Transformations at High Latitudes: Why do Red Knots Bring Body Stores to the Breeding Grounds?

Abstract We examined changes in body composition of Red Knots (Calidris canutus islandica) following arrival on their High Arctic breeding grounds at Alert, Ellesmere Island, Canada. Knots arrived in late May and early June with large fat and muscle stores. In the next two weeks, fat and protein stores (pectoral muscles) declined, while increases occurred in gizzard, proventriculus, gut length, heart, liver, and possibly gonads. Most stores were used before egg laying occurred and were therefore not available for egg formation. Early development of ova in some females suggests that body stores may be incorporated into the earliest eggs. While stores may be used for survival when conditions are difficult after arrival, their rapid loss and the concomitant increase in other organs suggests that a major function may be to facilitate a transformation from a physiological state suitable for migration to one suitable, and possibly required, for successful breeding. Transformaciones a Altas Latitudes: ¿Por qué Calidris canutus islandica Lleva Reservas Corporales a los Sitios de Nidificación? Resumen. Examinamos los cambios en la condición corporal de individuos de Calidris canutus islandica luego de que éstos llegaran a sus territorios reproductivos a altas latitudes en el Ártico en Alert, isla Ellesmere, Canadá. Los individuos de C. c. islandica llegaron a fines de mayo y comienzos de junio con grandes reservas de grasa y músculo. Durante las dos semanas siguientes, las reservas de grasa y proteína (músculos pectorales) disminuyeron, mientras que la molleja, los proventrículos, el largo del intestino, el hígado y posiblemente las gónadas aumentaron de tamaño. La mayoría de las reservas fueron usadas antes del período de puesta de huevos, por lo que éstas no estuvieron disponibles para la formación de los huevos. En algunas hembras, el desarrollo temprano de los óvulos sugiere que las reservas corporales pueden ser incorporadas en los primeros huevos. Si bien las reservas pueden ser usadas para sobrevivir en el momento de la llegada cuando las condiciones son difí ciles, su rápida pérdida y el aumento concomitante en otros órganos sugiere que una de las funciones principales de las reservas podría ser facilitar la transformación de un estado fisiológico apropiado para la migración a un estado apropiado y posiblemente requerido para la reproducción exitosa.

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Use of Body Stores in Shorebirds After Arrival on High-Arctic Breeding Grounds

The Auk ◽

10.1093/auk/121.2.333 ◽

2004 ◽

Vol 121 (2) ◽

pp. 333-344 ◽

Cited By ~ 12

Author(s):

R. I Guy Morrison ◽

Keith A. Hobson

Keyword(s):

High Arctic ◽

Climatic Conditions ◽

Egg Laying ◽

The Arctic ◽

Nutrient Sources ◽

Marine Habitats ◽

Egg Formation ◽

Breeding Grounds ◽

Negative Exponential ◽

Egg Components

Abstract Stable-isotope analyses of egg components can illuminate the contributions of endogenous and exogenous nutrients to egg formation in cases where birds move from one isotopic biome to another just before egg-laying, as in Red Knots (Calidris canutus islandica) and Ruddy Turnstones (Arenaria interpres interpres) nesting in the northeastern Canadian High Arctic. Those populations use inshore marine habitats during the winter and northward migration periods, but switch to feeding and breeding in terrestrial C-3 habitats in the Arctic. Upon the birds' arrival at Alert, Nunavut, Canada, stable carbon (δ13C) and nitrogen (δ15N) isotope values for their red blood cells were consistent with those expected from an inshore marine diet. After the birds switched to a terrestrial diet, those values decayed in a negative exponential fashion until they reached asymptotic values consistent with a local terrestrial C-3 diet. Components of eggs laid later in the season, including lipid-free yolk, albumen, yolk lipid, and albumen lipid, generally showed isotope values consistent with routing from exogenous (i.e. local) nutrient sources, which supports the notion that High Arctic shorebirds are primarily income and not capital breeders. However, eggs in earliest clutches were enriched in 13C and 15N, which suggests that some residual marine nutrients were available for reproduction. The extent to which endogenous stores are transferred to eggs in High Arctic shorebirds may depend on year and climatic conditions.

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Do arctic-breeding Red Knots (Calidris canutus) accumulate skeletal calcium before egg laying?

