the best plumage condition (feather cover) was found in PL and GA but plumage condition in ME was not significantly inferior than in GA. Hens in GA had the dirtiest plumage and most bumble foot but no toe pad hyperkeratosis. Some toe pad hyperkeratosis occurred in the other systems. Most keel bone lesions were found in systems with perches. The highest mortality was registered in GA. Hens in systems with perches, sandbaths and nests had increased strength of humerus at slaughter.

4. More eggs were laid in nests with artificial turf than in welded wire floor nests. LSL hens laid larger proportions of eggs in the nests (94% and 92% in the two trials) than the other hybrids. Less than 1% of the eggs in ME and 2% in GA were laid in the sandbaths.

5. The use of perches in ME and PC was approximately 30% in the day time. At night the use was 93% in ME and 89% in PC in trial 1 and 96% in ME and 81% in PC in trial 2.

6. Hens in ME with the double sized sandbath both visited the sandbath and performed dust bathing behaviour most, followed by hens in GA, hens in ME with access to the bath from 16 weeks and last, hens in ME with access to the bath from 26 weeks.

7. It is concluded that enrichments of laying cages are used by the hens to a large     

Effect of perches in laying cages on welfare and production of hens

1. ISA Brown hens were caged in groups of 4 from 20 to 72 weeks at 675 cm²/bird. A control treatment in conventional cages was compared with 4 treatments involving softwood perches. In deep cages they were located across the front, across the rear and across both; in wide, shallow cages there was one long perch across the front. For half of each treatment perches were circular in cross section, and for half they were rectangular.

2. Time spent overall in daytime perching was relatively consistent over the laying cycle, from 47% in period 1 to 41% in period 10. Perch arrangement had a major influence on perching time, which varied from 20% on the rear perch to 85% on the long perch. Predominant activities on front perches were feeding and drinking; on rear perches, preening and resting.

3. Perches were heavily used for roosting at night: the proportion varied from 60 to 72% on front or rear perches, through 72 to 78% on long perches, and 99% on two perches.

4. Physical condition was also affected by treatment. Foot damage was less in birds with rectangular perches than with circular perches; rear perches resulted in less damage than the control. Tibia breaking strength was greater in birds from cages with perches. There was some evidence of reduced feather damage, especially where there was sufficient perching space for all birds.

5. Egg production on a hen‐d basis across 12 laying periods was 83% in cages with perches compared to 85% in control cages, with no significant differences between treatments. Hens were seen to lay from perches; this probably accounted for the higher proportion of cracked eggs from cages with perches. This proportion varied from 4% with rear perches to 18% with two perches, compared to 2% in control cages.

6. Although not all effects of perches were beneficial, overall they made an appreciable contribution to bird welfare. They should be considered in combination with other potential modifications to cages.     

Factors influencing bacterial eggshell contamination in conventional cages,furnished cages and free-range systems for laying hens under commercial conditions

1.?The aim was to assess eggshell contamination in various laying hen-housing systems and to identify factors influencing this contamination.

2.?Fifty-eight laying hen farms in France were studied, including 21 flocks housed in conventional cages, 7 in furnished cages and 30 kept on-floor.

3.?Sixty eggs per flock were analysed to obtain counts of the total mesophilic flora. Data on equipment and hen management were collected.

4.?Mean bacterial count on eggshells tended to be higher in on-floor systems (4·82 ± 0·51 log CFU/eggshell) than in cage systems (4·57 ± 0·58 log CFU/eggshell, P = 0·09).

5.?Contamination increased with age of the hens, airborne dust concentration, manual packing of the eggs, and packing in plastic rather than in recycled-pulp egg-flats.

6.?The effect of the housing system on eggshell contamination, previously described in experimental assays, was confirmed under production conditions.     

Performance of a deep litter system for egg production

1. Medium hybrid hens were housed from 20 to 64 weeks in a deep litter house as flocks of 300, 370 and 370 and at stocking densities of 2–4 to 10–7 birds/m² in three successive laying cycles. Sister birds were housed in cages in an adjacent building as groups of 3 and 4, at 750 or 560 cm²/bird.

