Stephen P. Broker
(1) Biodiversity Worksheet Using the Nature Conservancy/Association for Biodiversity Information Publication, Precious Heritage: The Status of Biodiversity in the United States.
This introductory laboratory activity serves as the introduction to our study of biodiversity. I give my students a reading assignment taken from the publication,
Precious Heritage
. This well-illustrated book provides a comprehensive overview of a full range of topics in the study of biodiversity. It could easily serve as the basis for a study of biodiversity in the AP Environmental Science curriculum. I have selected one of the introductory chapters in the book to introduce my students to these following aspects of biological diversity: the geography and phytogeography of the United States; the total presently-known number of species on Earth; scientific nomenclature and taxonomic classification; U.S. biologists who pioneered the study of biodiversity; endemic species and non-native species; biogeography; definitions of biodiversity; exceptional species richness in regions of the U.S.; taxonomic groups, including plants, mammals, birds, reptiles, amphibians, fishes, insects, and other invertebrates. I run the activity the same way I conduct many laboratory classes, with information drawn from the assigned reading distributed among twelve stations set up on classroom tables or counters. Students work in pairs to visit each station for a period of time, review materials such as tables, graphs, photographs, and text, and answer the questions provided.
Instructions for the student. Read
Precious Heritage
, Chapter 3 A Remarkable Array: Species Diversity in the United States (pages 55-91), and answer the following questions.
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1. The phytogeography of eastern North America is most similar to that of what other part of the world? [Answer. Eastern Asia (forests)]
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2. Why is the snail darter (
Percina tanasi
) well known in the annals of North American endangered species? [Ans. It held up construction of the Tellico Dam on the Little Tennessee River; a single species conservation problem and political hot potato.]
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3. Describe the geography of the United States in terms of square miles of land, miles of coastline, overall size of the country, latitude and longitude, elevation, and diversity of ecosystems. [Ans. 3.5 million square miles of land, 12,000 miles of coastline, fourth largest country, 120 degrees longitude and 50 degrees latitude, 282 feet below sea level to 20,320 feet above sea level, wide array of ecosystems.]
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4. (a.) Why is Quaking Aspen (
Populus tremuloides
) considered by some to be the largest living organism? [Ans. 47,000 tree trunks may be connected underground through a common root system. They are genetically identical clones.]
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(b) Why is the creosote bush (
Larrea tridentata
) considered by some to be the oldest living tree or shrub? [Ans. Estimated age of 11,700 years, based on "fairy rings" of the shrub stems.]
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5. How many species inhabit the world? (Give the high and low estimates, and the "working estimate". What percentage of these species has been given a formal Latin (scientific) name? [Ans. 3 million to 100 million (estimated 14 million). A total of 1.5 million have formal Latin names.]
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6. Which taxa have been studied the most for their biological diversity? Which geographic region of the world has been most heavily studied for biological diversity? [Ans. Vertebrate animals and vascular plants. Economically developed countries of the Northern Hemisphere.]
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7. There are 250,000 vascular plants catalogued worldwide. What are the vascular plants? [Ans. These are plants that have vascular tissues, xylem and phloem, through which water and nutrients are transported. They include horsetails, club mosses, ferns, gymnosperms (cone-bearing plants), and angiosperms (flowering plants).]
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8. Identify some of the most poorly known organisms. Identify two major environments that are very poorly studied. [Ans. The most poorly known organisms are microorganisms, algae, fungi, and many groups of invertebrate animals. Deep-sea environments and soil horizons are poorly studied.]
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9. Write scientific names for each of the following species:
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American Burying Beetle – [Ans.
Nicrophorus americanus
]
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Shasta snow-wreath – [Ans.
Neviusia cliftonii
]
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Furbish lousewort – [Ans.
Pedicularis furbishiae
]
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Giant coreopsis – [Ans.
Coreopsis gigantean
]
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Desert shrub ocotillo –[Ans.
Fouquieria splendens
]
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American bison – [Ans.
Bos bison
]
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Pronghorn – [Ans.
Antilocapra americana
]
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10. Examine Figure 3.1. Estimated number of species in major groups (text page 59). Identify the four largest groups of organisms. Identify the four smallest groups of organisms. [Ans. Four largest groups = insects, other invertebrates, fungi, and bacteria. Four smallest groups = vertebrates, protozoa, plants, and algae.]
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11. What are symbiotic and parasitic organisms? [Ans. Symbiotic organisms are dissimilar organisms that live together in close association. Symbiosis is usually restricted to mutually beneficial species interactions. Parasitism is an interaction of species populations in which one (typically small) organism (the parasite) lives in or on another (the host), from which it obtains food, shelter, or other requirements. Parasitism usually implies that some harm is done to the host.]
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12. Approximately how many native vertebrate species are found in the United States? [Ans. More than 4,900 vertebrate species.]
