Why do brood parasitic birds lay strong-shelled eggs?

Brood parasitic birds constitute a model system for the study of coevolution. Such parasites are unique by having evolved unusually thick eggshells for their body size. Thick eggshells have been hypothesized to evolve as 1) a means of preventing damage to parasite eggs when the brood parasite lays its egg at a distance from the host clutch (the laying damage hypothesis); 2) a consequence of host puncture ejection (the puncture resistance hypothesis); 3) a means for the brood parasite to allocate calcium to development of a disproportionately large skeleto-muscular system in evicting parasite chicks (the chick vigour hypothesis); or 4) a means of protecting the cuckoo embryo from microorganisms in the nest of the host (the anti-bacterial protection hypothesis). Here we review the literature studying the evolutionary mechanisms promoting thick eggshells in avian brood parasites, and provide proposals for future studies to test their validity. Available data are insufficient to rigorously test exclusive predictions and assumptions of these not necessarily exclusive hypotheses, although the laying damage and the puncture resistance hypotheses seem to currently be the most well supported alternatives. We discuss how quantification of rejection modes (grasp ejection, puncture ejection and desertion) may disclose the validity of the puncture resistance hypothesis, and finally we provide perspectives for future research on testing this specific hypothesis.publishedVersion© 2012 The Authors; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0 (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

The Fauna and Flora of Horn Island, Mississippi

From 26 February 1944 until 4 February 1945, I was stationed with the U. S. Army on Horn Island, Mississippi, and decided to observe and record the animals and plants existing there. At the time, it seemed that little attention had been devoted to the wildlife of this island, but eventually it became apparent that some studies had been made. However, many of the observations have not been published and many of the records of the flora and fauna living on and around the island are scattered and unavailable. The most outstanding papers include those of Lloyd and Tracy (1901), Lowe (1921), and Pessin and Burleigh (1941). Cook (1942, 1943 a and b) described several of the animals observed. Smith and List (1955) recorded a number of amphibians and reptiles which were collected on Horn Island. Since 1945 more attention has been paid to this subject. Kopman (1946) enlightened the public regarding the seasonal activity of the animals and changing conditions in the Mississippi Sound region in his delightful “Wild Acres,” a book of the Gulf Coast country. From 1940 on many scientists and students of the Gulf Coast Research Laboratory visited Horn Island, but still comparatively little has been published. Rings and Richmond (1953) presented a brief survey on the mosquitoes collected by them during 1944 and 1945; the species listed by them, together with two additional ones, are included in this paper. The animals and plants actually collected or observed on Horn Island are listed in Part IV. Besides those collected by myself, species reported by other investigators are included. Longer study and more intensive collecting would doubtless result in many additions to the fauna and flora as known at present

The Fauna and Flora of Horn Island, Mississippi

From 26 February 1944 until 4 February 1945, I was stationed with the U. S. Army on Horn Island, Mississippi, and decided to observe and record the animals and plants existing there. At the time, it seemed that little attention had been devoted to the wildlife of this island, but eventually it became apparent that some studies had been made. However, many of the observations have not been published and many of the records of the flora and fauna living on and around the island are scattered and unavailable. The most outstanding papers include those of Lloyd and Tracy (1901), Lowe (1921), and Pessin and Burleigh (1941). Cook (1942, 1943 a and b) described several of the animals observed. Smith and List (1955) recorded a number of amphibians and reptiles which were collected on Horn Island. Since 1945 more attention has been paid to this subject. Kopman (1946) enlightened the public regarding the seasonal activity of the animals and changing conditions in the Mississippi Sound region in his delightful “Wild Acres,” a book of the Gulf Coast country. From 1940 on many scientists and students of the Gulf Coast Research Laboratory visited Horn Island, but still comparatively little has been published. Rings and Richmond (1953) presented a brief survey on the mosquitoes collected by them during 1944 and 1945; the species listed by them, together with two additional ones, are included in this paper. The animals and plants actually collected or observed on Horn Island are listed in Part IV. Besides those collected by myself, species reported by other investigators are included. Longer study and more intensive collecting would doubtless result in many additions to the fauna and flora as known at present

Annotated List of the Birds of Ohio

Author Institution: Academic Faculty of Population and Environmental Biology, College of Biological Sciences, The Ohio State University, and the Ohio Historical Society, Columbus, Ohi

Life Histories of North American Nuthatches, Wrens, Thrashers And Their Allies: Order Passeriformes

