vultures Archives - EcoEvo@TCD

09/12/201602/11/2017

A recipe for collaboration

Recently, along with Adam Kane, Kevin Healy, Graeme Ruxton and Andrew Jackson, we published a review on scavenging behaviour in vertebrates through time in Ecography.

This paper was my first review paper as well as my first paper written from afar, without ever actually meeting in a room with the co-authors for working on the project.

Difficulty: *

Preparation time: 5 month to submission

Serves: 5 people (but any manageable number of people who you like working with will do)

Ingredients:

An exciting topic:

For this recipe you will need an exciting topic.

In this case, prior to writing the review, we had often discussed the prevalence of scavenging behaviour through time and what ecological factors influence it.

Indeed, it came as a natural follow up to a paper published by the other co-authors earlier this year on ‘the scavenging ability of theropod dinosaurs’.

More generally, the topic should be broad enough to allow every person to look for anecdotes (did you know there was once a ‘scavenging bat called *Necromantis*?’ and to bring these together in an interesting, more generalised framework. Continue reading “A recipe for collaboration”

29/05/2015

V for Vulture

I have recently returned from a field trip to Swazliand where I was working with my long-time collaborator Prof Ara Monadjem to tag two African White-backed Vultures with high-spec trackers. These devices were purchased with a $20,000 grant from the Critical Ecosystem Partnership Fund and are currently sending their locations every minute via the mobile phone network. Up to now we have no idea where the Swazi population of this species forages and this is something the tracking data will reveal. With only a few weeks of tracking data we can see the birds have already ventured into Mozambique and South Africa.

Author

Adam Kane, kanead[at]tcd.ie

Photo credit

Andre Botha

24/10/201423/10/2014

Bird Feeders

It’s coming up to winter so people will be conscious that our garden birds need a helping hand to get through the cold months. Bird feeders will be stocked, bread served up and water dished out. In the UK alone, almost half of households provide supplementary food for birds throughout the year. And although songbirds are usually the species that come to mind when we think of provisioning food the same principle can apply to more exotic birds, notably vultures. Indeed conservationists have supplied extra food to these scavengers for decades. Instead of bread or berries, a carcass is left out for the vultures to feed on. A recent paper of ours advocates this technique for a population of African White-backed Vultures in Swaziland.

This country is home to the densest breeding population of this species so we should do our best to conserve them given the huge declines suffered by vultures throughout the Old World. In the paper we showed times when there isn’t enough food in Swaziland to feed the whole population which means the birds are forced to forage farther afield, most likely in South Africa. On the face of it this doesn’t seem problematic because South Africa has huge populations of herbivores which could supply carcasses to vultures. But the birds must fly over unprotected areas as well. This increases their chances that they’ll encounter a poisoned carcass, perhaps set out by a farmer to kill the terrestrial carnivores harassing his livestock.

It’s well known that vultures are particularly sensitive to poisons, especially NSAIDs. Their group foraging behaviour makes them even more susceptible too, the discovery of a carcass by one individual will bring in the rest of the soaring birds in visual range. The hope with creating vulture restaurants is the birds will focus on foraging for carrion in Swaziland, minimising the risk of poisoning.

Yet there are well known problems with supplying supplementary food for animals in general. They may act as an ecological trap for instance, drawing the birds into an area only for the fickle humans to stop the supply of food. Carrion is an unpredictable resource so vultures forage in a characteristic way to improve their chance of encountering it. If food is supplied in a predicable way there is a fear we may disrupt these behaviours. Another recently realised danger in providing supplementary food is that it can attract unwanted guests. Sites tailor made for vultures in South Africa were shown to draw in jackals and hyenas.

Given these issues practitioners need to think carefully about how they provide food. Perhaps the best approach is a series of sites supplying food at random which would best represent the distribution of naturally occurring carrion.

Author: Adam Kane, @P1zPalu, kanead[at]tcd.ie

Photo credit: Munir Virani

18/11/201307/11/2013

Cape Vulture Conservation

Conservationists try their best to stop endangered species sliding to extinction and keep the habitats of these life forms intact. Captive breeding programs, national parks, management of invasives etc. are all common measures in conservancy. But how do we know that these methods work? Perhaps an invasive species is actually serving as a food source for the conservation target, and, by killing off the former, we imperil the latter further still. Fortunately, we can avoid such disasters through experimentation and modeling, in other words, with some good science.

Consider the case of the Cape Vulture (Gyps coprotheres) in Southern Africa. This large scavenger patrols its habitat, often a huge range, foraging for carrion. It’s suffering a decline in numbers for a variety of reasons. Carcasses are often poisoned to kill predators that take farmer’s livestock with the vulture an innocent victim. Their social nature means tens of the birds can be killed by a single toxic carcass. More direct persecution comes in the form of poachers who have taken to poisoning the carcasses of their quarry. The rationale is to wipe out vultures who will identify the location of future crimes. Then there are accidental deaths that arise from bird collisions with electricity pylons and wind turbines. And it will take some time to convince otherwise those who value vulture brains for their clairvoyant properties.

