Protecting Sunflowers from Pigeons and Crows

Pigeons Crows Seedling Protection Sunflowers

The predators with feathers of the sunflower are the wood pigeons (or palombes), the feral rock pigeon (or city pigeon), the turtle doves, and the crows.

There is a whole range of control methods whose effectiveness will be multiplied by combining them with each other.

If any techniques are missing from this inventory, please feel free to share them with us in the comment section at the bottom of the page!

Risk Periods

Sunflower cultivation is subject to 2 periods of bird attacks:

At emergence by pigeons and crows;
At harvest by pigeons and turtle doves.

The columbids mainly attack seedlings at an early stage, causing plant loss if the stem is cut. Damage to cotyledons apparently has no consequences.

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Vigor at the Start: An Essential Prerequisite

The most critical phase is between sowing and emergence:

A good growth dynamic is therefore crucial at the start to not give birds time to settle.
A good soil drying and warming (>12°C) are important to promote regular sunflower emergence (the faster and more uniform the emergence, the less damage there will be).
Seed coating with trace elements can give an extra boost to emergence:
- Humic/fulvic acids 0.5 to 1 L/100 kg (no more to avoid germination problems).
- Zinc sulfate 30 g/100 kg;
- Manganese sulfate 30 g/100 kg;
- Bentonite-type clay to dry;
- Liquid amino acids 0.5 L/100 kg.

Caution: to sow sunflower with a single-seed drill, the seed must be well dried. This can take several hours (or even more than 24 h) and handling to spread the seeds on a tarp or in a bin and stir them one or more times. Anticipation is the key to success.

Different Damage Depending on the Birds

The damage caused by columbids or corvids differs in nature and impact on the fate of sunflower plants:

Crows and carrion crows generally attack the seed or uproot the seedling, leading to total plant loss.

Pigeons cause more or less harmful damage depending on the sunflower stage at their arrival.
- Post-sowing, birds attack seedlings up to stage B1 (1 leaf), they pull out seedlings, consume seeds, and young seedlings. If the apex is cut by the bird’s beak, plant loss is inevitable. However, when cotyledons begin to unfold, damage may be limited to their partial or total destruction. Holes a few centimeters wide, regular and visible, show that birds search for seeds following sowing lines. They consume seeds they have unearthed by probing the soil.
- At maturity, they consume seeds on the top of the capitulum, those accessible to them while perched on the sunflower head.

Method to Observe Pressure Level

Walk through the field and assess the percentage of affected plants:

Low: Limited and scattered damage, less than 5% of the stand destroyed.

Medium: Significant damage, between 5% and 10% of the stand destroyed, with entire zones affected.

High: Severe damage, more than 10% of the stand destroyed.

Pressure levels are indicative and do not reflect exact severity of infestation at a given time or subsequent damage. Other factors related to the crop and symptom or infestation dynamics intervene.

Factors Favoring Attacks

The vulnerability of a field is more related to its location, when situated in a risk zone, than to the effectiveness of protection systems. Despite the presence of protective devices, mainly deterrents, one in two sunflower fields is attacked by birds and had to be reseeded. Proximity to a town or a hedge favors attacks. These areas are conducive to the development of nesting sites and pigeon populations.

Control Methods

Agronomic Levers

Decoy Sowing

This technique consists of sowing a cereal with straw (barley or wheat) before sowing, for example, sunflower, to lure birds, then destroying it to avoid competition with the sunflower. The ideal is to do this during the final soil preparation in the inter-rows of future sunflower rows using a guidance system, at a density of about 60-70 kg/ha.

The goal is to sow the sunflower when the cereal shows its first leaf.. The cereal must be destroyed before the 4 to 6 leaf stage by hoeing.

It is also possible to sow barley simultaneously with sunflower. However, this approach requires rigor in hoeing to prevent the cereal from overtaking the sunflower.

Play the Collective

Coordinating sowings is a lever to consider at the scale of a territorial collective. This strategy relies on synchronizing sunflower sowings in a reduced area and thus sharing intended sowing dates among producers. This approach will allow a dilution effect and thus distribute damage across the entire field.

Sow Later

The sensitivity window of sunflower seedlings to wood pigeon damage is narrow: about two weeks from emergence to the first pair of leaves. Damage is lower the faster and more uniform the emergence is; to achieve this, sow in sufficiently warmed soil (8°C at 5 cm depth), preferably simultaneously with neighbors.

The risk of drought is increased but for those practicing no-till farming the fact of not working the soil helps retain soil moisture and thus limit this risk. To decide on sowing, recall that sunflower needs a cumulative temperature of about 90° days base 6°C between sowing and emergence. It is possible to average the minimum and maximum soil temperatures (take temperature at 8:00 and 14:00) and subtract 6 °C. Then accumulate daily average temperatures according to forecasted temperatures. It is recommended to sow when the cumulative temperature reaches 90° days within 10 to 15 days maximum.

Sow Denser

Bird damage is most often localized in an area, at the edge of a hedge or forest for example. At sowing, consider bird damage and sow at a higher density to compensate for plant losses.