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13. Examine Table 3.1. Number of native species known from the United States. Extract the following information from this table:
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Common Name | Phylum | Number of U.S. Species
[Ans.]
Nonlichenized fungi (not shown) more than 34,000
Lichens (not shown) 3,800
Mosses Bryophyta 1,400
Clubmosses Lycophyta 100
Horsetails Sphenophyta 10
Ferns Filicinophyta 444
Conifers Coniferophyta 104
Flowering plants Anthophyta 15,320
Jellyfish, corals, relatives Cnidaria 1,620
Flatworms Platyhelminthes 6,000
Roundworms Nematoda more than 5,300
Arachnids and relatives Chelicerata 9,557
Insects Mandibulata 96,406
Crustaceans Crustacea 9,675
Segmented worms (annelids) Annelida 3,360
Mollusks Mollusca 7,500
Echinoderms Echinodermata 1,110
Vertebrates Craniata more than 4,900
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14. Briefly identify each of the following nineteenth and early twentieth century biologists, and state which organisms they did research on:
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Spencer Fullerton Baird – [Ans. Assistant Secretary, then Secretary of the Smithsonian Institution; he conducted research on vertebrates.]
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David Starr Jordan – [Ans. Stanford University researcher; he did research on fishes.]
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C. Hart Merriam – [Ans. director of the Bureau of Biological Survey; he did research on mammals.]
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15. How many species have been formally described in the United States? What is the estimated number of species that inhabit the U.S.? [Ans. More than 200,000 species are known in the United States. Total numbers of U.S. species range from an estimated 300,000 to 600,000 species.]
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Alien Species
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16. How many alien plant and animal species (also called exotics, introduced, or non-native species) inhabit the United States? Why are alien species considered a threat to (U.S.) biodiversity? [Ans. Perhaps 3,500 introduced plants and 2,300 introduced animals are found in the U.S..]
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17. List all the species of exotic birds inhabiting Connecticut today. (Consult with Mr. Broker for this answer.) [Ans. The introduced or exotic birds found in the state of Connecticut are: Mute Swan, Ring-necked Pheasant, Rock Pigeon, Monk Parakeet, European Starling, House Finch, and House Sparrow.]
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18. List six species of exotic plants found in East Rock Park. [Ans. Six introduced plants in East Rock Park are: Japanese Knotweed, Japanese Barberry, Asiatic Bittersweet, Phragmites (Common Reed), Norway Maple, and Ailanthus (Tree-of-Heaven).]
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U.S. Species in a Global Context
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19. What are "biological boundaries", and how do they form? What is "one of the crucial facts of biogeography"? [Ans. Biological boundaries are barriers to the exchange of living organisms, such as oceans, mountains, deserts, gradations in rainfall or temperature. From the study of biological boundaries and of life on Earth, we know that species are not distributed evenly across the planet.]
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20. Define "species richness". [Ans. Species richness is the number of species present in a given area.]
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Quantifying Diversity
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21. The American ecologist Robert Whittaker proposed three separate types or measures of species richness. Define each of these following according to Whittaker's system. [Ans. Alpha diversity – the number of species in some small, homogeneous area, such as a study plot or a naturally defined ecological community. Beta diversity – the rate of change (or turnover) in species across adjacent habitats. Gamma diversity – the number of species in a large geographic region.]
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22. Define "endemism". [Ans. The restriction of a species or other taxonomic group to a particular geographic region.]
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23. Explain the following statement: "the presence of unique families or orders is particularly noteworthy from an evolutionary perspective". See page 66. [Ans. These higher taxonomic levels may include a number of fairly closely related species. Many regions of the world have endemic species. Regions that have endemic genera, families, or orders are particularly noteworthy.]
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National Patterns of Diversity
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24. What is the broad relation between biological diversity and latitude? [Ans. Biological diversity (alpha and gamma) increases with decreasing latitude. That is, there is greater biological diversity closer to the Equator and lesser diversity closer to the poles.]
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25. Examine Table 3.2. Global significance of selected U.S. plant and animal groups. Identify the five species groups that have the greatest significance (high levels of diversity) in the United States. List the U.S. percentage of global species represented by the top three groups. [Ans. The species groups with greatest significance in the U.S. are crayfishes, freshwater mussels, freshwater snails, gymnosperms, and freshwater fishes. U.S./global percentages are: Crayfishes – 61% Freshwater mussels – 29% Freshwater snails – 17%]
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26. List some of the species groups from among the freshwater organisms that are exceptionally diverse in the United States. Why is there such great species diversity and endemism in the nation's freshwater biota? [Ans. Again, they include freshwater mussels, freshwater snails, crayfishes, and several freshwater insect orders. There has been tremendous evolution through adaptive radiation and speciation in the nation's rivers and streams, lakes and ponds.]