Canadian Journal of Zoology ◽

10.1139/z96-257 ◽

1996 ◽

Vol 74 (12) ◽

pp. 2257-2261 ◽

Cited By ~ 21

Author(s):

Theunis Piersma ◽

Gudmundur A. Gudmundsson ◽

Nick C. Davidson ◽

R. I. Guy Morrison

Keyword(s):

Temporal Changes ◽

Egg Laying ◽

Ellesmere Island ◽

Calidris Canutus ◽

Skeletal Mass ◽

Terrestrial Arthropods ◽

Egg Formation ◽

Calcium Storage ◽

Subsequent Decrease ◽

Skeletal Calcium

Earlier studies have indicated that the diet of egg-laying female birds which eat only terrestrial arthropods has to be supplemented with calcium if they are to produce high-quality eggshells without interruption. During egg laying, females of tundra-breeding shorebird species may supplement their diet with fragments of mammalian skeletons, but as an alternative strategy they might store skeletal calcium before egg formation. We examine the possibility of calcium storage on the basis of temporal changes in the ash mass (a good indicator of skeletal mass) of male and female Red Knots (Calidris canutus islandica) collected during their stopover in Iceland in May and July, and after arrival on the breeding grounds in northernmost Ellesmere Island, Canada, in late May and early June. Significantly higher ash masses of females than of males, an increase in ash mass of females before the period of egg formation in mid-June in combination with a subsequent decrease, and the notable absence of temporal changes in ash mass of males, lead us to propose that female Red Knots do store skeletal calcium before egg laying. The rate of calcium storage would be 2.3 times higher after arrival on Ellesmere Island than during the stopover in Iceland, but the dietary components through which storage is achieved remain unclear. With an almost 50% change in the skeletal mass of females, Red Knots currently hold the record with respect to skeletal calcium dynamics in free-living egg-laying birds. The stored skeletal mass would allow them to produce at least half the clutch without further calcium intake.

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Three-Phase Fuel Deposition in a Long-Distance Migrant, the Red Knot (Calidris canutus piersmai), before the Flight to High Arctic Breeding Grounds

PLoS ONE ◽

10.1371/journal.pone.0062551 ◽

2013 ◽

Vol 8 (4) ◽

pp. e62551 ◽

Cited By ~ 21

Author(s):

Ning Hua ◽

Theunis Piersma ◽

Zhijun Ma

Keyword(s):

High Arctic ◽

Long Distance ◽

Calidris Canutus ◽

Three Phase ◽

Breeding Grounds ◽

Fuel Deposition ◽

Red Knot

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Productivity of laying hens when fed probiotic feed additive Amilocin

Kormlenie sel'skohozjajstvennyh zhivotnyh i kormoproizvodstvo (Feeding of agricultural animals and feed production) ◽

10.33920/sel-05-2107-05 ◽

2021 ◽

pp. 43-57

Author(s):

P. P. Kornienko ◽

E. G. Martynova

Keyword(s):

Laying Hens ◽

Physiological State ◽

Live Weight ◽

Positive Influence ◽

Research Data ◽

Egg Laying ◽

Biologically Active ◽

Feed Additive ◽

Active Components ◽

Normal Microflora

The possibilities of increasing the productivity of different poultry species by increasing the absorption of feed nutrients can be realized through the use of new biologically active components that are usually added to traditional feed based on live cultures of microorganisms of the normal microflora of the gastrointestinal tract. The effectiveness of different probiotic drugs varies depending on the types and strains of microorganisms that are included in their composition, the dose of the drug, the scheme of its use, age, type, physiological state and productivity of animals. The research has been carried out to study the influence of the use of the probiotic feed additive Amilocin in the diets of laying hens of the cross Hisex Brown on their productivity. The positive influence of the studied feed additive on the live weight and livability of laying hens, egg productivity, quality and quantity of eggs obtained, morphological and biochemical parameters of the blood of experimental poultry, slaughter parameters and chemical composition of the meat of experimental laying hens has been established. The optimal rate of introduction of probiotic feed additive Amilocin into the diet of laying hens has been determined (0,5 g/head/day at the beginning of egg laying during 10 days, 1,0 g/head/day at the peak of egg laying during 10 days, followed by 1 g/head/day monthly for 10 days until the end of egg laying). The economics effectiveness of using the probiotic feed additive Amilocin per 1,0 ruble of costs was 1,24– 1,35 ruble. According to the research data recommendations for the use of the probiotic feed additive Amilocin have been proposed.

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How do red knots Calidris canutus leave Northwest Australia in May and reach the breeding grounds in June? Predictions of stopover times, fuelling rates and prey quality in the Yellow Sea

Journal of Avian Biology ◽

10.1111/j.2005.0908-8857.03730.x ◽

2005 ◽

Vol 0 (0) ◽

pp. 060118052425004-???

