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Working with Dynamic Crop Models
Methods, Tools and Examples for Agriculture and Environment
Working with Dynamic
Crop Models
Methods, Tools and Examples for Agriculture
and Environment

Third Edition
Daniel Wallach
Institut National de Recherche Agronomique (INRA), France

David Makowski
Institut National de Recherche Agronomique (INRA), France

James W. Jones
Agricultural and Biological Engineering Department, University of Florida,
Gainesville, FL, United States

François Brun
Acta, French Agricultural Technical Institutes, France
Academic Press is an imprint of Elsevier
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© 2019 Elsevier B.V. All rights reserved.
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This book and the individual contributions contained in it are protected under copyright by the
Publisher (other than as may be noted herein).

Notices
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broaden our understanding, changes in research methods, professional practices, or medical
treatment may become necessary.
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evaluating and using any information, methods, compounds, or experiments described herein.
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To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors,
assume any liability for any injury and/or damage to persons or property as a matter of products
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Preface

Given the complexity of environmental systems, including managed agricul-

tural systems, both as to their functioning and the complexities of intervention,
it is not surprising that a holistic system analysis point of view is often neces-
sary. System models are the translation of that point of view into mathematical
equations, and they make it possible to apply all the powerful machinery of
mathematics to understanding and managing those systems. However, it is hard
for system modelers, who often come from the application domain, to be aware
of and capable of correctly applying the many mathematical methods applicable
to system models. That is the purpose of this book; to provide system modelers a
single reference volume for all the basic mathematical tools and many of the
advanced tools that they need for working with system models. For each
method, there is a description of why it is important, what it involves, the prin-
ciples behind it, and how to apply it in practice using the R language. Numerous
examples are given, many of them from published studies, to illustrate when and
how the method is used. The R language, which has become very popular, has
many powerful functions that make it quite easy to apply many of the methods
described in this book. That is why we emphasize an understanding of the prin-
ciples behind the methods, the use of each method, and the R functions that can
be used, skipping in most cases the mathematical details of the calculations.
The first section of this book provides background, and includes an introduc-
tion to system models, a primer on the R programming language, an explanation
of methods of simulation, a review of statistical notions important for modeling,
and a specific chapter on regression analysis (after all, a system model is in fact
a regression model).
The second section includes basic methods that are very widely used by
modelers. That includes uncertainty and sensitivity analysis, calibration of crop
models using frequentist methods, parameter estimation using Bayesian
methods, and model evaluation. The final chapter in this section illustrates
how these different approaches can be combined in an overall modeling exer-
cise, using a simple model as an example and going through the calculations in
detail using R. All chapters have been updated, but in particular the treatment of
model calibration has been expanded compared to the second edition, with
emphasis on the specific problems of system models and examples from system
modeling.

xiii
xiv Preface

The last section is almost entirely new, treating (with one exception) topics
that were not covered at all in the second edition. This is the section on advanced
methods and new uses of system models. The chapters here treat metamodels
(how to approximate a system model by a simpler model), multimodel ensem-
bles (how to analyze the results from ensembles of models), gene-based model-
ing (how to combine agronomic and genetic information in a model), data
assimilation for dynamic models (how to update a system model using informa-
tion on an individual), and models as an aid to sampling.
This book can be used for self-study, as a reference volume, or as a textbook
for a course in modeling. Examples of the latter include courses at the
University of Florida, at Universidade de Passo Fundo in Brazil, at Nanjing
Agricultural University in China, and multiple short intensive courses around
the world. The chapters are mostly self-contained so that you can read, study,
or draw on the chapters in any order. Each chapter has a series of exercises at the
end to test your understanding and capability of applying the methods.
The principal authors of the chapters were as follows: Basics of agricultural
system models (JWJ), The R programming language and software (FB), Sim-
ulation with dynamic system models (JWJ), Statistical notions useful for
modeling (DW), Regression analysis (DW), Uncertainty and sensitivity analy-
sis (DM), Calibration of system models (DW), Parameter estimation with
Bayesian Methods (DM), Model evaluation (DW), Putting it all together in a
case study (FB), Metamodels (DM), Multimodel ensembles (DW), Gene-based
modeling (JWJ), Data assimilation for dynamic models (DM), and Models as an
aid to sampling (DM).
Acknowledgments

Third edition:
The authors express gratitude to Dr. C.E. Vallejos, Dr. M. Bhakta, Dr. K.J.
Boote, and Dr. M. Correll for providing data used in Chapter 13. The authors
also want to thank Dr. M. Bhakta, Dr. K.J. Boote, Dr. G. Hoogenboom, and
Dr. C.E. Vallejos for reviewing an earlier version of Chapter 13 (Gene-Based
Crop Models), and for making helpful suggestions for improving the chapter.

Second edition:
The authors gratefully acknowledge their home institutions:
l INRA (Institut National de la Recherche Agronomique).
l The University of Florida, Agricultural and Biological Engineering
Department.
l ACTA, head of the network of French Technical Institutes for Agriculture.
The following projects provided an invaluable framework and support for
discussing and applying methods for working with dynamic crop models:
l R
eseau Mixte Technologique Mod
elisation et Agriculture, funded by a grant
from the French Ministry for Agriculture and Fisheries.
l The project “Associate a level of error in predictions of models for agron-
omy and livestock” (2010–13), funded by a grant from the French Ministry
for Agriculture and Fisheries.
l AgMIP, the Agricultural Model Intercomparison and Improvement Project.
l The FACCE-JPI project MACSUR (Modeling European Agriculture with
Climate Change for Food Security).
l The INRA Metaprogramme ACCAF (Adaptation de l’agriculture et de la
for^et au changement climatique).
In addition, we owe thanks to:
l Luc Champolivier, Terres Inovia, for providing field water content
unpublished data.
l Sylvain Toulet, intern at INRA in 2012, Juliette Adrian, intern at ACTA in
2013, and Lucie Michel, intern at ACTA-INRA, for their contributions to
the examples.

xv
xvi Acknowledgments

l Senthold Asseng of the University of Florida, for working with the authors
and making use of the new material in this book in the graduate course,
“Simulation of Agricultural and Biological Systems.”
l All the students in the courses we have given on crop modeling, who have
enriched our thinking with their questions and remarks.
Chapter 1