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Plants
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27. List the flowering plant families that are particularly species rich in the United States. [Ans. The species rich flowering plants include members of the composite family (asters, sunflowers, goldenrods), peas, and grasses.]
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28. List six broad categories of coniferous trees found in the United States. [Ans. These include pines, firs, spruce, hemlocks, cedars, and cypresses.]
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29. How many plant species are endemic to the United States (north of Mexico)? [Ans. About 4,000 plant species are endemic to the U.S..]
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30. How many vascular plants are endemic to the Hawaiian Islands? [Ans. About 1.050 vascular plants are endemic to the Hawaiian Islands.]
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31. How many U.S. gymnosperms are endemic? [Ans. Some 45 gymnosperms (39% of the gymnosperm flora) are endemic to the U.S..]
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Mammals
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32. Where does the United States rank worldwide in terms of mammal diversity? Identify the order of mammals that constitutes half of all U.S. mammal species. Name some of these mammals. [Ans. The U.S. ranks 6th in mammalian diversity among the nations of the world. The order Rodentia constitutes almost half of all U.S. mammal species. The rodents include squirrels, gophers, and lemmings, chipmunks, beavers, etc.]
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33. List three mammals endemic to the United States. [Ans. The U.S. endemics include the giant kangaroo rat (
Dipodomys ingens
), the Mt. Lyell shrew (
Sorex lyelli
), and the black-footed ferret (
Mustela nigripes)
.]
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33. Complete the following table:
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Species | Mammalian Order [Ans.]
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Opossum Marsupialia
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Nine-banded armadillo Xenarthra
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Caribbean manatee Sirenia
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What do these three species have in common? [Ans. These three species are the only representatives of their orders found in the U.S..]
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Birds
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34. Approximately how many bird species breed in the United States? How many bird species are known to breed in Connecticut? [Ans. About 720 bird species breed in the United States. Some 173 species of birds were confirmed breeding in Connecticut during the 1982-1986 breeding bird survey. Several additional species have been confirmed breeding in Connecticut since then.]
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35. Briefly describe the level of endemism of birds in Hawaii. Then, list three birds endemic to the mainland United States. [Ans. Hawaii has 52 endemic bird species, a very high percentage of its total avifauna. Three mainland U.S. endemic birds are Yellow-billed Magpie, Lesser Prairie-Chicken, and Bachman's Sparrow.]
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36. The Whooping Crane (
Grus americana
) is a highly endangered species of bird in the United States and Canada. Name the most important nesting location of this species. What caused the severe decline in numbers of this bird? [Ans. Whooping Crane nests in central Canada's Wood Buffalo National Park. Hunting (direct exploitation) and agricultural conversion (habitat loss) brought the species to the brink of extinction.]
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Reptiles
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37. How many reptile species are endemic to the U.S.? [Ans. The U.S. has 90 endemic reptiles (32% of the U.S. total of 280 reptile species).]
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38. Give the common name and the Latin name for each of the venomous lizards found in the United States. [Ans. Gila Monster
Heloderma suspectum
and Mexican Beaded Lizard
Heloderma horridum.
]
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Amphibians
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39. With regard to one particular group of amphibians, the United States is the richest country on Earth. Name this amphibian group, and state how many species have been described and what percentage of the world total they represent. [Ans. The U.S. is the richest country for salamanders. There are 140 described species of salamanders. This comprises 40% of the world's total.]
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40. Which amphibian group is the most species-rich worldwide? [Ans. Frogs are the most species-rich amphibian group worldwide (90% of described species).]
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41. Allopatric speciation is "the origin of a new species through the acquisition of effective isolating mechanisms by a geographically isolated portion of the parental species." The process of allopatric speciation can result in great adaptive radiations and species-richness. What accounts for the great species-richness of plethodontid salamanders? [Ans. There is a large number of narrowly distributed species, due to their occurrence in the highly dissected Appalachian Mountains. Examples include the Shenandoah Salamander, the Tellico Salamander, Valley and Ridge Salamander, Peaks of Otter Salamander, Jordan's Salamander, Cumberland Plateau Salamander, Cheat Mountain Salamander, Southern Appalachian Salamander, Pigeon Mountain Salamander, White-spotted Salamander, Ravine Salamander, Southern Zigzag Salamander, Wehrle's Salamander, Weller's Salamander, and Yonahlossee Salamander. Geographic isolation led to numerous speciation events.]
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Freshwater Fishes
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42. Identify the top seven nations for diversity of freshwater fishes. Which freshwater fish family has high levels of endemism in the United States? [Ans. The countries with the greatest diversity of freshwater fishes are: Brazil, Venezuela, Indonesia, China, Democratic Republic of Congo, Peru, and United States of America. The minnow family (Cyprinidae) has great species diversity in the U.S..]