Seed Coating

To make seeds less visible to birds, it is possible to coat them with a mixture of components such as clay, vermicompost, molasses,... There is no repellent effect; birds simply do not see the seeds on the surface and thus do not consume them. There is also no effect on germination; it will occur when the seed has enough moisture to germinate, but this technique will help seeds in their development.

Strengthen Young Sunflower Plants at Start

It is possible to strengthen young sunflower plants at the start to limit the consequences of damage caused by birds. This reinforcement involves optimizing mineral and water absorption by the plant and thickening cell walls to create an unfavorable environment for pest birds.

Undercover Sowing

This technique consists of sowing a cover crop, for example barley or faba bean, then destroying it at or shortly after sunflower sowing. The goal of current tests is to create visual confusion without risking competition between sunflower and cover crop.

Resowing as a Last Resort

Resowing or replacing with another crop can be considered, but only after careful observation of damage. Indeed, cotyledon lesions have no consequences. The decision to resow should therefore be based solely on missing plants.

For more information on the subject, we invite you to read this article.

Physical Control

Adding Chili/Pepper to Seeds

For pepper, count 50 to 100 g of ground pepper per 100 kg of seed.
It is important to combine it with a binder such as humic and fulvic acids at 0.75 L/100 kg, which also promote root development.

Deterrents

Many models exist; scaring techniques use visual or sound signals. Measures should be taken to avoid bird habituation: Regular human presence often remains the most effective to prevent settlement of crows in the field.
It is also recommended to report damage to hunting federations. Reporting this information helps classify or not certain species as ESOD (species likely to cause damage) to allow hunters to intervene outside hunting season if needed.
Certain rules must be respected for the use of sound deterrents, in accordance with the regulations.

Operational advice:

1. Do not install deterrents too early, but just before the sensitive stage: from emergence to first pair of leaves.

2. Do not hesitate to move deterrents around the field every 2-3 days.

3. For sound deterrents, vary signals and intervals of broadcast.

4. Observe the landscape around the attacked crops to orient deterrents toward alternative food sources (like green leaves, berries, acorns, etc.).

5. Considering a combination of deterrents can reduce habituation, such as using gas cannons combined with balloons/kites or combined with pyrotechnic means for example.

At the end of the cycle, depredations are generally rarer than at emergence and may be caused from the start of maturation by some mammals. Early harvesting, as soon as maturity is reached, is the only way to limit seed removal by birds.

For more info, consult the overview of main deterrent models by Terres Inovia.

You can find several of the deterrents listed below on the website of the company Agriprotech.

Kites

These are the most used against birds; they are shaped like a predator. They generally have a large wingspan (about 1.2 m) which gives them visibility and credibility with pests. The goal of this type of deterrent is to imitate the flight of a raptor hunting its prey.

The erratic and sudden flight of the deterrent creates a stressful and seemingly dangerous environment for unwanted birds. To optimize the use of this protection against pests, it is recommended to place the object in the field and move it regularly every 4-5 days to avoid habituation by pests. Birds are intelligent and get used to the threat over time. Moreover, it is possible to install several in the same field (depending on the area) to increase the coverage of these systems.

Indicative price incl. tax: €50-85 each.

Helium-filled Balloons

The difficulty of this technique is finding robust balloons suitable for long-term outdoor flight. Aluminum foil balloons are preferable to latex balloons because they do not become brittle under the sun and are easier to reinflate. But they risk bursting in high heat. Attach 3 to 4 balloons per hectare at the end of a fishing line or nylon thread (strength > 5 kg) 15 to 20 m long. Changing balloon locations every 3 to 4 days can increase method effectiveness. Balloons must be reinflated every 3 to 5 days. To prevent crows from habituating too quickly, balloons should only be installed when damage risk exists.

Indicative price incl. tax: €50-85 each.

Reflective Strips

This shiny tape is feared by birds; its reflective effect and the noise it makes when moving scare birds.

Indicative price incl. tax: €30-60 per roll of 100 m length.

Flags

The movement created by these colorful turbine flags scares birds. They work with little wind (from 15 km/h).

Indicative price incl. tax: €60 each.

Large Bags Mounted on Stakes

Recycling is perfect for this; you can use bags inside big bags or old tarps. Remember to move them regularly because crows get used to their presence.

Scarecrows

Remember to move them regularly because crows get used to their presence.

Lasers

Birds perceive the movement of the green dot of the laser beam projected on the ground as danger and react on their survival instinct. They identify this movement as a threat but cannot understand what it is. Eventually, they leave the area. This technology being completely silent, it is an alternative to sound deterrents in areas near residences.

Various models are available at different price points, from torches to autonomous field devices. They allow targeting individuals, but little information exists on effectiveness on groups of columbids and corvids.

Drones

Options range from terrestrial drones to biomimetic flying drones, with environmental reaction capabilities (motion detectors). However, services are currently too costly for use in arable farming contexts.

Be sure to follow the regulations!