Basics of Agricultural System

Models
Chapter Outline
1 Introduction 3 4 Other Forms of System Models 17
2 System Models 5 4.1 Random Elements in
2.1 Systems Approach 5 Dynamic Equations 18
2.2 System Environment and 4.2 A Dynamic System Model
Boundary 5 as a Response Model 19
2.3 System Model and 5 Examples of Dynamic
Simulation 7 Agricultural System Models 20
2.4 State Variables U(t) 9 5.1 Simple Maize Crop Model 20
2.5 Explanatory Variables and 5.2 Dynamic Soil Water Model
Parameters 10 and Drought Index 24
3 Developing Dynamic 5.3 Population Dynamics
System Models 11 Models 32
3.1 Methods 11 Exercises 39
3.2 Example Development of a References 42
System Model 15

1 INTRODUCTION
Agricultural systems are complex combinations of various components. These
components contain a number of interacting biological, physical, and chemical
processes that are manipulated by human managers to produce the most basic of
human needs—food, fiber, and energy. Whereas the intensity of management
varies considerably, agricultural production systems are affected by a number
of uncontrolled factors in their environments, being exposed to natural cycles of
weather, soil conditions, pests, and diseases. In comparison to physical and
chemical systems, agricultural systems are much more difficult to manage
and control because of the living system components that respond to their phys-
ical, chemical, and biological environmental conditions in highly nonlinear,
time-varying ways that are frequently difficult to understand. These interactions
and nonlinearities must be considered when attempts are made to model and
predict agricultural systems’ responses to their environments and management.

Working with Dynamic Crop Models. https://doi.org/10.1016/B978-0-12-811756-9.00001-0

© 2019 Elsevier B.V. All rights reserved. 3
4 SECTION A Background

Dynamic system models are increasingly being used to describe agricultural

systems to help scientists incorporate their understanding of the interactions
among components for use in predicting the performance of agricultural sys-
tems for better achieving goals of farmers (e.g., food production, profits) and
of society (environmental quality, sustainability).
In this chapter, we present concepts of system models, with examples of var-
ious agricultural system models. We will also present methods for developing
system models. Many agricultural system models already exist, and in some
cases, there are multiple models of the same agricultural system. Examples
include multiple models of cropping systems (Rosenzweig et al., 2013;
Rotter et al., 2012); there are more than 27 wheat crop production system
models (Asseng et al., 2013). Thus, someone interested in analyzing a particular
system may be able to select from existing models and not have to develop a
new one. However, it is also very important for model users to understand the
models if they adopt an existing one. An understanding of model development
methods will allow them to attain a deeper understanding of a particular model’s
capabilities and limitations than they would otherwise have. Each model is a
simplification of the real system, with assumptions that may or may not be
acceptable for a particular application. It will help model users understand the
assumptions and relationships used in specific models and enable them to better
judge the suitability of a model for their purpose, potentially reducing the poten-
tial for using an existing model for purposes for which it was not designed or
evaluated. It will also help model users determine if modifications are needed
to an existing model, and if so, it will give them a basis for understanding how
this can be done.
System models can be viewed in two different, complementary ways. First, a
model can be treated as a system of differential or difference equations that
describes the dynamics of the system. Second, the model can be treated as a
set of static equations that describes how responses of interest at particular times
depend on explanatory variables. We present and discuss these two viewpoints
in this chapter. As we shall see, the different methods described in this book may
call for one or the other of these viewpoints.
In this chapter, we start off in Section 2 by presenting general systems con-
cepts and definitions that are needed in modeling systems. Then in Section 3,
we go through the process of developing a model of a system with two simple
interacting components that will help give students an intuitive understanding
of the system modeling process. In Section 4, we will present other forms of
models frequently used to present agricultural systems in various types of
applications. Example system models will be presented in Section 5 for sev-
eral important agricultural system components, demonstrating some of the
key features and relationships used in model development. A major emphasis
here is on dynamic models in which the time changes in system components
are modeled.
 Basics of Agricultural System Models Chapter 1 5

2 SYSTEM MODELS
A system is a set of components and their interrelationships that are grouped
together by a person or a group of persons for purposes of studying some part
of the real world. Usually, a group of persons works together to define the sys-
tem that they intend to analyze, and in many cases the individuals are from dif-
ferent disciplines because of the scope of the system they intend to study. The
selection of the components to include in a particular system model depends on
the objectives of analysts and on their understanding and perspectives of the real
world. A system may have only a few components or it may have many com-
ponents that interact with each other and that may be affected by factors that are
not included in the system. Conceptually, a system may consist of only one
component; however, in this book we focus on the more common situation that
exists in agricultural systems where the complexities of interactions among
components are required to understand the performance of the overall system
being studied.

2.1 Systems Approach

A systems approach starts with the definition of the system to be studied and
includes the development of a system model and the use of that model to
analyze the system. This definition should include a stated purpose or purposes
of the study, description of components of interest, interactions among com-
ponents to be modeled, and external variables that influence the behavior of
components. Thus, it is important that all participants in a study have a shared
vision of the system, including a common understanding of the objectives
of the analyses that will be performed and of the system and its components
and context. The systems approach provides an effective framework for
interdisciplinary research, and thus it is important that the analyses include
all disciplines at the start of a project and that an explicit definition of
the system, its components, the interactions among system components, and
the interactions of those components with other factors are agreed upon and
clearly communicated.

2.2 System Environment and Boundary

A system has an environment as well as components and interactions among
them. The boundary of a system separates the system components from the envi-
ronment. A system environment may include anything in the real world except
the components being studied. We usually describe a system environment as
factors that affect the behavior of components in the system but are not affected
by them. For example, many agricultural systems are affected by weather
conditions, but regardless of how the system components behave, they do not
6 SECTION A Background

FIGURE 1.1 Schematic diagram of a cropping system model showing interactions between soil
and crop components in the system and influences of explanatory variables from the environment. In
this system, it is assumed that weather, management, pests in the biotic environment and soil vari-
ables in the soil environment (e.g., below 1 m in depth) influence the system but are not affected by
system components.