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43. Identify three species of so-called "ancient fishes." (These fishes are classified in taxa with evolutionary histories of many millions of years.) [Ans. Ancient fishes (showing little evolutionary change over millions of years) include the bowfin (
Amia calva
), gars (Family Lepisosteidae), and the paddlefish (
Polyodon spathula
).]
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Insects
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44. Identify the four largest insect orders in the United States. [Ans. The four largest insect orders in the U.S. are: Coleoptera (beetles, 25,030 species); Diptera (flies, 20,627 species); Hymenoptera (bees and relatives, 18,107 species); Lepidoptera (butterflies and moths, 12,261 species).]
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45. The U.S. is extremely rich in bee species, particularly in the arid southwest. What are some of the evolutionary adaptations of these U.S. bees? [Ans. Most of our native bees are solitary. Many burrow into the ground to nest. Many U.S. species coevolved with flowering plants, as there are many wildflowers specialized for bee pollination.]
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46. Explain the term "coevolutionary arms race" as it is applied to insects and flowering plants. [Ans. This term refers to plants evolving specific chemical defenses to ward off foraging caterpillars, and to insect larvae evolving the ability to overcome these chemical toxins.]
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47. Larry Gall of Yale University did his doctoral research in ecology and evolutionary biology on the
Catocala
moths of West Rock Ridge. What are these moths, and why are they significant in the eastern United States? [Ans. The Catocala moths are underwing moths. They consist of about 105 U.S. species. The eastern U.S. is their global center.]
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48. Briefly discuss the species richness of Hawaii's picture-wing fruitflies. [Ans. There are perhaps 100 species of picture-wing flies in Hawaii. They exhibit complex courtship rituals, including defense of mating territories (leks).]
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49. Describe the species richness of freshwater insects in the United States. [Ans. The United States is species-rich in freshwater invertebrates, including caddisflies, mayflies, and stoneflies. More of these species are found in the U.S. than in any other country.]
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50. Dragonflies and damselflies are indicators of environmental health. Explain this statement for the odonates, and describe the species diversity of U.S. dragonflies and damselflies. [Ans. Odonate larvae are fully aquatic and sensitive to the health of their rivers, streams, ponds, and other wetlands. There are 450 species of odonates in the U.S., approximately 8% of worldwide species.]
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Other Invertebrates
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51. Three groups of invertebrates show great species richness in the United States. Identify these three groups. [Ans. The U.S. is particularly species-rich in freshwater mussels, freshwater snails (including tree snails), crayfishes, and subterranean invertebrates (found in caves and other underground habitats).]
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52. How are the tree snails of the Hawaiian Islands similar ecologically to the terrestrial snails of the western U.S. mountain ranges? [Ans. Both the Hawaiian Islands and the western mountain ranges of the U.S. serve as isolated habitats for the speciation of snails over time.]
(2) West Rock Ridge Bio-Blitz
My students will conduct a series of bio-blitzes to study the diversity of West Rock Ridge through fall, winter, and spring seasons. We will survey a series of sites on the ridge top, the eastern slopes, and the surrounding lowlands to learn about preferred habitats of West Rock's indigenous vertebrates. For example, the Wintergreen site has a red maple swamp that serves as a lekking area for the migratory American Woodcock. The rocky outcrops on the ridge top hold hibernacula for Northern Black Racers and Eastern Hognose Snakes (also Northern Copperheads). There is considerable zonation of canopy and subcanopy trees along transects from lowlands to uplands. We also will develop species lists for all plants and animals observed at the ridge during our series of field trips there. These lists will be measured against those lists that I have assembled over my years of field work at West Rock Ridge. Our field trips to East Rock Park, West Rock Ridge, and elsewhere in Connecticut focus on the geology, soils, topography, representative plants and animals, forms of natural and human-induced disturbance, land use practices, and management issues of such diverse habitats as forested uplands, freshwater wetlands, agricultural and pasture lands, and urban environments. In past years, my science students have been able to observe live animals in the classroom, including fishes, salamanders, frogs and toads, snakes, turtles, birds, and small mammals. (All wild animals brought in for educational purposes are treated with respect and care and are returned unharmed to the exact locations where they were captured.)