Fortunately, some vultures survive these incidents and that’s where rehabilitation centres come in. People at these facilities nurse the birds back to health and release them into the wild. The problem is some of the injuries suffered may be insidious, leaving a permanent but unnoticeable effect on the animal’s health.

We used resightings data on a population comprised of rehabilitated and wild birds to estimate their chances of survival and found that the rehabs have a significantly lower chance of surviving year on year (90% Vs 72%). By modeling different proportions of rehab and wild birds we showed that a 50:50 mix of the two groups is the threshold beyond which the population will decline.

That’s not to say that we think rehabilitation is a bad idea, it’s obviously better to get the bird back in the wild where it can contribute to the survival of the species than leave it to die from its injuries. Rather we suggest that vulture conservation should be focused on prevention instead. This is achievable. In India, farmers have stopped using drugs on their cattle which poisoned the vulture population en masse. Pylons and turbines can be equipped with signals that alert the birds to their presence.

Conservation practice coupled with a scientific understanding can only better our ability to stop the slide to extinction.

Author:

Adam Kane, kanead[at]tcd.ie, @P1zPalu

Photo credit;

Phil Perry

03/07/2013

How to build a vulture trap

Last month I spent a month in Mbuluzi Game Reserve in Swaziland attempting to build a walk-in trap that will allow me to capture vultures. I want to be able to tag the birds with GPS trackers and ask a host of interesting questions from which a flood of Nature papers will follow.

Step 1 - Clear the area — Step 1 – Clear the area

Step 2 - Create some support for the poles — Step 2 – Create some support for the poles

Step 3 - Erect the frame — Step 3 – Erect the frame

Step 4 - Add the mesh — Step 4 – Add the mesh

Step 5 - bait the area (this sickly Waterbuck had died) — Step 5 – bait the area (this sickly Waterbuck had died)

Step 6 - record everything that comes down — Step 6 – record everything that comes down

Step 7 - play the waiting game (perching African White-backed Vultures) — Step 7 – play the waiting game (perching African White-backed Vultures)

We’ll have to wait for the vultures to get habituated to the area before adding the front to the trap. Once this happens we can proceed. So this is a ‘to be continued’…

Author

Adam Kane: kanead[at]tcd.ie

Photo credit

Adam Kane

24/05/2013

May I take your order?

My PhD involves studying the foraging behaviour of vultures. So far I’ve done theoretical work and also had the luck to get some second hand empirical data. But I’d like to be able to get some field data first hand. To that end I’m setting off to Swaziland on Saturday with the intention of building a vulture restaurant and a walk-in trap. The first item takes a little explaining. Vultures are carrion feeders, which means their food source is unpredictable, the bird never knows when the next wildebeest is going to drop dead. So they’re quite sensitive to declines in food availability. But a vulture restaurant is a conservation tool that acts as a supplementary feeding station for the birds. The people organizing the restaurant can deposit carrion at the site thereby providing an extra food supply for the vultures. This is done to keep the birds within an area, to feed them during times of food scarcity or in my case to aid in their capture.

Alongside the restaurant we’re going to build a walk-in trap, a simple structure that the birds walk into before we close the door behind them and have a PhD’s worth of data points. Well, it’s not quite that easy. I want to be able to find out to where these birds are foraging at a high temporal resolution so we will be putting GPS tags on the vultures once we capture them. This means some poor soul will be entering the trap and extracting the birds one by one, each animal getting tagged before being released back into the wild. I should stress this has been done before on many occasions and the birds are all freed within minutes without any ill effects.

So far a lot of research done in this area provides us with broad-scale movement patterns. With my finer scale data I’ll hopefully be able to pick out some quite specific aspects of vulture foraging behaviour. Wish me luck!

Author

Adam Kane: kanead@tcd.ie

Photo credit

Wikimedia commons

19/04/201305/04/2019

School of Natural Sciences Postgraduate Symposium: Part 1/4

Postgraduate students from Trinity College Dublin's School of Natural Sciences — Postgraduate students from Trinity College Dublin’s School of Natural Sciences

On the 15^th and 16^th April we had one of my favourite events at Trinity College Dublin: the annual School of Natural Sciences Postgraduate Symposium. Over the course of two days many of our PhD students presented their work to the School. We also had two amazing plenary talks from Dr Nick Isaac (CEH) and Professor Jennifer McElwain (UCD). For those of you who are interested in exactly what we work on here at EcoEvo@TCD, here are the abstracts from the PhD student presentations. Check out the TCD website for more details! Continue reading “School of Natural Sciences Postgraduate Symposium: Part 1/4”