affect weather. A cropping system (Figure 1.1) may include soil and a crop that
interact with each other and with the environment. The environment may have
several variables that define the characteristics of the environment that directly
influence some of the system component processes. The soil and crop system is
usually defined as a homogeneous field or a representative area in the field that is
exposed to weather throughout the course of a season. The boundary of this sys-
tem would be an imaginary box immediately surrounding this representative
uniform area in the field (e.g., with dimensions of 1 ha by 1 ha or of 1 m by
1 m in area), and a lower boundary in the soil at 1 m in depth. The environment
would be everything in the soil and atmosphere outside this imaginary box that
would affect the soil and crop behavior in the system. Note that each system
component may have multiple variables that describe the conditions of system
components at any particular time. For example, the soil component may include
soil water content, mineral nitrogen content, and soil organic matter that change
from day to day. The crop component may include above-ground biomass, leaf
area, and depth of roots in the soil.
This example also illustrates another important point: assumptions have to be
made when choosing a system’s components and its environment. Here it is
assumed that the temperature and humidity in the canopy are equal to the values
of these variables in the air mass above the canopy. In reality, the soil and crop
conditions affect canopy temperature and humidity through the transfer of heat
and water vapor into the air above the crop, and thus the system does affect the
immediate environment of the crop. This interaction may be important in many
situations such that the system would include the canopy temperature and
 Basics of Agricultural System Models Chapter 1 7

humidity. In the example, the assumption is that those effects are small relative to
the influences of external factors, such as that of the external air mass. This
assumption is made in most, but not all, existing cropping system models.
This example of a system and its environment can also be used to illustrate
the implications of incorporating additional components into a system. If can-
opy air temperature and humidity are added to the soil and crop components, the
system will include another component, the canopy air environment. This will
cause the model to become more complex in that explicit mathematical relation-
ships would be needed to model the dynamics of canopy air temperature and
humidity in addition to the soil and crop conditions. The environment for this
expanded system would still include weather explanatory variables above the
crop canopy.

2.3 System Model and Simulation

2.3.1 System Model
A system model is a mathematical representation of the system, including all the
interrelationships among components and effects of the environment on those
components. The model description includes all the equations of processes that
cause components to change, all the environmental variables that influence
components in the system, all important properties of the system’s components,
and all the assumptions that were made to develop a particular model. It is com-
mon to find two models of the same system that are very different due to choices
made by those who developed each model. For example, the 27 wheat models
used in the Asseng et al. (2013) study differ in the mathematical formulations
used to model the same overall components and in the assumptions that were
made to develop each model. This is true even though most of these wheat crop
models have the same components and respond to the same environmental fac-
tors. The differences in the models are due to differences in assumptions among
models about what controls the development and growth processes in the crop
and how soil water and nitrogen change over time. These differences lead to
differences in mathematical functions used to represent system dynamics and
even to the variables used to describe the status of the crop and soil conditions
at any point in time.

2.3.2 Simulation
Simulation refers to the numerical solution of the system model to produce
values of the variables that represent the system components over time. Although
in some literature, a model is referred to as a “simulation model,” this terminol-
ogy hides an important and distinctive difference between a system model and
its solution. Computer code should be developed based on the mathematical
description and explicit assumptions. Otherwise, the assumptions and
8 SECTION A Background

relationships may be hidden in the computer code and not easily understood or
communicated to each modeling team member and to the outside world. Sim-
ulation is discussed in more detail in Chapter 3.

2.3.3 General Form of a Dynamic System Model

The general form of a dynamic system model in continuous time is:

dðU1 ðtÞ
¼ g1 ðUðtÞ, XðtÞ, θÞ
dt
⋮ (1)
dðUS ðtÞ
¼ gS ðUðtÞ, XðtÞ, θÞ
dt

where t is time, U(t) ¼ [U1(t), …, US(t)]T is the vector of state variables (defined
below) at time t, X(t) is the vector of environmental variables at time t (some-
times referred to as exogenous, forcing, or driving variables), θ is the vector of
system component properties that are included in the model to compute rates of
change, and g1, g2, …, gS are some functions. The state variables U(t) could
include, for example, leaf area index (leaf area per unit of soil area), crop
biomass, root depth, soil water content in each of several soil layers, etc. The
explanatory variables X(t) typically include climate variables (such as daily
maximum and minimum temperatures) and management variables (such as
irrigation dates and amounts). As discussed in Section 2.5, in the rest of this
book we will use X(t) and θ to refer to explanatory variables and parameters,
respectively, which is not quite the same definition as above.
The model of Equation (1) is a system of first-order differential equations
that describes rates of changes in each of the state variables of the system. It
is dynamic in the sense that the solution (simulation) of the system of equations
describes how the state variables evolve over time. It describes a system in the
sense that there are several state variables that interact.
Continuous time dynamic systems are sometimes modeled using discrete
time steps; in this case, the models are mathematically represented as a set of
difference equations. We will later show how this is useful in simulation of
the dynamic system model and the interpretation of dynamic models as response
functions. By writing the left side of Equation (1) as a discrete approximation of
the derivative, it is straightforward to develop the general form of a dynamic
system model in discrete time:

U1 ðt + ΔtÞ ¼ U1 ðtÞ + g1 ½UðtÞ, XðtÞ, θΔt

⋮ (2)
US ðt + ΔtÞ ¼ US ðtÞ + gS ½UðtÞ, XðtÞ, θΔt
 Basics of Agricultural System Models Chapter 1 9

There is an important concept underlying the use of Equations (1), (2) to rep-
resent dynamic systems. Note that numerical methods are almost always needed
to solve for behavior of system model variables over time, and Equation (2) is a
highly useful and simple approach for solving dynamic system models.
However, if the intent is to closely approximate the exact mathematical solu-
tion of a dynamic system model (i.e., if it could be solved analytically), one
needs to select the time step Δt such that the numerical errors associated with
approximating continuous time by discrete time steps are acceptable. Opera-
tionally when solving the model, one can evaluate the effects of choosing dif-
ferent values of Δt on important model results. On the other hand, model
developers may select the Δt when developing the model because of the level
of understanding of processes in the system and on the availability of environ-
mental variables. In this case, all the model equations and explanatory vari-
ables have to be developed specifically for the chosen time step, and this
may require different approximations to the processes than those used when
solving a model using continuous time. The mathematical form of such
discrete-time models may be represented as in Equation (2), and such models
were referred to as “functional models” by Addiscot and Wagenet (1985). An
example is modeling soil water flow versus soil depth and over time using
the Richards equation (continuous time model) versus using a so-called
tipping bucket approach (with a daily time step). This will be discussed more
in Chapter 3.
In some agricultural system models, such as in many dynamic crop models,
Δt is 1 day. One reason for this choice of time steps in many crop models is that
highly important weather data may be available only on a daily basis (e.g., daily
rainfall). In this case, the Δt on the left side becomes 1 and it disappears on the
right side of the equation. Note that Equation (2) is an approximation to the con-
tinuous model form. The choice of difference equations to model dynamic sys-
tems may mean that the model developer must use functional relationships that
approximate the underlying physical, chemical, or biological processes
involved. Thus, the development of functions (gi) that compute changes in
the state variables need to take into account the time step used in discrete time
models.