(3) Case Study: Common Raven (Corvus corax)
This lesson is designed to be used over a period of days, as my students work with and extract important information from a comprehensive set of published and unpublished biology field notes. I have studied the feeding, territorial, and breeding biology of the Common Raven (
Corvus corax
) at West Rock Ridge during 2002, 2003, 2004, and 2005 breeding seasons, and I have produced written and audio-recorded notes on many aspects of the life history of this large corvid species. The Common Raven is believed to have been part of the Connecticut avifauna prior to 1700. It was extirpated from the state as the result of direct persecution, habitat loss, and loss of food sources (carcasses of large mammals). This species has undergone a natural range expansion back into the northwestern and northeastern portions of the State of Connecticut since 1988, and it is rapidly expanding its range southward through many regions of the state. Ravens have been sighted on occasion at West Rock since the mid- to late-1980s, but they are not known to have bred there prior to 2002. For the past four years, the same pair of adult ravens has occupied territory at West Rock Ridge near the quarry cliffs overlooking Konold's Pond, performing courtship rituals, building and rebuilding a large stick nest, defending territory against vultures, hawks, and falcons, obtaining and storing food sources, laying eggs, and hatching and raising young. The July 2004 issue of
The Connecticut Warbler
(the state journal of ornithology) carried an article that I wrote on the 2003 nesting season. I have made additional, unpublished field notes from the two most recent breeding seasons. By working with my field notes, my students will develop observational skills that can be used in the study of territoriality, pair bond formation, nest construction, mating, egg-laying, incubation, nestling and fledgling stages, feeding, food caching, and agonistic behaviors for this avian species. I anticipate that we will be developing tables and charts of information that document the various behaviors of the ravens. Following is an annotated sampling of field notes from the 2004 winter and spring breeding seasons. The notes contain references to a series of cliff face landmarks that define the locations of the observed behaviors of the ravens under study.
Sunday, January 4, 2004 (1340-1440 hour; 39o F, steady light rain) – Two Common Ravens seen from the Quarry Site, center column, flying in the vicinity of the 2003 nest crevice and further north. One raven then seen to fly south low, along the east edge of Konold's Pond, disappearing beyond the South Prom cliff. The second raven is seen and heard in the north cove area, just south of the north point. Relocating to the nest site, this raven is heard further to the north, beyond the north point. Then, the first raven returned from the south, flying out past me and disappearing beyond the north point.
Tuesday, February 3
(0930-1000) – At 0941, the cliff top deer carcasses are checked. A raven is pushed off the most recently deposited deer carcass. It circles between the nest crevice and the north point for a period of four minutes, then flies out beyond the northwest corner of Konold's Pond and loops south. Its calls were heard from 0941 until 0947, as it was in flight. During the circling, the raven's "kronk" calls often were grouped in fours. At one point, the bird nearly hovered in position. It flew close to the cliff on four or five occasions, circling. The newest, non-dissected, deer carcass showed exposed red meat for the first time. Nest-building has not yet begun. One small, foot-long branch, previously noted, is present on the nest ledge, along with a few small twigs.
Thursday, February 5
(1500-1525, 34o F, gray, cloudy, slight breeze) – No Common Raven observed. Foot-long branch is no longer on the nest ledge. The ledge is fairly cleaned of, or devoid of, nest material.
Thursday, February 12
(1416-1449, 36-37o F) – Arriving at the center column, one raven is seen and heard, and it dive-bombs an immature Red-tailed Hawk over the quarry space. A second raven is observed shortly thereafter (1425), from the nest crag area. At 1431, both ravens are observed, trading dives with the Red-tailed Hawk. A new audibilization is heard from the ravens, a castinette-like sound, followed by a low grunting sound. This is being given when the ravens are in pursuit of the hawk. No nest-building has begun, but these birds appear highly territorial. I depart as the ravens' pursuit of the red-tail continues. [School vacation interrupts observations for a week.]
Sunday, February 22
(1200-1340, 41-43o F) – No Common Ravens are observed, but nest-building has begun! The 2003 nest ledge has no branches on it, but a foot or so to the north, a number of broken-off branches have been placed at the base of the sapling that emerges here from the cliff and stretches outward (west) from the cliff face. At 1302, both ravens are seen in flight, each doing dives with barrel rolls. One raven (the male?) departs across Konold's Pond, flying over open water, then to the island, where I lose track of him at 1309. Reexamining the nest from the more southern vantage point, I see that nest-building is progressing with some large branches having been put in place. More whitewash is evident on the cliff above the nest crag.
Tuesday, February 24
(1519-1535, 35o F) – Two Common Ravens fly into the quarry space opposite the center column, coming from the north. The second raven is carrying a large branch, which it drops as it flies ca. 100 feet above the quarry floor. The two ravens circle for a minute in the quarry, doing barrel roll dives. They then fly into the nest recess, circling there for about a minute, and they both depart north beyond the north point. After the ravens have departed, the nest is examined. It is found to have had a small amount of nest material added to it. Future nest observations should be made from the more southern vantage point.
Wednesday, February 25
(1510-1540, 37o F) – During the period 1519-1522 hours, both ravens are in the quarry space. They flew in at eye level, coming in from the north, perhaps from the nest recess. After circling for three minutes, they disappeared to the south over Baldwin Drive and the center of West Rock Ridge. Checking the nest, it is found to have additional material added, but this appears to be a slow process of addition. One large branch has been added, and it projects outward to the west, some 2 to 3 feet beyond the present, rough nest dimensions. A smaller branch is below the large one, also projecting outward. The rock surface of the nest ledge appears to be unchanged. Two of the deer carcasses appear to show some work on them by mammalian predators.