Author(s):

Phil F. Battley ◽

Danny I. Rogers ◽

Jan A. van Gils ◽

Theunis Piersma ◽

Chris J. Hassell ◽

...

Keyword(s):

Yellow Sea ◽

The Yellow Sea ◽

Calidris Canutus ◽

Prey Quality ◽

Breeding Grounds ◽

Northwest Australia

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Declines in Wintering Populations of Red Knots in Southern South America

The Condor ◽

10.1093/condor/106.1.60 ◽

2004 ◽

Vol 106 (1) ◽

pp. 60-70 ◽

Cited By ~ 4

Author(s):

R. I. Guy Morrison ◽

R. Kenyon Ross ◽

Lawrence J. Niles

Keyword(s):

Population Decline ◽

Food Resource ◽

Limulus Polyphemus ◽

Tierra Del Fuego ◽

Calidris Canutus ◽

The North ◽

Dramatic Decline ◽

Breeding Grounds ◽

Wintering Areas ◽

Key Sites

AbstractSurveys of the North American race of the Red Knot (Calidris canutus rufa) on its main wintering areas on the coasts of Patagonia and Tierra del Fuego (Argentina and Chile) showed a dramatic decline in the wintering population: totals in 2003 were about 30 000 compared to 67 500 in the mid-1980s. Numbers at the principal wintering site, Bahia Lomas, fell by approximately 50%, from 45 300 in 2000 to 22 000–25 000 in 2002–2003. Numbers at peripheral sites on the coast of Patagonia declined dramatically, decreasing 98% compared to numbers in the mid-1980s. The results showed that declines at core sites did not result from birds moving to other places within the known wintering (or other) areas, but reflected a general population decline, with most birds now restricted to key sites in Tierra del Fuego. This phenomenon may explain why long-term declines noted elsewhere have only recently become apparent at key wintering areas. Possible reasons for the declines are discussed. Banding studies in Delaware Bay have shown that in recent years an increasing proportion of Red Knots is unable to gain sufficient weight for migration to the breeding grounds. This is likely due to reductions in their main food resource, eggs of the horseshoe crab Limulus polyphemus. The resulting increase in mortality could account for the magnitude and severity of the declines we observed.Disminuciones en las Poblaciones Invernantes de Calidris canutus rufa en el Sur de Sur AméricaResumen. Censos de la raza norteamericana de Calidris canutus (rufa) en sus áreas de invernada principales en las costas de la Patagonia y Tierra del Fuego (Argentina y Chile) mostraron una disminución dramática en la población invernante. Los totales en 2003 fueron aproximadamente 30 000, comparados con 67 500 a mediados de los años 80. Los números en el sitio principal de invernada (Bahía Lomas) decayeron en aproximadamente un 50%, de 45 300 en 2000 a 22 000–25 000 en 2002–2003. Los números en sitios periféricos en la costa de Patagonia declinaron dramáticamente, en un 98% en comparación con los números de mediados de los ochenta. Los resultados mostraron que las disminuciones en los sitios núcleo no fueron el resultado de que las aves se movieran a otros sitios dentro del rango invernal conocido, o a otras áreas. En cambio, reflejaron una disminución general de la población; la mayoría de las aves están ahora restringidas a sitios claves en Tierra del Fuego. Este fenómeno podría explicar por qué las disminuciones poblacionales de largo plazo detectadas en otros lugares sólo se han hecho aparentes ahora en las áreas claves de invernada. Se discuten las posibles causas de las disminuciones. Estudios de anillamiento en la bahía de Delaware han mostrado que en años recientes una mayor proporción de las aves es incapaz de incrementar su peso hasta los niveles necesarios para la migración hacia las áreas de invernada. Esto probablemente es debido a reducciones en su principal recurso alimenticio, los huevos de Limulus polyphemus. El incremento en mortalidad resultante podría explicar la magnitud y la severidad de las disminuciones poblacionales que observamos.

