# Question About Egg Disposal & Embryo Development for Pigeon Cote Project



## Howard Nye (Oct 14, 2009)

Hi all,

My colleague and I have received permission (and been awarded a grant) to erect a pigeon cote and conduct a pilot project on humane pigeon population management at my workplace in the place of the trapping that was previously going on. Our project is to construct a pigeon cote in which the local pigeons will voluntarily roost, and perform birth control in the form of egg removal and replacement with false eggs, as is the typical method with companion birds (like mine). This kind of pigeon cote system has proven to be much more effective than lethal area control strategies in various European cities (as documented by Haag-Wackernagel, Daniel (1995), Regulation of the Street Pigeon in Basel, Wildlife Society Bulletin 23: 256-260; and the Pigeon Control Advisory Service http://www.picasuk.com/lethal_bird_control.html).

I have two questions about the egg replacement component of this project:

(1) How are pigeon eggs typically disposed of? My practice has been to freeze them and then crush and burry them. My concern is to make very sure that the disposed eggs do not actually incubate. I was wondering if others had other methods. I was thinking for this project that perhaps we could freeze, crush, and then perhaps compost the eggs (or perhaps skip the freezing stage and just crack them open and compost the shells and contents).

(2) My understanding is that a safe cut-off point for egg disposal, at and before which point we can be quite sure that there is no chick with mental states, is the eggs having been incubated for no more than about 7 days (although it’s always best to get the eggs as soon as possible – at home I’ve usually been able to get them the same day they have been laid or the day after that). The evidence I know of for this comes mainly from:

i) Guglielmone & Panzica’s Early Appearance of Catecholaminergic Neurons in the Central Nervous System of Precocial and Altricial Avian Species 1985 (url: https://www.ncbi.nlm.nih.gov/pubmed/3995559), which found catecholaminergic neurons appearing only after 8 days of incubation, and 

(ii) Chen et al.’s Molecular Profiling of the Developing Avian Telencephalon: Regional Timing and Brain Subdivision Continuities 2013 (url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3863995/), which found brain areas in zebra finch embryos which correspond to those of adults only after 10 days of incubation and could not find such areas at 8 days of incubation or earlier. Zebra finches like pigeons are altrical, but likely develop a bit more rapidly, as they hatch at 12-15 of incubation in contrast to pigeons who hatch at 16-18 days of incubation.

I was wondering 

(a) do others agree that 1 week is a safe cut-off point for egg disposal at and before which point one can be confident that there is no chick with mental states (and if others disagree, what might a safe alterative cut-off point be)?, and
(b) do others know of evidence other than (i) and (ii) relevant to neural development and the likely onset of mental states in embryonic pigeons (whose mental lives are supported, like ours, by their telencephalon and especially pallium, although, while they play the same sorts of functional roles, our mammalian pallium is largely cortical or has neurons arranged in layers while their avian pallium is largely nuclear or has neurons arranged in clusters; see Jarvis et al.’s Jarvis et al Avian Brains & a New Understanding of Vertebrate Evolution 2005, url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2507884/ ). 

Many thanks,
Howard


----------