Friday, February 27
(1501, 45o F, beautiful clear sky, bright sun, 0-15 mph gusts of wind from the WSW or SW) – On arrival, I approached the top of the cliff and heard raven kronking before I came into view. Two ravens lift up in the air at the carcass site, and then an immature Red-tailed Hawk lifted up directly from the deer carcass. Moments later, as the two ravens and the red-tail circled, I realized that two additional immature Red-tailed Hawks were up in the air. The ravens circled west and south of me to the quarry space, then headed south out of sight. On inspection of the nest from directly above and from the more southern vantage point, it was apparent that substantial nest-building had taken place in the last two days, with five to eight large sticks now lying over the flat rock surface. There was additional nest-building work at the base of the cliff tree where the nest building had initially begun. The long branch jutting out to the west is no longer there, or no longer so prominent. The deer carcasses are being consumed down to the bone. They should be moved by the next weekend in order to remove the hawks from the area of the raven nest.
Saturday, February 28
(1650-1730, 51o F.) – At the raven nest site, no birds are seen on the deer carcasses. Looking down on the nest crevice, I see one raven, and a moment later the second, flying below me. The second raven is carrying three small sticks. One of the ravens made three low or soft kronk calls, not expressing a lot of objection to seeing me. Both birds flew low to the north and perched on a rock ledge just out of sight, on this side of the north point. I did a quick inspection of the nest from the southern sloping rock ledge. There are now about ten sticks on the bare rock nest shelf, all parallel to each other and bundled up, running parallel to the ridge line. The nest is also taking shape around the base of the cliff sapling. The second raven was carrying the sticks in its bill and did not drop them when it flew north and perched. At 1723, I heard two cries, then three more, seemingly from a raven to the west over Konold's Pond, but I did not see the bird.
Monday, March 1
(1532 arrival at the south prom, 60o F, with hazy white clouds on the horizon and a bright sun. The cliff face is fully illuminated by the sun.) – No ravens are observed. At 1547, I relocate to the raven nest site. At 1556, I check the raven nest and find that an incredible rounded stick nest is taking shape. Viewing is from directly above and from the more southern ledge vantage point. Flies are observed on the deer carcasses for the first time. At 1607, I may have caught a glimpse of one raven, disappearing low behind the north point. Two minutes later I conclude that the bird seen was probably a crow. Departure from the ridge top at ca. 1615.
Wednesday, March 3
(0915) – Three adult peregrine falcons are observed from the quarry site, center column. The peregrines dive-bombed a Red-tailed Hawk near the quarry. One of the females departed the area shortly thereafter. The other female and the male gave several passes by me on the quarry cliff and then continued soaring out over Konold's Pond and to the distant north. Observations of the peregrines were made discontinuously over the period 0915-0940. At 1245 (50o F), one male and one female peregrine are observed in the air above the quarry. Then, they dive bomb a Red-tailed Hawk to the north. They are observed in the air for about 4 minutes. They disappear high to the south. At 1315, the raven nest is checked. New nest-building seems to have taken place, but no ravens are seen. At 1658 from the south prom outer ledge, I observe one Common Raven for several seconds, gliding out from the nest recess. It then disappears from sight. At this time of day, it is a cold, windy, very overcast day. The sun is visible in the cloud break to the west. At 1701, a raven flies north to the north point, moves to the center of the ridge, and then disappears to the north. At 1708, both ravens are seen flying in from the north. First assuming perch sites to the north, the two birds then fly into the nest recess. One raven has a mouth-full of what appears to be an excelsior-like material, light tan in color. At 1713, one raven does a quick loop flight out from the cliff and then back in and out of sight. At 1716, both ravens come out from the nest recess. One enters the quarry, flying right in front of me, and then lands on a column at the south end of the quarry. Between 1718 and 1719, a raven gathers branches from live trees north of and upslope of the nest recess, breaking the branches off from the tree and then flying in to the nest. At 1720, the second raven flies in to the nest. Two minutes later, a raven comes out from the nest, carrying nest material, loops around once, and then returns to the nest. Over the course of the next minute or so, a raven either goes in to the nest or leaves it. At 1725, both ravens are upslope on the cliff gathering sticks. One flies to the nest. The other raven is seen to be stripping bark from the lower trunk of an Eastern Redcedar tree. At 1728, both ravens are perched on the upper north edge of the quarry. At 1729, one raven goes in to the nest carrying sticks. It is followed a minute later by the second raven carrying bark strips. During the next five minutes, both ravens gather bark strips from the redcedars growing along the upper slopes of the ridge. At 1738, both ravens fly into the quarry and glide just below me. They circle once, one of the birds gives three "kwarks", and they then disappear to the south at 1739. At 1752, I examine the redcedar tree where the ravens had been concentrating their nest gathering efforts. The ravens have definitely been pulling off strips of cedar bark; the tree trunk is all frayed. A sample of loose bark is collected from the tree. 53o F.
