Variation during breeding in parameters that influence blood oxygen carrying capacity in shearwaters
Variation during breeding in parameters that influence blood oxygen carrying capacity in shearwaters
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DOI：
10.1071/zo00047
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发表时间：
2000-01-01
影响因子：
0.8
通讯作者：
Baldwin, J
中科院分区：
文献类型：
--
作者：
Davey, C;Lill, A;Baldwin, J
在维多利亚的菲利普岛采集了30只成年短尾剪翅鸭（Puffinus tenuirostris），在其繁殖周期的7个关键阶段，测定了影响血液携氧能力的参数（全血血红蛋白含量、红细胞压积和红细胞计数）。调查的目的是确定在鸟类的7个月的繁殖周期中，血液携氧能力的变化是否与它们所经历的能量需求的变化相关，或者是其他生理变化的偶然副产品。所有的血液参数在育种过程中变化显着，但变化的模式只有部分与可能的模式，改变能源需求的父母由他们的时间表的育种活动。可以想象的主要趋势与能源需求的是，显着更高的值记录这些血液参数在雏鸟阶段比早在繁殖周期。这可能反映了父母喂养雏鸟的长途觅食旅行的高成本，但也可能是在为繁殖结束后不久进行的长途迁徙做准备时发生的。它涉及到血液携氧能力比繁殖周期中记录的最低平均值增加10%，因此还必须采用其他机制来实现在这个阶段可能需要的有氧代谢的增加。在繁殖周期的早期，缺乏对血液携氧能力与能量需求的调节，这表明，要么氧气输送在当时不是有氧代谢的限速过程，要么输送是通过其他机制增强的。在产卵，女性有一个较低的红细胞压积和红细胞计数比男性，这可能是由于雌激素抑制红细胞生成或增加与蛋黄合成相关的血液渗透压。不成熟的，非繁殖鸟类参加殖民地的成年人的质量相似，但没有显示出增加的参数确定血氧携带能力，发生在成年人以后的繁殖周期。改变能量需求（脱水，洞穴缺氧和差分响应捕获应力），可能会影响模式的变化，在繁殖过程中的成年人的血液携氧能力的其他因素进行了讨论。
Parameters that influence blood oxygen carrying capacity (whole-blood haemoglobin content, haematocrit and red blood cell count) were measured in samples of 30 breeding, adult short-tailed shearwaters (Puffinus tenuirostris) on Phillip Island, Victoria at seven key stages of their reproductive cycle. The aim of the investigation was to determine whether variation in blood oxygen carrying capacity during the birds' 7-month breeding cycle was correlated with variation in the energy demands they experienced or was an incidental by-product of other physiological changes. All the blood parameters varied significantly during breeding, but the pattern of variation was only partly correlated with the likely pattern of changing energy demand imposed on parents by their schedule of breeding activities. The main trend conceivably related to energy demand was that significantly higher values were recorded for these blood parameters during the nestling stage than earlier in the breeding cycle. This could have reflected the high costs of the very long foraging trips undertaken by parents feeding nestlings, but it could also have occurred in preparation for the long migration undertaken soon after breeding finished. It involved an similar to 10% increase in blood oxygen carrying capacity above the lowest mean value recorded during the breeding cycle and so other mechanisms must also be employed to achieve the increase in aerobic metabolism likely to be required at this stage. The lack of adjustment of blood oxygen carrying capacity to energy demand early in the breeding cycle suggests that either oxygen delivery was not a rate-limiting process for aerobic metabolism at that time or that delivery was enhanced through other mechanisms. At egg laying, females had a lower haematocrit and erythrocyte count than males, which could be attributable to either estrogenic suppression of erythropoiesis or an increase in osmotic pressure of the blood associated with yolk synthesis. Immature, non-breeding birds attending the colony were of similar mass to adults, but did not show the increase in the parameters determining blood oxygen carrying capacity that occurred in adults later in the breeding cycle. Factors other than changing energy requirements (dehydration, burrow hypoxia and differential responsiveness to capture stress) that might have influenced the pattern of variation in blood oxygen carrying capacity of adults during breeding are discussed.