2. Hen housed egg production was lower on litter (208 to 235) than in cages (230 to 253). However, the estimated 52‐week values for litter were comparable to or better than standards published by the National Farmers’ Union.

3. Ambient temperatures were well controlled in both houses, but atmospheric dust and ammonia were a problem in the litter system and ammonia was a problem in the deep pit cage house. Litter condition was good at all stocking densities.

4. There was a trend for production to increase with stocking density on litter, but to decrease in cages.

5. Most egg quality variables were similar in the two systems, although there were more dirty eggs from litter and shell thickness was slightly greater in eggs from cages.

6. Body weight increase was initially faster in birds on litter; caged hens were equally heavy by the end of lay, but a greater proportion of their body mass was lipid.

7. The severity of feather damage and loss was correlated with stocking density for hens both on litter and in cages, being worse at the higher densities. Median cage scores were greater than values from litter at low densities but less than those from high densities. Beak trimming reduced feather damage on litter but had no effect in cages.

8. Mortality was low (1 to 3%) for all flocks, except those in year 3 which had not been beak trimmed and which suffered from cannibalism both in cages and on litter.     

Effects of nest linings,pecking strips and partitioning on nest use and behaviour in modified battery cages

1. Nine groups of 4 ISA Brown hens were housed in modified battery cages each containing 3 nest sites. Egg laying was performed exclusively in these sites.

2. In experiment 1, each cage contained one unlined nest (type A), one lined with neoprene rubber (type B) and one lined with rubber with an additional peckable strip of artificial grass attached above the nest rear (type C). Positions of the nests were systematically altered over 45 d.

3. Hens spent most time in and made most visits to nest type C. More eggs were laid in nest types B and C than in nest type A.

4. In experiment 2, all nests were of type C, but nests were divided within each cage either by wire mesh, or a solid nest partition, or no partition. Nesting behaviour was monitored over 20 d for each of the 3 conditions.

5. Hens spent most time in, and made most visits to the nests when solid partitions were present. However, disturbance of nesting birds was also significantly increased by solid partitions. There were no significant effects of partition type on the number or positions of eggs laid in the nests.     

Influence of pre‐incubation treatment on hatching results of broiler breeder eggs produced at 37 and 59 weeks of age

1. The influence of temperature in the nest box, temperature during storage, storage time and pre‐setting temperature on the hatchability of broiler breeder eggs produced by birds of 37 and 59 weeks of age was examined.

2. All treatments that can be characterised as being less optimal for embryo survival than the control treatment affected the hatchability of fertile eggs more in the case of eggs produced by older birds.

3. A higher temperature in the nest box, longer storage periods, higher storage temperature, especially at longer storage periods, and higher pre‐setting temperature significantly reduced the hatchability of fertile eggs from the older birds.

4. For the younger birds, a significant reduction of hatchability was found only for the longest storage period.     

Feather damage in hens caged individually

1. The plumage of hens housed singly in cages was generally in good condition after one year. There was slightly more feather loss where hens could peck their neighbours’ plumage (adjacent cages) than where this was not possible (spaced cages).

2. It was concluded that most, though not all, of the feather damage seen in the individually‐caged birds was due to abrasion, but that abrasion was likely to be relatively unimportant in multi‐bird cages.

3. There were no significant differences in egg production or food intake associated with the two kinds of housing.

4. In the adjacent cages there was an increase in maintenance requirement related to increased feather damage, which amounted to about 7% for an increase of about one unit in feather‐loss score. In the spaced cages the increase was less.

5. Hens with increased feather damage also showed increased egg production.     

Analysis of landing behaviour of three layer lines on different perch designs

1. The prevalence of keel bone deformities in laying hens is high and is partly associated with unsuitable perch designs, which impose a risk of injury due to an unstable footing.

2. Over two experiments, 9 or 10 hens of each of three layer lines (Lohmann Selected Leghorn (LSL), Lohmann Tradition (LT) and Lohmann Brown (LB)) were filmed while landing on three different perch types, including steel perches of various diameters, a commercial mushroom-shaped plastic perch and a newly developed prototype perch with a soft surface material.

3. Data on landing behaviour (safe vs. unsafe or failed landing) following downward jumps were collected for 25, 50 and 60 cm vertical distances and 75 cm horizontal distance between a wooden start perch and the different destination perches.

