The Breeding Biology of an Endangered Hawaiian Honeycreeper, the Laysan Finch

Morin, Marie P.

doi:10.2307/1369250

Cited by 14 publications

(8 citation statements)

References 29 publications

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“…Among the 12 years when caterpillars were sampled, the pattern of annual variation was clear, in spite of differences in methods of sampling. Marked temporal variation in passerine bird production as a result of fluctuations in food supply is a characteristic of seasonally arid habitats in both tropical (Marchant 1960, Grant and and temperate regions (Maclean 1976, Rotenberry and Wiens 1991, Morin 1992, Lloyd 1999. Other components of nestling diets were sampled in only a few years, yet their annual variation is consistent with that of the relationships for caterpillars (Gibbs and Grant 1987a).…”

Section: Gibbs and Grant 1987a) Early Breeding Is Noteworthy Becaumentioning

confidence: 67%

Effects of El Nino Events on Darwin's Finch Productivity

Grant¹,

Grant²,

Keller³

et al. 2000

Ecology

104

165

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JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. Ecological Society of America is collaborating with JSTOR to digitize, preserve and extend access to Ecology.Abstract. We studied the effects of heavy and prolonged rainfall associated with four El Nifio events on the reproduction of Darwin's finches on the Galapagos island of Daphne Major. Rainfall varied in the El Nifio years from 195 mm to 1359 mm, exceeding the maximum in the other years by 40% to 1000%. Two species were studied: Geospizafortis, Medium Ground Finch, and G. scandens, Cactus Finch. Almost all eggs, nestlings, and fledglings produced by banded females were recorded in the El Nifo years of 1983, 1987, 1991, and 1998. Finch production in these years was compared with production in 10 other years of breeding in the period 1976-1990; there was no breeding in three drought years, 1985, 1988, and 1989. Breeding differed in the two sets of years in several ways. More broods were produced in El Nifo years than in non-El Nifo years (maximum 10 clutches per female vs. five clutches), the period of breeding was longer (maximum eight months vs. four), average clutch sizes (range 2-6 eggs) were distinctly larger (four vs. three), and average egg and fledgling production per female was larger by a factor of four. The two species differed in some features of breeding, but differences were minor in comparison with the marked seasonal and annual variation. Finch production varied among El Niflo years, being greatest in the year of most rain over the longest period (1983), and least in the next wettest year (1998). The surprisingly low production in 1998 is attributed in part to interactions with other finches, and in part to exceptionally high temperatures. Temperature, although postively correlated with rainfall, had an independent negative effect upon hatching and overall breeding success of G. fortis. Breeding by both species in the year of birth (hatch) occurred in two El Nifio years with the most extended wet seasons: 1983 and 1987. Young breeders had lower clutch sizes and breeding success than did contemporaneously breeding older birds.Observations in different El Niflo years show that finch population responses to major climatic perturbations such as elevated rainfall vary for two major reasons: the perturbations themselves vary in strength and duration, and responses to them are determined, in part, by preceding conditions. Those preceding conditions, in turn, are determined by whether drought or normal conditions precede the perturbation, and on the interval since the previous El Nifo event. Thus, perturbations of natural systems can be fully understood only in a broad temporal context. ing strength, occurring in the tropical eastern Pacific, but affecting extratro...

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Section: Gibbs and Grant 1987a) Early Breeding Is Noteworthy Becaumentioning

confidence: 67%

Effects of El Nino Events on Darwin's Finch Productivity

Grant¹,

Grant²,

Keller³

et al. 2000

Ecology

104

165

View full text Add to dashboard Cite

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“…For all tests we divided the nestling period into two stages: early (::=; 14-day-old chicks) and late (> 14-day-old chicks). The Laysan Finch (Telespiza cantans), Palila's most closely related living relative (James and Olson 1991), has a nestling period of similar length, and growth rate is highest at day 14 (Morin 1991(Morin , 1992. In addition, Palila chicks are well feathered and begin to thermoregulate about that time (van Riper 1978).…”

Section: Discussionmentioning

confidence: 99%

“…However, Laysan Finch nestlings fledge on average 3 days earlier than Palila nestlings. Because the birds are of similar adult mass, the faster growth and earlier fledging date of the Laysan Finch could be partly attributable to a diet more variable than the Palila's (Morin 1991). Rates of food delivery to nestlings are known for several species of Hawaiian honeycreepers (Eddinger 1970, van Riper 1978, 1980, Lockwood 1994, Kepler et al 1997, VanderWerf 1998, Simon et al 2000.…”

Section: Visitation Ratesmentioning

confidence: 99%

Nesting Behavior of Palila, as Assessed from Video Recordings

Laut¹,

Banko²,

Gray³

2003

Pacific Science

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We quantified nesting behavior of Palila (Loxioides bailleui), an endangered Hawaiian honeycreeper, by recording at nests during three breeding seasons using a black-and-white video camera connected to a videocassette recorder. A total of seven nests was observed. We measured the following factors for daylight hours: percentage of time the female was on the nest (attendance), length of attendance bouts by the female, length of nest recesses, and adult provisioning rates. Comparisons were made between three stages of the 40-day nesting cycle: incubation (day I-day 16), early nestling stage (day 17-day 30 [i.e., nestlings:::;; 14 days old]), and late nestling stage (day 31-day 40 [i.e., nestlings> 14 days old]). Of seven nests observed, four fledged at least one nestling and three failed. One of these failed nests was filmed being depredated by a feral cat (Felis catus). Female nest attendance was near 82% during the incubation stage and decreased to 21 % as nestlings aged. We did not detect a difference in attendance bout length between stages of the nesting cycle. Mean length of nest recesses increased from 4.5 min during the incubation stage to over 45 min during the late nestling stage. Mean number of nest recesses per hour ranged from 1.6 to 2.0. Food was delivered to nestlings by adults an average of 1.8 times per hour for the early nestling stage and 1.5 times per hour during the late nestling stage and did not change over time. Characterization of parental behavior by video had similarities to but also key differences from findings taken from blind observations. Results from this study will facilitate greater understanding of Palila reproductive strategies.

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“…Flint, USFWS, oral commun., 2011). Reproductive failure of Laysan Finches and Laysan Teal at Laysan Island during extensive storms and extreme events have also been documented (Morin, 1992a;Kristof and others, 2011), highlighting the potential negative impacts of increasing storm intensity on NWHI avifauna.…”

Section: Sea-level Risementioning

confidence: 95%

“…The six climate change scenarios examined all predicted increases in temperatures and decreases in precipitation. The NWHI endemic land birds have demonstrated strong demographic responses to climatic variability including reduced rainfall (Morin, 1992a;Work and others, 2004) and increased temperatures (Reynolds and others, 2007;Work and others, 2010). For seabirds, environmental stochasticity can alter the distribution of prey associated with specific oceanic water masses (Polovina and others, 2001;Bograd and others, 2004) and alter prey composition in foraging areas (Brodeur and others, 1999;Grebmeier and others, 2006).…”

Section: Sea-level Risementioning

confidence: 99%