Thursday, March 4
(1448 arrival at West Rock) – A female Peregrine Falcon is seen up in the air at the quarry site. As I move out to the outer ledge observation shelf, a raven flies in to the quarry from the south, carrying nest material in its bill. The Peregrine Falcon immediately attacks, in the direction of the center column. The raven drops the nest material and retreats from view, seeking shelter in the trees in front of the nest site. At 1455, the female peregrine is still circling overhead. At 1456, the peregrine defecates in the air, and at 1500, it perches on the high sentinel. At 1515, the peregrine jumps off its perch site, and in another minute and a half she disappears to the south over the centerline of the ridge. During the last period of time, there have been several raven "kronks" coming form the north. At 1524, both ravens are circling in the space between the nest site and the north point. 1531, both ravens have been gathering branches along the lower north edge of the quarry (well below my line of sight toward the nest). Both now fly to the nest, one carrying nest material and the other without. At 1533, both land at the base of the cedar tree I examined yesterday. Each bird gets a large mouthful of cedar bark shavings, and each flies to the nest, dropping down into the crevice from above. At 1536, another trip is made to the nest with cedar bark. At 1537.30, both ravens are back to the cedar tree. At 1540, one raven flies to the nest with bark shavings. At 1541, the second raven flies to the nest, without nest material. At 1545, both ravens come out from the nest and fly to the vicinity of the north point, wing tip to wing tip. One lands out of sight on the cliff slope. At 1551, one raven is observed stripping bark from a thin grape vine on the talus slope below the nest site. The vine is suspended from a small tree or shrub. The bird wrestles with the vine while balanced on it. At 1554, this raven flies off the talus slope carrying one or two sticks, and it goes to the nest. At 1555, a raven flies in low to the nest. At 1556, both ravens are out in the air, then both fly in to the nest. At 1559, one raven comes out "kronking", agitated by a low-flying Turkey Vulture (one of four flying by). Kronking, the raven then lands on the top of the quarry and begins digging at grass and tree roots. The raven then lands upslope of the rock overhang and digs up three clumps of green moss and flies with the moss to the nest. 1604 departure from West Rock. [Continuation of notes is not published here.]
(3) Case Study - Peregrine Falcon (Falco peregrinus)
The Peregrine Falcon (Falco peregrinus) is known to have bred or attempted to breed in Connecticut during the period 1850-1948. All peregrine breeding from this historical period took place on trap rock ridges in the central valley lowlands of Connecticut, The four known nest sites consist of Talcott Mountain in the Avon-Farmington area, Ragged Mountain in Kensington/Berlin, the Hanging Hills of Meriden (West Peak), and Sleeping Giant (Mount Carmel) in Hamden/North Haven. In addition, Peregrine Falcon is known to have nested on the Travelers Tower (Travelers Insurance Company) in downtown Hartford during the period 1943-1948. It was extirpated as a breeding bird in the United States east of the Rocky Mountains by the mid-1960s due to pesticide poisoning of peregrines. Additional higher order consumers whose populations were decimated by the bioaccumulation of DDT pesticide included Bald Eagles, Ospreys, and Brown Pelicans. The eastern race of the Peregrine Falcon,
Falco peregrinus anatum
, was driven to extinction. As the result of an extensive program of reintroduction of the peregrine since the 1960s, this species has recovered as a breeding bird throughout the eastern United States, and it was recently removed from the federal list of endangered species. In recent years, it has occurred in Connecticut as a fall and spring migrant. It has returned to Connecticut as a breeding bird only since the mid-1990s, and it is currently listed as a state-endangered species.
For the past seven years, I have carried out extensive field work on peregrines attempting to breed at West Rock Ridge in the Greater New Haven area. I first discovered a pair of peregrines at West Rock on Sunday, June 10, 1999 during my participation in the New Haven, Connecticut Summer Bird Count, an annual survey of birds that follows the guidelines of the early winter National Audubon Society sponsored Christmas Bird Counts (see below). That discovery has led to more than five hundred hours of field observations on Peregrine Falcon behavior. The unbanded male occupied his West Rock breeding site during the years 1999 through 2004. His mate that year was a US Fish & Wildlife Service-banded and color-banded female. The band information enabled me to trace the origins of this female. She was hatched out on Riverside Church in New York City in 1998 and was banded by a New York Department of Conservation biologist on June 4 of that year. Too young to lay eggs in 1999, this female returned to West Rock in 2000 as a mature falcon with the same mate, and on March 29 at 2:30 P.M. she laid an egg in her cliff nest – the first peregrine falcon egg to be laid on a Connecticut cliff since 1940. I witnessed the egg emerging from her body and being deposited in the nest scrape. The full details of this nesting effort and two subsequent years in which eggs have been laid at the West Rock cliff site (2001 and 2005) will be published in The Connecticut Warbler journal in future years.