2.4 State Variables U(t)

State variables are quantities that describe the conditions of system components
at any particular time. These state variables change with time in dynamic system
models as system components interact with each other and with the environment.
A system may have only a few or many state variables. State variables play a cen-
tral role in dynamic system models. The collection of state variables determines
what is included in the system under study. A fundamental choice is involved
here. For example, if it is decided to include soil mineral nitrogen within the
10 SECTION A Background

system being studied, then soil mineral nitrogen will be a state variable and the
model will include an equation to describe the evolution over time of this vari-
able. If soil mineral nitrogen is not included as a state variable, it could still be
included as an explanatory variable, that is, its effect on plant growth and devel-
opment could still be considered. However, in this case the values of soil mineral
nitrogen over time would have to be supplied to the model; they would not be
calculated within the model. The limits of the system being modeled are different
in the two cases.
The choice of state variables is also fundamental for a second reason. It is
assumed that the state variables at time t give a description of the system that is
sufficient for calculating the future trajectory of the system. For example, if
only root depth is included among the state variables and not variables describ-
ing root geometry, the implicit assumption is that the evolution of the system
can be calculated on the basis of just root depth.
Furthermore, past values of root depth are not needed. Whatever effect they
have is assumed to be taken into account once one knows all the state variables
at time t. Given a dynamic model in the form of Equation (1) or (2), it is quite
easy to identify the state variables. A state variable is a variable that appears
both on the left side of an equation, so that the value is calculated by the model,
and on the right side because the values of the state variables determine the
future trajectory of the system.

2.5 Explanatory Variables and Parameters

We adopt definitions for parameters and explanatory variables that are consis-
tent with the various applications used throughout the rest of this book. Param-
eters are quantities that are unknown and are not measured directly. They must
be estimated using observations of system behavior. Examples are the photope-
riod sensitivity of a crop cultivar or the relative rate of decomposition of soil
organic matter. These quantities are properties of the components of a system
model. There may be other characteristics that can be measured, such as the soil
depth or the carbon content in soil organic matter. Those are referred to as
explanatory variables. In order to simulate dynamic system models, the values
of all state variables must be known at time t ¼ 0 when the simulation begins.
Some or all of these state variable initial values could possibly be measured and
thus not be considered as parameters. However, initial conditions of state vari-
ables can also be considered as parameters if they are not measured but rather
are estimated from past data.
Explanatory variables include the variables that are measured directly or
known in some other way for each situation where the model is applied. They
are variable in the sense that they may vary between situations or vary over time.
They include all environmental and management variables as well as system
component properties that are known or measured.
22 SECTION A Background

FIGURE 1.5 Forrester diagram of the simple maize crop growth model. The model has three state
variables (TT(t), B(t), and LAI(t)) and three daily weather explanatory variables (TMAX(t), TMIN(t),
and I(t)). See text for definitions of variables.

solar radiation, and crop biomass. However, this approach provides a good first
approximation to LAI development under potential growth conditions.
Figure 1.5 shows the Forrester diagram of this system, showing the three
system state variables, the system boundary, the processes that cause these vari-
ables to change versus time, parameters that were used in the functions used to
compute the rates of change of state variables, and the explanatory weather vari-
ables that must be known in order to simulate crop growth. Note that there are
three rectangular boxes or levels to represent the three state variables. Note also
that the rate of accumulation of thermal time age of the crop, dTT(t), depends
only on daily maximum and minimum temperatures and an explanatory
variable, Tbase (Equation 11). Thermal age of the crop is the accumulation
(integration) of this rate.
 
TMIN ðtÞ + TMAXðtÞ
dTT ðtÞ ¼ max  Tbase; 0 (11)
2
Equation (11) shows that dTT(t) is restricted to nonnegative values. The rate of
leaf area expansion depends on thermal age of the crop in that leaves expand
only during a vegetative phase of crop growth, which is defined in this model
by TTL, the thermal age of the crop when the crop ends its vegetative phase and
begins reproductive growth. The rate of expansion is also reduced as LAI
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Length to end of tail 18 1/2 inches, to end of wings 11 3/8; extent of
wings 22 1/2; wing from flexure 8; tail 10 1/2; bill along the ridge
1 4 1/2/12; tarsus 1 10 1/2/12; first toe 8/12, its claw 10/12; middle toe
1 2/12, its claw 6/12.

Adult Female. Plate CCCLVII.

The Female is similar to the male, and little inferior in size.
Five American specimens compared with several European, present
no appearances indicative of a specific difference. Some individuals
of both countries are larger than others, and the tail differs much in
length, according to age or the growth of the feathers. The largest
specimen in my possession, presented to me by Dr Richardson,
and marked as shot by Mr Drummond, measures as follows:—
Length to end of tail 20 1/2 inches; bill along the ridge 1 7/12; tail
11 3/4; wing from flexure 8 9/12; tarsus 2; middle toe 1 1/12, its claw
7 1/2/12.
In this individual the feathers on the fore neck are white for
more than half their length from the base. In the other specimens this
white part is fainter or light grey, and of less extent.
 PINE GROSBEAK.

Pyrrhula Enucleator, Temm.

PLATE CCCLVIII. Male and Female.