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Variations in Calcium Use by Birds During the Breeding Season

The Condor ◽

10.1093/condor/103.3.592 ◽

2001 ◽

Vol 103 (3) ◽

pp. 592-598 ◽

Cited By ~ 4

Author(s):

André A. Dhondt ◽

Wesley M. Hochachka

Keyword(s):

Breeding Season ◽

High Frequency ◽

Molothrus Ater ◽

Egg Laying ◽

Surprising Result ◽

Very High Frequency ◽

Cyanocitta Cristata ◽

Egg Formation ◽

Calcium Sources ◽

Very High

Abstract During the breeding season birds need increased amounts of dietary calcium during egg laying and nestling rearing. Passerines acquire calcium shortly before and during laying and do not store calcium for egg formation. Many passerines need to eat extraneous calcium in the form of snail shells or calcareous grit to acquire the element. However, very little is known about variation in the dependency of birds on extraneous calcium, and where this calcium is acquired. Using reports from volunteers who provided extraneous calcium sources at feeder sites across North America we documented that (1) the use of extraneous calcium varied during the breeding season; (2) the location in which species preferentially took the calcium varied with typical feeding location, aside from swallows which, somewhat surprisingly, favored calcium offered on the ground; (3) Brown-headed Cowbirds (Molothrus ater) did not visit calcium sites more often than other blackbirds; (4) calcium use varied among species with thrushes, wrens, and woodpeckers taking calcium only rarely, and swallows, pigeons, and corvids taking calcium frequently. The most surprising result perhaps was the very high frequency of calcium use in jays; Blue Jays (Cyanocitta cristata) may hoard calcium in the fall. Variaciones en el Uso de Calcio por Aves durante la Época Reproductiva Resumen. En la época reproductiva, las aves necesitan incrementar la cantidad de calcio en la dieta durante el período de postura de huevos y cría de los pichones. Las aves paserinas adquieren calcio poco antes y durante la postura y no lo almacenan para la formación de los huevos. Muchas aves paserinas necesitan ingerir calcio de fuentes externas como conchas de caracoles o cascajo calcáreo para adquirir este elemento. Sin embargo, se sabe muy poco sobre la variación en el grado de dependencia de las aves de calcio externo y sobre dónde adquieren este calcio. Con base en reportes de voluntarios que suministraron fuentes externas de calcio en comederos a través de Norteamérica, documentamos que (1) el uso de calcio externo varió durante la época reproductiva; (2) el sitio en donde las especies tomaron el calcio preferencialmente varió de acuerdo al sitio típico de alimentación, con excepción de las golondrinas, que de manera algo sorprendente, prefirieron el calcio ofrecido en el suelo; (3) Molothrus ater no visitó sitios con calcio con más frecuencia que otros ictéridos; (4) el uso de calcio varió entre especies: los túrdidos, troglodítidos y carpinteros muy rara vez tomaron calcio, mientras que las golondrinas, palomas y córvidos lo hicieron frecuentemente. Quizás el resultado más sorprendente fue la muy alta frecuencia de uso de calcio en Cyanocitta; C. cristata podría acumular calcio durante el otoño para uso futuro.

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Factors affecting individual variation in nest-defense intensity in colonially breeding Black-tailed Gulls (Larus crassirostris)

Canadian Journal of Zoology ◽

10.1139/z11-063 ◽

2011 ◽

Vol 89 (10) ◽

pp. 938-944 ◽

Cited By ~ 9

Author(s):

Kentaro Kazama ◽

Yasuaki Niizuma ◽

Kentaro Q. Sakamoto ◽

Yutaka Watanuki

Keyword(s):

Individual Variation ◽

Physiological State ◽

Breeding Birds ◽

Egg Laying ◽

Nest Defense ◽

Laying Date ◽

Plasma Testosterone ◽

Factors Affecting ◽

Corvus Macrorhynchos ◽

Males And Females

The physiological state of parent birds combined with the value of their clutch may affect the intensity of their nest defense. In colonially breeding birds, nest-defense intensity may also be affected by the behavior of neighbors. We investigated individual variation in the nest-defense intensity among colonial Black-tailed Gulls ( Larus crassirostris Vieillot, 1818) over 2 years. Only 30%–40% of males attacked a decoy of an egg predator (Large-billed Crow ( Corvus macrorhynchos Wagler, 1827)), and the other males and females rarely attacked. Males attacking the decoy had higher levels of plasma testosterone than males that did not attack. Each male’s, but not female’s, nest-defense intensity was consistent throughout the incubation period and also across years. The intensity was not related to egg-laying date, clutch size, or age of offspring. The intensity was likely to be higher when individuals had one or more neighbors, representing higher nest-defense intensity in the year where gulls had larger number of adjacent neighboring nests (5.23 nests), but this trend was not observed in the year where they had smaller number of the neighboring nests (3.73 nests). Thus, in addition to testosterone levels, behavior of neighbors also influences the nest-defense intensity.

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