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HARTMAN BAKKEN,BRADLEY; SABAT,PABLO. |
Nectar-feeding birds oscillate between avoiding overhydration when they are feeding and preventing dehydration during fasts. Here, we examined how resting rates of total evaporative water loss (TEWL) and metabolic water production (MWP) influence water balance in the green-backed firecrown (Sephanoides sephanoides), a Chilean hummingbird. We hypothesized that a circadian rhythm in TEWL would assuage the dehydration risk that hummingbirds face during the night. However, we did not find support for this idea. In resting hummingbirds, rates of TEWL during the day (54 ±6 µLh-1,n = 8) and night (65 ± 12 h-1, n = 5) were similar. Rates of MWP were also similar between the day (22 ±3 µL h-1, n = 8) and night (23 ± 2 µL h-1, n = 5). MWP rates were significantly... |
Tipo: Journal article |
Palavras-chave: Circadian rhythm; Evaporative water loss; Hummingbird; Osmoregulation; Water balance. |
Ano: 2007 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2007000300001 |
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Missagia,Caio C.C.; Alves,Maria Alice S.. |
Legitimate flowers visitors pollinate the flower during the visit and thus influence the production of fruits and seeds. We tested whether the visitation rate of potential pollinators is associated with the amount of seeds per fruit produced by the self-compatible bromeliad Tillandsia stricta (Bromeliaceae). We determined whether hummingbirds are legitimate visitors by testing for a correlation between visits and pollination (seed production) at the Guapiaçú Ecological Reserve (Reserva Ecológica de Guapiaçú), state of Rio de Janeiro. We tested 30 flowers, five of which were also monitored to test the possibility of spontaneous self-pollination. The remaining 25 flowers were exposed to floral visitors. Twenty-two flowers formed fruits and seeds, from which... |
Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Atlantic forest; Hummingbird; Pollination; Self-compatibility. |
Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702015000300260 |
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