derived class can be called with base copy constructor

Question

in the following code example i have two class, one is derived from the other, they only differ in the output message ("base" vs "derived")

from the main i call both of them, then i use the copy constructor from Base with Derived as a parameter, and it works. even though i don't have a prototype function for such a call :

#include <iostream>

class Base {
public:
    Base() {
        std::cout << "base default constructor\n";}
    Base(int i) {
        std::cout << "base parameters constructor\n";}
    Base(Base const & src) {
        std::cout << "base copy constructor\n"; *this = src;}
    Base & operator=(Base const & rhs) {
        std::cout << "base assignation operator\n"; return *this;}
    ~Base() {
        std::cout << "base default destructor\n";}
};

class Derived : public Base {
public:
    Derived() {
        std::cout << "derived default constructor\n";}
    Derived(int i) {
        std::cout << "derived parameters constructor\n";}
    Derived(Derived const & src) {
        std::cout << "derived copy constructor\n"; *this = src;}
    Derived & operator=(Derived const & rhs) {
        std::cout << "derived assignation operator\n"; return *this;}
    ~Derived() {
        std::cout << "derived default destructor\n";}
};

int main () {

    Base    base1(1); std::cout << "\n";
    Derived derived1(1); std::cout << "\n";
    Base    base2(derived1); std::cout << "\n";

    return 0;
}

and the output :

base parameters constructor

base default constructor
derived parameters constructor

base copy constructor
base assignation operator

base default destructor
derived default destructor
base default destructor
base default destructor

i was expecting an error like (inversion of output for the call of Derived derived2(base1);) :

main.cpp:36:24: error: no matching function for call to ‘Base::Base(Derived&)’
   36 |  Base base2(derived1);
      |                     ^
main.cpp:23:2: note: candidate: ‘Base::Base(const Base&)’
   23 |  Base(Base const & src) {
      |  ^~~~

why does it works ?