Quick Look
Do hens that use perches lay fewer eggs on the floor? In this study, the link was weak. Perch use rose and floor laying fell as young hens spent more time in the laying house, but the two measures did not closely track each other. The paper does not show that adding a perch will move eggs into nest boxes.
Study at a Glance
Species: Chicken
Breed/line: Two purebred Rhode Island Red lines
Number of birds: 12–16 hens per pen; no single total bird count was reported
Duration: First 11 weeks in the laying house, across four tests
Journal: Genetics Selection Evolution
Year: 2021
Focus: Perching, floor eggs, learning, and inherited variation
Study Overview
Floor eggs require extra collection and may carry contamination risk. The researchers asked whether families whose hens perched more also laid fewer floor eggs, and whether both behaviors changed as hens gained experience. This was a breeding and observation study, not a coop-design trial. [1]
How Was the Study Conducted?
Hens were reared in cages without perches, then moved at 17 weeks to family-group floor pens. Each pen held 12–16 hens, several perch surfaces, and eight metal nest boxes. Staff counted nest and floor eggs daily, and counted perching birds during one daily egg-collection visit. The authors analyzed weekly records from the first 11 weeks of four tests, using pedigrees to estimate inherited variation. A separate small DNA pilot tested identification of the parents of floor eggs. No pens were randomly assigned to perch and no-perch groups. [2]
Key Findings
About 5% of hens were observed perching at the single daily visit. This is a snapshot, not the share that ever perched.
Perch use increased over the test period, while floor eggs decreased. The fitted floor-egg trend fell 3.32–4.89 percentage points per week in Line 1 and 2.47–3.53 points in Line 2 across tests. These are model slopes, not backyard predictions.
The observed pen-level correlation between perching and floor eggs was only −0.09 ± 0.05 and −0.05 ± 0.04 in the two lines (Table 2), close to zero.
Estimated genetic correlations were −0.26 ± 0.14 and −0.19 ± 0.27 (Table 2), with substantial uncertainty.
Estimated heritability of floor-egg percentage was 0.52 ± 0.05 and 0.45 ± 0.05 using weekly data (Table 2). This describes variation in these populations; it does not mean half of one hen's behavior is fixed by genes.
The DNA pilot identified parents for 172 embryos from floor eggs. A blind check correctly assigned parents for 60 eggs with known pedigree. This was a breeding research method, not a home-flock tool. [2]
Strengths of the Study
Daily egg counts across several tests, two lines, pedigrees, and reported uncertainty help separate family patterns from observed pen behavior. Table 2 makes the weak observed relationship clear.
Limitations of the Study
The hens came from two commercial breeding lines and had no early perch experience. Perching was counted at only one moment per day, and individual hens were not tracked in the main pen analysis. The study did not compare perch designs or test adding perches. Some statistical models required simplification. These findings cannot establish a perch-installation cure for floor eggs or predict another breed's behavior. [1]
Poultry Nerds Takeaway
When pullets lay on the floor, observe whether nest use improves as they gain experience. In this facility it did. Keep nests usable and investigate the actual laying pattern in your coop. Perches can serve other purposes, but this study gives no basis to promise that more perches will solve floor laying.
Questions Poultry Keepers Ask
Will adding perches stop my pullets from laying eggs on the floor?
This study cannot answer directly: every pen had perches, with no no-perch comparison. Perch use was weakly associated with floor eggs at the pen level. [2]
How long do new layers take to learn to use nest boxes?
Floor laying declined during the first 11 weeks in this facility. The researchers did not establish a universal training deadline for backyard hens.
If my chickens perch a lot, will they use the nest boxes?
Not necessarily. The observed correlations were close to zero. Check nest use directly instead of using perch use as a substitute measure.
Are floor eggs caused by genetics or coop management?
Both may matter. The study found inherited variation in these breeding lines, while floor laying also changed as birds experienced the house. It cannot assign a fixed cause to any backyard flock.
Original Research
Wolc, A., Settar, P., Fulton, J. E., Arango, J., Rowland, K., Lubritz, D., & Dekkers, J. C. M. (2021). Heritability of perching behavior and its genetic relationship with incidence of floor eggs in Rhode Island Red chickens. Genetics Selection Evolution, 53, 38. DOI: 10.1186/s12711-021-00630-5. Publisher article. Legal open-access full text.
Keep Exploring
Explore more studies in the Poultry Nerds Research Library. For related keeper experience on perch choices, see Bryant's Roost: Perches for Chickens. This study did not test those design claims.
Research Review
This article summarizes a peer-reviewed scientific publication and explains its practical application for poultry keepers, breeders, and educators. It is an original review written by Poultry Nerds and is not a reproduction of the original manuscript. Readers are encouraged to review the complete publication using the original publisher and open-access links provided above.
Unless otherwise noted, the findings discussed apply only to the species, breed, age, and production system evaluated by the researchers. Results from a single study should not automatically be generalized to all poultry species, breeds, or management systems. Additional research may support, refine, or contradict these findings as scientific knowledge evolves.