Estimation of Crayfish Abundance and Size-structure in Diets of White Ibis Chicks

  title={Estimation of Crayfish Abundance and Size-structure in Diets of White Ibis Chicks},
  author={Nathan J. Dorn and Garth Herring and Dale E. Gawlik},
Abstract We investigated the use of crayfish gastroliths and exoskeleton pieces for quantifying crayfish abundance and size-structure in diets of White Ibis (Eudocimus albus) chicks in the Everglades. We then quantified crayfish and fish abundance from various small hard parts and intact fish heads in 23 boluses, taken from two nesting colonies in Water Conservation Area 3 (WCA 3) and Arthur R. Marshall Loxahatchee National Wildlife Refuge (Lox) in the Florida Everglades during May 2006. We… 

Aquatic prey switching and urban foraging by the White Ibis Eudocimus albus are determined by wetland hydrological conditions

The results support the suggestion of depth-dependent diets; prey composition depends on the current landscape water levels around the colonies, and also suggests that previous drying events can lead to increased reliance on alternative food sources.

Structure and population dynamics of the secondary burrower crayfish Procambarus acanthophorus from a tropical Mexican wetland

Catch size, sex ratio, structure and dynamics, as well as mortality, of a population of the secondary burrower crayfish Procambarus acanthophorus Villalobos, 1948, from tropical wetland La

Resistance of crayfish (Procambarus spp.) populations to wetland drying depends on species and substrate

  • N. DornJ. Volin
  • Environmental Science
    Journal of the North American Benthological Society
  • 2009
The substrate-specific survival of P. fallax helps explain their persistence at relatively high densities in peat-dominated wetlands that dry every 1 to 3 y and their small populations in marl-dominated marshes with similar drying frequencies.

Intraguild predation between spawning smallmouth bass (Micropterus dolomieu) and nest‐raiding crayfish (Orconectes rusticus): implications for bass nesting success

It is hypothesized that the rates of nest abandonment and bass guarding behaviour will be positively related to crayfish abundance and that bass consumption of cray Fish will mitigate energy loss due to nest guarding against cray fish.

Feather mercury concentrations and physiological condition of great egret and white ibis nestlings in the Florida Everglades.

Benefits of adjacent habitat patches to the distribution of a crayfish population in a hydro-dynamic wetland landscape

This is the first study through time and across both habitat types analyzing the distribution and size structure of P. fallax population in the Everglades and indicates that relative predation risk by aquatic predators was greater in sloughs for all sizes and higher for smaller individuals in both habitats.

Energetics of Great Egrets Foraging in Upland Agricultural Fields

The Great Egret's ability to capitalize on different energy sources during different foraging situations likely improves foraging efficiency and energy intake over time.

A classification scheme for avian diet types

A classification scheme for avian diet types that takes into account the number of food categories consumed and the volumetric proportion of each category eaten to indicate the diet type of a species is proposed, using binomial terminology.

Food availability is expressed through physiological stress indicators in nestling white ibis: a food supplementation experiment

The nutritionally mediated increases in FCORT and HSP60 provide compelling evidence that white ibis nestlings can be physiologically affected by environmental food levels.

Stability of Avian Fecal Corticosterone Metabolite Levels in Frozen Avian Feces

It is demonstrated that avian fecal corticosterone samples are accurate even after freezing and, thus, studies that seek to address conservation questions may rely on these data.



A comparison of three methods to investigate the diet of breeding double-crested cormorants (Phalacrocorax auritus) in the Beaver Archipelago, northern Lake Michigan

In order to understand the role of waterbirds in aquatic food webs it is important to first get an accurate depiction of their diet. Three methods of dietary assessment (pellets, regurgitate and

Comparison of Pellets versus Collected Birds for Sampling Diets of Double-Crested Cormorants

For many fish-eating birds, two types of samples can be used to determine diets of adults during both breeding and nonbreeding periods: esophagus and gizzard contents of birds collected at feeding

A Bioenergetic Model of Shorebird Predation on Infaunal Amphipods

  • J. Grant
  • Environmental Science, Biology
  • 1981
Investigation of the potential effects of predation by shorebirds on a population of the sand-burrowing amphipod Acanthohaustorius millsi Bousfield suggested that the P/B ratio of the A. millsi population is affected through changes in P resulting from size-selective predation, while B is buffered by growth of smaller individuals.

Nesting season food habits of 4 species of Herons and Egrets at Lake Okeechobee, Florida

Pronounced interannual and intercolony variation in diet composition suggested that Great Egrets and Little Blue Herons switched prey types as hydrologic conditions and habitat availability changed, and have implications for managing the Lake Okeechobee ecosystem.

Food of Breeding Great White Egrets in an Agricultural Area of Southern Chile

The food of the Great White Egrets is influenced both by spatial availability patterns and profitability of prey type, and differences were found amongst the orders of insects taken in the same periods.

Distribution and relative abundance of the crayfishes Procambarus alleni (Faxon) and P. fallax (Hagen) in Southern Florida

Reexamination of archived samples showed that P. fallax had been collected as early as 1985 but had been misidentified or overlooked, and methods for distinguishing live and preserved specimens of these morphologically similar species are provided.

The Diet of Nestling Abdim's Stork Ciconia abdimii in Niger

The high dependency on amphibians in July was a surprise, but suggests that toads may be the key prey for the adult storks during the incubation period when toads become active while major new insect generations have not yet emerged.


It is suggested that declines in both the numbers of nesting ibises and in reproductive success at the two sites resulted from the relative unavailability of crayfishes during dry periods.

Feeding Ecology and Prey Selection in the White Ibis

The energetic relationships of prey selection on a region-wide basis is determined in the White Ibis in order to elucidate the tactics used by such a species in meeting its annual energy requirements.


It is suggested that the phenotypic variability in plumage, bill coloration, and begging calls the authors describe enables parental ibises to identify more easily their offspring at the colony site.