An attempt has been made to give as full a life history as possible of the best-known subspecies of each species and to avoid duplication by writing briefly of the others and giving only the characters of the subspecies, its range, and any -habits peculiar to it. In many cases certain habits, probably common to the species as a whole, have been recorded for only one subspecies. Such habits are mentioned under the subspecies on which the observations were made. The distribution gives the range of the species as a whole, with only rough outlines of the ranges of the subspecies, which in many cases cannot be accurately defined. The egg dates are the condensed results of a mass of records taken from the data in a large number of the best egg collections in the country, as well as from contributed field notes and from a few published sources. They indicate the dates on which eggs have been actually found in various parts of the country, showing the earliest and latest dates and the limits between which half the dates fall, indicating the height of the season. The plumages are described in only enough detail to enable the reader to trace the sequence of molts and plumages from birth to maturity and to recognize the birds in the different stages and at the different seasons

A Multi-Scale Analysis of Grassland Bird Habitat Relationships in the St. Lawrence River Valley

I used a combination of 10 vegetation variables and 10 landscape variables to model abundance and occurrence of six grassland bird species in agricultural grassland (n=55) throughout Jefferson County, NY during the 2004 and 2005 field seasons. Landscape composition was quantified by classifying the proportion of land use within a 1 km radius from the center of all survey fields. Land use classification was based on 2003 aerial photo interpretation. Bobolinks (Dolichonyx oryzivorous) and Savannah Sparrows (Passerculus sandwichensis) were the most abundant species, followed by Grasshopper Sparrows (Ammodramus savannarwn), Eastern Meadowlarks (Sturnella magna), Upland Sandpipers, (Bartramia longicauda) and Henslow\u27s Sparrows (Arrmzodramus henslowii). Bird habitat models generated through best subsets regression and stepwise multiple regression indicated that perimeter-area ratio and variables associated with area, such as distance to nearest edge and distance to forest edge, generally explained most of the variance in grassland bird species richness and abundance, and individual species abundance. Vegetation variables, including grass cover, legume cover, litter depth and the number of plant species, also entered into the grassland bird-habitat models. Bobolink and Savannah Sparrow abundance increased in fields high in forb cover and plant diversity. A significant proportion of the variance in Grasshopper Sparrow and Savannah Sparrow abundance was explained by a decrease in vegetation cover, while an increase in vegetation cover explained a significant amount of the variance in Eastern Meadowlark abundance. As with the Bobolink, the most important predictor variables for Grasshopper Sparrow and Savannah Sparrow were related to area. Henslow\u27s Sparrow abundance increased as the proportion of development in the surrounding landscape decreased. In contrast, Upland Sandpiper abundance increased as the proportion of development in the surrounding landscape increased. My models differed between years and also produced some results that differed from those of other grassland bird habitat-selection studies from the Midwest and Northeast, thus suggesting that grassland bird habitat selection is dynamic among years, and that habitat requirements are broad across regions. Average obligate grassland bird density in the agricultural grasslands of Jefferson County ranged from 0.04 to 3.77 birds/ha across both years. Grassland bird densities in Jefferson County compared favorably to grassland bird densities at 13 U.S. Fish and Wildlife Service National Wildlife Refuges in Region 5, thus suggesting that anthropogenic grasslands planted with non-native, cool season grasses are a valuable resource for grassland bird conservation in the Northeast

A Multi-Scale Analysis of Grassland Bird Habitat Relationships in the St. Lawrence River Valley

