SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                  SCHEDULE 13D
                                 (Rule 13d-101)

           INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO
           13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO 13d-2(a)

                               (Amendment No. 13)

                          CAPSTEAD MORTGAGE CORPORATION
             -------------------------------------------------------
                                (Name of Issuer)

                     COMMON STOCK, PAR VALUE $0.01 PER SHARE
           -----------------------------------------------------------
                         (Title of Class of Securities)

                                   14067E 40 7
        ----------------------------------------------------------------
                                 (CUSIP Number)

                                Randal A. Nardone
                      Chief Operating Officer and Secretary
                      Fortress Registered Investment Trust
                         sole member of Fortress CAP LLC
                           1251 Avenue of the Americas
                            New York, New York 10020
                                 (212) 798-6100
        -----------------------------------------------------------------
                  (Name, Address and Telephone Number of Person
                Authorized to Receive Notices and Communications)

                                    Copy to:

                                J. Gregory Milmoe
                         Skadden, Arps, Slate, Meagher &
                                    Flom LLP
                                Four Times Square
                          New York, New York 10036-6522
                                 (212) 735-3000

                                   May 7, 2003
        -----------------------------------------------------------------
             (Date of Event Which Requires Filing of This Statement)

         If the filing person has previously filed a statement on Schedule 13G
to report the acquisition which is the subject of this Schedule 13D, and is
filing this schedule because of Rule 13d-1(e), 13d(f) or 13d-1(g), check the
following box |_|.

                                                            (Page 1 of 13 Pages)




CUSIP No. 14067E 40 7                13D                    Page 2 of 13 Pages
-------------------------------------------------------------------------------
1        NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)
          Fortress CAP LLC
-------------------------------------------------------------------------------
2        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP     (a) |_|
         Not applicable                                       (b) |_|
-------------------------------------------------------------------------------
3        SEC USE ONLY
-------------------------------------------------------------------------------
4        SOURCE OF FUNDS
         Not applicable
-------------------------------------------------------------------------------
5        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
           PURSUANT TO ITEM 2(d) or 2(e)                          |_|
-------------------------------------------------------------------------------
6        CITIZENSHIP OR PLACE OF ORGANIZATION
         Delaware
-------------------------------------------------------------------------------
  NUMBER OF SHARES       7     SOLE VOTING POWER           - 0 -
BENEFICIALLY OWNED       ------------------------------------------------------
           BY EACH
  REPORTING PERSON       8     SHARED VOTING POWER         - 2,294,659 -
              WITH       ------------------------------------------------------

                         9     SOLE DISPOSITIVE POWER      - 0 -
                         ------------------------------------------------------

                         10    SHARED DISPOSITIVE POWER    - 2,294,659-
                         ------------------------------------------------------

11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         - 2,294,659 -
-------------------------------------------------------------------------------
12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES
                                                                         |_|
-------------------------------------------------------------------------------
13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
         16.4% (based on 14,007,752 shares of Common Stock outstanding as of
         April 30, 2003)
-------------------------------------------------------------------------------
14       TYPE OF REPORTING PERSON
         CO
-------------------------------------------------------------------------------




CUSIP No. 14067E 40 7                13D                    Page 3 of 13 Pages

-------------------------------------------------------------------------------
1        NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)
         Fortress Registered Investment Trust
-------------------------------------------------------------------------------
2        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP     (a) |_|
         Not applicable                                       (b) |_|
-------------------------------------------------------------------------------
3        SEC USE ONLY
-------------------------------------------------------------------------------
4        SOURCE OF FUNDS
         WC
-------------------------------------------------------------------------------
5        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
            PURSUANT TO ITEM 2(d) or 2(e)                         |_|
-------------------------------------------------------------------------------
6        CITIZENSHIP OR PLACE OF ORGANIZATION
         Delaware
-------------------------------------------------------------------------------
      NUMBER OF       7  SOLE VOTING POWER           - 0 -
         SHARES          ------------------------------------------------------
   BENEFICIALLY       8  SHARED VOTING POWER         - 2,294,659 -
       OWNED BY
           EACH          ------------------------------------------------------
      REPORTING       9  SOLE DISPOSITIVE POWER      - 0 -
    PERSON WITH          ------------------------------------------------------
                     10  SHARED DISPOSITIVE POWER    - 2,294,659 -
-------------------------------------------------------------------------------
11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         - 2,294,659 -
-------------------------------------------------------------------------------
12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES
                                                        |_|
-------------------------------------------------------------------------------
13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
         16.4% (based on 14,007,752 shares of Common Stock outstanding as of
         April 30, 2003)
-------------------------------------------------------------------------------
  14     TYPE OF REPORTING PERSON
         CO
-------------------------------------------------------------------------------