In Wilson’s time, this beautiful bird was rare in Pennsylvania; but

since then it has occasionally been seen in considerable numbers,
and in the winter of 1836 my young friend J. Trudeau, M. D.
procured several in the vicinity of Philadelphia. That season also
they were abundant in the States of New York and Massachusetts.
Some have been procured near the mouth of the Big Guyandotte on
the Ohio; and Mr Nuttall has observed it on the lower parts of the
Missouri. I have ascertained it to be a constant resident in the State
of Maine, and have met with it on several islands in the Bay of
Fundy, as well as in Newfoundland and Labrador. Dr Richardson
mentions it as having been observed by the Expedition in the 50th
parallel, and as a constant resident at Hudson’s Bay. It is indeed the
hardiest bird of its tribe yet discovered in North America, where even
the Rose-breasted Grosbeak, though found during summer in
Newfoundland and Labrador, removes in autumn to countries farther
south than the Texas, where as late as the middle of May I saw
many in their richest plumage.
The Pine Grosbeak is a charming songster. Well do I remember how
delighted I felt, while lying on the moss-clad rocks of Newfoundland,
near St George’s Bay, I listened to its continuous lay, so late as the
middle of August, particularly about sunset. I was reminded of the
pleasure I had formerly enjoyed on the banks of the clear Mohawk,
under nearly similar circumstances, when lending an attentive ear to
the mellow notes of another Grosbeak. But, Reader, at
Newfoundland I was still farther removed from my beloved family;
the scenery around was thrice wilder and more magnificent. The
stupendous dark granite rocks, fronting the north, as if bidding
defiance to the wintry tempests, brought a chillness to my heart, as I
thought of the hardships endured by those intrepid travellers who, for
the advancement of science, had braved the horrors of the polar
winter. The glowing tints of the western sky, and the brightening stars
twinkling over the waters of the great Gulf, rivetted me to the spot,
and the longer I gazed, the more I wished to remain; but darkness
was suddenly produced by the advance of a mass of damp fog, the
bird ceased its song, and all around seemed transformed into chaos.
Silently I groped my way to the beach, and soon reached the Ripley.
The young gentlemen of my party, accompanied by my son John
Woodhouse, and a Newfoundland Indian, had gone into the interior
in search of Rein Deer, but returned the following afternoon, having
found the flies and musquitoes intolerable. My son brought a number
of Pine Grosbeaks, of different sexes, young and adult, but all the
latter in moult, and patched with dark red, ash, black and white. It
was curious to see how covered with sores the legs of the old birds
of both sexes were. These sores or excrescences are, I believe,
produced by the resinous matter of the fir-trees on which they obtain
their food. Some specimens had the hinder part of the tarsi more
than double the usual size, the excrescences could not be removed
by the hand, and I was surprised that the birds had not found means
of ridding themselves of such an inconvenience. One of the figures
in my plate represents the form of these sores.
I was assured that during mild winters, the Pine Grosbeak is found in
the forests of Newfoundland in considerable numbers, and that some
remain during the most severe cold. A lady who had resided there
many years, and who was fond of birds, assured me that she had
kept several males in cages; that they soon became familiar, would
sing during the night, and fed on all sorts of fruits and berries during
the summer, and on seeds of various kinds in winter; that they were
fond of bathing, but liable to cramps; and that they died of sores
produced around their eyes and the base of the upper mandible. I
have observed the same to happen to the Cardinal and Rose-
breasted Grosbeaks.
The flight of this bird is undulating and smooth, performed in a direct
line when it is migrating, at a considerable height above the forests,
and in groups of from five to ten individuals. They alight frequently
during the day, on such trees as are opening their buds or blossoms.
At such times they are extremely gentle, and easily approached, are
extremely fond of bathing, and whether on the ground or on
branches, move by short leaps. I have been much surprised to see,
on my having fired, those that were untouched, fly directly towards
me, until within a few feet, and then slide off and alight on the lower
branches of the nearest tree, where, standing as erect as little
Hawks, they gazed upon me as if I were an object quite new, and of
whose nature they were ignorant. They are easily caught under
snow-shoes put up with a figure of four, around the wood-cutters
camps, in the State of Maine, and are said to afford good eating.
Their food consists of the buds and seeds of almost all sorts of trees.
Occasionally also they seize a passing insect. I once knew one of
these sweet songsters, which, in the evening, as soon as the lamp
was lighted in the room where its cage was hung, would instantly
tune its voice anew.
My kind friend Thomas M’Culloch of Pictou in Nova Scotia, has
sent me the following notice, which I trust will prove as interesting to
you as it has been to me. “Last winter the snow was exceedingly
deep, and the storms so frequent and violent that many birds must
have perished in consequence of the scarcity of food. The Pine
Grosbeaks being driven from the woods, collected about the barns in
great numbers, and even in the streets of Pictou they frequently
alighted in search of food. A pair of these birds which had been
recently taken were brought me by a friend, but they were in such a
poor emaciated condition, that I almost despaired of being able to
preserve them alive. Being anxious, however, to note for you the
changes of their plumage, I determined to make the attempt; but
notwithstanding all my care, they died a few days after they came
into my possession. Shortly after, I received a male in splendid
plumage, but so emaciated that he seemed little else than a mass of
feathers. By more cautious feeding, however, he soon regained his
flesh, and became so tame as to eat from my hand without the least
appearance of fear. To reconcile him gradually to confinement, he
was permitted to fly about my bedroom, and upon rising in the
morning, the first thing I did was to give him a small quantity of seed.
But three mornings in succession I happened to lie rather later than
usual, and each morning I was aroused by the bird fluttering upon
my shoulder, and calling for his usual allowance. The third morning, I
allowed him to flutter about me some time before shewing any
symptom of being awake, but he no sooner observed that his object
was effected than he retired to the window and waited patiently until I
arose. As the spring approached, he used to whistle occasionally in
the morning, and his notes, like those of his relative the Rose-
breasted Grosbeak, were exceedingly rich and full. About the time,
however, when the species began to remove to the north, his former
familiarity entirely disappeared. During the day he never rested a
moment, but continued to run from one side of the window to the
other, seeking a way of escape, and frequently during the night,
when the moonlight would fall upon the window, I was awakened by
him dashing against the glass. The desire of liberty seemed at last to
absorb every other feeling, and during four days I could not detect
the least diminution in the quantity of his food, while at the same time
he filled the house with a piteous wailing cry, which no person could
hear without feeling for the poor captive. Unable to resist his
appeals, I gave him his release; but when this was attained he
seemed very careless of availing himself of it. Having perched upon
the top of a tree in front of the house, he arranged his feathers, and
looked about him for a short time. He then alighted by the door, and I
was at last obliged to drive him away, lest some accident should
befall him.
“These birds are subject to a curious disease, which I have never
seen in any other. Irregularly shaped whitish masses are formed
upon the legs and feet. To the eye these lumps appear not unlike
pieces of lime; but when broken, the interior presents a congeries of
minute cells, as regularly and beautifully formed as those of a honey-
comb. Sometimes, though rarely, I have seen the whole of the legs
and feet covered with this substance, and when the crust was
broken, the bone was bare, and the sinews seemed almost
altogether to have lost the power of moving the feet. An
acquaintance of mine kept one of these birds during the summer
months. It became quite tame, but at last it lost the power of its legs
and died. By this person I was informed that his Grosbeak usually
sang during a thunder-storm, or when rain was falling on the house.”
While in the State of Maine, I observed that these birds, when
travelling, fly in silence, and at a considerable height above the
trees. They alight on the topmost branches, so that it is difficult to
obtain them, unless one has a remarkably good gun. But, on waiting
a few minutes, you see the flock, usually composed of seven or eight
individuals, descend from branch to branch, and betake themselves
to the ground, where they pick up gravel, hop towards the nearest
pool or streamlet, and bathe by dipping their heads and scattering
the water over them, until they are quite wet; after which they fly to
the branches of low bushes, shake themselves with so much vigour
as to produce a smart rustling sound, and arrange their plumage.
They then search for food among the boughs of the taller trees.
 Loxia Enucleator, Linn. Syst. Nat. vol. i. p. 299.—Lath. Ind. Ornith. vol. i. p.
372.
Pine Grosbeak, Loxia Enucleator, Wils. Amer. Ornith. vol. i. p. 80, pl. 5, fig.
2.
Pyrrhula Enucleator, Ch. Bonaparte, Synopsis of Birds of United States,
p. 119.
Pyrrhula (Corythus) Enucleator, Richards. and Swains. Fauna Bor.-
Amer. vol. ii. p. 262.
Pine Grosbeak or Bullfinch, Nuttall, Manual, vol. i. p. 535.

