Bird Guide

Bird Guide – Under Construction

Gardens can play an important refuge role for birds, particularly in urbanised areas where natural habitats are increasingly fragmented.
In France, bird populations in agricultural landscapes have declined by around 30% over the past 30 years (MNHN/CRBPO, 2018), and many garden bird species rely heavily on hedgerow networks, winter food resources, and access to water.

A well-designed garden can substantially increase local bird species richness and significantly improve survival, especially during winter and the breeding season (BTO, 2019).

Welcoming birds into gardens is based on three core principles:

  • Providing a diverse range of natural food resources
  • Creating safe refuges throughout the year
  • Limiting human disturbance and pressures

This guide presents the key steps, supported by validated scientific and naturalist recommendations.

Step 1: Ensure regular winter feeding

In winter, birds may expend up to 30% more energy each night to maintain body temperature (Newton, 1998).
If feeding is initiated, continuity is essential: sudden interruption may weaken individuals that have become reliant on feeding stations. In France, bird feeding should remain primarily winter-based and carefully regulated in order to limit sanitary risks and ecological disturbance.

  • Provide food from December to late February.
  • Avoid feeding outside winter, due to increased sanitary risks and ecological disruption.
  • Shelled sunflower seeds can improve the survival of tits and finches by 12–19% (Brittingham & Temple, 1988).

Step 2: Install a secure feeder

Predators, particularly domestic cats, are a major cause of bird mortality in gardens.
In France, a domestic cat may capture 27 to 50 birds per year on average (LPO, 2020).

Recommendations:

  • Ideal height: 1.5–2 metres
  • Place the feeder more than 2 metres from dense cover to reduce ambush risk
  • Provide a nearby refuge perch (branch or hedge)

Well-designed feeding stations can attract up to 40% more bird species.

Step 3: Offer suitable seeds and keep them dry

Black sunflower seeds remain the most energy-rich option.
Fine seed mixes attract sparrows, dunnocks and robins.

Scientific background:
Moisture promotes mould growth, which can cause diseases such as trichomonosis, whose outbreaks may locally reduce greenfinch populations by 20–30% (Lawson et al., 2012).

Good practice:

  • Use covered feeders
  • Replace seeds every 2–3 days during wet weather

Step 4: Change water in bird baths regularly

Even in winter, access to clean water is essential.
Birds bathe to maintain plumage integrity, which is crucial for thermal insulation.

Clean water can reduce pathogen risks by around 60% (BTO hygiene study).

  • Use shallow containers (3–5 cm deep)

Step 5: Clean feeders and water points regularly

Studies show that most trichomonosis outbreaks are concentrated around feeders.

Recommended protocol:

  • Weekly cleaning with diluted white vinegar or hot water
  • Thorough scrubbing to remove food residues and droppings
  • Complete drying before reuse

Step 6: Manage abnormal bird aggregations (disease risk)

If weak or dead birds are observed:

  • Stop feeding immediately
  • Thoroughly clean all equipment
  • Move the feeding station 10–15 metres
  • Resume feeding only after one week

These measures can reduce pathogen transmission by up to 80%.

Step 7: Preserve vegetated refuge areas

Dense hedges, bramble patches and thickets are essential:

  • More stable temperatures than open air (+2 to +5°C in winter)
  • Protection from predators and harsh weather
  • Habitat for blackbirds, wrens and robins

Gardens with at least 30% vegetative cover can host up to 70% more bird species.

Step 8: Retain wild berries until late winter

Natural food resources are a priority.
Rosehip, hawthorn, ivy and elder form key structural food resources.

Ivy produces lipid-rich berries (~48% fat) essential for thrushes and warblers.

  • Avoid hedge cutting before late February

Step 9: Leave fallen leaves, dead wood and dry stems

These micro-habitats are crucial for invertebrates → direct food for insectivorous birds.

  • Leaf litter shelters arthropods, larvae and woodlice
  • Dry stems host over 50 insect species during winter
  • Ground dead wood can triple invertebrate density

These resources support both winter and spring feeding.

Step 10: Limit artificial night lighting

Light pollution disrupts:

  • Migration
  • Circadian rhythms
  • Predator–prey interactions

White LEDs attract 2–4 times more insects than warm LEDs (<3000 K).
Use timers, motion sensors and reduce light intensity.

Step 11: Reduce noise and motorised tool use

Repeated noise exposure can reduce breeding success by 10–30% in some species (Kleist et al., 2018).

  • Limit petrol mowers, leaf blowers and shredders
  • Preserve quiet zones during spring (March–June)

Step 12: Install appropriate nest boxes

Nest boxes compensate for the loss of natural cavities.

  • Orientation: east to south-east
  • Height: 1.8–3 metres

Types:

  • Tits: cavity nest box (Ø 28–32 mm)
  • Redstart: semi-open box
  • Tawny owl: large nest box

Nest boxes can increase breeding success by 20–50% when food availability and low disturbance are ensured (van Balen, 2002).

Step 13: Install winter roost boxes

These allow several tits to roost together at night, saving up to 20% of energy during cold periods.

Step 14: Provide water, sand, perches and bare ground

  • Sand baths: removal of excess oils and parasites
  • Bare ground: feeding areas for thrushes, blackbirds and dunnocks
  • Panoramic perches: hunting vantage points for insectivores
  • Perches near ponds: safety before drinking or bathing

Step 15: Create a pond (even a small one)

A pond can increase garden bird diversity by 30–60%:

  • Drinking and bathing water
  • Aquatic insects as food
  • Resting humid habitats

Even 2–3 m² can be sufficient.

Step 16: Diversify vegetation layers

Gardens with four strata (herbaceous, shrub, bush, tree) attract:

  • Tits
  • Warblers
  • Woodpeckers
  • Robins
  • Thrushes
  • Goldfinches

Plant diversity can increase bird species richness by 50–100%.

Step 17: Create or retain wild areas

Fallow patches act as food reservoirs in autumn and winter, providing:

  • Seeds
  • Thermal shelter
  • Insects
  • Hollow stems

A single 4–6 m² area can triple the presence of goldfinches and sparrows.

Step 18: Ecological planting – hedges, trees and shrubs

  • Diverse hedges provide optimal structure
  • Berry-producing shrubs supply late-season food
  • Trees with natural cavities offer nesting sites

Gardens with mixed hedges can host up to five times more nests.

Step 19: Replace uniform conifers

Thuja and leyland cypress offer poor refuge value and very few insects.
Replace them with native hedges: blackthorn, hazel, dogwood, hawthorn.

Observed bird presence can increase by around 60% within three years (LPO).

Step 20: Observe and record birds

Regular observation allows:

  • Identification of trends and behaviours
  • Contribution to LPO databases and citizen science programmes
  • Early detection of ecological imbalances

Monthly monitoring strongly improves the quality and reliability of local data.

A garden that becomes a living ecosystem

By applying these steps, your garden becomes a functional space for biodiversity:

  • More insects, therefore more birds
  • More refuges, therefore greater breeding success
  • Fewer disturbances, therefore more stable populations

Your garden becomes an active link in the local green ecological network.