CUSIP No. 14067E 40 7                13D                    Page 4 of 13 Pages
-------------------------------------------------------------------------------
1        NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)
         Fortress Investment Fund LLC
-------------------------------------------------------------------------------
2        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP              (a)  |_|
         Not applicable                                                (b)  |_|
-------------------------------------------------------------------------------
3        SEC USE ONLY
-------------------------------------------------------------------------------
4        SOURCE OF FUNDS
         Not applicable
-------------------------------------------------------------------------------
5        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
              PURSUANT TO ITEM 2(d) or 2(e)                 |_|
-------------------------------------------------------------------------------
6        CITIZENSHIP OR PLACE OF ORGANIZATION
         Delaware
-------------------------------------------------------------------------------
      NUMBER OF           7       SOLE VOTING POWER            - 0 -
        SHARES
   BENEFICIALLY          ------------------------------------------------------
      OWNED BY            8       SHARED VOTING POWER          - 2,294,659 -
          EACH
      REPORTING          ------------------------------------------------------
    PERSON WITH           9       SOLE DISPOSITIVE POWER       - 0 -

                         ------------------------------------------------------
                         10      SHARED DISPOSITIVE POWER     - 2,294,659 -

-------------------------------------------------------------------------------
11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         - 2,294,659 -
-------------------------------------------------------------------------------
12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11)
              EXCLUDES CERTAIN SHARES                              |_|
-------------------------------------------------------------------------------
13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
         16.4% (based on 14,007,752 shares of Common Stock outstanding as of
         April 30, 2003)
-------------------------------------------------------------------------------
14       TYPE OF REPORTING PERSON
         CO
-------------------------------------------------------------------------------




CUSIP No. 14067E 40 7                13D                    Page 5 of 13 Pages
-------------------------------------------------------------------------------
1        NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)
         Fortress Investment Group LLC
-------------------------------------------------------------------------------
2        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP     (a)  |_|
         Not applicable                                       (b)  |_|
-------------------------------------------------------------------------------
3        SEC USE ONLY
-------------------------------------------------------------------------------
4        SOURCE OF FUNDS
         Not applicable
-------------------------------------------------------------------------------
5        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
              PURSUANT TO ITEM 2(d) or 2(e)                        |_|
-------------------------------------------------------------------------------
6        CITIZENSHIP OR PLACE OF ORGANIZATION
         Delaware
-------------------------------------------------------------------------------
      NUMBER OF           7       SOLE VOTING POWER            - 0 -
         SHARES
   BENEFICIALLY          ------------------------------------------------------
       OWNED BY           8       SHARED VOTING POWER          - 2,294,659 -
           EACH
       REPORTING         ------------------------------------------------------
    PERSON WITH           9       SOLE DISPOSITIVE POWER       - 0 -

                         ------------------------------------------------------
                         10      SHARED DISPOSITIVE POWER     - 2,294,659 -
-------------------------------------------------------------------------------
11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         - 2,294,659 -
-------------------------------------------------------------------------------
12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES
                                                      |_|
-------------------------------------------------------------------------------
13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
         16.4% (based on 14,007,752 shares of Common Stock outstanding as of
         April 30, 2003)
-------------------------------------------------------------------------------
14       TYPE OF REPORTING PERSON
         CO
-------------------------------------------------------------------------------




CUSIP No. 14067E 40 7                13D                    Page 6 of 13 Pages
-------------------------------------------------------------------------------
1        NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)
         Fortress Principal Investment Holdings LLC
-------------------------------------------------------------------------------
2        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP     (a)  |_|
         Not applicable                                       (b)  |_|
-------------------------------------------------------------------------------
3        SEC USE ONLY
-------------------------------------------------------------------------------
4        SOURCE OF FUNDS
         Not applicable
-------------------------------------------------------------------------------
5        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
              PURSUANT TO ITEM 2(d) or 2(e)                        |_|
-------------------------------------------------------------------------------
6        CITIZENSHIP OR PLACE OF ORGANIZATION
         Delaware
-------------------------------------------------------------------------------
      NUMBER OF           7       SOLE VOTING POWER           - 0 -
        SHARES
   BENEFICIALLY          ------------------------------------------------------
       OWNED BY           8       SHARED VOTING POWER         - 2,294,659 -
           EACH
      REPORTING          ------------------------------------------------------
    PERSON WITH           9       SOLE DISPOSITIVE POWER      - 0 -

                         ------------------------------------------------------
                         10      SHARED DISPOSITIVE POWER    - 2,294,659 -
-------------------------------------------------------------------------------
11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         - 2,294,659 -
-------------------------------------------------------------------------------
12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES
         |_|
-------------------------------------------------------------------------------
13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
         16.4% (based on 14,007,752 shares of Common Stock outstanding as of
         April 30, 2003)
-------------------------------------------------------------------------------
14       TYPE OF REPORTING PERSON
         CO
-------------------------------------------------------------------------------