Adult Male. Plate CCCLVIII. Fig. 1.

Bill short, robust, bulging at the base, conical, acute; upper mandible
with its dorsal outline convex, the sides convex, the edges sharp and
overlapping; lower mandible with the angle short and very broad, the
dorsal line ascending and slightly convex, the sides rounded, the
edges inflected; the acute decurved tip of the upper mandible
extending considerably beyond that of the lower; the gape-line
deflected at the base.
Head rather large, ovate, flattened above; neck short; body full. Legs
short, of moderate strength; tarsus short, compressed, with six
anterior scutella, and two plates behind, forming a thin edge; toes
short, the first proportionally stout, the third much longer than the two
lateral, which are about equal; their scutella large, their lower surface
with large pads covered with prominent papillæ. Claws rather long,
arched, much compressed, laterally grooved, and acute.
Plumage soft, full, rather blended, the feathers oblong. At the base of
the upper mandible are strong bristly feathers directed forwards. The
wings of moderate length; the primaries rounded, the second and
third longest, and with the fourth and fifth having their outer webs
slightly cut out. Tail rather long, emarginate, of twelve strong, broad,
obliquely rounded feathers.
Bill reddish-brown. Iris hazel. Feet blackish-brown, claws black. The
general colour of the plumage is bright carmine tinged with vermilion;
the feathers of the fore part of the back and the scapulars greyish-
brown in the centre; the bristly feathers at the base of the bill
blackish-brown; the middle of the breast, abdomen, and lower tail-
coverts, light grey, the latter with a central dusky streak. Wings
blackish-brown; the primaries and their coverts narrowly edged with
reddish-white, the secondaries more broadly with white; the
secondary coverts and first row of small coverts tipped with reddish-
white, the smaller coverts edged with red.
Length to end of tail 8 1/2 inches, to end of wings 6 1/4, to end of
claws 6 3/4; extent of wings 14; wing from flexure 4 3/4; tail 4; bill
along the ridge 7 1/2/12, along the edge of lower mandible 7/12; tarsus
9 1/2/ ; first toe 4 1/2/12, its claw 5/12; middle toe 8/12, its claw 5/12.
12

Female. Plate CCCLVIII. Fig. 2.

The female is scarcely inferior to the male in size. The bill is dusky,
the feet as in the male. The upper part of the head and hind neck are
yellowish-brown, each feather with a central dusky streak; the rump
brownish-yellow; the rest of the upper parts light brownish-grey.
Wings and tail as in the male, the white edgings and the tips tinged
with grey; the cheeks and throat greyish-white or yellowish; the fore
part and sides of the neck, the breast, sides, and abdomen ash-grey,
as are the lower tail-coverts.

Length to end of tail 8 1/4 inches, to end of wings 6 1/4, to end of

claws 6 3/4; extent of wings 13 1/2; wing from flexure 4 1/2; tail 3 10/12;
tarsus 9 1/2/12; middle toe and claw 1 1/12.
Young fully fledged. Plate CCCLVIII. Fig. 3.
The young, when in full plumage, resemble the female, but are more
tinged with brown.

Fig. 1.

Fig. 2.

An adult male from Boston examined. The roof of the mouth is

moderately concave, its anterior horny part with five prominent
ridges; the lower mandible deeply concave. Tongue 4 1/2 twelfths
long, firm, deflected at the middle, deeper than broad, papillate at the
base, with a median groove; for the distal half of its length, it is cased
with a firm horny substance, and is then of an oblong shape, when
viewed from above, deeply concave, with two flattened prominences
at the base, the point rounded and thin, the back or lower surface
convex. This remarkable structure of the tongue appears to be
intended for the purpose of enabling the bird, when it has insinuated
its bill between the scales of a strobilus, to lay hold of the seed by
pressing it against the roof of the mandible. In the Crossbills, the
tongue is nearly of the same form, but more slender, and these birds
feed in the same manner, in so far as regards the prehension of the
food. In the present species, the tongue is much strengthened by the
peculiar form of the basi-hyoid bone, to which there is appended as it
were above a thin longitudinal crest, giving it great firmness in the
perpendicular movements of the organ. The œsophagus a b c d, Fig.
1. is two inches 11 twelfths long, dilated on the middle of the neck so
as to form a kind of elongated dimidiate crop, 4 twelfths of an inch in
diameter, projecting to the right side, and with the trachea passing
along that side of the vertebræ. The proventriculus c, is 8 twelfths
long, somewhat bulbiform, with numerous oblong glandules, its
greatest diameter 4 1/2 twelfths. A very curious peculiarity of the
stomach e, is, that in place of having its axis continuous with that of
the œsophagus or proventriculus, it bends to the right nearly at a
right angle. It is a very powerful gizzard, 8 1/2 twelfths long, 8 twelfths
broad, with its lateral muscles 1/4 inch thick, the lower very distinct,
the epithelium longitudinally rugous, of a light reddish colour. The
duodenum, f, g, first curves backward to the length of 1 1/4 inch, then
folds in the usual manner, passing behind the right lobe of the liver;
the intestine then passes upwards and to the left, curves along the
left side, crosses to the right, forms about ten circumvolutions, and
above the stomach terminates in the rectum, which is 11 twelfths
long. The cœca are 1 1/4 twelfth in length and 1/4 twelfth in diameter.
The entire length of the intestine from the pylorus to the anus is
31 1/2 inches (in another male 31); its greatest breadth in the
duodenum 2 1/2 twelfths, gradually contracting to 1 1/4 twelfth. Fig. 2.
represents the convoluted appearance of the intestine. The
œsophagus a b c; the gizzard d, turned forwards; the duodenum, e f;
the rest of the intestine, g h the cœca, i; the rectum, i j, which is
much dilated at the end.