Presented to the Graduate Faculty of the Department of Biological Sciences of the State University of New York College at Brockport in Partial Fulfillment for the Degree of Master of ScienceI used a combination of 10 vegetation variables and 10 landscape variables to model abundance and occurrence of six grassland bird species in agricultural grassland (n=55) throughout Jefferson County, NY during the 2004 and 2005 field seasons. Landscape composition was quantified by classifying the proportion of land use within a 1 km radius from the center of all survey fields. Land use classification was based on 2003 aerial photo interpretation. Bobolinks (Dolichonyx oryzivorous) and Savannah Sparrows (Passerculus sandwichensis) were the most abundant species, followed by Grasshopper Sparrows (Ammodramus savannarwn), Eastern Meadowlarks (Sturnella magna), Upland Sandpipers, (Bartramia longicauda) and Henslow's Sparrows (Arrmzodramus henslowii). Bird habitat models generated through best subsets regression and stepwise multiple regression indicated that perimeter-area ratio and variables associated with area, such as distance to nearest edge and distance to forest edge, generally explained most of the variance in grassland bird species richness and abundance, and individual species abundance. Vegetation variables, including grass cover, legume cover, litter depth and the number of plant species, also entered into the grassland bird-habitat models. Bobolink and Savannah Sparrow abundance increased in fields high in forb cover and plant diversity. A significant proportion of the variance in Grasshopper Sparrow and Savannah Sparrow abundance was explained by a decrease in vegetation cover, while an increase in vegetation cover explained a significant amount of the variance in Eastern Meadowlark abundance. As with the Bobolink, the most important predictor variables for Grasshopper Sparrow and Savannah Sparrow were related to area. Henslow's Sparrow abundance increased as the proportion of development in the surrounding landscape decreased. In contrast, Upland Sandpiper abundance increased as the proportion of development in the surrounding landscape increased. My models differed between years and also produced some results that differed from those of other grassland bird habitat-selection studies from the Midwest and Northeast, thus suggesting that grassland bird habitat selection is dynamic among years, and that habitat requirements are broad across regions. Average obligate grassland bird density in the agricultural grasslands of Jefferson County ranged from 0.04 to 3.77 birds/ha across both years. Grassland bird densities in Jefferson County compared favorably to grassland bird densities at 13 U.S. Fish and Wildlife Service National Wildlife Refuges in Region 5, thus suggesting that anthropogenic grasslands planted with non-native, cool season grasses are a valuable resource for grassland bird conservation in the Northeast.SUNY BrockportBiological SciencesMaster of Science (MS)Environmental Science and Ecology These

Birds from British Columbia

p. 123-158 ; 24 cm.Includes bibliographical references

Patterns of Singing by House Wrens with Respect to the Breeding Cycle

I recorded the songs and studied the reproductive behavior of a population of marked House Wrens (Troglodytes aedon) to identify patterns of singing and correlate them with behavioral contexts and stages of the breeding cycle. I found that House Wren singing could be organized into three hierarchical regimes: routine patterns of daily singing, context-specific patterns of singing and long-term fluctuations in singing rate throughout the breeding cycle. During routine daily singing, predictable structural changes occurred. Songs were clustered in discrete groups called bouts. The songs within a bout were more similar in structure than songs from different bouts. Although I found no distinctive combination of notes associated with any particular context, three context-specific patterns of singing were identified. These included male:male, courtship and within-pair singing. Songs delivered in these contexts differed from songs sung in the absence of close listeners by virtue of increased length and complexity of the introductory portion of the song. Through playback experimentation, I found that introductory notes evoke a stronger response from listeners than other notes. These notes have rapid attenuation characteristics and transmit well only for short distances. Use of songs that emphasize these notes would be consistent with providing the appropriate privacy of communication between individuals in contexts where public broadcast may unnecessarily attract rivals. Long-term fluctuations in singing rate correlated with the various stages of the breeding cycle in a predictable fashion. The highest rate of singing occurred during the establishment of a territory, following which singing rate declined through the end of the egg-laying period. During the late egg-laying period, many birds entered a brief silent period. In the incubation period, singing levels rose to moderate levels, then dropped off again after the young hatched. Over the course of the nesting cycle, the proportion of short songs increased. I propose the Neighborhood Watch Hypothesis as a possible explanation of the evolutionary advantage of large, variable repertoires. This hypothesis asserts that the large repertoire and long-term pattern of singing by established residents facilitate their recognition and expulsion of intruders who pose a threat to eggs and young

THE PRAIRIE NATURALIST Volume 4, Nos. 3 and 4. September–December 1972

THE SANDHILL CRANE WITH EMPHASIS ON ASPECTS RELATED TO NORTH DAKOTA ▪ Douglas H. Johnson and Robert E. Stewart SIZE AND COLORATION CHARACTERISTICS OF NEOTENIC SALAMANDERS IN DEVILS LAKE, N. D. ▪ Douglas W. Larson BIRDS\u27 EGGS: AN AID TO NATURE APPRECIATION ▪ S. O. Kolstoe BIRD MORTALITY AT FOUR TOWERS IN EASTERN NORTH DAKOTA — FALL 1972 ▪ Michael Avery and Tom Clement POPULATION IRRUPTION OF THE LEAST WEASEL (Mustela nivalis) IN EAST CENTRAL NORTH DAKOTA ▪ John T. Lokemoen and Kenneth F. Higgin