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FIGURE 2.1 Cenozoic time scale based on Berggren et al. (1995). Epochs and Ages are divisions of the geologic time scale and correspond to the stratigraphic sequence of rocks and fossils. Epochs and Ages are scaled to absolute time using a combination of paleomagnetic and radioisotopic data. The seabird faunas are from Warheit (1992) and are based on the association of fossil-bearing rock formations from the North Pacific formed during a single, but broadly defined interval of time. The...

Sphenisciformes

Ritualized and nonritualized behavior of penguins is similar among species whether they inhabit the parched deserts of Patagonia or the ice-bound coasts of Antarctica. All penguins except the Yellow-eyed and the Fjordland Penguin (Eudyptes pachyrhynchus) are colonial. Characteristically, most penguin colonies are large. Colonies of Gentoo Penguins (Pygoscelis papua) can number 100 or fewer, but others like Macaroni (Eudyptes chrysolophus), King (Aptenodytes patagonicus), and Chinstrap...

Diet

Diet studies of seabirds abound, and we probably know more about what seabirds eat than any other aspect of their foraging ecology. Diet studies, coupled with information on the marine resource base, can reveal other aspects of seabird foraging behavior, such as where birds go to feed, foraging site fidelity, trip duration, and energetic considerations. The type of prey seabirds select can have important fitness consequences, particularly during the chick-rearing period (Pierotti and Annett...

The Orders Of Seabirds

3.2.1 Order Sphenisciformes, Family Spheniscidae Penguins are flightless and easily recognized. On land they stand upright and walk with a shuffling gait, occasionally sliding forward on their bellies. At sea, the legs, set well to the rear, serve as a rudder along with the tail. The forelimbs are modified into stiff flippers which cannot be folded and which lack flight feathers (Figure 3.1). The wing bones are flattened and more or less fused, while the scapula and coracoid are both large....

Oceanographic Considerations

Global oceanic circulation patterns are important determinants of where seabirds feed (Hunt 1991a). In the absence of any circulation, many of the nutrients in the ocean would be unavailable to surface-feeding organisms, primarily because of the pycnocline, a vertical density gradient that forms at some depth below the surface and inhibits vertical mixing. The pycnocline forms primarily from the differential warming of the oceanic surface water by the sun, relative to the water at depth. A...

Cd

Pelecaniform, but probably not a pelican. Q_ 24. Harrison and Walker (1977) created Prophaethontidae for this species. Ji 25. Originally described as Pelecanus. c ) 26. May be synonymous with Miopelecanus gracilis. 27. Tentatively Pelecanus. 70 28. Age described as from Miocene. 29. Originally described as Pelecanus conspicillatus novaezealandiae. O 30. Warheit and Olson (unpubl. data) concluded that there are no conclusive data to differentiate this species from Pseudodontornis...

Mate Choice

In order to optimize reproduction, birds must choose a mate that will enable them to produce as many high-quality offspring as possible, i.e., a mate whose genotype will enable the offspring to inherit the best combination of genes possible (good genes hypothesis, see Andersson 1994). All other things being equal, females should seek a male that provides good parental care (Trivers 1972, Halliday 1983, Qvarnstrom and Forsgren 1998). Foraging skills and resource provisioning (both qualitative...

Conclusions

Through long-term studies, ornithologists have come to appreciate environmental variability as a fact of life for seabirds and that, perhaps, no years are normal (Schreiber and Schreiber 1989, Chastel et al. 1993). Seabirds appear to have evolved to exist in a stochastic system where weather patterns can be severe and unpredictable. Additionally, population levels may be in a constant state of flux brought on by stochastic weather patterns, as suggested by Schreiber and Schreiber (1989) FIGURE...

Rande Gerber Net Worth

FIGURE 7.6 A feeding flock of Brown Pelicans and Laughing gulls in Florida. Unusual weather parameters can affect a seabird's ability to find food and to catch it. (Photo by R. W. Schreiber.) FIGURE 7.6 A feeding flock of Brown Pelicans and Laughing gulls in Florida. Unusual weather parameters can affect a seabird's ability to find food and to catch it. (Photo by R. W. Schreiber.) Whether this change in feeding areas is related to the direct effect of wind levels on bird flight or its effect on...

Breeding Systems And Social Organization

This topic is discussed in detail by Coulson (Chapter 6) and is only briefly mentioned here. The high frequency of coloniality among seabirds is perhaps surprising given the potential fitness costs of breeding at high densities, which include increased competition for food, nest sites, and mates, increased transmission of parasites and diseases, cuckoldry, cannibalism, and infanticide (Brown et al. 1990, Burger and Gochfeld 1990, 1991, M0ller and Birkhead 1993, Danchin and Wagner 1997)....

Black Headed Gull Threat Postures For Upright Behavior

Owing to their colonial habit, communication in seabirds is an important part of their existence and most seabird colonies are noisy and active. They use a combination of calls and postures to find a mate, defend a territory, and communicate their intentions to neighbors. Communication means expressing a motivation (such as aggression) via a posture, movement, or vocalization, or a combination of these, in response to a stimulus from another individual, usually a conspecific. Often it is...

July

FIGURE 6.12 Foraging trips of a radio-tagged Black-legged Kittiwake during a spring and neap tide series. Black areas correspond to the time bird was on a foraging trip. Diagonal lines approximate the periods of flood (F) and ebb (E) tides. (From Irons 1998, used with permission.) particular sites and returned to them frequently, suggesting that kittiwakes rely more on local knowledge or memory than information transfer to locate prey patches (Irons 1998). A similar pattern was found among...