The trachea is 2 inches 2 twelfths long, of uniform diameter. 1 1/2

twelfth broad, with about 60 rings; its muscles like those of all the
other species of the Passerinæ or Fringillidæ.
In a female, the œsophagus is 2 inches 10 twelfths long; the
intestine 31 inches long.
In all these individuals and several others, the stomach contained a
great quantity of particles of white quartz, with remains of seeds; and
in the œsophagus of one was an oat seed entire.
Although this bird is in its habits very similar to the Crossbills, and
feeds on the same sort of food, it differs from them in the form and
extent of its crop, in having the gizzard much larger, and the
intestines more than double the length, in proportion to the size of
the bird.
 ARKANSAW FLYCATCHER.

Muscicapa verticalis, Bonap.

PLATE CCCLIX. Male and Female.

This species extends its range from the mouth of the Columbia
River, across our continent, to the shores of the Gulf of Mexico; but
how far north it may proceed is as yet unknown. On the 10th of April
1837, whilst on Cayo Island, in the Bay of Mexico, I found a
specimen of this bird dead at the door of a deserted house, which
had recently been occupied by some salt-makers. From its freshness
I supposed that it had sought refuge in the house on the preceding
evening, which had been very cold for the season. Birds of several
other species we also found dead on the beaches. The individual
thus met with was emaciated, probably in consequence of a long
journey and scanty fare; but I was not the less pleased with it, as it
afforded me the means of taking measurements of a species not
previously described in full. In my possession are some remarkably
fine skins, from Dr Townsend’s collection, which differ considerably
from the figure given by Bonaparte, who first described the species.
So nearly allied is it to the Green-crested Flycatcher, M. crinita, that
after finding the dead bird, my son and I, seeing many individuals of
that species on the trees about the house mentioned, shot several of
them, supposing them, to be the same. We are indebted to the
lamented Thomas Say for the introduction of the Arkansaw
Flycatcher into our Fauna. Mr Nuttall has supplied me with an
account of its manners.
“We first met with this bold and querulous species, early in July, in
the scanty woods which border the north-west branch of the Platte,
within the range of the Rocky Mountains; and from thence we saw
them to the forests of the Columbia and the Wahlamet, as well as in
all parts of Upper California, to latitude 32°. They are remarkably
noisy and quarrelsome with each other, and in the time of incubation,
like the King Bird, suffer nothing of the bird kind to approach them
without exhibiting their predilection for battle and dispute. About the
middle of June, in the dark swamped forests of the Wahlamet, we
every day heard the discordant clicking warble of this bird, somewhat
like tsh’k, tsh’k, tshivait, sounding almost like the creaking of a rusty
door-hinge, somewhat in the manner of the King Bird, with a
blending of the notes of the Blackbird or Common Grakle. Although I
saw these birds residing in the woods of the Columbia, and near the
St Diego in Upper California, I have not been able to find the nest,
which is probably made in low thickets, where it would be
consequently easily overlooked. In the Rocky Mountains they do not
probably breed before midsummer, as they are still together in noisy
quarrelsome bands until the middle of June.”
Dr Townsend’s notice respecting it is as follows: “This is the Chlow-
ish-pil of the Chinooks. It is numerous along the banks of the Platte,
particularly in the vicinity of trees and bushes. It is found also, though
not so abundantly, across the whole range of the Rocky Mountains;
and among the banks of the Columbia to the ocean, it is a very
common species. Its voice is much more musical than is usual with
birds of its genus, and its motions are remarkably quick and graceful.
Its flight is often long sustained, and like the Common King Bird, with
which it associates, it is frequently seen to rest in the air, maintaining
its position for a considerable time. The males are wonderfully
belligerent, fighting almost constantly, and with great fury, and their
loud notes of anger and defiance remind one strongly of the
discordant grating and creaking of a rusty door hinge. The Indians of
the Columbia accuse him of a propensity to destroy the young, and
eat the eggs of other birds.”

Tyrannus verticalis, Say, Long’s Exped. vol. ii. p. 60.

Musicapa verticalis, Ch. Bonaparte, Synopsis of Birds of United States, p.
67.
Arkansaw Flycatcher, Musicapa verticalis, Ch. Bonaparte, Amer. Ornith.
vol. i. p. 18, pl. 2, fig. 2.
Arkansaw Flycatcher, Nuttall, Manual, vol. ii. p. 273.

Adult Male. Plate CCCLIX. Fig. 1.

Bill rather long, stout, tapering, broader than high, unless toward the
end. Upper mandible with its dorsal outline straight and declinate,
until at the tip, where it is deflected, the ridge narrow, the sides
convex, the edges sharp, with a slight notch close to the very narrow
tip. Lower mandible with the angle short and broad, the dorsal line
ascending and very slightly convex, the ridge broad and flat at the
base, the sides convex, the edges sharp, the tip acute. The gape-
line almost straight. Nostrils basal, elliptical, partly covered by the
bristly feathers.
Head rather large; neck short; body slender. Feet very short; tarsus
slender, compressed, with six anterior scutella, which are so large
below as almost to meet behind; toes free, slender, of moderate
length. Claws moderately arched, much compressed, acute.
Plumage soft and blended. Strong bristles along the basal margin of
the upper mandible, and over the nostrils. Wings rather long, broad;
the first five primaries much attenuated toward the end, the first more
so, the fifth least; this attenuation being chiefly produced by an
incision on the first web; the first four are nearly equal, the third
longest, the fourth half a twelfth shorter, the third one-twelfth shorter
than the hind, and exceeding the first by nearly two-twelfths; the
other primaries gradually broader and more rounded; outer
secondaries abrupt and slightly emarginate. Tail rather long, almost
even, of twelve broad, abruptly rounded and acuminate feathers.
Bill black. Iris brown. Feet and claws black. The general colour of the
upper parts is ash-grey, the back tinged with yellow; the wing-coverts
and quills chocolate-brown, with brownish-white edges, those of the
inner secondaries broader. Upper tail-coverts and tail black,
excepting the outer web of the lateral feather on each side, and the
basal margin of the next. There is a patch of bright vermilion on the
top of the head, tinged with orange-yellow behind. Throat greyish-
white, the sides and fore part of the neck pale ash-grey, shaded on
the fore part of the breast into pure yellow, which is the prevalent
colour of the lower parts; lower wing-coverts yellow, the middle ones
tinged with grey.
Length to end of tail 9 inches, to end of wings 7, to end of claws 7,
extent of wings 15 1/4; tail 3 7/8; wing from flexure 5 1/2; bill along the
1/2
ridge 9/12, along the edge of lower mandible 1 1/12; tarsus 8 /12; first
toe 3 1/2/12, its claw 4 1/2/12; third toe 7/12, its claw 4/12.

