A question for pilots flying into tropical Mexico or points south


New Member
I study a species of large swift (like a swallow, but more aerial) that nests in colonies of tens of thousands in huge caves in Mexico (and south to northern Argentina).

My biggest study colony is 100 miles or so due west of Tampico. 50,000 swifts (larger than a Mourning Dove, black, and streamlined) leave this pit daily in the morning, and seem to head toward the Gulf of Mexico coast, then return to the cave in the evening.

On Mexican weather radar, I believe I have seen them coming and going to the coast around Tampico--they could also be anywhere over coastal plains or mountains from Tampico south on the east coast, and from Mazatlan south on the Pacific coast.

My question: have you ever seen a flock of smallish birds that might fit this description?

They can be in a fairly dense stream while commuting, in a "kettle" of hundreds or thousands circling, or spread diffusely across a large area while foraging. They may go very high and may forage near the ground. They may also go out over the sea.

Any information you have would be very useful to me.

Thanks much,
David Whitacre, Boise, Idaho
(208) 608-3373


Well-Known Member
A swift larger than a mourning dove? Cool! I'd love to see them. Supposed to be headed down that way tomorrow, I'll keep an eye peeled. I'd guess they're lower than our cruising altitudes, though?


Well-Known Member
If they're anything like Barn Swallows I bet they like to congregate on airport property due to the hangars (airplane barns) to roost in and large open areas to hunt airborne insects close to the ground. Here in the northeast we have thousands of them whizzing around the ramp area in the summer months just after sunset snapping up the flying bugs.

I'd like to see a photo of this species if you have one Dave. Yes I'm bird geek as well as an airplane geek.


New Member
This is what a White-collared Swift looks like. Very streamlined and fast. Yes, bigger than a mourning dove. There is a related species in western Mexico that is absolutely huge--as large as a kestrel (sparrow-hawk)--these nest around Mexico City and can be seen over the Pacific lowlands, for example at Mazatlan.

I don't know what altitude they may reach, but I think they might sometimes go up to several thousand feet. They rely heavily on lift, and rarely flap once they have reached their foraging areas. I think that maybe in seabreeze fronts they may go very high at times.