|
Registro Completo |
|
Biblioteca(s): |
Embrapa Pantanal. |
|
Data corrente: |
17/11/1997 |
|
Data da última atualização: |
05/04/2017 |
|
Autoria: |
FREELAND, W. J.; JANZEN, D. H. |
|
Título: |
Strategies in herbivory by mammals: the role of plant secondary compounds. |
|
Ano de publicação: |
1974 |
|
Fonte/Imprenta: |
American Naturalist, v.108, n.961, p.269-289, May/June, 1974. |
|
Idioma: |
Inglês |
|
Conteúdo: |
Large herbivores must select food from a wide variety of plant parts, species, and strains. These differ in nutritional value (protein, carbohydrate, etc.), toughness, spinosity, etc. Even greater differences are found in types and concentrations of secondary compounds. Every plant produces its own set of secondary chemical compounds, which to a great extent are unique to it or its species. Ingestion of natural concentrations of these compounds can lead to either death or severe physiological impairment. The ubiquitous nature of these compounds would make herbovory impossible unless animals had mechanisms for degrading and excreting them. An animal displaying no obvious symptoms of poisoning is not free of the problem of ridding itself of toxic compounds; if it is eating plants, ir almost certainly has this problem. Herbivores are capable of detoxifying and eliminating secondary compounds. Limitations of these mechanisms force mammalian herbivores to consume a variety of plant foods at any one time, to treat new foods with caution, to ingest small amounts on the first encouter, and to sample food continuously. Selection of food is based on learning in response to adverse internal physiological effects, and herbivores probably cannot predict these from the smell or taste of new foods. herbivores prefer to eat familiar foods and can seek out and consume foods that rectify specific nutritional deficiencies induced by detoxification. They should prefer to feed on foods that contain small amounts of secondary compounds, and their body size and searching strategies should be adapted to optimize the number of types of foods available with respect to the total amount of food that can be eaten and will be present in future. Natural selection can increase the efficiency ofm degrading particular secondary compounds. Specialist herbivores, like koala and mountain viscacha, are expected where a large amount of several related toxic foods is present in a year-round supply. However, few large herbivores are specialized on such a restricted range of foods. MenosLarge herbivores must select food from a wide variety of plant parts, species, and strains. These differ in nutritional value (protein, carbohydrate, etc.), toughness, spinosity, etc. Even greater differences are found in types and concentrations of secondary compounds. Every plant produces its own set of secondary chemical compounds, which to a great extent are unique to it or its species. Ingestion of natural concentrations of these compounds can lead to either death or severe physiological impairment. The ubiquitous nature of these compounds would make herbovory impossible unless animals had mechanisms for degrading and excreting them. An animal displaying no obvious symptoms of poisoning is not free of the problem of ridding itself of toxic compounds; if it is eating plants, ir almost certainly has this problem. Herbivores are capable of detoxifying and eliminating secondary compounds. Limitations of these mechanisms force mammalian herbivores to consume a variety of plant foods at any one time, to treat new foods with caution, to ingest small amounts on the first encouter, and to sample food continuously. Selection of food is based on learning in response to adverse internal physiological effects, and herbivores probably cannot predict these from the smell or taste of new foods. herbivores prefer to eat familiar foods and can seek out and consume foods that rectify specific nutritional deficiencies induced by detoxification. They should prefer to feed on foods that cont... Mostrar Tudo |
|
Palavras-Chave: |
Herbivoro; Herbivory; Mammal; Nutritional value; Plant. |
|
Thesagro: |
Mamífero; Planta; Valor Nutritivo. |
|
Categoria do assunto: |
-- |
|
Marc: |
LEADER 02679naa a2200229 a 4500
001 1791909
005 2017-04-05
008 1974 bl --- 0-- u #d
100 1 $aFREELAND, W. J.
245 $aStrategies in herbivory by mammals$bthe role of plant secondary compounds.
260 $c1974
520 $aLarge herbivores must select food from a wide variety of plant parts, species, and strains. These differ in nutritional value (protein, carbohydrate, etc.), toughness, spinosity, etc. Even greater differences are found in types and concentrations of secondary compounds. Every plant produces its own set of secondary chemical compounds, which to a great extent are unique to it or its species. Ingestion of natural concentrations of these compounds can lead to either death or severe physiological impairment. The ubiquitous nature of these compounds would make herbovory impossible unless animals had mechanisms for degrading and excreting them. An animal displaying no obvious symptoms of poisoning is not free of the problem of ridding itself of toxic compounds; if it is eating plants, ir almost certainly has this problem. Herbivores are capable of detoxifying and eliminating secondary compounds. Limitations of these mechanisms force mammalian herbivores to consume a variety of plant foods at any one time, to treat new foods with caution, to ingest small amounts on the first encouter, and to sample food continuously. Selection of food is based on learning in response to adverse internal physiological effects, and herbivores probably cannot predict these from the smell or taste of new foods. herbivores prefer to eat familiar foods and can seek out and consume foods that rectify specific nutritional deficiencies induced by detoxification. They should prefer to feed on foods that contain small amounts of secondary compounds, and their body size and searching strategies should be adapted to optimize the number of types of foods available with respect to the total amount of food that can be eaten and will be present in future. Natural selection can increase the efficiency ofm degrading particular secondary compounds. Specialist herbivores, like koala and mountain viscacha, are expected where a large amount of several related toxic foods is present in a year-round supply. However, few large herbivores are specialized on such a restricted range of foods.
650 $aMamífero
650 $aPlanta
650 $aValor Nutritivo
653 $aHerbivoro
653 $aHerbivory
653 $aMammal
653 $aNutritional value
653 $aPlant
700 1 $aJANZEN, D. H.
773 $tAmerican Naturalist$gv.108, n.961, p.269-289, May/June, 1974.
Download
Esconder MarcMostrar Marc Completo |
|
Registro original: |
Embrapa Pantanal (CPAP) |
|
