Diet complexity in early life affects survival in released pheasants by altering foraging efficiency, food choice, handling skills and gut morphology.
نویسندگان
چکیده
Behavioural and physiological deficiencies are major reasons why reintroduction programmes suffer from high mortality when captive animals are used. Mitigation of these deficiencies is essential for successful reintroduction programmes. Our study manipulated early developmental diet to better replicate foraging behaviour in the wild. Over 2 years, we hand-reared 1800 pheasants (Phasianus colchicus), from 1 day old, for 7 weeks under different dietary conditions. In year one, 900 pheasants were divided into three groups and reared with (i) commercial chick crumb, (ii) crumb plus 1% live mealworm or (iii) crumb plus 5% mixed seed and fruit. In year two, a further 900 pheasants were divided into two groups and reared with (i) commercial chick crumb or (ii) crumb plus a combination of 1% mealworm and 5% mixed seed and fruit. In both years, the commercial chick crumb acted as a control treatment, whilst those with live prey and mixed seeds and fruits mimicking a more naturalistic diet. After 7 weeks reared on these diets, pheasants were released into the wild. Postrelease survival was improved with exposure to more naturalistic diets prior to release. We identified four mechanisms to explain this. Pheasants reared with more naturalistic diets (i) foraged for less time and had a higher likelihood of performing vigilance behaviours, (ii) were quicker at handling live prey items, (iii) were less reliant on supplementary feed which could be withdrawn and (iv) developed different gut morphologies. These mechanisms allowed the pheasants to (i) reduce the risk of predation by reducing exposure time whilst foraging and allowing more time to be vigilant; (ii) be better at handling and discriminating natural food items and not be solely reliant on supplementary feed; and (iii) have a better gut system to cope with the natural forage after the cessation of supplementary feeding in the spring. Learning food discrimination, preference and handling skills by the provision of a more naturalistic diet is essential prior to the release of pheasants in a reintroduction programme. Subsequent diet, foraging behaviour, gut morphology and digestive capabilities all work together as one nutritional complex. Simple manipulations during early development can influence these characteristics to better prepare an individual for survival upon release.
منابع مشابه
Adaptive foraging does not always lead to more complex food webs.
Recent modeling studies exploring the effect of consumers' adaptivity in diet composition on food web complexity invariably suggest that adaptivity in foraging decisions of consumers makes food webs more complex. That is, it allows for survival of a higher number of species when compared with non-adaptive food webs. Population-dynamical models in these studies share two features: parameters are...
متن کاملEffects of different three live foods on growth performance and survival rates in Beluga (Huso huso) larvae
To determine the best live food and to reevaluate the optimal weaning period for beluga fish (Huso huso) larvae, seven experimental diets: Daphina (DP), Chironomids (CH), Gammarid (G), Daphina + formulated diet (DPFD), Chironomids + formulated diet (CHFD), Gammarid + formulated diet (GFD ) and formulated diet (FD ) in triplicate groups were fed to 4662 sixteen-days-old larvae which were captu...
متن کاملMultiple behavioural, morphological and cognitive developmental changes arise from a single alteration to early life spatial environment, resulting in fitness consequences for released pheasants.
Subtle variations in early rearing environment influence morphological, cognitive and behavioural processes that together impact on adult fitness. We manipulated habitat complexity experienced by young pheasants (Phasianus colchicus) in their first seven weeks, adding a third accessible dimension by placing elevated perches in their rearing pens mimicking natural variation in habitat complexity...
متن کاملThe Ecological Causes and Consequences of Prey Choice and Ontogenetic Niche Shifts in the Common Goby
THE ECOLOGICAL CAUSES AND CONSEQUENCES OF PREY CHOICE AND ONTOGENETIC NICHE SHIFTS IN THE COMMON GOBY Angus Charles Jackson Foraging behaviour of the common goby, Pomatoschistus microp s was investigated in both the United Kingdom and Sweden, with the aim of establishing causes and consequences of prey choice and ontogenetic shifts in diet. Goby life-cycle could be clearly divided into two stag...
متن کاملEffects of different three live foods on growth performance and survival rates in Beluga (Huso huso) larvae
To determine the best live food and to reevaluate the optimal weaning period for beluga fish (Huso huso) larvae, seven experimental diets: Daphina (DP), Chironomids (CH), Gammarid (G), Daphina + formulated diet (DPFD), Chironomids + formulated diet (CHFD), Gammarid + formulated diet (GFD ) and formulated diet (FD ) in triplicate groups were fed to 4662 sixteen-days-old larvae which were captu...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Journal of animal ecology
دوره 84 6 شماره
صفحات -
تاریخ انتشار 2015