My field notes record data on four additional females and one additional male peregrine that have occupied the West Rock site during the period 2001-2005. The females have included a bird that was banded in the 1999 fall migration at Assateague National Wildlife Refuge on the Eastern Shore of Virginia, two additional color-banded females whose origins have not yet been determined, and most recently, a female banded in the nest by a Connecticut State Department of Environmental Protection biologist, on a bridge in Middletown, Connecticut. The second male peregrine observed at West Rock was the partner of this Middletown bird during the 2005 breeding season.
My students will use a variety of materials from the scientific and popular literature to learn about the captive breeding program that is successfully restoring peregrines to their former range in the eastern United States, and they will apply their knowledge to the specific case of the West Rock Peregrines. As with the study of Common Ravens at West Rock Ridge, I have made written and audio-recorded field notes of my peregrine observations. I presently have assembled more than sixty microcassettes of field notes on the West Rock peregrines, each containing ninety minutes of recorded information. Some of these recorded notes are transcribed, but many have not yet been converted to computer files. To date, none of the information has been published. My students will assist in many aspects of the compilation and interpretation of these data.
(4) Connecticut Christmas Bird Count Data.
In 1900, Frank Chapman of the American Museum of Natural History in New York and a group of similarly dedicated birders initiated a census of birds during early winter that more than a century later is still held every year and is recognized as the longest running wildlife census in the world. The Christmas Bird Count, as it was initially proposed, was a one-day (December 25) effort to go out in the field and locate and count all the birds in a defined area. The Christmas Bird Count was established in direct response to the late Victorian tradition in America, known as the side hunt, of going out on Christmas Day and shooting birds and other wildlife for the dinner table and for sport. In the era of the millinery trade, birds were being shot by the hundreds of thousands by professional market hunters to satisfy the style fashions of women and men who considered themselves best dressed when wearing the feathers or wings or whole bodies of birds on their hats, coats, and gowns. Conservation-minded citizens, including these ornithologists, reached the conclusion that we were devastating our wildlife through such wanton consumptive use and that a different relation with the natural world had to be developed. Today, the National Audubon Society and local Audubon chapters or birding organizations conduct several thousand bird counts throughout the United States and the Americas. These counts, which are held on designated days during the period December 14 through January 5, take place in defined fifteen-mile count circles, and they begin at 12 Midnight and proceed until the following 12 Midnight. Birders with experience ranging from beginners to highly skilled field observers have the task of checking all suitable habitat for anything that has feathered wings (caged or domesticated birds excluded). For many of us, the Christmas Bird Count is one of the highlights of the birding year.
For nearly twenty years, I served as the compiler of the New Haven Christmas Bird Count, and I continue to serve as compiler for the statewide Connecticut Christmas Bird Counts, a task that I have assumed for the past eighteen years. Each year, I tabulate the results of all Christmas Bird Counts held wholly or partially in the state, comparing the results with the previous thirty years of count data. I then write a review article that is published in
The Connecticut Warbler
(Connecticut's journal of ornithology) on the results of the year's bird counts. There are six bird counts conducted in the northern regions of Connecticut (Hartford and Storrs CBCs are examples), five mid-state counts (including Woodbury-Roxbury and Quinnipiac Valley), and seven coastal counts (among them, Greenwich-Stamford, New Haven, and New London). The spreadsheets of birding data that I have produced and that I add to each year now cover the period 1960-2004 in Connecticut. These CBC data offer rich material for studying the population trends for 250 species of birds that occur in the state during early winter. They lend themselves to potential science classroom study and also to science fair projects. My students will use these data to determine trends in winter bird populations over the last several decades.
For example, a number of bird species have increased in numbers dramatically in recent years, including such "southern species" as Turkey Vulture, Black Vulture, Red-bellied Woodpecker, Tufted Titmouse, Carolina Wren, and Northern Cardinal. Other species, including many grassland and deep forest birds, have gone through significant declines in numbers during the same years. These species include American Black Duck, Ring-necked Pheasant (an introduced species), Ruffed Grouse, Sharp-shinned Hawk, American Kestrel, American Woodcock, Loggerhead Shrike, Brown Thrasher, European Starling (another introduced species), Eastern Meadowlark, and Evening Grosbeak. I envision my students working with this large database of information to develop projects on such topics as arrivals and losses of bird populations, causes of population fluctuations, habitat loss in Connecticut, successful conservation measures to restore birds to the region, and the occurrence of rare, vagrant species.