Literature Cited

COULSON. 1990. Survival of the kittiwake in relation to sex, year, breeding experience and position in the colony. Journal of Animal Ecology 59 1063-1071. AEBISCHER, N. J., J. C. COULSON, AND J. M. COLEBROOK. 1990. Parallel long term trends across four marine trophic levels and weather. Nature 347 753-755. ASHMOLE, N. P. 1963. The regulation of numbers of tropical oceanic seabirds. Ibis 103 458-473. ASHMOLE, N. P. 1971. Seabird ecology and the marine environment. Pp....

Breeding Habitat

Habitat use in seabirds can be divided into nesting habitat and foraging habitat. While many land birds, such as passerines, often use the same habitat for both of these functions, seabirds do not. Instead seabirds nest on land and forage in estuarine or oceanic waters, often far from their nest sites. Further, since many seabirds have delayed breeding, they may spend years at sea, coming to land only occasionally until they begin breeding Species in the four orders of marine birds fall into...

Introduction Of Wader Birds

Most seabird systems (e.g., species, communities, populations) are large in both temporal and spatial scale. For example, it is now firmly established that many seabird populations and communities are affected by climatic cycles, some of which operate globally and over periods extending from several years to decades (e.g., El Nino-Southern Oscillation and the North Pacific decadal oscillation see Chapter 7). In general, seabirds are long lived with each bird experiencing a variety of climatic...

The Importance Of Seabird Fossils

2.3.1 Paleontology and the Structure of Seabird Communities Press and Siever (1982) define paleontology as the science of fossils of ancient life forms, and their evolution and define a fossil as an impression, cast, outline, track, or body part of an animal or plant that is preserved in rock after the original organic material is transformed or removed. Olson and James (1982a) extended the definition of fossil to also include subfossil bones (bones that have not become mineralized), such as...

Weather Effects On Feeding

The broad variation in seabird flight style and abilities leads to a wide variety of feeding methods, and while there are data on the effects of weather on birds in their colonies, the data for how it affects birds at sea are scant. Most often, our knowledge is derived from what we can measure on land. Weather affects the ability of seabirds to find food due to (1) wind speed and direction and precipitation affecting flight (2) cloud cover, precipitation, clarity of water, and turbidity of...

Disadvantages In Colonial Breeding

There are several obvious disadvantages in colonial breeding 1. Competition for food near the colony may be increased however, this will be moderated as the distances individuals travel to feed increase. Many seabirds travel over 50 km to feed, the exceptions being mainly gulls and terns. In birds generally, particularly those with a short feeding range when breeding, colonial breeding may make it more difficult to exploit food resources in their environment which are evenly or randomly...

Latitude

FIGURE 9.5 Relationship between chick growth duration (expressed as TUM, see text) and latitude in seabirds. TUM not normally distributed in either taxonomic order. (a) Sphenisciformes rs -0.84, p 0.0002, n 14. (b) Procellariiformes rs -0.20, p 0.11, n 61 filled circles, Diomedeidae squares, Pelecanoididae light triangles, Procellariidae black triangles, Hydrobatidae. (c) Pelecaniformes rs -0.66, p 0.0001, n 32 filled circles, Phaethontidae squares, Sulidae light triangles, Fregatidae black...

Comparing The Demography Of The Four Orders Of Seabirds

Within seabirds, minimum age at first breeding and life expectancy (log transformed) are somewhat related to the log of mass (y 0.092x + 0.666, r2 0.0788, p < 0.01 and y 0.1148x + 1.675, r2 0.1532, p < 0.001). These relationships express the allometric component of demographic pattern and indicate that body mass is a significant, but not fundamental, determinant of the variation in demographic traits in seabirds. They represent a first-order tactic which expresses the biomechanical...

Relationships Between Seabirds And The Physical Ocean Environment

Seabirds should congregate to feed in areas of high prey availability. Studies have correlated seabird abundance with prey abundance at local (Safina and Burger 1985, 1989), regional (Hunt et al. 1990), and multiple (Russell et al. 1992) scales. Recent research has examined factors responsible for concentrating aggregations of prey to determine whether these aggregations are random or predictable. In specific situations, both physical oceanographic phenomena and biotic activity have been shown...

Why Are Seabirds Different

Seabirds have dramatically different life-history characteristics, or demography, from most land birds, such as members of the order Passeriformes (Table 1.2). In fact, their life history characteristics are often referred to as extreme long life (20 to 60 years), deferred maturity (breeding age delayed to up to 10 years of age), small clutch size (in many cases one egg), and extended chick-rearing periods (often up to 6 months). Passerine birds, in comparison, have shorter lives and larger...

North Pacific Seabird Communities

I have previously reviewed the fossil history of seabirds from the North Pacific and related this history to plate tectonics and paleooceanography Warheit 1992 . In what follows I highlight some of the findings from this study, focusing primarily on the seabird communities from central and southern California. The California Current upwelling system today is one of the primary eastern boundary systems, and, along with the Benguela and Humboldt upwelling systems of the Southern Hemisphere,...

Adaptations And Lifestyles Of Marine Birds

Life at sea and feeding on marine organisms presents several challenges to seabirds, and it undoubtedly has played an important role in shaping their life histories and physiology. Feeding in the marine environment requires that seabirds deal with high physiological salt loads. One of the methods they use to accomplish this is through their salt glands, an extra-renal kidney located in the orbit of the eye see Chapter 14 . They also limit their ingestion of salt water, getting most of their...