Marie Read / Western Grebe (Aechmorphus occidentalis), pair during 'rushing' courtship display in which they run across water's surface in synchrony, near Escondido, California, USA, January.

Marie Read / Eared grebes (Podiceps nigricollis), pair, one adult feeding one of two chicks riding on the other adult's back, Bowdoin National Wildlife Refuge, Montana, USA

Marie Read / Eared grebes (Podiceps nigricollis), pair, one adult carrying food (damselfly) for two chicks riding on the other adult's back, Bowdoin National Wildlife Refuge, Montana, USA

Marie Read / Eared grebes (Podiceps nigricollis), pair, one adult feeding chick riding on the other adult's back, Bowdoin National Wildlife Refuge, Montana, USA

Andy Rouse / Pair of Great crested grebes (Podiceps cristatus) courting, Cardiff, Wales, UK, March.

Andy Rouse / Pair of Great crested grebes (Podiceps cristatus) courting, Cardiff, Wales, UK, March.

Andy Rouse / Great crested grebes (Podiceps cristatus) pair in courtship 'weed dance' in morning light, Wales, UK, February.

Andy Rouse / Great crested grebe (Podiceps cristatus) swimming, backlit with morning light forming a bokeh affect on the water, Wales, UK, February. Highly commended in the Habitat Category of the BWPA (British W...

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) rival males fighting during mating season, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance at dawn, Cardiff, UK, March. Highly Commended in the Animal Behaviour Category of the BWPA Competition 2015.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) with young chicks on back, Cardiff, UK, April.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance at dawn, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship weed dance, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship weed dance, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) in urban environment Cardiff, UK

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance Cardiff, UK, March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) carrying chick while its mate approaches with food, Netherlands, May.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) pair in courtship display, The Netherlands. March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) pair in courtship display, The Netherlands. March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) pair in courtship display, The Netherlands. March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) with head low to the water in aggressive display, The Netherlands. March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) pair in 'weed dance' courtship display, The Netherlands. March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) pair in courtship display, The Netherlands. March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) two in territorial fight, The Netherlands, March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) two in territorial fight, The Netherlands, March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) two in territorial fight, The Netherlands, March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) pair in 'weed dance' courtship display, The Netherlands, March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) carrying chick on back, The Netherlands, May.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) with young chick on back, Cardiff, UK, April.

Andy Rouse / Great crested grebe (Podiceps cristatus) on lake, Wales, UK, June.

David Pattyn / Great crested grebe (Podiceps cristatus) attacking another grebe in the mating season during a territorial dispute. The Netherlands. April.

David Pattyn / Great crested grebe (Podiceps cristatus) pair performing their courtship dance in which they mimic each other's movements. The Netherlands. April.

David Pattyn / Great crested grebe (Podiceps cristatus) portrait. The Netherlands. April.

David Pattyn / Great crested grebe (Podiceps cristatus) stretching its wings. The Netherlands. April.

David Pattyn / Great crested grebe (Podiceps cristatus) with discarded fishing net around the neck. The Netherlands. April.

David Pattyn / Great crested grebe (Podiceps cristatus) pair performing their 'weed dance' in which they take a vertical position in front of each other and offer plant material to each other. The Netherlands. March...

David Pattyn / Great crested grebe (Podiceps cristatus) in a threathening posture trying to intimidate another grebe in a territorial dispute. Head low over the water and crest erected. The Netherlands. April.

David Pattyn / Great crested grebe (Podiceps cristatus) in a threathening posture trying to intimidate another grebe in a territorial dispute. Head low over the water and crest erected. The Netherlands. March 2013

David Pattyn / Great crested grebe (Podiceps cristatus) stretching its wings. The Netherlands. June 2014

David Pattyn / Great crested grebe (Podiceps cristatus) close-up in breeding plumage. The Netherlands.June 2014

David Pattyn / Great crested grebe (Podiceps cristatus) close-up in breeding plumage. The Netherlands. June 2014

David Pattyn / Great crested grebe (Podiceps cristatus) with fish to feed one of its chicks. The Netherlands. June 2014

David Pattyn / Great crested grebe (Podiceps cristatus) pair with chicks on the back of one begging for food, The Netherlands. June 2014