The welfare of game birds destined for release into the wild: a balance between early life care and preparation for future natural hazards

Abstract

Globally, over 110 million game birds are reared annually and released for recreational hunting. Game birds differ from other reared livestock because they experience two very distinct environments during their lives. Chicks are first reared in captivity for 6–12 weeks under managed, stable conditions and then released into the wild. A limited set of 13 studies have explored how the rearing conditions experienced by chicks influences their pre-release welfare, typically in terms of physical injury (feather-pecking) or behavioural assays of stress responses. However, no studies have considered the specific indicators of welfare of game birds after release. We therefore need to draw from studies that do not specifically investigate welfare but instead ones that examine how rearing environments influence post-release morphology, behaviour and survival. Consequently, we reviewed how reared and wild-born game birds differ and suggest methods by which more naturalistic rearing conditions may be achieved. We noted five areas where artificial rearing deviates substantially from natural conditions: absence of adults; unnatural chick densities; unnatural diet; unnatural physical environment; and exclusion of predation risk. Mimicking or introducing some of these elements in game bird rearing practice could bring two benefits: i) facilitating more natural behaviour by the chicks during rearing; and ii) ensuring that birds after release are better able to cope with natural hazards. Together, these could result in an improved overall welfare for game birds. For example, enrichment of the spatial environment may serve to both improve welfare pre-release and after release into the wild. However, some adaptations may induce poor welfare for a short period in the young birds. For example, exposure to predators may be temporarily stressful, but ultimately such experiences in early life may permit them to better cope with such threats when released into the wild. Therefore, to achieve an optimal welfare for the entirety of a game bird's life, a careful balance between the conditions experienced in early life and adequate preparation for later life in the wild is required.

Intensive Farming and Welfare Regarding Anti-Predator Behavior of Chukar Partridges (Alectoris chukar)

“…Many empirical approaches for stimulating and shaping AP behavior can be found in the literature [22][23][24] and are generally grouped in the following broad categories: (1) The flight initiation (FI) test aims at stimulating a flight response against a human intruder and is quantified by the distance, defined as the minimum distance for eliciting the flight response in birds; (2) The novel object (NO) tests simulate a happenstance with a novel item, usually associated with a food resource [25]; (3) The emergence/escape tests (ET) estimate the propensity of wandering into an unfamiliar or potentially dangerous environment from an instinctively harmless location [26]; Finally, (4) the predator exposure tests present the predator in a controlled manner to elicit its scrutiny or alarm calls under predation danger [27].…”

“…The early life of chicks in captivity is crucial for the development of such behaviors. Some training can induce stress in birds, but in the long term, these are beneficial [3], assuring the bird's survival in the wild once released.…”

“…Exposure to natural predators is considered normal and part of the natural niche. The AP training with the live predators can induce temporary stress in the birds [3], but in the long term, it is beneficial. All the birds were captured by hand-net and at the twilight time during the cool.…”

“…When released, captive birds face a sudden change in their habitat [3]. They are first provided intense human interventional care, and then, once released, exposed to no or minimal human interventions.…”

Sublethal effects of pesticide residues differ between strains of captive Grey partridge: Consequences in terms of rearing conditions

“…food unpredictability and quality, variable diet, vulnerability to predators and/or diseases). Food quality during captivity may thus also play a role in post-release survival and the success of the reintroduction process (Madden et al 2020). Traditionally, farm-strain birds are fed with highly-digestible commercial poultry food (Liukkonen-Anttila et al 1999, 2000 including genetically modified soya, wheat and corn that differs from their natural diet (in terms of energy supply, digestibility and quality).…”