         This Amendment No. 13 (this "Amendment") to the Statement on Schedule
13D dated January 21, 2000, as amended by Amendment No. 1 thereto dated February
22, 2000, Amendment No. 2 thereto dated July 12, 2000, Amendment No. 3 thereto
dated September 8, 2000, Amendment No. 4 thereto dated October 31, 2000,
Amendment No. 5 thereto dated December 28, 2000, Amendment No. 6 thereto dated
November 29, 2001, Amendment No. 7 thereto dated February 28, 2003, Amendment
No. 8 thereto dated March 19, 2003, Amendment No. 9 thereto dated March 21,
2003, Amendment No. 10 thereto dated March 23, 2003, Amendment No. 11 thereto
dated March 25, 2003 and Amendment No. 12 thereto dated March 25, 2003 (as so
amended, the "Schedule 13D") filed by Fortress CAP LLC, a Delaware limited
liability company ("Fortress CAP"), Fortress Registered Investment Trust, a
Delaware business trust ("Fortress Trust"), Fortress Investment Fund LLC, a
Delaware limited liability company ("Fortress Fund"), Fortress Investment Group
LLC, a Delaware limited liability company ("Fortress Group"), and Fortress
Principal Investment Holdings LLC, a Delaware limited liability company
("FPIH"), relates to the common stock, par value $0.01 per share (the "Common
Stock"), of Capstead Mortgage Corporation, a Maryland corporation ("Capstead").
This Amendment is filed jointly by Fortress CAP, Fortress Trust, Fortress Fund,
Fortress Group and FPIH (collectively, the "Reporting Persons"). All capitalized
terms used but not defined herein have the meanings ascribed to them in the
Schedule 13D.


Item 4.

         Item 4 of the Schedule 13D is hereby amended and replaced with the
following:

         The Reporting Persons expect that, under current market conditions for
Capstead Common Stock, they will continue, from time to time, to make additional
dispositions of Common Stock. The Reporting Persons specifically reserve the
right to change their intentions with respect to such matters, including as a
result of changes in the market price of the securities of Capstead, and may in
the future determine to (i) acquire additional securities of Capstead, through
open market purchases, private agreements or otherwise, (ii) take any other
available course of action, which could involve one or more of the types of
transactions or have one or more of the results described in the last paragraph
of this Item 4 or (iii) otherwise change their investment intent.

         Other than as described herein, none of the Reporting Persons has any
present plans or proposals which relate to or would result in: (a) the
acquisition by any person of additional securities of Capstead; (b) an
extraordinary corporate transaction, such as a merger, reorganization or
liquidation, involving Capstead or any of its subsidiaries; (c) a sale or
transfer of a material amount of assets of Capstead or any of its subsidiaries;
(d) any change in the Board of Directors or management of Capstead, including
any plans or proposals to change the number or terms of directors or to fill any
existing vacancies on the Board of Directors of Capstead; (e) any material
change in the present capitalization or dividend policy of Capstead; (f) any
other material change in Capstead's business or




corporate structure; (g) changes in Capstead's articles of incorporation,
by-laws or instruments corresponding thereto or other actions which may impede
the acquisition of control of Capstead by any person; (h) a class of securities
of Capstead being delisted from a national securities exchange or ceasing to be
authorized to be quoted in an inter-dealer quotation system of a registered
national securities association; (i) a class of equity securities of Capstead
becoming eligible for termination of registration pursuant to Section 12(g)(4)
of the Securities Exchange Act of 1934, as amended; or (j) any action similar
to those enumerated above.

Item 5.

         Item 5 of the Schedule 13D is hereby amended and supplemented to add
the following:

                  On May 7, 2003, in a privately negotiated block transaction,
         Fortress CAP sold 25,500 shares of Common Stock at $11.5356 per share,
         yielding aggregate net proceeds of $294,157.80. After these sales,
         Fortress CAP was the direct beneficial owner of 2,294,659 shares of
         Common Stock, which represents approximately 16.4% of the outstanding
         Common Stock.





                                   SIGNATURE


         After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.


                                      May 8, 2003


                                      FORTRESS CAP LLC


                                      By: /s/ Randal A. Nardone
                                          ---------------------------------
                                      Randal A. Nardone, as
                                      Chief Operating Officer and Secretary of
                                      Fortress Registered Investment Trust,
                                      sole member of Fortress CAP LLC





                                   SIGNATURE


         After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.


                                    May 8, 2003


                                    FORTRESS REGISTERED
                                    INVESTMENT TRUST


                                    By: /s/ Randal A. Nardone
                                        -----------------------------------
                                    Randal A. Nardone, as
                                    Chief Operating Officer and Secretary of
                                    Fortress Registered Investment Trust






                                   SIGNATURE


         After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.


                                    May 8, 2003



                                    FORTRESS INVESTMENT FUND LLC


                                    By: /s/ Randal A. Nardone
                                    -------------------------------------
                                    Randal A. Nardone, as
                                    Chief Operating Officer and Secretary of
                                    Fortress Fund MM LLC,
                                    managing member of
                                    Fortress Investment Fund LLC






                                   SIGNATURE


         After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.


                                    May 8, 2003



                                    FORTRESS  INVESTMENT GROUP  LLC


                                    By: /s/ Randal A. Nardone
                                    ---------------------------------
                                    Randal A. Nardone, as
                                    Chief Operating Officer and Secretary of
                                    Fortress Investment Group LLC






                                   SIGNATURE


         After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.


                                    May 8, 2003



                                    FORTRESS PRINCIPAL
                                    INVESTMENT HOLDINGS  LLC


                                    By: /s/ Randal A. Nardone
                                    -------------------------------
                                    Randal A. Nardone, as
                                    Secretary