Adult Female. Plate CCCLIX. Fig. 2.

The Female is rather smaller, but is similar to the male in colouring.
The young also is similar to the adult, but wants the red patch on the
head.
In the female mentioned above as having been found in Texas, the
mouth is half an inch wide, its roof anteriorly slightly concave, with
three median prominent lines, the palate flat, with its membrane or
skin diaphanous, as in Goatsuckers. The tongue is 7 twelfths long,
deeply emarginate and papillate at the base; triangular, extremely
depressed, tapering to a thin slit and bristly point. The posterior
aperture of the nares is 4 twelfths long, linear, papillate on the edges,
ending abruptly at its fore part, without a prolonged fissure.
Œsophagus, a, a, b, 2 inches 9 twelfths long, funnel-shaped for half
an inch, then cylindrical and nearly 4 twelfths in diameter, until it
enters the thorax. Proventriculus, c, 3 1/2 twelfths in diameter, and
with a belt of oblong glandules. Stomach c, d, elliptical, 7 1/2 twelfths
long, 6 twelfths broad, its lateral muscles of moderate strength, the
lower not distinct; the epithelium with broad longitudinal rugæ, and of
a dark reddish-brown colour. Intestine, e, f, g, 7 inches long, its
diameter at the anterior part 3 1/2 twelfths, gradually diminishing to
1 1/2 twelfth. Cœca extremely small, 1 twelfth long, 1/2 twelfth broad,
and 1 1/4 inch distant from the anus; cloaca i, globular.

Trachea 1 inch 10 twelfths long, tapering from a diameter of 2

twelfths to 1 twelfth; the rings ossified and firm, about 70 in number;
the lateral and sterno-tracheal muscles slender; the inferior laryngeal
muscles are strong but very short, forming a prominent knob, and
attached to the first bronchial ring. Bronchi wide, of about 20 half-
rings.
The digestive organs of this bird, and of the Flycatchers in general,
do not differ materially from those of the Thrushes and Warblers. The
pharynx and œsophagus, however, are much wider.
 SWALLOW-TAILED FLYCATCHER.

Muscicapa forficata, Gmel.

PLATE CCCLIX. Male.

Not having seen this handsome bird alive, I am unable to give you
any account of its habits from my own observation; but I have
pleasure in supplying the deficiency by extracting the following notice
from the “Manual of the Ornithology of the United States and of
Canada,” by my excellent friend Thomas Nuttall.
“This very beautiful and singular species of Flycatcher is confined
wholly to the open plains and scanty forests of the remote south-
western regions beyond the Mississippi, where they, in all probability,
extend their residence to the high plains of Mexico. I found these
birds rather common near the banks of Red River, about the
confluence of the Kiamesha. I again saw them more abundant, near
the Great Salt River of the Arkansa in the month of August, when the
young and old appeared, like our King Birds, assembling together
previously to their departure for the south. They alighted repeatedly
on the tall plants of the prairie, and were probably preying upon the
grasshoppers, which were now abundant. At this time also, they
were wholly silent, and flitted before our path with suspicion and
timidity. A week or two after, we saw them no more, having retired
probably to tropical winter-quarters.
“In the month of May, a pair, which I daily saw for three or four
weeks, had made a nest on the horizontal branch of an elm,
probably twelve or more feet from the ground. I did not examine it
very near, but it appeared externally composed of coarse dry grass.
The female, when first seen, was engaged in sitting, and her mate
wildly attacked every bird which approached their residence. The
harsh chirping note of the male, kept up at intervals, as remarked by
Mr Say, almost resembled the barking of the Prairie Marmot, ’tsh,
’tsh, ’tsh. His flowing kite-like tail, spread or contracted at will while
flying, is a singular trait in his plumage, and rendered him
conspicuously beautiful to the most careless observer.”

Muscicapa forficata Gmel. Linn. Syst. Nat. vol. i. p. 931.—Lath. Ind. Ornith.
vol. ii. p. 485.—Ch. Bonaparte, Synopsis of Birds of United States, p. 275.
Swallow-tailed Flycatcher, Muscicapa forficata, Bonap. Amer. Ornith.
vol. i. p. 15, pl. 2, fig. 1.
Swallow-tailed Flycatcher, Nuttall, Manual, vol. i. p. 275.

Adult Male. Plate CCCLIX. Fig. 3.

Bill of moderate length, rather stout, subtrigonal, depressed at the
base, straight; upper mandible with its dorsal outline nearly straight,
and declinate, to near the tip, which is deflected, slender,
compressed, and acute, the edges sharp and overlapping, with a
slight notch close to the tip; lower mandible with the angle rather
long and wide, the back broad at the base, the dorsal line ascending
and very slightly convex, the edges sharp, the tip acute. Nostrils
basal, roundish, partly covered by the bristly feathers.
Head rather large; neck short; body ovate. Feet short; tarsus with six
anterior very broad scutella. Toes free, slender; the first stout, the
lateral equal; claws rather long, arched, slender, much compressed,
very acute.
Plumage soft and blended. Bristles at the base of the upper
mandible strong. Wings rather long, the first four quills longest, with
their inner webs emarginate and attenuate at the end. Tail very long,
deeply forked, of twelve broad, rounded feathers.
Bill and feet black. Iris hazel. Upper part of the head, the cheeks,
and the hind part and sides of the neck, ash-grey; scapulars and
back darker and tinged with reddish-brown; the rump darker, the
upper tail-coverts black. Wings brownish black, all the feathers
margined with greyish-white, the anterior wing-coverts scarlet; tail-
feathers deep black, with their terminal margins white, the three
outer on each side pale rose-coloured to near the end. The throat,
fore part of neck and breast, pure white; the sides, abdomen, and
lower tail-coverts, and lower wing-coverts, pale rose-colour; the
axillary feathers bright scarlet.
Length to end of tail 11 1/2 inches, to end of wings 7 1/2; tail to the
fork 2 2/12, to the end 5 1/2; wing from flexure 5 1/8; bill along the
ridge 5/8, along the edge of lower mandible 7/8; tarsus 3/4; hind toe
3/ , 1/ 1/
8 its claw 4/12; middle toe 5 /12, its claw 3
2 /12.
2