4. The highest proportion of safe landings occurred on the prototype perch, whereas least safe landings were observed on steel perches, irrespective of their diameter. The mushroom-shaped perch was intermediate with regard to the safeness of landing.

5. A threshold of 50 cm vertical distance (34° slope) was identified as the optimum for downward jumps on perches in order to reduce the risk of unsafe or failed landings. Above this threshold, the proportion of safe landings declined significantly.

6. Brown shell layer types (LB and LT) had a lower proportion of safe landings compared to the white shell layer type (LSL), whereas no difference was found between LB and LT layer lines.

7. Although steel perches prevail in commercial housing, these perches were found to be least advantageous with regard to landing behaviour. The prototype perch provided the most stable footing on perching and is a promising alternative to replace commercial steel perches, thus helping to reduce the risk of perch-related keel bone injury.     

Nest box design and nesting material in a deep litter house for laying hens

1. Preferences of hens for different types of nest box were tested in two deep litter pens, each containing 300 Isabrown laying hens. Four types were offered: traditional wooden nests with litter, metal rollaway nests with plastic liners, wooden rollaway nests with artificial turf and autonests.

2. Most eggs were laid in traditional nests (70% in pen 1, 66% in pen 2). Metal rollaways were the next preferred type. These preferences were confirmed by analysis of records from individual nest boxes, and by observations of hens marked with wing tags.

3. Choice of nesting material was tested in one pen of 370 hens. Traditional nests were provided, containing either wood shavings or a mixture of buckwheat and oat husks.

4. Preferences for type of nesting material were equivocal. The majority of eggs were laid on wood shavings initially, but on buckwheat/oat husks later. Individual hens were inconsistent in their choice. A deep (100 mm) layer of nesting material was preferred to a shallow (25 mm) layer.

5. Individual, wooden nest boxes incorporating buckwheat/oat husk nesting material on a movable belt are probably the most suitable system for automation of egg collection in deep litter houses.     

Effects of cage shape,colony size,floor area and cannibalism preventatives on laying performance

1. Wire cages of variable width and depth, with a floor slope of 1 : 12, were used in two experiments to study the effects of cage depth, feeding space (= cage width), floor area, colony size and two methods of controlling cannibalism in White Leghorn x Australorp laying hens.

2. The least floor area (0.035 m²/bird) depressed production in two‐bird cages. Floor area had little effect on the performance of larger colonies.

3. Birds in colonies of three, four or six laid and survived equally well when feeding space/bird and floor area/bird were constant.

4. Production per hen d and food intake were higher, but return on estimated capital outlay was lower, with 102 mm than with 76 mm feeding space/bird when colony size and floor area/bird were constant.

5. Production and food intake of birds which were not treated to prevent cannibalism declined, and mortality increased, as cage depth increased from 385 to 915 mm concomitantly with increasing colony size from 2 to 7 birds and decreasing feeding space from 152 to 43 mm/bird.

6. Increasing cage depth did not increase the proportion of cracked eggs.

7. Mortality was higher among birds fitted with plastic spectacles than among debeaked birds.     

Nesting and floor laying by domestic hens in a commercial flock

1. The nesting behaviour of broiler breeders was studied in a commercial flock of nearly 4000 birds kept on deep litter by tagging a sample of 200 hens. Use of nest boxes by tagged birds was recorded on 52 d over 34 weeks.

2. Forty hens were never observed in nest boxes and 33 others were recorded only in ground‐level boxes. These 73 birds were recorded significantly less often in nest boxes and more often apparently laying on the floor than others. Fewer of them perched during observations and they started doing so later than birds which used raised nest boxes.

3. These results suggested that there were consistent floor layers, which had difficulty reaching raised nest boxes, as found previously in experimental conditions. Many or all floor layers may, however, have used ground‐level boxes sometimes.

4. Hens were inconsistent in their use of particular nest boxes, and some even nested in two distinct areas.

5. Most individuals were, however, consistent in their reaction to one or more features of the nest boxes, including height, aspect and area. Individual choices for these features varied, so no boxes were used particularly heavily, with the exception of those at ground level.