If the purpose of every species is to successfully propagate then, without question, good parenting is a hallowed task. For humans, the thought of abandoning their young in the care of another is a preposterous notion, but for some birds, insects and even fish it’s an exceptional evolutionary strategy. Known as brood parasites, these species surreptitiously leave the task of nurturing their offspring to the adults of another species.
Photo: Shardul Kelkar.
Common Iora Aegithina tiphia and Common Hawk-cuckoo Hierococcyx varius
Location: Devrukh, Ratnagiri, Maharashtra
Camera: Canon EOS 500D, Canon EF400 mm. f/5.6L USM, Shutter speed: 1/500 sec., Aperture: f/5.6, ISO 400,Focal length 400 mm.
Image taken: September 11, 2013, 9.06 a.m.
The cuckoo family is particularly infamous for its ‘lay and leave’ behaviour. Not merely do these intelligent birds lay their eggs in the nest of other species, occasionally even destroying the ‘native’ egg and replacing it with their own, evolution has gifted them the ability to ensure that their eggs match the colour of the host parents.
Photo: Aniruddha Dikshit.
Purple-rumped Sunbird Leptocoma zeylonica and Grey-bellied Cuckoo Cacomantis passerinus
Location: Karad, Maharashtra
Camera: Canon EOS 50D, Lens: Canon EF100-400 mm. f/4.5-5.6L IS USM, Shutter speed: 1/250 sec, Aperture: f/5.6, ISO 400, Focal length: 400 mm.,
Image taken: October 4, 2009; 8.32 a.m.
To bolster the odds of survival, the eggs of the brood parasite hatch before those of the host species, thanks to a process called ‘partial internal incubation’. The parasitic nestling is a born charlatan and takes advantage of its quick development and larger size to get rid of the competition by either ejecting its nest mates, or killing them.
Photo: Kishan Meena.
Long-tailed Shrike Lanius schach and Eurasian Cuckoo Cuculus canorus
Location: Barkheda pond, Shivdaspura, Jaipur
Camera: Canon Powershot SX60 HS, Lens: In-built, Shutter speed: 1/160 sec, Aperture: f/6.3, ISO 200, Focal length: 192.103 mm.,
Image taken: August 30, 2016; 10.11 a.m.
If a victim nest mate escapes a violent fate, there’s a good chance that it will starve to death as the bullying foster sibling grabs the food brought by the parent birds.
Photo: L.J. Mendis Wickramasinghe.
Jungle Babbler Turdoides striata and Common Hawk Cuckoo Hierococcyx varius
Location: Maha wewa, Sri Lanka
Camera: Canon EOS 5D Mark III, Lens: Canon EF600 mm. f/4L IS USM, Shutter speed: 1/250 sec.,Aperture: f/4.0, ISO 800, Focal length: 600 mm.
Image taken: January 31, 2014; 7.45 a.m.
It may seem that the adult brood parasite has little investment in the survival of its offspring beyond leaving its eggs in the care of suitable, if unsuspecting, host parents, but some birds prove otherwise.
Photo: Nagesh Vannur.
Ashy Prinia Prinia socialis and Asian Koel Eudynamys scolopaceus
Location: Tilari. Maharashtra
Camera: Canon EOS 7D, Lens: Canon EF 400 mm. f/5.6L USM,
Image taken: February 15, 2015.
Certain species of cuckoo keep a sharp eye on the host parents. Should the host parents realise that they are being duped and abandon the nest or invading egg, the cuckoo will destroy its nest. The demolition will force the host parents to rebuild, and give the cuckoo a chance to ‘re-parasite’.
Photo: Nitin Jain.
Common Tailorbird Orthotomus sutorius and Grey-bellied Cuckoo Cacomantis passerinus
Location: Pune, Maharashtra
Camera: Canon EOS 40D, Lens: Canon EF100-400 mm. f/4.5-5.6L IS USM, Shutter speed: 1/3200 sec., Aperture: f/5.6, ISO 320, Focal length: 400 mm.
Image taken: September 21, 2012; 11.03 a.m.
Certainly the sight of a tiny, harrowed host parent trying desperately to fill the gawping maw of its parasitic nestling is poignant. The anthropomorphist may even call brood parasitism unethical, but in the high-stakes game of evolution - human morality is but a whim.
Photo: Vinod Goel.
House Crow Corvus splendens and Asian Koel Eudynamys scolopaceus
Camera: Canon EOS 1D-X, Lens: Canon EF600 mm. f/4L IS II USM + 1.4x III, Shutter speed: 1/40 sec, Aperture: f/5.6, ISO 4000, Focal length: 840 mm.,
Image taken: September 14, 2014; 5.59 a.m.
First appeared in: Sanctuary Asia, Vol. XXXVI No. 10, October 2016.