Gas Cannons or "Bazookas"

Beware of neighbors! Gas cannons create a loud detonation intended to scare pests such as pigeons or corvids. The principle is to release gas from a cylinder into a chamber with a valve until a certain pressure is reached, then release and ignite the gas with a spark plug to create a detonation. Hence the name bird scarer cannons. The detonation occurs inside a tube to concentrate the explosion and direct the sound where desired.

To maximize effectiveness:

Position it against the wind so it stays in place and the detonation does not echo too far.
Do not aim it toward residences and, if possible, place it at least 300 meters away from them to avoid neighbor complaints.
Set the desired detonation type (random or double shots) and the interval between them (usually 10 to 20 minutes).

In France, there is no regulation on the use of gas cannons, but prefectural or municipal decrees may regulate their use. Moreover, noise pollution from these devices is regulated by public health code provisions, notably articles R. 1336-6 to R. 1336-9, which set noise limits related to professional activity. Under these provisions, the cannon can be equipped with a digital timer to automatically shut off during night hours (from 10 p.m. to 7 a.m.).

Drawback: theft and damage. It is common for a cannon or gas bottle to be stolen...

Indicative price incl. tax: €469 - 1860 each.

Pyrotechnics

Whistling pistols or blank pistols can be used to scare birds. Their use requires presence in the field. Varying cartridges prevents bird habituation.

Indicative prices: Pistol: €140-200, primers (x50/x100): €18-30, rockets (x50): €30.

Sound Deterrents

There are acoustic devices emitting frightening sounds for birds: cries of raptors or distress calls. These are commercially available and easy to install. Depending on the different cries broadcast, their effect lasts for varying durations.

Indicative price incl. tax: €350-450 each.

Regulatory Reminder

Sound deterrents can be used on all birds at any time. The provisions of the prefectural noise control order of December 31, 2014, must be respected, notably that noises must not be emitted:

from public roads or publicly accessible places
between 10 p.m. and 7 a.m. (which would constitute nighttime noise disturbance)
outside days when sowings must be protected.

It is advisable to notify the town hall of the concerned municipality(ies), so the mayor can respond to potential complaints from residents worried about these noises. Similarly, when few residents are concerned, informing them can avoid worries and interventions. The use of carbide cannons requires prior authorization from the mayor under the conditions of the December 31, 2014 order.

Encourage the Presence of Raptors

Installing raptor perches, used in large crops areas, can attract predators. Although often too weak to attack the wood pigeon (e.g., common buzzard), they can have a deterrent effect.

Call on a Falconer

Using a falconer is effective against wood pigeons but remains costly for individual use.

Avoid refuge areas

Abandoned buildings near plots offer refuges for pigeons; demolish them or block all access whenever possible.

Repellents

Foliar fertilizers with repellent effects usable directly on seedlings show limited effectiveness. No repellent product is authorized for seed protection.

Shooting

Regulations allow trapping and so-called "destruction" shooting outside hunting season in departments where the species is classified as "likely to cause damage."

The city pigeon

Since the ordinance of 8 September 2005, domestic pigeons or ownerless pigeons have the same status as poultry when found on neighboring lands. They are now subject to articles L 211-5, L 211-4 of the rural code and 564 of the civil code, which stipulate that outside hunting periods (from the 2nd Sunday of September to 28 February), those who suffer damage caused by these pigeons have the right to kill them without claiming ownership. These legal articles therefore allow owners or farmers, provided they have a valid hunting license for the current season, to destroy city pigeons by shotgun without formalities, except for leaving the shot pigeons on site and burying them after 24 hours if the owner has not retrieved them.

Moreover, municipalities, in application of articles L2212-1, L2212-2, L2542-2 and following of the general code of local authorities concerning the Mayor's police powers regarding safety, security, and public health, must also proceed to limit the populations of these birds or destroy them when they cause damage.

The wood pigeon

Also called palombe, it is a wild or game pigeon that can only be hunted from the 2nd Sunday of September to 28 February under conditions set by prefectural decree. Outside this hunting period, it can be scared off by shooting if it "attacks" crops. Owners or farmers, provided they have a valid hunting license for the current season, may carry out scaring shots with a shotgun against these pigeons.

We advise you to notify the town hall of the concerned municipality and neighbors to avoid possible concerns regarding the shootings.

The simultaneous use of several of these tools is recommended to increase effectiveness on the same plot. Furthermore, each device is placed at a specific location on the plot, so they do not cover the entire area potentially targeted by pigeons and crows. The scope of your overall bird control system can therefore be improved by combining several of these tools.

Alert

Since attacks do not only occur at the plot level, it is important to report all damage to your plots caused by birds (even if you reported damage in previous years) via forms provided by departmental organizations: DDT, Chamber of Agriculture, FDSEA, FNC according to department, town hall,... to have a complete overview of the situation and so that regulation actions can be conducted by authorized hunters or trappers, thus limiting the risk for subsequent years. The effectiveness of these actions is long-term.

Even though reporting does not entitle compensation, the census of damage caused by bird species (or the absence of reporting) is taken into account for the study of their classification or not on the list of harmful species.

Participate in the Terres Inovia bird damage survey

Sources

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